Prevalence and serotypes of Shiga toxin-producing Escherichia coli (STEC) in dairy cattle from Northern Portugal.

Andressa Ballem
Soraia Gonçalves
Isidro Garcia-Meniño
Saskia C Flament-Simon
Jesús E Blanco
Conceição Fernandes
Maria José Saavedra
Carlos Pinto
Hugo Oliveira
Jorge Blanco
Gonçalo Almeida
Carina Almeida

Open link

Publication date

January 2020

DOI

10.1371/journal.pone.0244713

Publisher

Public Library of Science (PLoS)

Journal

PLoS ONE

Abstract

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 frequ...