Molecular characterization and antimicrobial resistance profile of pathogenic Escherichia coli from goats with respiratory disease in eastern China.

Pathogenic Escherichia coli (E. coli) can cause a variety of intestinal and extra-intestinal infections in humans and animals. Similar with the intestinal disease, respiratory disease is also a major threat to the breeding industry of goats. But the reports on respiratory disease associated E. coli are very limited. In this study, E. coli and other pathogens were examined for the 77 submitted respiratory cases. The serotypes, virulence genes, phylogenetic group and antimicrobial resistance characteristics of the E. coli isolates were identified. The results showed that 34 cases (44.16%) were associated with E. coli and 22 cases showed mixed infections of E. coli with Mycoplasma ovipneumoniae, Mannheimia haemolytica or Pasteurella . Among the 49 E. coli isolates, O8 (32.65%), O9 (20.41%) and O89 (10.20%) were the predominant serotypes (31/49, 63.27%). 22 virulence genes were detected and the most prevalent genes were fimH (100%), yijp (100%), mat (97.96%), ompA (95.92%) ibeB (91.84%) and fyuA (77.55%). In addition, ibeA was detected in 6.12% (3/49) of the strains. Markers of extra-intestinal pathogenic E. coli (ExPEC) were also identified and 14 strains were classified as ExPECs. 14 (28.57%), 25 (51.02%), 3 (6.12%) and 7 (14.29%) strains belonged to phylogenetic group A, B1, B2 and D, respectively, and group A and B1 were the predominant ones. The E. coli strains showed high resistant (48.98%-100%) to the 14 selected antimicrobials and all of them were defined as multiple drug resistant (MDR) strains. This is the first systemically study on E. coli of goats respiratory diseases origin in eastern China. The results suggest that E. coli infection may play an important role in goat respiratory diseases and that goats are reservoir hosts of ExPECs, which needs continuous monitoring in the future.