Molecular characterization of Escherichia coli pathotypes from diarrheic and healthy dogs.

摘要

Escherichia coli (E. coli) strains are commensally inhabitants of the gastrointestinal tract of dogs. However, a variety of E. coli pathotypes have been associated with diarrheal illness in dogs. E. coli isolates from fecal samples of 65 dogs with acute diarrhea and 104 non-diarrheic dogs were examined to detect their pathotypes and phylotypes. One hundred sixty nine E. coli isolates from diarrheic and healthy dogs fall into four phylogenetic groups: A (56.80%), B1 (13.06%), B2 (12.42%) and D (17.15%). Out of E. coli isolates analyzed 32.54% isolates possessed at least one examined virulence gene and 65.08% of isolates were negative for all the examined genes. Necrotoxigenic E. coli isolates was the most prevalent pathotype which 26.15% and 21.15% of the isolates from diarrheic and healthy dogs were positive for cnf1 gene respectively. The stx1 gene was detected in 2 isolates (1.18%) from diarrheic and healthy dogs, whereas stx2 gene was found in two isolates from diarrheic dogs. Twelve (7.10%) eae positive isolates was considered as enteropathogenic pathotype, which 10.76% were from diarrheic and 4.80% were from healthy dogs. None of the isolates contained the ST1, LT1, cnf2 and ipaH genetic markers. In conclusion, this study has demonstrated similarities in phylogenetic distribution of E. coli isolates from diarrheic and healthy dogs; although there are differences in presence and prevalence of virulence genes between both groups.