Characteristics of one Escherichia coli strain isolated from the sick red panda excreting mucus-like faeces

The purpose of this study is to explore the main pathogens that caused one red panda to excrete mucus-containing faeces continuously. The anal swabs of sick red panda were collected for bacterial isolation, biochemical analysis, 16SrRNA sequencing identification, antimicrobial susceptibility testing, and research on pathogenicity in Mice. An Escherichia coli (E. coli) strain was isolated and determined. This strain was resistant to ampicillin, penicillin G, ceftiofur, and highly sensitive to levofloxacin, imipenem, azithromycin, kanamycin, and compound sulfamethoxazole. All mice died within 8-14 hours after injected intraperitoneally with 6×108 CFU/mL E. coli. Histopathology showed that the lungs, livers, kidneys, and spleens of mice killed by E. coli showed different degrees of congestion and hemorrhage. The E. coli isolated from the red panda is multidrug-resistant and highly pathogenic for mice. This study can provide references for drug use and enhance understanding of E. coli-induced diarrhea in red pandas.