Serotypes, Virulence Factors, and Antimicrobial Susceptibilities of Vaginal and Fecal Isolates of Escherichia coli from Giant Pandas

Abstract

ABSTRACTAlthoughEscherichia colitypically colonizes the intestinal tract and vagina of giant pandas, it has caused enteric and systemic disease in giant pandas and greatly impacts the health and survival of this endangered species. In order to understand the distribution and characteristics ofE. colifrom giant pandas, 67 fecal and 30 vaginalE. coliisolates from 21 giant pandas were characterized for O serogroups, phylogenetic groups, antimicrobial susceptibilities, and pulsed-field gel electrophoresis (PFGE) profiles. In addition, these isolates were tested for the presence of extraintestinal pathogenicE. coli(ExPEC) and diarrheagenicE. coli(DEC) by multiplex PCR detection of specific virulence genes. The most prevalent serogroups for allE. coliisolates were O88, O18, O167, O4, and O158. ExPEC isolates were detected mostly in vaginal samples, and DEC isolates were detected only in fecal samples. Phylogenetic group B1 predominated in fecal isolates, while groups B2 and D were frequently detected in vaginal isolates. Resistance to trimethoprim-sulfamethoxazole was most frequently observed, followed by resistance to nalidixic acid and tetracycline. All except five isolates were typeable by using XbaI and were categorized into 74 PFGE patterns. Our findings indicate that pandaE. coliisolates exhibited antimicrobial resistance, and potentially pathogenicE. coliisolates were present in giant pandas. In addition, theseE. coliisolates were genetically diverse. This study may provide helpful information for developing strategies in the future to controlE. coliinfections of giant pandas.