Putative virulence factors and adhesins in Shiga toxin-producing Escherichia coli from cattle of different ages from Argentina.

CÁCERES, ME, FERNÁNDEZ, D, RODRÍGUEZ, EM, ETCHEVERRÍA, AI, PADOLA, NL

Congreso; 9th International Symposium on Shiga Toxin (Verocytotoxin)-producing Escherichia coli (VTEC); 2015

Putative virulence factors and adhesins in Shiga toxin-producing Escherichia coli from cattle of different ages from Argentina.Introduction: Shiga toxin-producing Escherichia coli (STEC) are zoonotic pathogens ofsignificant public health concern. Several studies have confirmed that cattle are the mainreservoir of STEC in Argentina and other countries. The aim of this study was to analyzethe distribution of several putative virulence factors carried in plasmids and of adhesins, ina subset of STEC strains isolated from distinct categories of cattle -young calves, rearingcalves, adults- from Argentina.Methods: A PCR multiplex for the detection of katP, espP, subA, and stcE, and two PCRmonoplex for the detection of efa1 and iha in 255 STEC strains serotypes O157:H7 andnon-O157, were performed.Results and Discussion: Differences about the presence of espP and stcE genes betweenthe diferent bovine categories where not significative (p=0.0679 and p=0.2670respectively). However, statistically significant differences were found in the presence ofkatP and subA genes between calves and adults groups (p<0.0001). The presence of theefa1 also showed significant differences between bovine categories (p<0.0001), where theyoung calves group showed the highest percentage. In adult cattle iha was observed inSTEC isolated from adults (p=0.0126).The main profiles found in young calves were espP-ehxA (49,3%) eae-efa1-iha (36,2%), inrearing calves espP-subA-ehxA (37%) while in adults the principal profiles were espPsubA-ehxA (71,2%), iha (53,8%).Implications: This study provides a broad spectrum of putative virulence factors profilespresent in bovine STEC strains contributing to a better understanding of the pathogenicpotential of this bacteria in our region.