Escherichia coli is a facultative anaerobic bacterium frequently detected rate in the intestines of giant pandas. In this study, we isolated 169 anaerobic bacterial strains from fresh fecal samples of 13 giant pandas, including 13 strains of E. coli. Through whole-genome sequencing and analysis, we classified 13 E. coli strains into 9 distinct sequence types (STs), and identified 96 antibiotic resistance genes, 103 heavy metal resistance genes and 213 virulence genes. Notably, we observed the widespread presence of the mdtA, mdtB, mdtC and cusA, cusB, cusC, cusF gene in all E. coli isolates. Further genetic environment analysis revealed the presence of baeS/baeR upstream of mdtABC, a two-component system capable of regulating efflux pump expression to mediate resistance. The cusABCF operon was flanked by siderophore-related virulence genes (fepA and entD) upstream and the cusS/cusR regulatory system downstream. We also identified mobile genetic elements adjacent to these operons, which may facilitate the horizontal transfer of resistance and virulence determinants. This genome-based investigation systematically characterized antibiotic/metal resistance and virulence profiles in E. coli strains derived from giant panda, providing critical insights for safeguarding the health and welfare of this endangered species.
Liu et al. (Fri,) studied this question.