A longitudinal study of Escherichia coli strains isolated from captive mammals, birds, and reptiles in Trinidad

A longitudinal study was conducted of the prevalence and characteristics of Escherichia coli in mammals, birds, and reptiles housed at the Emperor Val ley Zoo. Trinidad. During a 6-mo study period. swabs were obtained from fec al samples that were randomly collected from the enclosures of animals from these three taxonomic groups every 3 wk. With snakes, both cloacal and fec al swabs were obtained. Fecal and cloacal swabs were cultured for E. coli o n eosin methylene blue agar. The production of mucoid colonies and hemolyti c colonies and non-sorbitol fermenter status were identified. The occurrenc e of O157 strains was determined amongst E. coli isolates that were non-sor bitol fermenters. and the disc diffusion method was used to determine the a ntibiograms of isolates. The frequency of E. coli isolation was significant ly higher in mammals compared with birds and reptiles. Overall. the frequen cies of isolation of E. coli from omnivores. herbivores. and carnivores. 87 .2%, 70.0%, and 57.3%, respectively. regardless of animal class, were signi ficantly different. Most (99.6%) of the E. coli isolates tested for antibio tic sensitivity exhibited resistance to one or more of the eight antimicrob ial agents used. The possession of phenotypic virulence markers by the E. c oli isolates studied and the generally high resistance to antimicrobial age nts may have health implications for the zoological collection.