Absence of vancomycin-resistant enterococci among highly ESBL-positive crows (Corvus splendens) foraging on hospital waste in Bangladesh

Background

Vancomycin-resistant enterococci (VRE) have emerged as a growing problem in hospitals; however, domesticated animals, poultry, and wild birds are acting as potential reservoirs. There is a knowledge gap in the Epidemiology of VRE from Bangladesh.

Methods

To study the prevalence of VRE and the mechanisms of resistance implicated among wild birds, 238 fecal samples were collected in 2010 from house crows (Corvus splendens) foraging on hospital waste in Bangladesh. Fecal samples were screened by analyzing color change in broth and screening for vanA and vanB resistant genes by PCR.

Results

Neither vanA nor vanB genes were detected from the fecal samples. The house crow does not seem to constitute a reservoir for VRE.

Conclusion

The zero prevalence is an indication that foraging on hospital waste does not constitute a major risk of VRE carriage in house crows and this is the first study to focus on the prevalence of VRE from wild birds in Bangladesh.

Dissemination of the multidrug-resistant extended-spectrum β-lactamase-producing Escherichia coli O25b-ST131 clone and the role of house crow (Corvus splendens) foraging on hospital waste in Bangladesh

Two hundred and thirty-eight faecal samples from crows foraging on hospital wastes were analysed for extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae. ESBL-producing crow isolates were characterized and compared with 31 patient isolates. Among the crows, 59% carried ESBL producers. These included Escherichia coli, Klebsiella pneumoniae, Raoultella terrigena and Enterobacter cloacae harbouring the genes for CTX-M-1, CTX-M-15, CTX-M-55, CTX-M-79, and CTX-M-14. Human isolates carried only the CTX-M-15 gene. Two-thirds of crow E. coli isolates and all human E. coli isolates were multidrug resistant. Crows and patients shared E. coli sequence types, including the epidemic E. coli O25b-ST131 clone. The scavenging behaviour of crows at poorly managed hospital waste dumps made them potential reservoirs of antibiotic resistance, including ESBLs.