Prevalence of Helicobacter pullorum in broiler chickens reared in intensive and extensive farms

Helicobacter pullorum infections are underestimated due to phenotypic similarities between the genera Helicobacter and Campylobacter. The aim of this work was to estimate the Helicobacter pullorum prevalence in 209 caecum contents collected from Italian broilers reared in 33 intensive and 9 extensive farms by using a Steele-McDermott membrane filter method modified. The isolate identifications were confirmed by a PCR assay based on 16S rRNA, followed by a RFLP-PCR to discriminate between H. pullorum and H. canadensis. Prevalences of Helicobacter pullorum intensive and extensive positive farms were 96.9 and 66.7%, respectively. Overall, 78.47% of the caecum samples were positive. In particular, the percentage of positive caecum collected from broilers reared in intensive farms was statistically significative higher than that detected in extensive farms (84.14 vs 57.7%). All strains isolated using the procedure set up in this work were classified as Helicobacter pullorum by PCR. In conclusion, in Italian broilers H. pullorum has an estimated prevalence of 78.47% and the percentage of positive samples among broilers reared in intensive farms might be higher than that of broilers reared in extensive farms. The isolation protocol used in this study was more sensitive that those published in previous paper. Moreover, it seems highly specific. In fact all isolates collected on presumptive positive samples were identified as H. pullorum by PCR and RFLP-PCR. This study was financed within the European Project FOOD-CT-200X-007076 named POULTRYFLORGUT (www.poultryflorgut.org). ________________________________________________________________________________