Open AccessPrevalence and serotypes of Shiga toxin-producing Escherichia coli (STEC) in dairy cattle from Northern Portugal
Author(s) -
Andressa Ballem,
Soraia Gonçalves,
Isidro García-Meniño,
Saskia-Camille Flament-Simon,
Jesús E. Blanco,
Conceição Fernandes,
María José Saavedra,
Carlos A. Pinto,
Hugo Oliveira,
Jorge Blanco,
Gonçalo Almeida,
Carina Almeida
Publication year - 2020
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0244713
Subject(s) - serotype , stx2 , shiga toxin , virulence , intimin , escherichia coli , biology , microbiology and biotechnology , veterinary medicine , feces , toxin , enterobacteriaceae , gene , medicine , biochemistry
The prevalence of Shiga toxin (Stx)-producing Escherichia coli (STEC) was determined by evaluating its presence in faecal samples from 155 heifers, and 254 dairy cows in 21 farms at North of Portugal sampled between December 2017 and June 2019. The prevalence of STEC in heifers (45%) was significantly higher than in lactating cows (16%) ( p <0.05, Fisher exact test statistic value is <0.00001). A total of 133 STEC were isolated, 24 (13.8%) carried Shiga-toxin 1 ( stx1 ) genes, 69 (39.7%) carried Shiga-toxin 2 ( stx2 ) genes, and 40 (23%) carried both stx1 and stx2 . Intimin ( eae ) virulence gene was detected in 29 (21.8%) of the isolates. STEC isolates belonged to 72 different O:H serotypes, comprising 40 O serogroups and 23 H types. The most frequent serotypes were O29:H12 (15%) and O113:H21 (5.2%), found in a large number of farms. Two isolates belonged to the highly virulent serotypes associated with human disease O157:H7 and O26:H11. Many other bovine STEC serotypes founded in this work belonged to serotypes previously described as pathogenic to humans. Thus, this study highlights the need for control strategies that can reduce STEC prevalence at the farm level and, thus, prevent food and environmental contamination.