Antibiotic Sensitivity Patterns and R Factors in Domestic and Wild Animals

Domestic animals subjected to routine production and health practices which contained a near maximal amount of antibiotic pressures, and wildlife subjected to minimal antibiotic pressures were investigated for the prevalence of antimicrobial resistant gram-negative enteric bacteria. Domestic animals subjected to large antibiotic pressures commonly occasioned by the use of drugs for both nonmedical animal production and health purposes showed a high prevalence of multiresistant organisms with R factors, whereas wild animals had the lowest prevalence of resistant organisms. Less than 2% of the wild animal isolates possessed R factors. It is probable that antimicrobial drugs facilitated the development, selection, and growth of antibiotic-resistant Escherichia coli in domestic animals.