By – Dr.KrutikaPramodKhiratkar and Dr. Swati Umap
Introduction :
Anti-microbialare the drugs used in the treatment of animals against various bacteria and other micro-organisms. They play a huge part in the control and prevention of diseases in animals. Various classes of antibiotics are present such as cephalosporins, penicillins, quinolones, aminoglycosides, tetracyclines, macrolides, and sulphonamides for the treatment of different conditions in animals. The antimicrobials are administered in animals by various routes i.e. orally in food and water, injection (intravenous, intramuscular and subcutaneous), intravaginal, intrauterine, and topically on the skin.
In animals, antimicrobials were first used to treat the mastitis condition in dairy cattle.They provide various benefits to the animals as growth promoter – mainly given to the young growing animals and poultry sector i.e. broilers and fatteners. These growth promoters enhance the nutrient absorption from the gut and reduction nutrients excretion and also decrease the toxin formation in animals thus showing a rise in the growth rate. Also these antimicrobials are used as metaphylaxis i.e. as a control measure for the spread of disease and in the treatment of diseased animals.
Antimicrobial residues :
Due to the immoderate uses in animals, these antimicrobials drug residues accumulate in the animals thus influencing the animals as well as human health. The accumulation of drug residues occurs in the human body by the ingestion of animal origin products such as milk, meat, and also by seafood. These residues have the potential of developing ill effects and lead to the development of drug resistance, drug hypersensitivity, mutagenicity, carcinogenicity, and teratogenic effects and disruption of normal intestinal flora in humans.
Regulatory bodies :
India shares a position of having one of the largest livestock sectors by accounting for about 11.6% of the world’s livestock population. India holds the fourth position globally for the consumption of the antimicrobials in food animals accounting for 4% of world consumption after China (23%), the United States (13%), and Brazil(9%). In India, to control the drug residues levels, the government body i.e. food safety and standard authority of India (FSSAI) have set up regulations in which drug residues are handled in food safety and standards (contaminants, toxins, and residue, 2011) in which for various antibiotics maximum residue level (MRL) i.e. the maximum concentration of the parent compound or drug that is acceptable in or on food (expressed in ppm) have been set up to control the overuse of antimicrobials.FSSAI has also set up the tolerance level on various antimicrobials for export purposes. For detection of these residue many analytical tools are used by the regulatory bodies and in the research field such as high pressure liquid chromatography (HPLC), gas chromatography, immunological kits (ELISA) and biosensors. Biosensors are the devices that convert a biological signal into a measureableelectrical signal and has a high specificity and fast response time.
Banned antimicrobials:
Government has taken several measures to eliminate the drug residues effects by banning various drugs used in animals. Colistin, also known as polymixin B is an antibiotic which is used as a last resort for the treatment of multi-drug resistant gram negative bacteria. Colistin formulations were given to the food producing animals which resulted in the development of some colistin resistant pathogens and could have been a threat to humans. Due to this colistin use has been banned in livestock in India to tackle the anti-microbial resistance.
Preventive measures:
The prevention of these drug residues can be done by following a proper and complete withdrawal period i.e. Withdrawal period is a time between the last doses of antibiotics given to food animals and the consumption of food animals or food derived from it. The withdrawal period is mentioned on each antibiotic which is used in animals but if not mentioned a withdrawal period of 28 days has to be followed. These are some preventive measures that should be followed:
- A proper drug residue guide should be followed by the veterinarian and food animal producers and the consumption of meat and milk should be allowed only after its withdrawal period.
- The animal should not be given an unapproved or special mixer of drugs by the veterinarian.
- Over the counter drug selling should be banned as it increases drug misuse in animals.
- A proper record of treatment given to the animal should be followed for all the animals on the farm.
- The use of drugs should be minimized by food producers and veterinarians.
- The herd or farm should be kept cleanly and hygienically and the management of animals should be good as it plays an effective role in the prevention of diseases.
- A quick and effective residue testing tool should be present at the farm for the detection of residues.
- Proper Education should be given to the farmers and students about the maleficent use and its ill effects on the animal as well as the human body.
