Genes encoding Shiga toxin and the intimin receptor detected in faecal samples collected from wild canids
Riboldi, Camila ImpericoLopes, Cassiane ElisabeteWitt, Patrícia Bernardes RodriguesValiati, Victor HugoSoares, João FábioSiqueira, Franciele Maboni
Background: Enteropathogenic Escherichia coli (EPEC) and Shiga toxin-producing E. coli (STEC) are diarrheagenic E.coli that can cause disease in humans. The pathotype EPEC leads to the attaching and effacing lesion, causing damage tothe microvilli following to diarrhea. STEC pathotypes produces cytotoxins, which in humans are responsible for hemorrhagic colitis or hemolytic uremic syndrome. Animals are the reservoirs of these pathotypes, especially ruminants. However,other animals species can be associated as carriers of EPEC and STEC strains. The aim of this study was to analyze wildcanid crab-eating fox (Cerdocyon thous) as potential natural carriers of STEC and EPEC E. coli.Materials, Methods & Results: Seven fecal samples were analyzed from the crab-eating fox of free-living, captured in aperi-urban area. Samples were collected from the rectal ampulla, and the animals were clinic evaluated, being consideredhealthy at the captured moment. The feces were inoculated on medium MacConkey agar, and then the plates were incubated at 37°C for 24 h. All colony forming units (CFU) were collected by plate washing with ultrapure water (2 mL) andposterior freezing at -20°C. The total bacterial DNA from the CFU collected was extracted, followed by PCR assay tosearch for three genes: stx1, stx2 (responsible for the synthesis of the Shiga toxin) and tir, which encodes the translocatedintimin receptor, related to the A/E lesion formation. Three samples were detected as positive, being one animal detected ascarrier of the stx2 gene (STEC strain), while two animals were identified as carrier of the tir gene (EPEC strains).The stx1gene was not identified on the samples. Also, in the samples, only the presence of one gene studied at a time was observed.Therefore, we have found out that the crab-eating fox...(AU)
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