Characterization of Shiga toxin-producing Escherichia coli isolated from dairy cows in Argentina

Abstract

Aims: To feno‐genotypically characterize the Shiga toxin‐producing Escherichia coli (STEC) population in Argentinean dairy cows. Methods and Results: From 540 STEC positive samples, 170 isolates were analyzed by multiplex PCR and serotyping. Of these, 11% carried stx1, 52%stx2 and 37%stx1/stx2. The ehxA, saa and eae were detected in 77%, 66% and 3%, respectively. Thirty‐five per cent of strains harboured the profile stx1, stx2, saa, ehxA and 29%stx2, saa, ehxA. One hundred and fifty‐six strains were associated with 29 different O serogroups, and 19 H antigens were distributed among 157 strains. STEC O113:H21, O130:H11 and O178:H19 were the most frequently found serotypes. The STEC O157:H7 were detected in low rate and corresponded to the stx2+, eae+, ehxA+ virulence pattern. Conclusions: We detected a diversity of STEC strains in dairy cattle from Argentina, most of them carrying genes linked to human disease. Significance and Impact of the study: The non‐O157 STEC serotypes described in this study are associated worldwide with disease in humans and represent a risk for the public health. For this, any microbiological control in dairy farms should be targeted not only to the search of O157:H7 serotype.

Impact of Management Practices and Distillers' Grains Feeding on the Prevalence ofEscherichia coliO157 in Feedlot Cattle in Minnesota

“…Previous studies have found that stx2, the gene most frequently associated with hemolytic uremic syndrome, was the most prevalent (Padola et al, 2004;Fremaux et al, 2006;Rivas et al, 2006;Fernández et al, 2010;Rasooly and Do, 2010). In our study, we found that stx2 was present in all isolates, and 55.2% of the times it was associated with stx1 (Table 7).…”

Emerging types of Shiga toxin-producing E. coli (STEC) O178 present in cattle, deer, and humans from Argentina and Germany

“…STEC O178:H19 strains were frequently isolated from beef in Germany (Beutin et al, 2007; Werber et al, 2008; Slanec et al, 2009) and Argentina (Sanz et al, 2007; Kruger et al, 2011). Cattle were identified as important reservoir for STEC O178:H19 in South America (Cergole-Novella et al, 2007; Oliveira et al, 2008; Fernandez et al, 2010; Kruger et al, 2011; Masana et al, 2011; Tanaro et al, 2012) and in Europe (Blanco et al, 2004; Aidar-Ugrinovich et al, 2007; European Food Safety Authority and European Centre for Disease Prevention and Control, 2012). Sporadic cases of human infections with STEC O178:H19 were reported from Germany (Bielaszewska et al, 2006; Werber et al, 2008) and Brazil (De Toni et al, 2009).…”

PCR and ELISA (VIDAS ECO O157®) Escherichia coli O157:H7 identification in Minas Frescal cheese commercialized in Goiânia, GO

“…The main E. coli O157:H7 reservoir is the gastrointestinal tract of cattle, being a source of potential contamination during milking procedures (Hussein and Sakuma, 2005). E. coli O157: H7 was detected in 6.8% of feces samples from cattle and 0.2% of dairy cows in Argentina (Padola, et al , 2004; Fernández, et al , 2010), while in the United States, LeJeune et al (2006) isolated this serotype in 0.6% of dairy cows from Ohio State. Undercooked beef, unpasteurized milk and use of water contaminated by cattle manure have been associated to human outbreaks of hemorrhagic colitis and hemolytic uremic syndrome (Hussein and Sakuma, 2005; Sandrini, et al , 2007; Karmali, et al , 2009).…”