Patotipos diarreogenicos e filogrupos de Escherichia coli isolada em fezes de cães e répteis não diarreicos

Abstract

Diarrheogenic E. coli could be classified in different pathovars according to specific pathogenic factors which makes this agent potentially pathogenic for humans and animals. It is widely important to identify animals carriers of E. coli to prevent and control infections in susceptible hosts, including humans. Thus, the present study aimed to isolate E. coli in clinical samples ofnon-diarrheic dogs that fed unconventional diets and dry food and reptiles from different living conditions, as well as to characterize the isolated strains in phylogenetic groups and pathovars of diarrheagenic E. coli according to pathogenic genes detection. 246 E. coli were isolated from 106 sampled dogs, being the phylogenetic groups B1 and B2 more common in dogs that ate dry food (60.4%) additionally to a propensity to isolate B2 strains by these animals (p = 0.0004). The phylogroups B1 and E were the most commonly isolated strains in dogs fed with unconventional diets (33.9% and 18.7%, respectively), being the isolation of group E higher in dogs fed with raw diets (p = 0,009). Dogs that fed raw food diets had a frequency of E. colipositive for pathogenic genes carriage, genes of CNF-1, intimin and group E statistically higher than dogs fed with cooked diet and dry food at multivariate analysis. Of 76 sampled reptiles, 52 were positive for E. coli with 88 isolated strains. The identification of E. coli was significantly higher in clinical samples of snakes and other canivore reptiles (p 0,05). Most of isolates werepositive for phylogroup B1, with approximately 89% of animals, mainly snakes and lizards, carrying only these group of E. coli. Two reptiles were positive for E. coli that carried the pathogenic gene for EAST-1, of which one was domesticated and another a wildlife reptile. The encoding gene of CNF-1 was found in 13 isolates of seven reptiles, of which two were domesticated chelonians. A higher identification of important pathogenic genes of E. coli inisolates of dogs that fed unconventional raw diets, as well as the detection of potentially pathogenic strains in clinical samples of reptiles suggests the role of these animals as possible reservoirs of pathogenic E. coli. Thus, the human contact with these animals that could be reservoirs of CNF1, intimin and EAST1 positive strains may represents a greater risk to people of exposure to pathogenic agents. Additionally, the present work reinforces the hypothesis that factors as diet and geographic origin could influence in the frequency of isolation and distribution of some phylogenetic groups and E. coli pathovars