Preliminary investigations of the distribution of Escherichia coli O149 in sows, piglets, and their environment.

Little is known about the sources and kinetics of enterotoxigenic Escherichia coli colonization in pigs during the pre-and post-weaning period. In this study, farrowing pens, sows, and piglets were tested for the presence of E. coli O149 by real-time polymerase chain reaction (PCR) after bacterial culture pre-enrichment on 2 farms, one with a history of post-weaning diarrhea (problem farm - PF) and the other without such a history (non-problem farm - NPF).

The Escherichia coli O149 rfb gene cluster and its use for the detection of porcine E. coli O149 by real-time PCR.

PCR or hybridization assays are widely used for the identification and detection of various Escherichia coli serogroups and serotypes. This study explored this approach for the detection of E. coli O149 in pigs, a dominant serogroup among those associated with porcine post-weaning diarrhea (PWD) worldwide.

Effect of plasmid pTENT2 on severity of porcine post-weaning diarrhoea induced by an O149 enterotoxigenic Escherichia coli.

A particularly virulent O149:H10 enterotoxigenic Escherichia coli clone harbours a newly characterized plasmid pTENT2 carrying the tetracycline-resistance tetA and the virulence genes estA, paa, and sepA that were not present in less virulent clones. The objectives of this study were to assess whether the additional genes on pTENT2 played a role in the increased severity of post-weaning diarrhoea and if they provided any potential advantage for the emergence of the highly virulent clone. Groups of pigs were dosed orally with isogenic pTENT2-positive and pTENT2-negative ETEC strains, and the clinical and pathological changes were compared between the groups.