Prevalence and antimicrobial resistance profile of potentially zoonotic enterobacterales isolated from macaws in zoos of Northeastern Brazil

Abstract

This study aims to examine the frequency and antimicrobial sensitivity of Enterobacterales isolated from macaws in zoos in Northeastern Brazil. Using the following methodology, 97 cloacal swabs were collected from nine macaw species housed in eight zoological institutions across six states in Northeastern Brazil. Samples were collected using Stuart medium, pre-enriched in peptone water, and then enriched in Brain-Heart Infusion, Selenite Cystine, and Rappaport Vassiliadis broths. We then streaked them on MacConkey agar, Eosin Methylene Blue agar, Brilliant Green agar, and Salmonella-Shigella agar. Colonies exhibiting unique morphologies underwent bacterial tests for identification. Any samples suspected of containing Salmonella were sent to the Oswaldo Cruz Foundation for serotyping. We used the Kirby-Bauer test for the antimicrobial sensitivity test. A total of 123 strains belonging to the order Enterobacterales were isolated from 81 (83.5%) cloacal swab samples from macaws, with 16 bacterial species identified. The most frequently observed species were Escherichia coli (64.0%), Citrobacter freundii (15.5%), and Serratia liquefaciens (14.4%). The antibiotics showing the highest resistance were fosfomycin (16.3%), followed by tetracycline (13.9%), and amoxicillin with clavulanate (12.2%). However, the strains demonstrated substantial sensitivity to meropenem (100.0%), tobramycin (98.4%), and chloramphenicol (97.7%). We observed multi-resistance in 9 (7.3%) of the isolates, with E. coli 5/9 (55.5%) proving to be the most prevalent among the multi-resistant strains. These findings indicate that macaws in Northeastern Brazilian zoos may harbor antimicrobial-resistant, potentially zoonotic enterobacteria, underscoring the need for captive wildlife monitoring. The findings have implications for animal, human, and environmental health, reinforcing the importance of One Health strategies.

Keywords: Enterobacteria; Multidrug resistance; One health; Psittacines.