Antibiotic residues in honey content
Antibiotic Residues in Honey
Dr Sapna Johnson
Dr Nimisha Jadon
Prof. H. B. Mathur
Prof. H. C. Agarwal
September, 2010
CENTRE FOR SCIENCE AND ENVIRONMENT
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CONTENTS
Pollution Monitoring Laboratory of CSE
3.1
3.2
Constituents of honey
3.3
Uses
3.4
Production and consumption
3.5
Major Brands of honey in India
3.6
Beekeeping in India
3.7
Pests and Diseases of Honey Bees
4.
Antibiotics
8
4.1
What are Antibiotics?
4.2
Major Classes of Antibiotics
4.3
Antibiotics authorized in Beekeeping
Regulations for Antibiotics in Honey
5.1 Codex
5.2 EU
5.3 US
5.4
5.5
5.6
Health Impacts
6.1 Chronic health effects of antibiotics
6.2 Antibiotic Resistance
Review of Literature
Sampling
Materials and Methods
10. Results and Discussion
11. Conclusions
12. References
13. Annexures I- III
14. Figures 1- 5
CSE Study: Antibiotics Residues in Honey
1. Pollution Monitoring Laboratory of CSE
The Centre for Science and Environment (CSE), a non-governmental organization based in
New Delhi, has set up the Pollution Monitoring Laboratory (PML) to monitor environmental
pollution. PML is an ISO 9001:2008 certified laboratory accredited by SWISO, CH-5610,
Wohlen, Switzerland, conducting Pollution Monitoring and Scientific Studies on Environmental
Samples. The Lab has highly qualified and experienced staff that exercise Analytical Quality
Control (AQC) and meticulously follow what is called Good Laboratory Practices (GLP). It is
equipped with sophisticated state-of-the-art equipments for monitoring and analysis of air,
water and food contamination, including Gas Chromatograph with Mass Detector (GC-MS),
Gas Chromatograph (GC) with ECD, NPD, FID and other detectors, High Performance Liquid
Chromatograph (HPLC), Atomic Absorption Spectrometer (AAS), UV-VIS Spectrophotometer,
Mercury Analyzer, Respirable Dust Sampler etc. Its main aim is to undertake scientific studies
to generate public awareness about food, water and air contamination. It provides scientific
services at nominal cost to communities that cannot obtain scientific evidence against
polluters in their area. This is an effort to use science to achieve ecological security.
2. Introduction
Honey has the image of being a natural and healthy product. However, today honey is
produced in an environment, polluted by different sources of contamination. The
contamination sources can be environmental and apicultural ones. Environmental
contaminants are pesticides, heavy metals, bacteria and radioactivity. These contaminants
are present in air, water, soil and plants and are transported to beehives by bees.
Contaminants from beekeeping practice includes acaricides used for parasitic mites (mainly
Varroa) control, bee repellents used at honey harvest, pesticides for wax moth and small hive
beetle control and antibiotics (Bogdonov, 2006).
Antibiotics are found in honey largely because they are used in apiculture for treatment of
bacterial diseases. Oxytetracycline is commonly used to treat European foulbrood disease
(EFB) and American foulbrood diseases (AFB) caused by
Paenibacilus (Bacillus)
larvae and
Streptococcus pluton bacteria, respectively. However, there are now reports of tetracycline
resistance in these bacteria because of its widespread use. Other antibiotics such as
erythromycin, lincomycin, monensin, streptomycin, enrofloxacin etc. are also reportedly used
The use of antibiotics in beekeeping is illegal in some EU countries. Moreover, there are no
Maximum Residue Limits (MRLs) established for antibiotics in honey according to the
CSE Study: Antibiotics Residues in Honey
European Community regulations (Mutinelli, 2003), which means that honey containing
antibiotic residues are not permitted to be sold.
The European Union (EU), on its part, regulates honey under the Council Directive
2001/110/EC. The standard for antibiotics in food (also referred to as Maximum Residue
Limits or MRLs) is listed in Regulation (EU) No 37/2010 – it stipulates that each antibiotic
must have an MRL before it can be used on a food-producing species. But there are no MRLs
for antibiotics in honey -- which means the EU does not allow use of antibiotics for treatment
of honeybees. For regulating residues of antibiotics in imported honey, the Union has set
what are called RPAs, or ‘Reference Points for Action'. RPAs are residue concentrations
which are technically feasible to detect by food control laboratories. When an RPA is
exceeded, the member state is obliged to reject the consignment. Till date, RPAs have been
established in honey for substances such as chloramphenicol and nitrofurans. EU has also
set a provisional MRL of 25 μg/kg or parts per billion (ppb) for oxytetracycline in honey.
Some countries, like Switzerland, UK and Belgium, have established Action Limits for
antibiotics in honey, which generally lies between 0.01 to 0.05 mg/kg for each antibiotic
group. Action Limits are the level of antibiotics in honey beyond which the sample is deemed
In the US, Canada and Argentina, preventive treatments with antibiotics are considered a
routine procedure to prevent outbreaks of AFB. Consequently, various strains of
P. larvae
showing resistance to antibiotics, such as oxytetracycline-HCl (OTC), have been discovered
in Argentina (Alippi, 2000) as well as in many areas of United States (Miyagi
et al., 2000). The
extensive use of antibiotics leads to an accumulation of residues in honey decreasing their
quality and making their marketing more difficult (Fuselli
et al., 2005). Antibiotic residues show
a relatively long half-life and they may have direct toxic effects on consumers e. g., allergic
reactions in hypersensitive individuals and disorder of the haemopoietic system, or cause
problems indirectly through induction of resistant strains of bacteria (Tillotson
et al., 2006).
In last few years, there have been reports of antibiotic contamination in honey exported from
India. The food and feed control authorities of the member states of the EU have found Indian
honey contaminated with prohibited antibiotics like nitrofuran and chloramphenicol. Indian
honey has also been found to be contaminated with tetracycline and streptomycin. In the US,
consignments of Indian honey have been found to be contaminated with ciprofloxacin.
To promote the exports of honey, the Ministry of Commerce and Industries, Government of
India has setup a Residue Monitoring Plan (RMP) to monitor the level of antibiotics, heavy
metals and pesticides contamination in honey destined for exports. The Export Inspection
Council (EIC) is responsible for implementing the RMP.
CSE Study: Antibiotics Residues in Honey
EIC has setup Level of Action limits (similar to standards) for antibiotics in exported honey.
Sample found to be containing antibiotics beyond the Level of Action is deemed non-
compliant. The monitoring result of RMP shows that a sizeable proportion of honey
consignments destined for exports were contaminated with antibiotics. In 2007, about 28% of
the samples tested did not meet the Level of Action for tetracyclines and 5.9% for
sulphonamides. In 2008, 23.9% samples and 11.6% samples did not meet the Level of Action
for tetracyclines and sulphonamides.
It is quite clear that India has setup an elaborate system to monitor the quality of honey
exported to the EU and the US. However, there is no standard for antibiotics in honey for the
domestic market. There is hardly any report on the antibiotic contamination of honey
consumed within the country. Similarly, India also imports honey, but there is no standard to
check the quality of honey being imported. This study was undertaken to fill this gap. The
objective of this study, therefore, is to find out the level of antibiotics in honey samples
available in the domestic market.
3.1 Definition
In Ayurveda honey is called as "Madhu". Its qualities are explained as follows.
"Vaatalam guru sheetam cha raktapittakaphapaham
Sandhatru cchedanam ruksham kashayam madhuram madhu "
"It has sweetness (madhura rasa) with added astringent as end taste (Kashaya anu rasa). It is
heavy (guru guna), dry (ruksha) and cold (sheeta). Its effect on doshas is as follows. It
aggravates vata, scrapes kapha and normalizes pitta and rakta. It promotes healing process."
The Codex Alimentarius Commission defines honey as "'the natural sweet substance
produced by honeybees from the nectar of flowers or from secretions coming from living
organisms feeding on plants, that bees gather, transform and combine with specific
ingredients, store and leave to ripen in the combs of the hive".
According to the PFA Rules, 1955 under section A.07.03 honey is defined as:
"Honey means natural sweet substance produced by honey bees from the nectar of blossoms
or from secretions of plants which honey bees collect, transform, store in honey combs for,
CSE Study: Antibiotics Residues in Honey
According to the Bureau of Indian Standards (BIS) specifications IS 4941:1994, honey is
defined as "natural sweet substance produced by honey bees from the nectar of blossoms or
from secretions of plants which honey bees collect, transform and store in honey combs for
honey bees". Further, honey is classified into three grades based on moisture content. It
prescribes less than 20 per cent moisture for 'special grade', 20-22 per cent for 'grade A' and
22-25 per cent for 'standard grade'. According to the specifications, rubber honey belongs to
medium grade (Grade A) with an average moisture content of 22 per cent.
3.2 Constituents of Honey
Honey is a mixture of sugars and other compounds. With respect to carbohydrates, honey is
mainly fructose (about 38.5%) and glucose (about 31.0%), (National Honey Board, 2008)
making it similar to the synthetically produced inverted sugar syrup which is approximately
48% fructose, 47% glucose, and 5% sucrose. Honey's remaining carbohydrates include
maltose, sucrose, and other complex carbohydrates. Honey also contains tiny amounts of
several compounds thought to function as antioxidants, including chrysin, pinobanksin,
vitamin C, catalase, and pinocembrin. But it contains only trace amounts of minerals. The
specific composition of any batch of honey depends on the flowers available to the bees that
produced the honey (USDA, 2007).
Various ingredients of honey have helped it to become not only a sweet liquid but also a
natural product with high nutritional and medicinal value. The medicinal quality, taste, texture,
color, aroma of honey differs according to the geographical area and the species of plants
from which it has been collected.
The main uses of honey are in cooking, baking, as a spread on breads, and as an addition to
various beverages such as tea and as a sweetener in some commercial beverages. Honey
can be used as instant energizer as it contains sugars which are quickly absorbed by our
digestive system and converted into energy.
In Ayurveda honey is called as "Yogavahi", substance which has the quality of penetrating the
deepest tissue. When honey is used with other herbal preparations it enhances the medicinal
qualities of those preparations and also helps them to reach the deeper tissues. Honey is also
used as a medicine because of its antioxidant and antibacterial properties.
CSE Study: Antibiotics Residues in Honey
3.4 Production and consumption
The annual world honey production is estimated at about 1.4 million tonnes (FAO, 2005). Asia
is the largest producer of honey, accounting for about 40% of the global production. China is
the largest producer of honey producing around 0.3 million tonnes annually.
Honey consumption in developing countries such as China, Argentina, India, Brazil and Egypt
is estimated to be 0.1 to 0.2 kg per capita. Developed countries consume generally higher
amounts. However, the per capita honey consumption does not follow the richness of the
countries, as it is also determined by cultural influences. In the European Union, the biggest
honey consumer is Greece with 1.8 kg per capita, followed by Germany with 1.5 kg, other EU
countries like Italy, Spain, France and Hungary are in the intermediate range with 0.6-0.9 kg,
while the UK is on the lowest end with 0.4 kg per capita annual consumption (Bogdanov,
India produces a total of 65,000 tonnes of honey every year (Indian Horticulture Database,
2009). Punjab, Haryana, Uttar Pradesh, Bihar and West Bengal are the major honey
producing states. Among the southern states, Tamil Nadu ranks first in honey production
followed by Kerala and Karnataka. Kashmir Apiaries Exports based in Doraha, Ludhiana,
accounts for 40 per cent of the total organized sector honey production in India.
India exports about 25,000 tonnes of honey annually to more than 42 countries including the
EU, the Middle East and the US.
3.5 Major brands of Honey in India
Currently, the domestic branded honey market is estimated at around Rs 250 crores. About
50% of honey is being used for religious and medicinal purposes. Dabur India Limited is the
biggest player in the branded honey market and holds a share of over 75 per cent. The
remaining share is taken up by brands like Baidyanath, Himani, Zandu, Mehsons, Himalaya
and other smaller companies. Traditional players such as Khadi and Village Industries
Commission (KVIC) and Himachal Pradesh Agro Industry Corporation (HPAIC) are also
aggressively expanding their network.
Imported Brands
Market for imported honey is growing in India. Some imported brands available Capilano
(Australia), Nectaflor (France), Darbo (Germany), Dana (Denmark), Lagnese (Germany),
Hero (Switzerland) etc.
CSE Study: Antibiotics Residues in Honey
3.6 Beekeeping in India
India is a vast country with varied climates and ecological conditions ranging from tropical to
sub-tropical in its southern, central and eastern regions, from sub-temperate to temperate
along its north and north west and semi arid to desert conditions towards the west. The major
geographical regions facilitating beekeeping development are classified into: 1) Southern
peninsular region; 2) North east region; 3) Indo-Gangetic plains; and 4) Northern hill region
The geographical position of India and the related agro-climatic condition favor the growth of
a wide variety of flora -natural and cultivated. The extensive area of forest and millions of
acres of cultivated land sustains a large proportion of insects and honeybees. Due to diversity
in flora, topography and activities of people, beekeeping and management is diverse.
Beekeeping in India has been adapted to various ecosystems, socioeconomic profiles and
habitat preferences.
India has four native species of honeybees and has also introduced exotic specie. The main
harvest of honey is from following species (Thomas
et. al, 2002)
Apis cerana or the Asiatic honey bee (or the Eastern honey bee):
Apis cerana
beekeeping is practiced in India since time immemorial. It is a good pollinator, and
has survival capacity due to the co-evolution of native floral sources, pests and
predators accustomed to the same climatic conditions. Beekeeping with
Apis cerana
is largely practiced in Southern and Central India.
Apis dorsata (the rock bee or giant bee):
Apis dorsata contributes a large share of
honey production in India. It is found in foothills of Himalayas and northern regions of
the country. In central India in the forests and plains large number of
Apis dorsata
colonies are present from which the tribals collect large amount of honey. The
Sunderban forests in West Bengal and Southern part of India are also rich in
Apis
Apis florea (Little bee): It is common in central part of India, occurs in arid and desert
region of extreme climates, and also in plains and forests. A large quantity of
Apis
florae honey is collected from the Kutch area of Gujarat.
Trigona irridipennis (Dammar bee): It is common in all parts of the country. It is a very
small bee and collects nectar from small flowers. Since the quantity of honey
produced is small, these bees are not commercially used. It is a very important crop
pollinator and the honey has repute in folk medicine.
Apis mellifera (European honey bee or western honey bee): It is an exotic species
imported initially to Punjab from Western Countries and has become popular among
commercial beekeepers because of its higher honey yield. The
mellifera gradually
spreads to Himachal, Bihar, Uttar Pradesh, West Bengal and recently to Kerala,
Karnataka and Maharashtra. Currently, largest amount of honey is produced from
Apis mellifera. The EU allows imports of honey produced by
Apis mellifera bees only.
CSE Study: Antibiotics Residues in Honey
3.7 Pests and Diseases of Honeybees
Honeybees are affected by protozoan, bacterial, viral and acarine diseases. There are a
number of diseases which affect the honeybee in India. Of the major diseases which affect
honeybee are the Acarine and Nosema diseases of the adult bees and the brood diseases of
larval stages. Out these brood diseases, the European foul-brood disease and the Thai Sac-
brood disease are common in India. Table 1 gives the diseases affecting the honeybees and
the recommended practice of treatment.
Table 1: Major Diseases and Pests of Honey Bees
Organism
Treatment
Diseases
PROTOZOAN
Nosema apis.
Fumigation of combs and hive parts with acetic
acid or formalin Drug treatment of fumagillin is useful in controlling the infection. The drug is administered by giving a feed of 100 mg fumagillin per colony in 250 ml of sugar syrup for 10 days continuously.
Streptococcus
Antibiotics preferably terramycin
oxytetracycline - terramycin is given dissolved in
sugar syrup @ 100 mg of active terramycin in a
litre of syrup. The terramycin syrup (freshly
prepared) is fed every seventh day. The disease
can also be controlled by fumigation with ethylene
oxide. Quarantine is a must to prevent entry of
any of the bee diseases.
Bacillus larvae
The disease can be controlled by total destruction
of the diseased colony including the hive, frames, bees and honey or use of tylosin tartarate.
Prevalent in South India and caused severe loss
to bee keeping industry in 1990s. No effective
method to control this disease is known as yet.
Prevention is better than cure. It is better to isolate
the infected colonies. Reported in Kerala,
Karnataka and Tamil Nadu
Acaricide –Chlorobenzylate, Menthol
Varroa Mites
Fluvalinate and coumafos Thymol, oxalic acid , formic acid
CSE Study: Antibiotics Residues in Honey
4. Antibiotics
4.1 What are Antibiotics?
Antibiotics are medicines - therapeutically used to protect the health and welfare of humans
and animals. It inhibits or abolishes the growth of microorganisms such as bacteria, fungi or
The term antibiotic originally referred to any agent with biological activity against living
organisms; however, ‘‘antibiotic" now refers to substances with antibacterial, anti-fungal, or
anti-parasitical activity. There are currently about 250 different chemical entities registered for
use in medicine and veterinary medicine (Kümmerer and Henninger, 2003).
4.2 Major Classes of Antibiotics
Antibiotics can be grouped by either their chemical structure or mechanism of action. They
are often complex molecules which may possess different functionalities within the same
molecule. Therefore, under different pH conditions antibiotics can be neutral, cationic, anionic,
or zwitterionic. They are divided into different sub-groups such as ß-lactams, amphenicols,
tetracyclines, macrolides, aminoglycosides, fluoroquinolones and others.
Beta lactams
-Lactams are antibiotics that have a -lactam ring nucleus with a heteroatomic ring structure,
consisting of three carbon atoms and one nitrogen atom, used to treat bacterial infections by
attacking the cell walls of bacteria. e .g penicillins, ampicillin, cloxacillin, amoxicillin
Amphenicols are a class of antibiotics with a phenylpropanoid structure. They function by
blocking the enzyme peptidyl transferase on the 50S ribosome subunit of of bacteria e.g
chloramphenicol, thiamphenicol,azidamphenicol and florfenicol
Tetracyclines are antibiotics with four ("tetra-") hydrocarbon rings ("-cycl-") derivation ("-ine")
defined as "a subclass of polyketides having an octahydrotetracene-2-carboxamide skeleton"
used for treatment of bacterial brood diseases e.g. oxytetracycline, chlortetracycline,
Macrolides are basic and lipophilic antibiotics with a 14 membered macrocyclic lactone ring
linked via glycosidic linkages and are potent against wide variety of gram positive and
CSE Study: Antibiotics Residues in Honey
negative bacteria used for the treatment of infectious diseases in cattle, sheep, swine and
poultry e.g. tylosine, erythromycin, lincomycin
Aminoglycosides consist of an aminocyclitol ring connected to two or more amino sugars
linked via a glycoside link used for the treatment of bacterial brood diseases e.g
streptomycin, gentamycin, neomycin, spectinomycin
Fluoroquinolones which have a fluorine atom attached to the central ring system, typically at
the 6-position and are used as growth promoters e.g ciprofloxacin, ernofloxacin, norfloxacin.
Reliable and up-to-date data on antibiotic consumption (for both animals and humans) is not
widely available.
4.3 Antibiotics authorized in Beekeeping
Beekeepers use antibiotics at relatively high doses, as therapeutic agents to treat clinical
infections (bacterial brood diseases), or they may be administered at low, sub therapeutic
doses as ‘growth promoters'. Beekeeping with the use of antibiotics is less labour intensive
and more profitable.
A list of products approved for use world-wide for fighting bee diseases is listed in Table 2.
Acceptable Daily Intakes (ADIs) established either by the Joint FAO/WHO Meeting on
Pesticide Residues (JMPR) or the Joint FAO/WHO Expert Committee on Food Additives
(JECFA) are also indicated in the Table 2. These chemicals include Acaricides- Folbex VA
(bromppropyllate), Perzin(coumafos), Apistan(Fluvalinate), Bayvarl(flumetrine) used against
mites and antibacterial substances such as sulfonamides, tetracyclines, erythromycin tylosin
and streptomycin used in the treatment of bacterial brood diseases. Maximum Residue Limits
(MRLs) have been established for all food producing species for sulfonamides and
tetracyclines but there are no MRLs for honey (Mutinelli, 2003).
CSE Study: Antibiotics Residues in Honey
Table 2 : List of Products approved in Apiculture
Substance
Major Application
Proprietary
ADI (mg/kg bw per day)
Pesticide/Acaricide
Amitraz (Apivar)
Pesticide/Acaricide
Pesticide/Acaricide
Pesticide/Acaricide
Chlortetracycline
Coumaphos (Perizin) a
Cymiazole hydrochloride (Apitol)
Pesticide/Acaricide
Enilconazol (imazalil)
Pesticide/Acaricide
Flumethrin (Bayvarol)
Lincomycin hydrochloride
Paradichlorobenzene
Streptomycin/dihydrostreptomycin Veterinary drug
Tau-fluvalinate (Apistan )
Thymol b Pesticide
Tylosin tartrate
a Temporary ADI withdrawn in 1980; no ADI allocated in 1990 b. Substances considered by many national authorities as generally regarded as safe Source : Joint FAO/WHO Expert Committee on Food Additives. Meeting (70th : 2008: Geneva, Switzerland).Evaluation of certain veterinary drug residues in food : seventieth report of the Joint FAO/WHO Expert Committee on Food Additives.(WHO technical report series ; no. 954)
CSE Study: Antibiotics Residues in Honey
5. Regulations for Antibiotics in Honey
Honey is an important commodity which is traded internationally. For international trade, all
member countries generally accept standards set by the Codex Alimentarius. However,
individual countries also have their own separate standards. Following standards of antibiotics
in honey were reviewed: Codex Alimentarius, EU, US, Canada, Australia and India. A
comparison of these regulations is given in Table 3.
5.1 Codex
Codex Alimentarius standard for Honey (
Codex Stan 12- 1981 Rev 1 1987 Rev2 2001) defines
honey and lays down standards on its essential composition and quality (moisture content,
sugar content, electrical conductivity etc.). The standard contains provisions relating to
contaminants, hygiene, labeling and methods of analysis. CODEX STAN 12-1981 for honey in
section 4.2, for residues of pesticides and veterinary drugs, states that the products covered by
this standard shall comply with those maximum residue limits for honey established by the
Codex Alimentarius Commission. Internationally agreed safety requirements of a number of
veterinary medicines in food have been recommended by Joint FAO/WHO Expert Committee
on Food Additives (JECFA) and adopted by Codex.
However, no Maximum Residue Limits
(MRLs) have been set for antibiotics in honey or even proposed.
5.2 The European Union (EU)
EU regulates honey under the Council Directive 2001/110/EC. The standard for antibiotics in
food (also referred to as Maximum Residue Limits or MRLs) is listed in Regulation (EU) No
37/2010 – it stipulates that each antibiotic must have an MRL before it can be used on a food-
producing species. But there are no MRLs for antibiotics in honey -- which means the EU does
not allow use of antibiotics for treatment of honeybees.
EU has adopted detailed legislation on use of and monitoring for veterinary drugs. Council
regulation 2377/90 places residues in animal products in 4 Annexes. Each pharmacologically
active substance must have a Maximum Residue Limit (MRL) status before it can be
registered for use in a food producing species. It covers 700 substances of which 200 are
regulated by MRL.
Annex I has the list of pharmacologically active substances for which a MRL has been
fixed. No MRL for antibiotics in honey has been listed in Annex I.
Annex II is the list of substances for which there is no need to set an MRL as they are
unlikely to raise public health concerns, because any use in food-producing animals,
especially the use in bees, is generally regarded as safe. Examples of such substances
include formic acid, lactic acid, oxalic acid, thymol and menthol , fluvalinate, phenol etc.
CSE Study: Antibiotics Residues in Honey
Annex III is the list of pharmacologically active substances for which a MRL cannot be set
definitively but which may be given a provisional MRL for a defined period. A provisional
MRL of 25 ppb has been set for Oxytetracycline in honey.
Annex IV is the list of substances for which it appear no MRL can be set because they
pose a risk to human health in whatever quantity and no exception for honey would be
applicable. This list includes antibiotics like chloramphenicol, dimetridazole, metronidazole,
nitrofurane including furazolidone, ronidazole.
Pharmacologically active substances not listed in Annexes I, II or III are not allowed to be used as
veterinary drugs, if the animal is used for food production. According to Article 14 of the Council
regulation 2377/90 "the administration to food-producing animals of veterinary medicinal products
containing pharmacologically active substances which are not mentioned in Annexes I, II or III shall
be prohibited within the Community….". Standards for antibiotics in honey is not listed in Annexes
I, II or III. This means that the use of antibiotics in honeybees is not permitted and antibiotics in
honey are therefore considered "unauthorised substances".
EU rules on setting of MRLs for pharmacologically active substances have been updated by
Regulation (EC) No 470/2009. This legislation has, for the first time, introduced a mechanism for
the extrapolation of MRLs from one species/food commodity to another. In addition the legislation
elaborates the principles by which the European Commission can establish so-called "Reference
Points for Action" (RPAs) for residues of pharmacologically active substances for which MRLs
have not been (nor can not be) established. RPAs are residue concentrations which are technically
feasible to detect by food control laboratories. In the event that the RPA is exceeded, the Member
State is obliged to reject the consignment as it cannot be legally placed on the EU market (Article
23 of Regulation (EC) No 470/2009).
If a food control laboratory in an EU Member State unequivocally confirms and quantifies the
presence of a substance at a concentration below the RPA (where an RPA has been established)
in an imported consignment (i.e. the decision limit CC as defined in Article 6 of Commission
Decision 2002/657/EC has been exceeded), the Member State competent authority is obliged to
permit the consignment to be placed on the market, however, it is also obliged to follow certain
administrative procedures including, in some circumstances, informing the Commission services.
Till date, RPAs have been established in honey for substances such as chloramphenicol and
nitrofurans. EU has also set a provisional MRL of 25 parts per billion (ppb) for oxytetracycline in
honey, chloramphenicol (0.3 ppb) and nitrofurans (1.0 ppb).
CSE Study: Antibiotics Residues in Honey
Residue limits (tolerances) for veterinary drugs, food additives and unavoidable contaminants in
meat, poultry, and egg products, are set by the Food and Drug Administration (FDA). MRL for
Veterinary drugs are found in Title 21, Part 556 (21 CFR 556). These tolerances are for the
parent compound (the original chemical form of the compound given to the animal), or for the
compound's metabolites (the chemical forms into which the compound is metabolized by the
animal), or for a combination of parent plus metabolites. All tolerances are provided in units of
parts per million (ppm).
There are no limits for veterinary drugs in honey which implies that it
should be absent.
5.4 Australia
In Australia/New Zealand Food Standards Code (the Code) -
Standard 2.8.2 for Honey defines
honey and sets certain compositional requirements for the product.
Standard 1.4.2 Standard lists
the maximum permissible limits for agricultural and veterinary chemical residues present in food.
Schedule 1 lists all of the agricultural and veterinary chemical limits in particular foods. If a
maximum residue limit for an agricultural or veterinary chemical
in a food is not listed in
Schedule 1 there must be no detectable residues of that agricultural or veterinary chemical
in that food. Commodity and commodity groups which are referred to in this Standard are listed in
Schedule 4 which specifies the part of the commodity to which the maximum or extraneous residue
limit refers and honey is listed under Animal Food Commodity.
Australia has set MRL for only
Oxytetracycline in honey at 300 ppb. Other antibiotics in honey is not allowed.
Source: http://www.foodstandards.govt.nz
5.5 Canada
Health Canada's Veterinary Drugs Directorate (VDD) in agreement with the Canadian Food
Inspection Agency (CFIA) has amended the joint Policy on Administrative Maximum Residue
Limits/ Maximum Residue Limits (AMRLs/MRLs) for Veterinary Drugs in Food Products to include
Working Residue Levels (WRLs) for antimicrobials used in honey. WRLs are recommended levels
for drug residues in honey below which there is considered to be no undue risk to human health.
The WRLs for honey have been derived by extrapolating lowest established AMRL/MRL values of
antimicrobials that are approved for use in other food-producing animals.
Chloramphenicol and
Nitrofuran antibiotics are banned in Canada. AMRL for Oxytetracycline is fixed at 300 ppb
and WRL of Erythromycin is 30 ppb.
Source: The Veterinary Drugs Directorate of Health Canada at http://www.hc-sc.gc.ca/vetdrugs-
5.6 India
Honey is regulated by three standards at present; the Prevention of Food Adulteration (PFA) Act,
the Bureau of Indian Standards (BIS) and the Agricultural Produce Grading and Marking Act
CSE Study: Antibiotics Residues in Honey
(Agmark). The export of honey is monitored by the Exports Inspection Council which has set ‘Level
of Action' for antibiotics in exported honey.
(a) PFA Act, 1954, which is mandatory, defines honey and lays down standards for its
essential composition and quality (sucrose content, hydroxymethylfurfural, moisture content
etc.)
but there are no standards for veterinary drugs/antibiotics in honey.
(b) Bureau of Indian Standards has set standards for Extracted Honey in IS 4941:1994.This
standard lays down specification for general requirements for 11 parameters (specific gravity,
moisture, total reducing sugar, acidity, hydroxymethylfurfural etc.).
But there are no
standards for antibiotics.
IS 6695: 1998 – Honey Bees - Code for conservation and maintenance, in Annex B, Clause
3.2 has listed notifiable Honey Bee disease and their treatment. Terramycin (Oxytetracycline)
is recommended for treatment of European Foul Brood disease. For American Foul Brood the
treatment only specifies "Antibiotics'—no name is mentioned.
(c) AGMARK standard set up by the Directorate of Marketing and Inspection of the
Government of India under the provisions of the Agricultural Produce (Grading and Marking)
Act 1937 as amended in 1986. Honey is regulated under the Honey Grading and Marking
Rules, 2008. This Rule gives specifications for quality of honey, method of packing, marking
and labeling. Honey is classified into three grades - Special, Grade A and Standard – and
their quality specifications is mentioned.
Schedule II (Grade designation and quality of Honey) of Honey Grading and Marking Rules,
2008 defines Honey as follows: "Honey" shall be obtained from the natural sweet substance
produced by honey bees from the nectar of blossoms or from secretions of plants, which
honey bees collect, transform and store in honey combs for ripening.
Clause (V) of Schedule II specifies that: Honey shall comply with restrictions in regards to
Metallic Contaminants (rule 57), Crop Contaminants (rule 57 A), Naturally occurring toxic
substances (rule 57 B), insecticides and pesticides residue (rule 65) and other food safety
requirements as laid down under Prevention of Food Adulteration Rules, 1955 as amended
from time to time for domestic purposes.
Clause (VI) of Schedule II specifies that: Honey shall comply restrictions in regards to heavy
metals, pesticides and other food safety requirements as specified in Codex Alimentarius
Commission or as per buyer's requirements for export purposes.
The Honey Grading and Marking Rules, 2008, therefore, links honey standards for domestic
consumption to Prevention of Food Adulteration Rules, 1955 and for exported honey with
Codex Alimentarius Commission or the standard of the importing country. Since Prevention of
CSE Study: Antibiotics Residues in Honey
Food Adulteration Rules, 1955 doesn't specifies any antibiotic standards for honey, under
AGMARK also there is not standard for antibiotics in honey.
(d) Export Inspection Council: The Government of India, Department of Commerce
(Ministry of Commerce and Industry), under the Export Inspection Council of India (EIC) Act
monitors the quality of products exported from India. To promote the exports of honey, the
Ministry of Commerce and Industries, Government of India has setup a Residue Monitoring
Plan (RMP) to monitor the level of antibiotics, heavy metals and pesticides contamination in
honey destined for exports. The Export Inspection Council (EIC) is responsible for
implementing the RMP.
EIC has setup ‘Level of Action' (similar to standards) for antibiotics in exported honey.
Sample found to be containing antibiotics beyond the Level of Action is deemed non-
compliant. The Level of Action for Chloramphenicol is 0.3 ppb, Nitrofurans 1 ppb,
Tetracyclines (group) 10 ppb, Streptomycin 10 ppb and Sulphonamides (group) 20 ppb.
Table 3. Comparison of different regulation for Antibiotics in Honey
Class Antibiotic
Codex EU2 USA3 Australia4 Canada
Fluoroquinolones
FAO/WHO, 2008 Codex Alimentarius: Veterinary Drugs Residues in Food Maximum Residue Limits. Http://www.codexalimentarius.net/mrls/vetdrugs/jsp/vetd-q-e.jsp
EU- Http://www.emea.europa.eu/index/indexv1.htm. Veterinary medicines and Information technology Units Committee for Veterinary medicinal products
USA- Tolerances for residues of new animal drugs in food in Title 21, Part 556 (21 CFR 556). http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=556
Australia /New Zealand Food Standards Code http://www.foodstandards.govt.nz
Canada HC 2008a Health Canada WRLs in honey. http://hc-sc-gc.ca/dhp-mps/legislation/vet/pol/cfia-acia_amr-ram_table_e.htmll HC 2008 b Health Canada. Drugs& Health Products, Veterinary Drugs, Administrative Maximum Residue Limits (AMRLs)(MRLs) set by Canada and Maximum Residue limits available at http://www.hc-sc.gc.ca/dhp-mps/vet/mrl-lmr/mrl
According To Export Inspection Council of India's Residue Monitoring Plan (RMP) Honey 2010-2011
Maximum residue level (ppb or part per billion)
AMRL – is administrative MRL means that the scientific evaluation and decisions are complete and that regulatory process to publish this information is in progress. Once the regulatory process is complete the AMRL becomes an MRL
RPA – Reference point for action set by EU
10. WRL – Working Residue Levels. There are no MRLS for antibiotics in honey therefore WRLs are set. WRLs are recommended
levels for drug residues in honey below which there is considered to be no undue risk to human health. The WRLs for honey have been derived by extrapolating from AMRL/MRLs for antimicrobials that are approved for use in other food-producing animals such as chickens, swine and cattle.
11. LOA- Level of Action- is the concentration of a drug residue in a sample at which it is deemed non-compliant.
CSE Study: Antibiotics Residues in Honey
6. Health Impacts
Antibiotics used in food animals can affect the public health because of their secretion in
edible animal tissues in trace amounts usually called residues. For example, oxytetracycline
(Saridaki-Papakonstadinou
et al, 2006 ) and Chloramphenicol residues (Ortelli
et al., 2004)
have been found above the regulatory standards in honey. Some drugs have the potential to
produce toxic reactions in consumers directly while some other are able to produce allergic or
hypersensitivity reactions (Vellicer, 2004). For example, -lactam antibiotics can cause
cutaneous eruptions, dermatitis, gastro-intestinal symptoms and anaphylaxis at very low
doses. Such drugs include the penicillin and cephalosporin groups of antibiotics (Paige
et al.,
1997). Indirect and long term hazards include microbiological effects, carcinogenicity,
reproductive effects and teratogenicity. Microbiological effects are one of the major health
hazards in human beings. Antibiotic residues consumed along with edible tissues like milk,
meat, eggs and honey can produce resistance in bacterial populations in the consumers.
These bacteria might then cause difficult-to-treat human infections. Certain drugs like 3-
nitrofurans and nitroimidiazoles can cause cancer in human population. Similarly, some drugs
can produce reproductive and teratogenic effects at very low doses consumed for a
prolonged period of time.
6.1 Chronic health effects
Chronic health effects of some antibiotics detected in the present study are discussed below :
Oxytetracycline (Class: Tetracycline)
Oxytetracycline (OTC) is a broad-spectrum antibiotic used to treat a variety of infections and
is also used as a growth promoter in animals. Symptoms of chronic exposure to
oxytetracycline include blood changes (leucocytosis, atypical lymphocytes, lung congestion,
toxic granulation of granulocytes and thrombocytopenia purpura). Liver injury and delayed
blood coagulation may also occur. It can damage calcium rich organs such as teeth and
bones and sometimes causes nasal cavities to erode. Children under 7 years of age may
develop a brown discoloration of the teeth. Infants of mothers treated with OTC during
pregnancy may develop discoloration of the teeth. Some other chronic effects of
oxytetracycline includes increased sensitivity to the sun , wheezing and asthmatic attack.
Toxicological studies indicate that this drug is not mutagenic, carcinogenic, or terratogenic.
Erythromycin (Class: Macrolides)
Erythromycin (ERY) is effective against many gram-positive organisms and is useful in the
treatment of
staphylococcal infections in animals and humans. Exposure to erythromycin
(especially long courses at antimicrobial doses, and also through breastfeeding) has been
CSE Study: Antibiotics Residues in Honey
linked to an increased probability of pyloric stenosis in young infants a condition that
causes severe vomiting in the first few months of life (Maheshwai, 2007).
Erythromycin is a reproductive hazard (terratogen) with chronic exposure. Cardiac
malformation was observed in infants of women who had taken erythromycin in their early
pregnancy (JECFA, 1997)
Enrofloxacin (Class: Fluoroquinolones)
Enrofloxacin (ENR) a fluroquinolone antibiotic which acts by inhibition of bacterial DNA
gyrase Embryo lethality and terratogenicity of fluoroquinolone antibacterials in rats and
rabbits has been suggested (Guzman
et al., 2003). Chromosomal aberrations evaluated in
cultures of human peripheral lymphocytes from eight healthy donors, exposed to the
antimicrobial enrofloxacin or to its major metabolite ciprofloxacin suggested a genotoxic effect
of enrofloxacin and ciprofloxacin (Gorla et al , 1999). It is also associated with increased
photosensitivity. The Food and Drug Administration's Center for Veterinary Medicine has
proposed to withdraw approval for use of the fluoroquinolone antimicrobial, enrofloxacin, in
poultry based not on drugs direct toxicity but on potential for increasing human pathogen
resistance. Source: http://www.fda.gov/cvm/Documents/baytrilDDL.pdf
Chloramphenicol (Class: Amphenicol)
Chloramphenicol (CAP) a bacteriostatic antimicrobial previously used in veterinary medicine.
It has been found to be potentially carcinogenic, which makes it an unacceptable substance
for use with any food producing animals, including honey bees. The United States, Canada,
and the European Union (EU), as well as many other countries, have completely banned the
usage of CAP in the production of food. Chloramphenicol is anticipated to be a human
carcinogen and genotoxic from studies in humans. It is toxic to blood, kidney, liver. Repeated
or prolonged exposure to Chloramphenicol can lead to target organ damage, bone marrow
toxicity. The most serious effect of chloramphenicol is aplastic anaemia which is idiosyncratic
(rare, unpredictable, and unrelated to dose) and generally fatal and could presumably be
triggered by residues (Payne
et al, 1999) Several reports document human fatalities resulting
from ophthalmic preparations containing chloramphenicol, with total exposure dozes that
could be achieved from food residues (Settepani,1984).
Ampicillin (Class: ß-lactam)
Ampicillin (AMP) is a penicillin derivative -lactam antibiotic is widely used in cattle, swine,
honey bees and poultry to treat infections and as feed or drinking water additives to prevent
some diseases. Workers from an antibiotic-producing factory developed asthma and
eosinophilia on inhalation of ampicillin and related substance (Davfes
et al, 1974). Ampicillin
may cause recurrent cholestatic hepatitis (Koklu
et al, 2003). Repeated contact may cause
CSE Study: Antibiotics Residues in Honey
allergic reactions, asthmatic attack, exfoliative dermatitis, anemia, thrombocytopenia,
thrombocytopenic purpura, eosinophilia, leukopenia, and agranulocytosis.
6.2 Antibiotic Resistance
Antibiotic resistance is the ability of a microorganism to withstand the effects of an antibiotic.
If even at a large dose, the antibiotic is not effective in treating an infection, then the
microorganism that is responsible for the infection is declared as resistant to that antibiotic
(Goosens, 2005).
Antibiotic resistance is a global public health concern today. The U.S. Centers for Disease
Control and Prevention (CDC, 2000) has described antibiotic resistance as "one of the world's
most pressing health problems", because "the number of bacteria resistant to antibiotics has
increased in the last decade [and] … many bacterial infections are becoming resistant to the
most commonly prescribed antibiotic treatments." The World Health Organization (WHO) has
identified antibiotic resistance as "one of the three greatest threats to human health."
Its primary cause is long-term over-exposure to antibiotics through their use as medicines in
humans, as well as in animals, horticulture and for food preservation. The types of antibiotics
used in animals are frequently the same as, or closely related to, those used in humans.
Factors influencing the development of resistance include drug concentration, duration of
exposure, organism type, antimicrobial type and host immune status (WHO, 1997).
Antibiotic resistance in bacteria evolves via natural selection through random mutation. When
a bacterium is exposed to an antibiotic it starts making changes in its DNA to withstand the
effects of the medicine. Once it acquires a specific antibiotic-resistant gene, it quickly passes
it on to its next generation. Nature has developed different systems for transfer of genes
between bacteria (conjugation, transformation, transduction and transposition) and these
mechanisms have proven effective in the promotion of resistant genes. If a bacterium carries
several resistant genes, it is called multi-resistant or, informally, a superbug. When resistant
bacteria are themselves pathogenic or can transfer their resistance genes to pathogenic
bacteria, adverse health effects can result.
Adverse consequences of selecting resistant bacteria in animals include:
• the transfer of resistant pathogens to humans via direct contact with animals,
or through the consumption of contaminated food or water;
• the transfer of resistance genes to human bacteria; • an increase in the prevalence of resistant bacteria in animals;
CSE Study: Antibiotics Residues in Honey
• an increase in the incidence of human infections caused by resistant
and potential therapeutic failures in animals and humans.
• residues of antimicrobial agents in food of animal origin in excess of the
agreed acceptable maximum residue levels (MRLs) may contribute to the
generation of resistance in bacteria in humans.
Several WHO consultations and other expert bodies have identified links between antibiotic
use in animals and the emergence of mainly food-borne bacteria which are resistant to
important antibiotics which are used in treating infectious diseases in humans. In December
2003, an expert workshop was jointly convened by the Food and Agriculture Organization of
the United Nations (FAO), the World Organization for Animal Health (OIE) and the World
Health Organization (WHO) to make a scientific assessment of resistance risks arising from
non-human use of antibiotics/antimicrobials. The workshop concluded that "there is clear
evidence of adverse human health consequences due to resistant organisms resulting from
non-human usage of antimicrobials. These consequences include infections that would not
have otherwise occurred, increased frequency of treatment failures (in some cases death),
and increased severity of infections".
In recent years, more evidence has emerged of an association between use of antibiotic
agents in food animals and antibiotic resistance among bacteria isolated from humans. An
outbreak of human nalidixic acid-resistant
Salmonella typhimurium DT104 infection in
Denmark was traced to a pig farm. Another outbreak of the same infection, reported in the
United Kingdom, was traced to a dairy farm where Fluoroquinolones had been used on the
cattle a month before the outbreak. In the United States, there was a marked increase in the
proportion of domestically acquired
Campylobacter infections that were Fluoroquinolone-
resistant, following the first approved use of Fluoroquinolones in food animals in 1995 (WHO,
The WHO, in fact, has recommended that antibiotics which are also licensed in human
medicine should not be used any more as growth promoters in livestock. An EU resolution to
this effect was put in place in 1999. Since then, studies from Denmark, Germany and Italy
have shown a significant reduction in Vancomycin-resistant
Enterococci isolations from
poultry and poultry-derived food products. Some European member states (such as
Denmark) have, with insignificant or no consequence either on disease rates in animals or on
meat market prices, voluntarily suspended the use of all growth promoters irrespective of their
human health importance.
The major challenge in combating antibiotic resistance lies in the development and
implementation of methods for their prudent use. Attention also must be paid to the
CSE Study: Antibiotics Residues in Honey
development of mechanisms for safety assessments of antibiotics intended for ‘food' animal
use. There is a significant difference between ‘traditional' chemical residue-based
determination of safety of animal drugs and the determination of safety in the context of
antibiotic resistance. Some ‘methodologies' have been proposed for the latter, but none have
been implemented so far.
7. Review of Literature
Antibiotic residues in honey have recently become a major consumer concern. It has become
evident that residues of antibiotics in honey originate mostly not from the environment but
from improper beekeeping practices. There are several international reports of antibiotic
residues in honey samples, however there are very few reports of antibiotics in honey sold in
domestic market in India. There are reports of tests conducted by Agricultural Processed
Food Product Export Development Agency (APEDA) and EIC from 2005 onwards show high
levels of antibiotics and heavy metals in honey exported from India to EU and US. In 2006,
about 14 per cent samples were contaminated with tetracycline. In 2007-08, about 28 per
cent samples were contaminated with this ame antibiotic. Of the 362 honey samples it tested
in 2009-2010 by the EIC, 29.2 per cent samples had more than the prescribed limit of
antibiotics and heavy metals (EIC documents).
Another consignment belonging to Lee Bee Impex, a big exporter based in Ludhiana in
Punjab, was barred from entering the US market in 2007—the honey was found to have
originated in China and had residues of fluoroquinolone.
According to the Alert Notices issued by FSA (Food Standards Agency) of UK in March 2003
on the contamination of Indian foods based on the tests at importing points Dabur Honey was
contaminated with antibiotic Streptomycin (Mayande, 2007).
In the period 2000-2001, 248 samples of locally produced and imported honey were
monitored for the presence of residues of veterinary drug residues. Streptomycin was
detected in 4 out of 248, tetracycline in 2 out of 72, sulfonamides in 3 out of 72 samples. No
residues of lactam antibiotics and chloramphenicol were found. In imported honey samples
streptomycin was detected in 51 out of 102 samples, tetracyclines in 29 out of 98 samples,
sulfonamides in 31 out of 98 samples, chloramphenicol 40 out of 85 samples. For the
streptomycin and tetracycline contamination, most cases involved the beekeeper admitting to
having added foreign honey to his production (Reybroeck, 2003).
Of the 75 samples of honey obtained commercially in Switzerland, 34 which originated from
Asian countries, 13 samples (17%) contained chloramphenicol residues. Concentration of
chloramphenicol measured in honey between 0.4 and 6.0 μgkg-1, with six samples containing
CSE Study: Antibiotics Residues in Honey
approximately 0.8–0.9 μgKg-1 (just below the Swiss limit) and two containing approximately 5
μgkg-1 (Ortelli
et al, 2004).
Another study in which 251 honey samples produced across Greece were analysed by Liquid
chromatography to detect tetracycline-derived residues. 29% of the samples had tetracycline
residues. Majority of samples contained residues from 0.018-0.055 mg/kg of honey while
some others had residues in excess of 0.100mg/kg (Saridaki-Papakonstadinou
et al, 2006 )
Centre for Food Safety (CFS) found that two of the 19 samples of honey collected for
examination for antibiotics contained trace amounts of chloramphenicol, one brand of honey
produced in Jiangxi (under batch number 20060424, with "best before" date 24.4.2008) and
another brand produced in Zhuhai (with "best before" date 30.6.2008). Other antibiotics found
in the honey samples in trace amount, namely streptomycin, sulfamethoxazole (a kind of
sulfonamides) and ciprofloxacin (a kind of quinolone), they can normally be used in food
animals. (CFS, 2006)
In February 2006, the Florida Department of Agriculture and Consumer Services reported that
residues of two fluoroquinolones of concern, ciprofloxacin and enrofloxacin were found in
honey samples that was traced back to a firm from China. The State subsequently, on August
14, 2006, FDA issued Import Alert No. 36-04 requiring detention without physical examination
of honey due to presence of fluoroquinolones.
Nectar and Honey samples collected from bee hives during the peak flowering seasons of
rubber (March to April) and banana (December to January) plantation crops in southern part
of Tamil Nadu were analysed for antibiotic residues. Nectar and honey samples showed 4-17
and 11-29 g/kg of streptomycin, 2-29 and 3-44 g/kg of ampicillin and 17-34 and 26-48
g/kg of kanamycin respectively (Solomon
et al, 2006 ).
Out of the 3855 honey samples tested 1.7% samples were non compliant with the EU
standards Antibiotic were detected in the honey samples in the range- Streptomycin 3 –
10,820μg/kg, Sulfonamides 5 – 4,592μg/kg, Tetracyclines 5 – 2,076μg/kg, Chloramphenicol
0.1 – 169μg/kg, Nitrofurans 0.3 - 24.7μg/kg, Tylosine 2 – 18μg/kg, Quinolones <1 - 504μg/kg
(Diserens, 2007).
50 honey samples comprising chestnut, pine, linden and multiflower honeys collected from
the hives in Southern Maramar region of Turkey were analysed for erythromycin residues by
Liquid Chromatography-mass spectrometry using Electrospray ionization in the positive ion
mode (LC-ESI-MS). Four of the honey samples were contaminated with erythromycin
residues at concentrations ranging from 50 to 1776 ngg-1. An erythromycin-fortified cake
feeding assay was also performed in a defined hive to test the transfer of erythromycin
CSE Study: Antibiotics Residues in Honey
residue to the honey matrix. In this test hive, the residue level in the honey,3 months after
dosing, was approximately 28 ngg-1. (Gunes
et al , 2008).
Another study aimed to assess oxytetracycline (OTC) residue levels in honey after treatment
of honeybee colonies with two methods of application (in liquid sucrose and in powdered icing
sugar. The samples of honey were extracted up to 12 weeks after treatment and following
metal chelation and analysed by HPLC showed that the current method of application of
Oxyteracyclin(Terramycin) in liquid form results in very high residue levels in honey with
residues of 3.7 mg/kg, eight weeks after application(Thompson
et al 2005).
Recently researchers have developed a method to simultaneously detect the presence of 17
antibiotics (macrolides, tetracyclines, quinolones, and sulfonamides) in honey samples taken
from supermarkets while five were collected from various private beekeepers throughout
Granada and Almería. The results of the study show that one of the commercial honey
samples contained 8.6 μg/Kg, while another contained traces of sarafloxacin and residues of
tylosin, sulfadimidine and sulfachlorpyridazine were found in the honey from one bee
farm(Vidal
et al 2009).
A total of 57 real royal jelly samples collected from beekeepers and supermarkets were
analyzed for seven fluoroquinolones used in beekeeping, viz. ciprofloxacin, norfloxacin,
ofloxacin, pefloxacin, danofloxacin, enrofloxacin, and difloxacin, were analysed by high
performance liquid chromatography with fluorescence detection. Ofloxacin, ciprofloxacin, and
norfloxacin, were detected in concentrations ranging from 11.9 to 55.6 ng/g in some royal jelly
samplesmand difloxacin was found at concentrations of about 46.8 ng/g in one sample
though it is rarely used in beekeeping (Zhou
et al , 2009).
8.Sampling
A total of 12 branded honey samples were collected randomly from different shops in Delhi in
the month of July 2009. 10 honey samples were from Indian companies and two were
imported honey. Sample details and related information is given in Annexure I. The samples
were analyzed at PML during 2009-2010.
9. Materials and Methods
Each honey sample was analyzed in triplicate for 6 antibiotics of 5 major classes using High
Performance Liquid Chromatography (HPLC) with Diode Array detector (DAD) and
Fluorescence Detector (FLD). Published methods were used for the extraction and clean up
and validated at PML.
CSE Study: Antibiotics Residues in Honey
9.1 Equipments
• HPLC Agilent technologies (1100 series) equipped with DAD, FLD, and Post Column
Derivatization unit.
• HPLC Column: Zorbax ODS column, C18 – 5 m, 4.6mm x 250mm
• HPLC Column: Zorbax Eclipse XDB column, C8- 3 m, 4.6mm x 150mm
• Vacuum manifold
• Solid Phase extraction Cartridges – SampliQ OPT 3 ml, 60 mg cartridges, SampliQ OPT 6
ml, 150 mg cartridges and SampliQ C18 endcapped, 3 mL tubes, 500 mg cartridge
• 250 μL syringe from Hamilton Co. • Syringe filters 4mm syringe filter 0.45 μm, PFTE
• Vortex • Sonicator • Centrifuge of Remi equipments • Nitrogen evaporator, with 500C water bath
9.2 Chemicals
All the solvents used (acetonitrile, methanol and ethyl acetate) were HPLC grade. Other
reagents used for the analysis like Formic acid, Acetic acid, Potassium di-hydrogen
phosphate, di-Potassium hydrogen phosphate, Ammonia, Sodium Hydroxide, Potassium
Hydroxide, Sodium Chloride etc. were of analytical grade and purchased from Merck Ltd.
Water used was HPLC grade (Milli-Q).
9.3 Glassware
All the glassware used - beaker, volumetric flask, conical flask, funnel, pipettes, sample
tubes, centrifuge tubes etc. - were cleaned with detergent and 10% nitric acid and rinsed
thoroughly with distilled water before use.
9.4 Standards
Antibiotic reference standards were obtained from Sigma chemicals USA. The purity of the
reference standards used is as follows:
Oxytetracycline hydrochloride: 98.1%
Chloramphenicol palmitate: 97.9%
• Erythromycin
• Enrofloxacin:
• Ciprofloxacin:
CSE Study: Antibiotics Residues in Honey
9.5 Sample extraction, Clean up and Analysis
9.5.1 Oxytetracycline (Class: Tetracyclines)
a.
Standard solutions and reagents preparation
Stock standard solution (100 μ
g/mL)
Accurately weighed 2.5 mg of oxytetracycline into 25 mL volumetric flask; dissolved in
methanol and diluted to volume. Stock solutions were stored at 4ºC for about 1 month.
Working standard solutions (5-100 ng/mL)
Working standard solutions (5-100ng/mL) were prepared from stock standard solution by
appropriate dilution with 0.01M oxalic acid in a 10 mL volumetric flask. The solution was
mixed thoroughly and prepared fresh every day.
10mM oxalic acid
1.26 g oxalic acid dihydrate dissolved in water in 1L volumetric flask and diluted to a final
volume with water and mixed well by inversion and prepared daily.
McIlvaine buffer-pH 4.0
Mix 1L of 0.1M citric acid with 625 mL of 0.2M anhydrous Na2HPO4 in a 2L volumetric flask
and pH adjusted to 4.
Na2EDTA-McIlvaine buffer solution (0.1M)
To 1.625 L McIlvaine buffer add 60.5 g disodium EDTA dihydrate and mixed until dissolved.
Prepared weekly.
b. Sample preparation
Extraction by liquid-liquid extraction (LLE)
5 g sample of honey was dissolved in 20 mL of 0.1 M Na2EDTA-Mcllvaine buffer at pH 4. The
solution was vortexed for 5 minutes, filtered and made ready for SPE clean-up procedure
(Pagliuca et. al., 2002).
Clean-up by solid phase extraction (SPE)
After extraction, sample was loaded on a SampliQ OPT 3 ml (60 mg) cartridge previously
conditioned with 1 mL methanol and 1 mL water. The SPE cartridge was then washed with 10
mL water. Finally, the sample was eluted with 1 mL ethyl acetate directly in sample tube. After
evaporating the solvent at 40ºC under nitrogen stream, the residues were reconstituted with 1
mL HPLC mobile phase (Pagliuca
et. al., 2002).
CSE Study: Antibiotics Residues in Honey
c. Analysis
The sample was analysed by (Pagliuca et. al., 2002) with some modifications using HPLC
equipped with DAD detector and Zorbax Eclipse XDB C8 3 μm (150 x 4.6 mm I.D.) column at
30ºC in isocratic conditions with mobile phase; aqueous oxalic acid (0.01M), acetonitrile and
methanol (70:15:15). The flow rate was 1.0 mL/minute. The DAD detector monitored the
eluent at 360 nm and measured spectra from 200 to 400 nm. The sample injection volume
was 100 μL. Retention time of oxytetracycline was 2.7 minutes.
9.5.2 Chloramphenicol (Class: Amphenicol)
a. Standard solutions and reagents preparation
Stock standard solutions (100 μ
g/mL)
Accurately weighed 2.5 mg of chloramphenicol into 25 mL volumetric flask and dissolved in
acetonitrile and diluted to volume. Stock solutions were stored at 4ºC for about 1 month.
Working standard solutions (5-100 ng/mL)
Working standard solutions (5-100 ng/mL) were prepared everyday from stock standard
solution by the appropriate dilutions with acetonitrile and water (20:80 ratio) in 10 mL
volumetric flasks.
b. Sample preparation
Extraction by liquid-liquid extraction (LLE)
5 g honey sample was weighed into 50 mL capped centrifuge tube (Zhao & Ball 2009). This
was followed by addition of 5 mL of water and vortexed for 3 minutes to mix the sample
thoroughly. 5 mL of ethyl acetate was then added to the centrifuge tube. The tube was tightly
capped and vortexed for 5 minutes. The tube was then centrifuged at 3,200 rpm for 5
minutes. The upper organic layer was carefully transferred to another tube using disposable
pipettes. This process was repeated twice and supernatant was combined and evaporated to
dryness with a controlled nitrogen flow drier at 50ºC and reconstituted into 5 mL of water,
vortexed and sonicated to completely dissolve the residue. The sample was then ready for
Clean-up by solid phase extraction (SPE)
For SPE clean up, SampliQ OPT 3 mL (60 mg) cartridges were preconditioned with 3 mL
methanol and then equilibrated with 5 mL of water (Zhao and Ball, 2009). The 5 mL sample
extract was then loaded to cartridge and passed through the cartridge slowly (0.5 mL/min).
The SPE cartridges were rinsed with 5 mL water twice. The entire effluent was discarded. Full
vacuum was applied to the cartridge for 3 minutes to completely dry the resin. Finally, the
residues were eluted with 5 mL of 20:80 methanol/ethyl acetate (2.5 mL x 2) at a rate of 1
CSE Study: Antibiotics Residues in Honey
mL/min. The eluent was collected into clean tubes and dried under nitrogen stream at 50ºC.
The residue was reconstituted in 1 mL of 20:80 Acetonitrile/water. The sample was vortexed
and sonicated to completely dissolve the residue in the tubes.
c. Analysis
The sample was analysed by HPLC equipped with DAD detector using a Zorbax Eclipse XDB
C8 3 μm (150 x 4.6 mm I.D.) column in gradient conditions in gradient conditions given below,
with mobile phase - Acetonitrile (A) and Water–pH (8.5) (B) adjusted with 0.01% ammonia
(Zhao & Ball, 2009). The column temperature was maintained at 30ºC.
Water(pH 8.5 adjusted with
Flow (ml /min)
0.01% ammonia)
The DAD detector monitored the eluent at 280 nm and measured spectra in UV range. The
sample injection volume was 100 μL. The retention time of Chloramphenicol was at 8.7
9.5.3 Ampicillin (Class: -Lactam)
a. Standard solutions and reagents preparation
Stock standard solutions (100 μ
g/mL)
Accurately weighed 2.5 mg of ampicillin into 25 mL volumetric flask and dissolved in
acetonitrile-water (1:1) and diluted to volume. Stock solutions were stored at 4ºC for about 1
Working standard solutions (5-100 ng/mL)
Working standards (5-100 ng/mL) were prepared everyday from stock standard solution by
appropriate dilutions with acetonitrile – water (1:1) in 10 mL volumetric flask.
25mM Phosphate buffer (KH2PO4)
Accurately weighed 3.4 g of KH2PO4 into 1L volumetric flask and dissolved in water and the
pH was adjusted to 3 with phosphoric acid and diluted to volume.
Extraction solution-0.1M phosphate buffer (pH-9.2)
Accurately weighed 13.8 g of sodium di-hydrogen orthophosphate monobasic; monohydrate,
into a 1L volumetric flask and dissolved in water and adjusted to pH 9.2 with drop-wise
addition of 10N NaOH and diluted to volume with water.
CSE Study: Antibiotics Residues in Honey
Sodium chloride solution (2%)
Accurately weighed 20 g of NaCl and dissolved in water, transferred to a 1L volumetric flask
and diluted to volume with water.
b. Sample preparation
Extraction by liquid-liquid extraction (LLE)
5 g of honey sample was weighed into 50 mL capped centrifuge tube (Wang, 2004). 20 mL of
extraction solution was added and the centrifuge tube was capped tightly and vortexed for 5
minutes until honey was completely dissolved. The tubes were then centrifuged at 4,000 rpm
for 10 minutes at room temperature to remove particles from solution and thereby avoid
plugging the SPE cartridge. After centrifugation the upper layer was carefully transferred to
another tube using disposable pipettes. The sample was then ready for SPE clean up.
Clean-up by solid phase extraction (SPE)
For SPE clean up, SampliQ C18 endcapped, 3 mL tubes, 500 mg cartridges were
preconditioned sequentially with 10 mL methanol, 10 mL water, 10 mL NaCl solution (2%)
and then equilibrated with 2 mL of extraction solution (Wang,2004). The sample extract was
then loaded on cartridge and passed through the cartridge slowly under vacuum. The SPE
cartridges were then rinsed with 5 mL of water. The entire effluent was discarded. Evacuated
the cartridge to dryness by applying full vacuum for 5 minutes. Finally eluted with 3 mL of
acetonitrile at a flow rate of 1-2 mL/min under vacuum in a 5 mL test tube. The eluent was
evaporated to dryness using nitrogen evaporator at 40ºC-50ºC under a stream of nitrogen.
The residue was reconstituted in 1 mL of Acetonitrile : Water (1:1 ratio). The sample was
vortexed and sonicated to completely dissolve the residues in the tube.
c. Analysis
The sample was analysed by HPLC equipped with DAD detector using a Zorbax ODS C18 5
μm (250x4.6 mm I.D.), at room temperature (25ºC) in isocratic conditions with 25 mM KH2PO4
(pH-3) and acetonitrile (70:30 ratio) mobile phase (Huber & Onigbinde, 2002). The flow rate
was 0.8 mL/min. The DAD detector monitored the eluent at 204 nm and measured spectra in
UV range. The sample injection volume was 100 μL. The retention time of ampicillin was 2.6
CSE Study: Antibiotics Residues in Honey
9.5.4 Enrofloxacin and Ciprofloxacin (Class:Fluoroquinolones)
a. Standard solutions and reagents preparation
Stock standard solutions (100 μ
g/mL)
Accurately weighed 2.5 mg each of enrofloxacin and ciprofloxacin separately into 25 mL
volumetric flasks and dissolved in acetonitrile : acetic acid in water (2%) (16:84 ratio) and
diluted to volume. Stock solutions were stored at 4ºC for about 1 month.
Working standard solutions
Working standard solutions of ciprofloxacin (10 -100 ng/mL) and enrofloxacin (5 - 50 ng/mL)
were prepared everyday from stock standard solutions by appropriate dilutions with
acetonitrile: acetic acid in water (2%) (16:84) in 10 mL volumetric flask .
Formic acid solution (0.1%)
1 mL of pure formic acid was added into a 1L volumetric flask and diluted to a final volume
with water and mixed well by inversion.
Acetic acid solution (2%)
Placed 20 mL of acetic acid in 1L volumetric flask and diluted to volume with water.
b. Sample preparation
Extraction by liquid-liquid extraction (LLE)
2.5 g of honey sample was weighed into 50 mL centrifuge tube. 5 mL water was added and
the tube was vortexed for 1 minute until all of the honey dissolved (USFDA Method 2006).
Thereafter, 10 mL of acetonitrile and 200 μL acetic acid was added to the sample. The
centrifuge tube was capped tightly and vortexed for approximately 30 seconds. 2 g of NaCl
was added and the centrifuge tube was again vortexed for 15 seconds. The tube was then
centrifuged at 2,400 rpm for 5 minutes and upper organic layer was carefully transferred to
another tube using disposable pipettes. This process was repeated twice and supernatant
was combined and passed through sodium sulfate cartridge. Sample was then evaporated to
dryness with a controlled nitrogen flow at 50ºC before being reconstituted into 1 mL of
acetonitrile : 2% acetic acid in water (16:84 ratio), vortexed and sonicated to completely
dissolve the residue.
c. Analysis
The sample was analysed by HPLC equipped with Fluorescence (FLD) detector (Verdon
et.
al., 2005) using a Zorbax ODS C18 5 μm (250x4.6 mm I.D.), at room temperature (25ºC) in
gradient conditions given below. The flow rate was 1 mL/min. The FLD detector monitored the
eluent at excitation wavelength - 295 nm and emission wavelength - 500 nm. The sample
CSE Study: Antibiotics Residues in Honey
injection volume was 100 μL. The retention time was 5.4 minutes for ciprofloxacin and 6.6
minutes for enrofloxacin.
0.1% Formic
Flow(ml /min)
9.5.5 Erythromycin (Class: Macrolides)
a. Standard solutions and reagents preparation
Stock standard solutions (1000 μ
g/mL)
Accurately weighed 25 mg of erythromycin into 25 mL volumetric flask and dissolved in
methanol and diluted to volume. Stock solutions were stored at 4ºC for about 1 month.
Working standard solutions (0.1-10 μ
g/mL)
Working standard solutions (0.1 – 10 μg/mL) were prepared everyday from stock standard
solution in a 10 ml volumetric flask by appropriate dilutions with methanol-water (1:1 ratio).
20mM Phosphate buffer (K2HPO4)
Accurately weighed 3.48 g of K2HPO4 into 1L volumetric flask dissolved in water and diluted
0.1M phosphate buffer ( pH-8)
Accurately weighed 13.8 g of monobasic sodium- phosphate (monohydrate); dissolved in
water and adjusted to pH 8 with drop-wise addition of 10N NaOH. Transferred to a 1L
volumetric flask and diluted to volume with water.
Sodium chloride solution (2%)
Accurately weighed 20 g of NaCl, dissolved in water. Transferred to a 1L volumetric flask and
diluted to volume with water.
b. Sample preparation
Extraction by liquid-liquid extraction (LLE)
2.5 g of honey sample was weighed into 50 mL capped centrifuge tube. 20 mL of 0.1 M
phosphate buffer (pH-8) was then added and the tube was capped tightly and vortexed for 5
minutes until honey was completely dissolved. The tube was then centrifuged at 4,000 rpm
for 10 minutes at room temperature to remove undissolved particles from solution and
thereby avoid plugging the SPE cartridge. After centrifugation the upper layer was carefully
transferred to another tube using disposable pipettes (Wang, 2004).
CSE Study: Antibiotics Residues in Honey
Clean-up by solid phase extraction (SPE)
For SPE clean up, SampliQ OPT 6 mL (150 mg) cartridges were preconditioned sequentially
with 10 mL methanol, 10 mL water, 10 mL NaCl solution (2%) and then equilibrated with 2
mL of 0.1M phosphate buffer (pH 8.0) (Wang, 2004). The sample extract was then loaded on
cartridge and passed through the cartridge slowly under vacuum with a flow rate of 1 mL/min.
The SPE cartridge was then rinsed with 5 mL of water at a flow rate of 2 mL/min, followed by
5 mL of 40% methanol in water with the same flow rate and the entire effluent was discarded.
The cartridge was then dried by applying full vacuum for 5 minutes. Finally, the erythromycin
residues were eluted from the cartridge with 5 mL of methanol at a flow rate of 1-2 mL/min
under vacuum in 15 mL tube. The eluent was evaporated to dryness using nitrogen
evaporator at 40ºC- 50ºC under a stream of nitrogen. The residues were reconstituted in 1
mL of Methanol: Water (1:1). The sample was vortexed and sonicated to completely dissolve
the residue in the tubes.
c. Analysis
The sample was analysed by HPLC equipped with DAD detector (Civitareale
et. al., 2004)
using a Zorbax ODS - C18 5 μm (250x4.6mm I.D.), at room temperature (25ºC) in isocratic
conditions with 20 mM K2HPO4 and acetonitrile (30:70) as mobile phase. The flow rate was
1.4 mL/min. The DAD detector monitored the eluent at 210 nm and measured spectra in UV
range. The sample injection volume was 100 μL. The retention time of erythromycin was 4.9
10. Results and Discussion
Pollution Monitoring Lab (PML) tested 12 honey samples – 10 Indian and 2 Imported samples
purchased from Delhi Market for the presence antibiotic residues. Six antibiotics from five
classes – oxytetracycline (tetracycline), chloramphenicol (amphenicol), ampicillin (-Lactam),
enrofloxacin and its metabolite ciprofloxain (fluoroquinolones) and erythromycin (macrolides) -
were analysed with HPLC-DAD/FLD .
Validation The HPLC- DAD/FLD methods were tested for repeatability and reproducibility to
determine accuracy and precision for all the 5 classes analysed. The performance
characteristics for the HPLC DAD/FLD methods with respect to method specific validation
requirements are summarized in Table 4. Validation study was carried out at three different
concentrations and a limit of quantification (LOQ) was established for all the five classes.
The calibration curves prepared at five different concentrations were obtained using the linear
least squares regression procedure of the peak area versus the concentration. The linearity
CSE Study: Antibiotics Residues in Honey
of calibration curve for - oxytetracycline, chloramphenicol, ampicillin, ciprfloaxacin,
enrofloxacin, erythromycin was good with the correlation coefficients (
r2) is above 0.995 for 3
calibration curves, prepared on different days. The recovery and repeatability of the method
were evaluated by the analysis of spiked samples with oxytetracycline, chloramphenicol,
ampicillin, ciprfloaxacin, enrofloxacin, erythromycin at three different concentrations The limit
of detection for oxytetracycline, chloramphenicol, ampicillin, ciprfloaxacin, enrofloxacin,
erythromycin in honey was 1.45, 0.87, 1.38, 2.55, 1.31, 17 μg/kg. Recoveries were more than
70% with relative standard deviation (RSD) of <10% for all the antibiotics (Table 4).
Table 4. Validation of analytical methods for antibiotic residues in Honey using HPLC
DAD/FLD.
Class Tetracycline Amphenicol -Lactam
Fluoroquinolone Fluoroquinolone
Macrolide
Antibiotic Oxytetracycline Chloramphenicol
Ampicillin Ciprofloxacin Enrofloxacin Erythromycin
Linearity (R2) 0.997
1.45 0.87 1.38 2.55 1.31 17
4.82 2.92 4.60 8.55 4.36 58
70.78 90.8 80.53
Each sample was analysed in triplicate. At least one control (matrix blank) was run with every
set of sample. No interference was encountered from the controls or honey fortified with
oxytetracycline, chloramphenicol, ampicillin, ciprfloaxacin, enrofloxacin, erythromycin. The
antibiotics detected in the honey samples were identified on the basis of retention time of
reference standard peaks within (+/- 0.25 minutes) (Table 4) and the identity was confirmed
by spiking the sample extract with known concentrations of standard at 2 different levels.
Antibiotics detected in the different Indian and imported honey samples are given in
(Annexures II & III).
CSE Study: Antibiotics Residues in Honey
Oxytetracycline, a tetracyclines antibiotic, most commonly used against bacterial foul brood
diseases by beekeepers was detected in 50% of the honey samples (6/12) (Figure 1). The
Level of Action set by Export Inspection Council, India for tetracyclines is 10 μg/kg.
Oxytetracycline was detected in the range of 27.1 to 250.4 μg/kg in the 12 honey samples
analysed. The average concentration detected in Dabur Honey was 91.3 μg/kg (9 times),
Patanjalis Pure Honey was 27.1μg/kg (2.7 times), Khadi honey was 250.4 μg/kg (25 times),
Gold honey was 57.7 (5.7 times) higher than the Level of Action set by EIC.
Interestingly, Oxytetracycline was also detected in imported brands -the average
concentration of Oxytetracycline in Capilano's pure and natural honey from Australia was 151
μg/kg 15 times the EIC standard, but within the Australian standard of 300 μg/kg for
Oxytetracycline in honey, in Nectaflor Natural Blossom Honey from Switzerland was 112
μg/kg -11 times the EIC standard
Chloramphenicol, a broad spectrum antibiotic, and a potential carcinogen banned
from use in food producing animals, including honey bees in Canada, the United States,
the European Union and other countries. It was detected in 25% of the honey samples (3/12)
in the ranged from 3.6 - 4.4 μg/kg. The highest level of 4.4 μg/kg was detected in Gold Honey
manufactured by Vardhaman Food & Pharmacetuticals, which is 15 times higher than the
Level of action of 0.3 μg/kg set by Export Inspection Council, India for Chloramphenicol.
Chloramphenicol was also detected in both the imported samples at a level of 3.6 μg/kg in
Capilano's honey (Australia) and at a level of 3.7 μg/kg in Nectaflor Natural Blossom Honey
CSE Study: Antibiotics Residues in Honey
(Switzerland), 12 times higher than the EIC standard. Results from different laboratories
showed that a great part of Chinese honey and also of honey from various countries, contains
chloramphenicol in quantities greater than the EU regulatory standard of 0.3 g/kg
(Reybroeck, 2003; Ortelli et al., 2004).
Ampicillin a -lactam antibiotics, widely used in veterinary medicine for the treatment and
prevention of bacterial diseases was detected in 67% of honey samples (8/12). The average
concentration of ampicillin detected in honey samples was in the range of 10.1-614.2 μg/kg.
The average concentration of ampicillin in Umang honey was 208.1μg/kg. Highest level of
ampicillin was detected in Nectarflor Natural Blossom Honey (Switzerland) at a concentration
of 614.2 μg/kg. There is no level of action given by EIC for lactam class. Ampicillin, is
therefore, an unauthorized and illegal substance in honey.
In a study from Tamil Nadu, India Ampicillin examined in honey collected during peak
flowering seasons of rubber (March and April) and banana (December and January) was
detected in the range of 3-44 μg/kg (Solomon et al. 2006).
Enrofloxacin, a synthetic antibacterial belonging to fluoroquinolone class approved to treat
bacterial infections in cattle, but in no other food animal. Use of fluoroquinolones to treat any
honey bee disease is considered to be an unapproved drug by FDA. Enrofloxacin was
detected in 83% of the samples -10 out of 12 samples analysed. The average concentration
ranged from 10.9 to 144.8 μg/kg, the highest amount being present in Capilano's Pure &
Natural Honey (Imported brand).The average concentration of enrofloxacin detected in
domestic samples was- Dabur Honey -88.7 μg/kg, Himalaya forest Honey - 63.8 μg/kg and
Patanjalis Pure Honey - 75.1 μg/kg and Umang Honey 122.1 μg/kg.
Ciprofloxacin, a metabolite of enrofloxacin (derived by enrofloxacin dethylation) which has
been restricted to use in medicine, was found in only 1 out of 12 samples (8%) at a
concentration of 19.9 μg/kg in Baidyanath Wild Flower Honey. No standard.
Erythromycin an important macrolide widely used to protect honey bees from bacterial
diseases was detected in 42 % of the samples in 5 out of 12 samples. It was detected at a
range of 69.7 to 280.3 μg/kg, the highest being in Nectaflor Natural Blossom Honey
(Switzerland). The average concentration detected in Himalaya Forest Honey was 69.7 μg/kg,
Mehsons Pure Honey was 85 μg/kg, Patanjali Pure Honey was 186 μg/kg and Gold honey
was 231.3μg/kg. There is no level of action given by EIC for Macrolide class. There are
reports of erythromycin residues in honey where 8% of the honey samples were found to be
contaminated with erythromycin at a concentration ranging from 50 -1776 μg/kg (Gunes,
CSE Study: Antibiotics Residues in Honey
2008). Vidal et al. (2009) reported presence of upto 8.6 μg/kg erythromycin in three out of 16
samples of honey in Granada & Almeria.
11. Conclusions
It is clear from the results that 11 out of the 12 samples of honey analyzed were non
compliant with EIC standard for honey to be exported for antibiotics. Multiple antibiotics were
detected in all domestic and imported brands of honey tested-except Hitkari Honey of Hitkari
Pharmacy, Delhi was found to be free of antibiotics. Highest number of antibiotics - 5 out of 6
were detected in imported Nectaflor Natural Blossom Honey, followed by Patanjalis Pure
honey which had 4 antibiotics. The number of antibiotics in other brands was 3 each in Dabur,
Himalaya Forest and Khadi Honey, 2 each in Mehsons Pure Honey, Himflora Gold, Umang
Honey and Baidyanath Wild flower Honey. No antibiotic was detected in Hitkari Honey. Three
antibiotics were detected in imported brand from Australia (Capilano Pure and Natural Honey)
One reason for this could be the prevalent practice whereby honey is collected from different
sources and then pooled before being packed and distributed for sale. Widespread
contamination of different components of environment by antibiotics has been reported
including milk, eggs, meat and honey etc. (Khaskheli, 2008; Schneider, 2001; Gunes 2008).
The concentrations detected in the present study honey samples are low and not likely to
cause any acute effect, chronic health effects cannot be ruled out. There is a need to regulate
and monitor the level of antibiotics in honey as continuous long term exposure to low levels
of antibiotics could in due course of time lead to antibiotic resistance in pathogenic bacteria
making their treatment difficult.
CSE Study: Antibiotics Residues in Honey
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CSE Study: Antibiotics Residues in Honey
Annexure I: Details of the samples analysed for antibiotic residues
Brand Name
Expiry Date
Batch No.
Dabur India Ltd. Vill. Billanwali
Best before 18 months from
Lavana P.O. Baddi Distt. Solan H.P.
Himalaya Forest Honey
The Himalaya Drug Company,
Best before 2 years from date
No sugar added and
Makali, Bangalore - 562123
Mehsons Pure Honey
Mehsons (India) Ltd., Kamla
Best before 18 months from
Agmark honey special
Bhawan, Madari Gate, Bareilly
grade, awarded for
purity & quality, gold medal london
Food Max E-45, Sec-8, NOIDA (UP)
Best before 18 months from
Patanjali Pure Honey
Patanjali Ayurved Ltd., D - 38,
Best before 12 months from
Industrial Area, Haridwar,
Uttarakhand - 249401
Baidyanath Wild Flower
Shree Baidyanath Ayurved Bhavan
Best before 18 months from
Pvt. Ltd., Gwalior Road Jhansi
Khadi Gram Udyog Sewa Samiti,
Best before 12 months from
Agmark honey grade-A
Distt. Madhyapura, Bihar
Vardhman Food & Pharmaceuticals,
Best before 18 months from
Agmark honey grade-A
Plot No. 3/59, HSIDC Ballabgarh,
Faridabad, Haryana
Hitkari Pharmacy, WZ - 322, Skur
Best before 18 months from
Agmark honey grade-A
Pur Village, Delhi - 110034
Udyog Bhartiya Registered KVI
Best before 18 months from
Agmark honey grade-A
society C-9, R. P. Singh Delhi 7
Capilano Pure & Natural
Capilano Honey Ltd., 399 Archerfield
5-Feb-08 4-Feb-11
Road, Richlands - 4077, Australia
Nectaflor Natural Blossom
Blossom Honey, A6293 Narimpex
Imported & Marketed
AG, Biel, Switzerland
By: L-Comps & Impex Pvt. Ltd. 182/63, Industrial Area, Chandigarh, Month of Import Apr - 09
CSE Study: Antibiotics Residues in Honey
Annexure II: Antibiotic residues in Honey samples in ppb μ
Antibiotic
Ampicillin
No. of
antibiotics
detected
Level of Action (LOA) -
Export Inspection
Council, India (μg/Kg)
Himalaya Forest Honey
Mehsons Pure Honey
Patanjali Pure Honey
Baidyanath Wild Flower
Capilano Pure & Natural
150.8±6.3 3.6±1.4
12 012 Nectaflor
112.0±10.0 3.7±0.4
Notes:
1. Analysis carried out in triplicate
2. SD -Standard deviation
3. ND = not detected; the values of antibiotics in honey is in microgram per kilogram (μg/kg), also referred to as parts per billion (ppb)
CSE Study: Antibiotics Residues in Honey
Annexure III Antibiotic residues in Honey samples
Antibiotic Oxytetracycline
Ampicillin
Level of Action (LOA) - Export
Inspection Council, India
(μg/Kg)
Samples analysed
No. samples tested positive
% of samples above LOA
0-100 (g/kg or ppb)
100-200 (g/kg or ppb)
>200 (g/kg or ppb)
Note: LOD – Limit of detection (μg/Kg)
CSE Study: Antibiotics Residues in Honey
Figures 1: HPLC Chromatogram of (a) Oxytetracycline standard 100 ng/mL (b) Oxytetracycline detected in Honey
sample (007)
CSE Study: Antibiotics Residues in Honey
Figures 2: HPLC Chromatogram of (a) Chloramphenicol standard 100 ng/mL (b) Chloramphenicol detected in Honey
sample (012)
CSE Study: Antibiotics Residues in Honey
Figures 3: HPLC Chromatogram of (a) Ampicillin standard 200 ng/mL (b) Ampicillin detected in Honey sample (007)
CSE Study: Antibiotics Residues in Honey
Figures 4: HPLC Chromatogram of (a) Enrofloxacin (50 ng/mL) & its metabolite ciprofloxacin standard (100 ng/mL)
(b) Enrofloxacin detected in Sample (011)
CSE Study: Antibiotics Residues in Honey
Figures 5: HPLC Chromatogram of (a) Erythromycin standard 5 μg/mL (b) Erythromycin detected in Honey sample
Source: http://www.cseindia.org/userfiles/Antiboitics_Honey.pdf
Mould in the Home Fact Sheet Potential allergens such as pollen, mould spores and dust mite are commonplace in the daily environment and are found both inside and outside the home. Although most individuals are exposed to these allergens on a regular basis with little impact on health, regular exposure to some allergens, particularly indoor moulds can cause severe health problems, especially when present in large quantities.
Topic Introduction Immersion Freezing of Biological Specimens: Rationale, Principles,and Instrumentation Guenter P. Resch,1,5 Marlene Brandstetter,1 Angela M. Pickl-Herk,2 Lisa Königsmaier,3Veronika I. Wonesch,1,4 and Edit Urban3 1IMP-IMBA-GMI Electron Microscopy Facility, Institute of Molecular Biotechnology, 1030 Vienna, Austria2Max F. Perutz Laboratories, Medical University of Vienna, 1030 Vienna, Austria3Institute of Molecular Biotechnology, 1030 Vienna, Austria4University of Applied Sciences Wiener Neustadt, 2700 Wiener Neustadt, Austria