Antimicrobial Resistance in Acinetobacter baumannii Isolated From Healthy Animals.

The study investigates the prevalence and antimicrobial resistance of Acinetobacter baumannii in healthy ruminants and poultry from rural Guntur, Andhra Pradesh, India. The objective is to understand its distribution across body systems and assess antibiotic resistance patterns to aid in surveillance and control strategies. A total of 104 samples were collected from healthy livestock (ruminants and poultry) across digestive, respiratory, excretory, reproductive, udder and urogenital systems. Microbiological identification and MALDI-TOF MS confirmed A. baumannii isolates. Antibiotic susceptibility testing was performed using the Kirby Bauer disc diffusion method against multiple antibiotic classes, including penicillin, aminoglycosides, cephalosporins, fluoroquinolones, carbapenems, and tetracyclines. A prevalence rate of 66% (69/104) was observed. The highest prevalence was in the udder system (~43%), followed by the excretory (~17%), reproductive (~17%), urogenital (8.7%), digestive (~7%) and respiratory (5.8%) systems. Isolates were resistant to aminoglycosides, cephalosporins, and lincosamides, with intermediate to fluoroquinolones, meropenem, and vancomycin and susceptible to tetracyclines according to CLSI guidelines. The detection of multi-drug resistance A. baumannii in healthy livestock is alarming to human health highlights its zoonotic potential and the urgent need for antimicrobial surveillance. This pioneering study emphasizes the importance of monitoring animal populations to mitigate the risk of transmission to humans and the environment.