Assessing the presence of Stx2e-producing E. coli virotypes in samples of oral fluid of growers and fatteners

Edema disease is a multifactorial infectious disease caused by specific E. coli virotypes possessing fimbriae F18 and toxin Stx2e that cause significant losses in the post-weaning period. The aim of this study was to assess the presence of Stx2e-producing E. coli verotypes in Slovenian commercial pig farms in relation to the biosecurity and technological measures undertaken by the owners. Samples of oral fluid were collected from growers and fatteners at 5–6 weeks, 7–8 weeks, 12 weeks and 14 weeks of age on 37 commercial pig farms, using the Verocheck® diagnostic kit for the real-time PCR detection of Stx2e. The results of RT-PCR and the questionnaire were statistically analyzed. The prevalence of E. coli strains producing Stx2e was 64.9%. Statistically significant association between the prevalence of Stx2e producing E. coli strains and the type of the farm and feed origin was proved. No association was found between prevalence and farm size, presence of quarantine or previous outbreaks of edema disease. None of the studied age groups showed a statistically significant dominance in prevalence compared to other age groups, which contradicts the current theoretical data. Further studies are needed to estimate the proportion of Stx2e produced by the EDEC pathotype compared to other E. coli strains.