Étude de prévalence et associations des gènes de virulence et résistance aux antimicrobiens d’Escherichia coli de la flore intestinale du poulet sain
Avian Pathogenic E. coli (APEC) belong to the extra-intestinal pathogenic E. coli (ExPEC) pathotype, and may be a virulence and antimicrobial resistance (AMR) gene reservoir for ExPEC in humans. The aim of this study was to evaluate the effect of addition to the feed of a prebiotic or an organic acid on the prevalence of ExPEC-associated virulence genes and antimicrobial resistance (AMR) genes and the association between these genes in E. coli of the intestinal microflora of healthy chickens. Caecal contents from 29-day-old chickens having received one of these feed ingredients in comparison to a control group were examined for the presence of virulence genes iucD, tsh, and papC and AMR genes blaTEM, blaSHV, tetA, tetC, blaCMY-2, aadA1, and aac3 by PCR. The prevalence of iucD was significantly higher in the control group than in the prebiotic and organic acid groups and prevalence of papC was affected by the use of the organic acid. The prevalence of blaCMY-2-positive E. coli isolates was higher in the control group than the prebiotic or organic acid groups, as demonstrated by Hydrophobic–grid membrane filter (HGMF) DNA probe colony hybridization. In addition, the prevalence of E. coli isolates positive for tetA, blaTEM, aadA1 or tsh was affected by the use of these feed ingredients. Overall, associations between the presence of iucD and tsh, blaTEM and aadA1, and iucD and blaCMY-2 were observed. This study demonstrates that the use of certain feed ingredients could reduce the risk of exposure in a public health perspective.
Poulets sains Antimicrobial resistance genes Virulence genes Healthy chickens Caecal E. coli Feed ingredients prebiotic Organic acid ExPEC APEC HGMF PCR