High-Level Multidrug-Resistant Escherichia coli Isolates from Wild Birds in a Large Urban Environment

Intensive clinical use of antibiotics together with inadequate sanitation in an urban environment may contribute to the dissemination of multidrug-resistant (MDR) bacteria in the community. Wild birds living in these areas may become colonized with such organisms and further disseminate these resistant bacteria. In this study, we examined Escherichia coli isolates from the intestine of wild birds in Rio de Janeiro, Brazil, for those expressing extended-spectrum beta-lactamase (ESBL), carbapenemase, and other drug resistances. We obtained 353 E. coli isolates from 112 birds admitted to three wildlife centers in Rio de Janeiro state, from July 2010 to December 2013. MDR isolates were found in 43 (38%) birds, including 14 carrying E. coli isolates that expressed ESBL. All ESBL-encoding genes were blaCTX-M type, and no carbapenemase-producing isolates were found. MDR isolates belonged to a variety of lineages. Multilocus sequence type clonal complexes 648 and 155 accounted for carriage in 9 (21%) of 43 birds with MDR isolates. The study birds were nonmigratory, and the bacteria obtained from them likely mirrored urban circulating genotypes. Altogether, these findings indicate a high level of environmental contamination with clinically relevant drug resistance genes in Rio de Janeiro. A large proportion of the MDR strains belonged to clonal lineages.