Livestock Antibiotics Use and Antimicrobial Resistance.

Background/Objectives: Antibiotic resistance or antimicrobial resistance (AMR) in livestock is a growing global concern that threatens both human and animal health. The overuse and misuse of antibiotics in livestock production have led to an increased propensity for the development of AMR bacterial strains in animals, which can be spread to humans through the consumption of contaminated animal products, direct contact, or environmental exposure. This review aims to summarize the development and transmission of AMR in livestock, explore its underlying mechanisms and impact on human and animal health, and discuss current practices and potential strategies for mitigation and prevention. Methods: For this narrative review, we searched articles on PubMed and Google Scholar using the terms antibiotic resistance, livestock, and environment, alone or in combination. Results: The history of antibiotic use in livestock and its link to increased AMR, along with the involved mechanisms, including the enzymatic breakdown of antibiotics, alterations in bacterial targets, horizontal gene transfer, and efflux pumps, are important. Antibiotics in livestock are used for growth promotion, disease prevention and control, and metaphylactic use. The role of livestock and the environment as reservoirs for resistant pathogens, their impact on human health, chronic infections, allergic reactions, toxicity, and the development of untreatable diseases is important to understand AMR. Conclusions: Given the widespread use of antibiotics and the potential consequences of AMR, collaborative global efforts, increased public awareness, coordinated regulations, and advancements in biological technology are required to mitigate the threat AMR poses to human and animal health. Regulatory solutions and the development of new therapeutic alternatives like antimicrobial peptides and bacteriophage therapy, and preventive measures such as DNA and mRNA vaccines, are future perspectives.