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

CÁCERES, MARÍA EMILIA; FERNÁNDEZ, DANIEL; RODRÍGUEZ, EDGARDO M.; ETCHEVERRÍA, ANALÍA I.; PADOLA, NORA L.

Boston

Simposio; 9 th Internacional Symposium on Shiga Toxin (Verocytotoxin) Producing Escherichia coli Infections (VTEC 2015); 2015

VTEC 2015

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