Virulence profiles of Shiga toxin-producing Escherichia coli and other potentially diarrheagenic E.coli of bovine origin, in Mendoza, Argentina

Abstract

This study described a group of strains obtained from a slaughter house in Mendoza, in terms of their pathogenic factors, serotype, antibiotype and molecular profile. Ninety one rectal swabs and one hundred eight plating samples taken from carcasses of healthy cattle intended for meat consumption were analyzed. Both the swab and the plate samples were processed to analyze the samples for the presence of virulence genes by PCR: stx1, stx2, eae and astA. The Stx positive strains were confirmed by citotoxicity assay in Vero cells. The isolates were subsequently investigated for their O:H serotype, antimicrobial susceptibility and molecular profile by Random Amplification of Polymorphic DNA (RAPD). Twelve E.coli strains were identified by their pathogenicity. Nine were from fecal origin and three from carcasses. Three strains carried the stx1 gene, three the stx2 gene, two carried eae and four the astA gene. The detected serotypes were: O172:H-; O150:H8; O91:H21; O178:H19 and O2:H5. The strains showed a similarity around 70% by RAPD. Some of the E.coli strains belonged to serogroups known for certain life-threatening diseases in humans. Their presence in carcasses indicates the high probability of bacterial spread during slaughter and processing.

Shiga toxin-producing Escherichia coli (STEC) O22:H8 isolated from cattle reduces E. coli O157:H7 adherence in vitro and in vivo

“…Ruminants are the primary reservoir of EHEC O157:H7 (Yoon and Hovde, 2008)and have been recently recognized as important reservoirs for other STEC serotypes, some of them associated with human disease (Parul et al, 2016). In Argentina, cattle have been identified as a source of non-O157 STEC and some of these strains have been previously associated with hemolytic uremic syndrome (HUS), bloody and non-bloody diarrhea (Fernandez et al, 2013;Masana et al, 2011;Pizarro et al, 2013). Despite the carriage of Shiga toxins genes, posing a significant threat to human health, the combination with other virulence factors needs to be further assessed in order to evaluate the pathogenic potential of STEC strains.…”

Prevalence, Molecular Characterization and Antibiotic Susceptibility of Escherichia Coli Isolated from Duck Meat and Giblets

“…A large variety of serotypes have been isolated from patients with gastrointestinal disease and many of these serotypes as well as others have been isolated from birds and animals. The serotypes associated with illness in humans include members of O serogroups 26, 91, 103, 111, 113, 121, 145 and 157 (Karmali et al 2010;Pizarro et al 2014).…”

ウシ由来大腸菌が保有する病原性に関与する遺伝子群の包括的実態調査

“…But, recently it is required to differentiate DEC accord-* Yumi_Akiyama@pref.hyogo.lg.jp ing to pathogenic factors. Pizarro et al screened 5 kinds of pathogenic genes by PCR to detect DEC of bovine origin in Argentina 5) . Cattle are the main reservoir of E. coli strains which may cause food poisoning.…”