Antibiotics and its uses in the Poultry Industry- Found in Egg and Chicken

Antibiotics in Eggs and Chicken- But How?

The chicken and eggs that we are consuming is highly likely to be laden with antibiotic resistant pathogens. Antibiotics found in egg and chicken could have adverse effects on Humans.

Antibiotic Residues and Antibiotic-Resistant Pathogens in Poultry

Inthe absence of any reg the absence of any regulations in India for limiting non-therapeutic use of antibiotics in animals, the animals are given overdoses of antibiotics.

Due to this unregulated and indiscriminatory use of antibiotics, India has emerged as a global hotspot for antibiotic resistance (ABR).

Resistance rates are increasing to even the most critical antibiotics in common pathogens and hence number of treatment failures are rising.

These antibiotics are used for disease prevention as a substitute for hygiene, sanitation and hospitable conditions for rearing animals and also to promote early growth in animals especially poultry.

Chickens in India

The chickens in India are fed antibiotics like colistin that are said to be the last line of defence and only used for critically ill patients. Feeding chickens with such rarely used drugs for growth promotion is adversely affecting the global health scenario.

India due to rampant, indiscriminate and unregulated use of antibiotics has created many superbugs, multidrug-resistant pathogens. This antibiotic resistance developing in various pathogens is the biggest global health crisis that we are facing.

The traces of these antibiotics and other chemicals are also found in the meat and eggs that come from these chickens.

Inthis blog, we would discuss, antibiotics, its usage in poultry and health crisis that injudicious of these antibiotics is causing.

First, let’s take a sneak peek into Poultry Industry.

Poultry Industry

Poultry is rearing of birds like chicken, turkey, quail emu, ducks, ostrich and other birds by humans for their flesh, eggs and entertainment. Hence, poultry is a wide term which is generally used as a synonym to chicken meat and eggs.

Reason being that chicken is the most common and popular type of poultry in the world. This is especially true in the Indian context. Broilers are the chickens that are specially bred for meat.

While layers are egg-laying hens farmed for eggs.

A broiler chicken lives less than six weeks before slaughter under intensive farming practices. Free-range chickens live almost 8 weeks and organic around 12 weeks.

The global poultry production in 2015 was 111 million tons. Global poultry production is expected to increase by 24% in the next decade to reach 131 million tons in 2025.

Poultry meat production would be dominating more than half of the growth of all the additional meat produced by 2025.

Indian Landscape

India produced almost 7 millions of tonnes of meat in 2015–16. India is the 5th largest producer of meat in the world. Out of the 7 million tonnes, 54% was red meat, the rest being poultry meat.

India is the largest producer of milk in the world, the third-largest producer of egg, and the fourth-largest producer of chicken.

Chicken is the most popular and consumed meat in India because of primarily two reasons.

It is relatively cheaper compared to other meats

It is not subject to extreme religious prohibitions and cultural taboos.

After chicken buffalo meat/carabeef is India’s most consumed animal protein due to its affordability.

The Indian poultry market was approx. worth INR 1,750 Billion in 2018. The market is projected to grow at a CAGR of 16.2% during 2019–2024 and reach a market capitalisation of INR 4,340 Billion by 2024.

In other countries when people are moving towards a vegan or vegetarian diet, in India people are turning non-vegetarians.

One of the biggest reason being the fake protein marketing campaign that people training extensively in gyms and elsewhere need meat or animal diet for protein whereas there are better, easy to digest and healthier protein options in a plant-based diet. Hundreds of world-class vegan athletes are proof that a vegan diet can provide all nutrients.

Over 90% of domestic purchases are still through the wet market as traditional consumer prefer to get meat dressed in front of them. The processed chicken market is also expected to grow over 25% in the long-term.

Due to a dramatic increase in consumption and global demand, the backyard business has now become a global market. And all kinds of cheap tricks are being employed to increase production and hence profits.

Chickens are kept under the inhospitable conditions and the same chickens are fed to end consumer.

1.They are kept in cramped spaces filled with hundreds and thousands of chickens which peck and fight each other

2.They are not given proper nutrition.

3.They are provided with proper sanitation and hygiene

4.They are administered with high doses of critical antibiotics as a replacement for good nutrition, sanitation and hygiene.

Many studies have been conducted on Indian poultry market and farms and they have found out the pathetic conditions these chickens live in and how absolutely unhealthy their meat and eggs are.

Ona chicken farm in the Rangareddy district near the southern metropolis of Hyderabad, some 5,000 birds peck at one another, loitering around a warehouse which doesn’t have sanitation and will become cramped as they grow.

They are given feed which is inherently mixed with antibiotics like colistin.

But why give so much antibiotics to chickens?

Reason being, it was found that by-products of antibiotic production (dried Streptomyces aureofaciens broth) contain a high level of vitamin B12. Upon feeding these to poultry animals resulted in higher and earlier growth.

Eventually, it was discovered that the trace amounts of these antibiotics remaining in these byproducts accounted for this growth. Since then the antibiotics are being used on poultry in large quantities to enhance production in poultry.

This unregulated and indiscriminate use of antibiotics in food animals poses a great threat to the environment, food chain and humans’ health causing bioaccumulation of residues and multi-drug resistant pathogens.

We will understand antibiotic resistant in detail but for of all let’s understand antibiotics.

What is an Antibiotic?

Antibiotics are medicinal chemicals/drugs that are used to inhibit or destroy the growth of microorganisms. They are created by microorganisms as well but most of them are manufactured synthetically.

Antibiotic literally translates to against life.

The term antibiotic refers to any agent with biological activity against living organisms. Generally, by ‘‘antibiotic” people refer to substances with antibacterial, anti-fungal, or antiparasitic activity.

Antibiotics were discovered in the 1920s and they became a revolutionary discovery. Before that people were dying of bacterial infections. With the advent of antibiotics, surgery became safer and it became easier to treat infections.

Antibiotics are widely used for the treatment and prevention of infectious diseases.

Classification of Antibiotics

Antibiotics are often complex molecules which may possess different functionalities within the same molecule. Antibiotics are divided into different classes such as Fluoroquinolones, Aminoglycosides, β-lactams, macrolides, amphenicol, etc. Let’s take a cursory glance at this classification.


Fluoroquinolones: This antibiotic has a fluorine atom attached to the central ring system. Fluoroquinolones are active against both Gram-positive and Gram-negative bacteria and are used to treat infectious diseases such as infectious diarrhoea, typhoid fever (enteric fever), lower respiratory tract infections, skin and skin structure infections, bone and joint infections, etc. Examples include Enrofloxacin, Ciprofloxacin, and Norfloxacin.

Tetracyclines: This a group of antibiotics with four (“tetra-”) hydrocarbon rings (“-cycl-”) derivation (“-ine”). Examples are Oxytetracycline, Chlortetracycline, Doxycycline, and tetracycline. Doxycycline is used to treat bacterial infections such as respiratory tract infections due to Hemophilus influenzae, Streptococcus pneumoniae, or Mycoplasma pneumonia.

Aminoglycosides: Aminoglycosides derived from bacteria of the genus Streptomycesand are named with the suffix -mycin, e.g. Neomycin, Kanamycin. Whereas the ones derived from Micromonospora are named with the suffix -micin for example, Gentamicin, Netilmicin, etc. Neomycin is used to treat conjunctivitis. Aminoglycosides are used in the treatment of severe infections of the abdomen and urinary tract.

β-Lactam: This class contains a β-lactam ring nucleus with a heteroatomic ring structure, consisting of three carbon atoms and one nitrogen atom. Examples are penicillin, ampicillin, cloxacillin, amoxicillin.


The Discovery of Penicillin…


The discovery of penicillin led to remarkable progress in antibiotic research and uses. This led to a revolution of sorts and humanity witnessed a drastic reduction in mortality and morbidity due to infectious diseases during the 1980s. This, in turn, turned into complacency amongst the medical fraternity.

It also resulted in extreme misuse or inappropriate use of antibiotics with an emphasis on curative medicine rather than disease prevention.

This inappropriate and unregulated use by people across the globe but primarily Indians for humans and animals alike has resulted in multidrug-resistant pathogens across the globe, which are becoming increasingly difficult to cure.

Use of Antibiotics in Poultry

Antibiotics are used primarily for three applications in the Indian poultry industry.

Therapeutic Agents: This is the primary use of antibiotics, for treating disease. The infected animals are given a course of antibiotics, generally involving high doses for a relatively short period of time.

Prophylactic Agents: This application of antibiotics is for prevention of diseases. Subtherapeutic doses of antibiotics are given to animals mixed with feed or drinking water when symptoms are not present but suspected. Antibiotics are administered regularly periodically for several days during the life cycle of the broiler chicken.

Growth Promoters: This is the most unessacary application of antibiotics in animals. Antibiotics are used to increase growth-rate and productivity. Growth promotion characterized by administration of very low-dose of antibiotics regularly, over the lifetime of the animal. The dose is given via food.

This is different from therapeutic and prophylactic usage in terms of dose and administration method. As for both of them are dose is high and administered through water. Antibiotic growth promoters suppress the gut bacteria leaving more nutrients for the chicken to be absorbed for greater weight gain. Research also shows that ‘benefits’ from the use of growth promoters are more noticeable in sick animals or those ‘housed in cramped, unhygienic conditions’.

What about regulations on Antibiotics?


Due to unregulated non-therapeutic use of antibiotics in animals especially chickens, antibiotic resistance in microbes has been increasing. Let’s understand it in more detail.

Antibiotic Resistance

Antibiotic Resistance or more broadly Antimicrobial resistance is the resistance of a microorganism towards an antimicrobial drug towards which it was earlier sensitive.

Upon excessive usage, these microbes develop genetic mutation which helps them fight these drugs and hence they become resistant to them.

Resistant pathogens like bacteria, parasites, fungi, viruses can bear the wrath of antimicrobial medicines, such as antibiotics, antifungals, antivirals, and antimalarials.

Hence, the infection which was earlier treated easily just by the administration of antimicrobial drugs now persist longer, sometimes not treatable, cause more damage to the body and they spread to others also.

The evolution of resistant microbes is a natural process that happens when micro-organisms are exposed to antimicrobial drugs but overuse and misuse of antimicrobial medicines have accelerated this process exponentially.

Acountless number of drug-resistant microbes have emerged as a result of genetic changes, acquired due to mutation or transfer of genetic material, and subsequent selection processes.

What is antibiotic resistance?

Resistance can also develop as a result of the transfer of genetic material between bacteria. Microorganisms resistant to a certain antimicrobial may also be resistant to other antimicrobials that share a similar mechanism of action.

This is known as cross-resistance. It is generally found between agents that are closely related chemically (e.g. Neomycin and kanamycin (both Aminoglycoside), but may also exist between unrelated chemicals e.g. erythromycin (macrolide)-lincomycin (lincosamide).

Micro-organisms may also be resistant to various unrelated antimicrobials. Due to a result of animal use of antibiotics, foodborne microbes may become resistant to the antibiotics used to treat human diseases.

Animal-based foods act as a source of foodborne disease in humans and as a carrier of resistant foodborne pathogens. Resistant bacteria proliferate and make other bacterias also resistant.

Data From Studies

As per various studies conducted between 2002–13, across various private and government medical colleges/hospitals in India, high levels of resistance against common antibiotics were found in several bacteria known to cause common and severe infections, such as following

1.Resistance to Ciprofloxacin: It was observed to be highly prevalent in various types of bacteria like E. coli, Klebsiella spp., Pseudomonas spp., Enterobacter spp., Citrobacter spp., Acinetobacter spp., Enterococcus spp., Methicillin-resistant S. aureus (MRSA).

2.Resistance against Doxycycline: It was found to be present in Klebsiella spp., Pseudomonas spp., Enterobacter spp., Citrobacter spp., and Acinetobacter spp.

3.Enterococcus spp. and Methicillin-resistant S. aureus (MRSA) was found to be resistant against Tetracycline antibiotic of class Tetracycline.

Ina more recent study conducted by the Centre for Science and Technology, New Delhi in 2017 found some of the startling facts about multidrug resistance in microbes found in the poultry environment.

The study was titled — ‘Antibiotic Resistance in Poultry Environment’.

Samples of litter and soil were collected from 12 randomly selected poultry farms from sampling in four key poultry producing states in north India, Uttar Pradesh, Haryana, Rajasthan and Punjab.

217 isolates of three types of bacteria — E. coli, Klebsiella pneumoniae and Staphylococcus lentus, were extracted and tested for resistance against 16 antibiotics.

Ten of these 16 antibiotics have been declared Critically Important (CI) for humans by the World Health Organization (WHO). Five of ten the critically important antibiotics belonged to the ‘highest priority’ category and the remaining five were ‘high priority’.

The Conclusions of the Study

The study found that antibiotics were being used in these poultry farms and that the litter was used as manure in neighbouring agricultural lands.

Asa control, 12 other soil samples were also collected at a distance of 10 to 20 kilometres from the respective farms, where the litter was not being used as manure.

1. 100% of the E. coli were multi-drug resistant.

2.92% of K. pneumoniae were multi-drug resistant.

3. 78% of S. lentus isolated from the poultry environment were multi-drug resistant.

4.About40% of E. coli isolates were resistant to at least 10 of 13 antibiotics

5.About 30% of K. pneumoniae were resistant to at least10 of 13 antibiotics against which these bacteria were tested for resistance.

6.E. coli and K. pneumoniae were found to have very high resistance to antibiotics such as penicillins, fluoroquinolones, third and fourth generation cephalosporins and carbapenems, which is the last resort antibiotic used in hospitals.

7. The study also found strong similarity in the resistance pattern of E. coli from the litter and from agricultural soil in the surrounding areas where the litter was used as manure.

8. The study indicated that multi-drug resistant E. coli being created in the poultry farms was entering the environment through the litter.

9. 40% of the chicken meat samples investigated contained one or more antibiotics.

Regulations on Antibiotic in Chicken

Regulation (EC) No 854/2004 of the European Parliament and of the Council of 29 April 2004, lays down specific rules for the organization of official controls on products of animal origin intended for human consumption.

Maximum residue levels (MRLs) for veterinary medicinal products in foodstuff of animal origin including meat, fish, eggs and honey have been established in EU.

Since January, 1st 2006 according to Regulation the antibiotics cannot be used as feed additives in the EU.

There are strict regulations for residues and the administration of antibiotics in animal products in Europe, USA and Canada as well. But such regulations are absent or not strict in India.

Indian Scenario

Food Safety and Standards Authority of India (FSSAI) has been established under the Food Safety and Standards Act (FSS Act), 2006.

It was established to lay down science-based standards and regulate the manufacture, storage, distribution, sale and import food for human consumption in India.

FSS Act, 2006, has repealed central acts like Prevention of Food Adulteration Act, 1954, Meat Food Products Order, 1973 for putting a single reference point for all matters relating to food safety and standards.

Tolerance limits have been set for antibiotics and other pharmacologically active substances by FSSAI only for seafood like under the Food Safety and Standards (Contaminants, Toxins and Residues) Regulations, 2011.

There are no tolerance limits set for antibiotics and other pharmacologically active substances in poultry meat and meat products by FSSAI.

Export Inspection Council of India (EIC), was set up by the Indian government under section (3) of the Export (Quality Control and Inspection) Act, 1963, for implementation of the act.

The Act was enacted for quality control and inspection and for matters connected with export. EIC has set up a comprehensive Residue Monitoring Plan (RMP) for export to the EU for fresh poultry meat and poultry meat products for quality control in export purposes.

EIC has adopted the EU council regulations and framework and MRLs for different antibiotics.

There are no such regulations present for domestic consumption of chicken, while for exports EU standard is followed by the EIC. No MRLs have been set for these antibiotics in India.

So, while the chicken sent for export is tested extensively for quality, no such provisions are made for the domestic market. And consumers in the domestic market are consuming poultry products ridden with antibiotics and multi-drug-resistant bacteria.

And the conventional consumer is not even aware of all this.


Poultry meat is the most popular in India due to the fact that it is not associated with extreme religious taboos and its cheaper prices.

The Indian poultry market was approx. worth INR 1,750 Billion in 2018. The market is projected to grow at a CAGR of 16.2% during 2019–2024 and reach a market capitalisation of INR 4,340 Billion by 2024.

Due to a dramatic increase in consumption and global demand, the backyard business has now become a global market. And all kinds of cheap tricks are being employed to increase production and hence profits.

Chickens are kept under the inhospitable conditions and the same chickens are fed to end consumer.

1.They are kept in cramped spaces filled with hundreds and thousands of chickens which peck and fight each other

2.They are not given proper nutrition

3.They are not provided with proper sanitation and hygiene

4.They are administered with high doses of critical antibiotics as a replacement for good nutrition, sanitation and hygiene.


The Fine Print-

Tests conducted by the Centre for Science and Environment found astonishing results. Isolates from samples from different poultry were found to be resistant to various highest priority, critically important antibiotics.

The residues of six antibiotics, Oxytetracycline, Chlortetracycline, Doxycycline, Enrofloxacin, Ciprofloxacin and Neomycin were found in chicken samples from Delhi NCR by HPLC.

100% of the E. coli and 92% of K. pneumoniae were multi-drug resistant. 78% of S. lentus isolated from the poultry environment were multi-drug resistant. About E. coli isolates and 30% of K pneumoniae were resistant to at least 10 of 13 antibiotics.

Hence, we need to be very cautious when consuming such products because they are the source of various multidrug-resistant pathogens.

Consumers are advised to limit consumption of such food items, for which are no proper regulations in the domestic market.

We need to be more aware of our food choices and their repercussions.

And push regulatory authorities to have strict framework and regulations for domestic market similar to the export market.

Let’s be a more aware consumer and the change that we want to see!

Happy Healthy Eating to all our reader!!! 🙂

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