| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 144.22 KB | Adobe PDF |
Advisor(s)
Abstract(s)
Shiga toxin-producing Escherichia coli (STEC) strains are food-borne
pathogens that can be transmitted to humans through many different
routes, but mainly through consumption of contaminated foods. STEC
strains are characterized by the production of Shiga toxins (Stx) that are
encoded by two genes stx1 and/or stx2. Each toxin can be subdivided
into subtypes and, currently, there are three known subtypes for stx1
(stx1a, stx1c, and stx1d) and seven for stx2 (stx2a, stx2b, stx2c, stx2d,
stx2e, stx2f, and stx2g). Others virulence factors, such the production of
intimin protein, encoded by eae gene, are associated with severe
outcomes of STEC-associated diseases. The most common STEC serotype
implicated worldwide is E. coli O157:H7, but many other STEC strains are
associated with severe human diseases. Ruminants, especially cattle, are
a major reservoir for O157 and non-O157 STEC. Information on STEC
prevalence in Portuguese dairy cattle is limited, so we analysed for the
presence of STEC 329 faecal specimens collected from the rectum of
healthy dairy cattle. The samples were collected from adult lactating
cows (n=194) and from heifers (n=135) with ages among 6 to 18 months,
between March and June 2019, at milk farms (n=17) in the North region
of Portugal. After enrichment, in modified TSB with novobiocin, samples
were analysed by real time PCR to detect the presence of stx1, stx2 and
eae in accordance to ISO/TS 13136:2012(E). In addition, conventional
PCR for the detection of sxt1 and stx2 gene subtypes was performed
according to the guidelines of the VTEC European Union Reference
Description
Keywords
Food safety Shiga toxin Pathogens E. coli Cattle
Citation
Ballem, A.; Gonçalves, S.; Ferreira, A.I.; Fernandes, C.; Saavedra, M.J.; Pinto, C.; Oliveira, H.; Almeida, Gonçalo; Almeida, Carina (2019). Prevalence of shigatoxigenic Escherichia coli in bovine cattle: a survey in the North Region of Portugal. In 1º Simpósio INIAV para a Segurança Alimentar. Vila do Conde
Publisher
INIAV