Prevalence and characteristics of attaching and effacing strains of Escherichia coli isolated from diarrheic and healthy sheep and goats.

Objective: To determine the prevalence and characteristics of attaching and effacing Escherichia coli (AEEC) in diarrheic and healthy small ruminants.

Animals: 502 lambs and kids with diarrhea and 511 healthy sheep and goats.

Procedure: Fecal samples from diarrheic and healthy sheep and goats were screened for the eae gene. In addition, E coli isolates with positive results for the eae gene (E coli eae+) were analyzed for the espB gene, production of verotoxins (VT), and serogroup.

Results: A significantly higher prevalence of healthy lambs and kids were infected with AEEC, compared with diarrheic lambs and kids and healthy adult sheep and goats. Some differences in the characteristics of E coli eae strains isolated from diarrheic and healthy animals were detected. Thus, the espB gene was detected more frequently among E coli eae+ strains isolated from healthy animals than in those isolated from diarrheic animals, and VT production was only detected in E coli eae+ strains isolated from healthy lambs and kids. The E coli eae+ isolates belonged to several O serogroups. However, 17 of 40 (42.5%) isolates from diarrheic lambs and only 4 of 168 (2.4%) isolates from healthy sheep belonged to serogroup 026.

Conclusions And Clinical Relevance: Our results suggest that E coli eae+ 026 strains may play a role in diarrheal disease in lambs, whereas E coli eae+ strains that also had VT production and eae+ strains that had positive results for the espB gene did not appear to be associated with diarrhea in small ruminants.