Abstract
Antibiotics utilization in livestock has always been a debatable topic. They have been used in animal feed not only as antimicrobial agents but also for promoting growth and to improve their performance. Nevertheless, it has become a major concern in terms of food safety and human health. Antibiotics added to animal feed to treat infections and to improve their health have led to the emergence of antibiotic-resistance bacterial variants. Although in animal feed, antibiotics have been a regular supplement to improve their productivity and overall health of the livestock, the over utilization of these drugs for animals have led to multidrug resistance in both livestock and human health which cannot be treated using conventional clinical treatments. This has created a major economic and health concern about the antibiotic use in animal feed. The microbial cells become resistant to antibiotics through several methods, like cell membrane modification to inhibit drugs, alteration of the drug binding and recognition site, enzymatic alteration, chemical modification of the antibiotic, etc. These drug-resistant variants proliferate in the animals and are transmitted to the other animals and to humans primarily through practices like exposure to them in the farm houses, slaughter houses and meat consumption. This review summarizes the details of antibiotics, their use and over exploitation in animal nutrition. The study also focuses on the mechanism of drug resistance by bacteria, its economic impact, and various challenges to mankind. Significant emphasis on the possible solutions to combat the issue has also been provided in this review.
Keywords: Animal Feed, Antibiotics, Antimicrobial Resistance, Food Safety, Human Health, Livestock.