Occurrence and Antimicrobial Resistance Traits of Escherichia coli from Wild Birds and Rodents in Singapore

Abstract

Antimicrobial resistance (AMR) in Escherichia coli (E. coli) poses a public health concern worldwide. Wild birds and rodents, due to their mobility, are potential vehicles for transmission of AMR bacteria to humans. Ninety-six wild birds’ faecal samples and 135 rodents’ droppings samples were collected and analysed in 2017. Forty-six E. coli isolates from wild birds and rodents were subjected to AMR phenotypic and genotypic characterisation. The proportion of E. coli isolates resistant to at least one of the antimicrobials tested from wild birds (80.8%) was significantly higher than that of isolates from rodents (40.0%). The proportion of E. coli isolates resistant to each antimicrobial class for wild birds was 3.8% to 73.1% and that for rodents was 5.0% to 35.0%. Six out of 26 E. coli isolates from wild birds (23.1%) and two out of 20 (10.0%) isolates from rodents were multi-drug resistant (MDR) strains. These MDR E. coli isolates were detected with various antimicrobial resistance genes such as blaTEM-1B and qnrS1 and could be considered as part of the environmental resistome. Findings in this study suggested that wild birds and rodents could play a role in disseminating antimicrobial resistant E. coli, and this underscores the necessity of environment management and close monitoring on AMR bacteria in wild birds and rodents to prevent spreading of resistant organisms to other wildlife animals and humans.

Assessment and Antibiotic Resistance Profiling in Vibrio Species Isolated from Wild Birds Captured in Danube Delta Biosphere Reserve, Romania

“…Isolation of resistant bacterial strains from wilds birds highlights the potential hazard to both humans and animals given the transmission to humans and animals and vice versa [ 74 , 75 , 77 ]. The fecal shedding of the resistant strains allows environmental contamination.…”

Study on Bacteria Isolates and Antimicrobial Resistance in Wildlife in Sicily, Southern Italy

“…Although 87% (20/23) of the E. coli strains tested were found to be phenotypically resistant to ampicillin, only for six of these strains, could the resistance be attributable to the presence of resistance genes. In fact, as reported by several authors, there are multiple complex mechanisms that lead a bacterium to be resistant to antimicrobials, and phenotypic expression does not always correspond to genotypic resistance and vice versa [ 18 , 34 , 35 ]. This is evident in E. coli strains id.…”

“…Transported by plasmids or contained within transposons, there are integrons that provide bacteria with a gene capture system perfectly adapted to the challenges of multiple antibiotic treatment regimens and that have been considered to contribute to the release of “superbugs” [ 14 ]. Several studies conducted over the last decade showed that wildlife and, particularly, migratory birds could acquire resistant bacteria present in contaminated environments and become a reservoir and carrier for AMR spread [ 15 , 16 , 17 , 18 ].…”

Virulence Determinants and Multidrug Resistance of Escherichia coli Isolated from Migratory Birds

“…They have been recognized as an important source for the environmental dissemination of AMR [ 21 , 23 , 24 ]. Multidrug resistant (MDR) E. coli has been from migratory birds in different parts of the world [ 25 , 26 , 27 , 28 ]. Fecal transmission of MDR E. coli from migratory birds to water bodies in different areas has been reported [ 29 , 30 ].…”