Antimicrobial Resistance in Farm Animals in Brazil: An Update Overview

SIMPLE SUMMARY: Beyond their use of treating human and animal diseases, antimicrobial agents have also been employed in animal feeding as “growth promoters”, being administrated at low doses throughout the husbandry period, and leading to beneficial effects, mainly for large-scale production. However, the consequent selective pressure has helped to increase antimicrobial resistance frequencies in isolates from animals globally. Brazil is a major food producer and exporter; therefore, it is of great value to look at the panorama of bacterial resistance associated with farm animals. Since 1998, many drugs have been prohibited from being used as growth promoters in Brazil. However, neither data on the prophylactic and therapeutic use of antimicrobial agents in farms, nor results of contemporary and integrated surveillance programs regarding antimicrobial resistance associated with food production animals, are still publicly available. This review aims to update and discuss the available Brazilian data on this topic emphasizing legal aspects, occurrence, and genetics of the resistance reported by studies published since 2009, focusing on producing animals and derived foods with the most global public health impact. Data here compiled may be useful to monitor and evaluate the local situation and serve as a basis for establishing parameters for the future. ABSTRACT: In animal husbandry, antimicrobial agents have been administered as supplements to increase production over the last 60 years. Large-scale animal production has increased the importance of antibiotic management because it may favor the evolution of antimicrobial resistance and select resistant strains. Brazil is a significant producer and exporter of animal-derived food. Although Brazil is still preparing a national surveillance plan, several changes in legislation and timely programs have been implemented. Thus, Brazilian data on antimicrobial resistance in bacteria associated with animals come from official programs and the scientific community. This review aims to update and discuss the available Brazilian data on this topic, emphasizing legal aspects, incidence, and genetics of the resistance reported by studies published since 2009, focusing on farm animals and derived foods with the most global public health impact. Studies are related to poultry, cattle, and pigs, and mainly concentrate on non-typhoid Salmonella, Escherichia coli, and Staphylococcus aureus. We also describe legal aspects of antimicrobial use in this context; and the current occurrence of genetic elements associated with resistance to beta-lactams, colistin, and fluoroquinolones, among other antimicrobial agents. Data here presented may be useful to provide a better understanding of the Brazilian status on antimicrobial resistance related to farm animals and animal-derived food products.