A longitudinal study on thermophilic Campylobacter spp. in commercial turkey flocks in Northern Italy: occurrence and genetic diversity

Poultry are recognized as main reservoir of thermophilic campylobacters, but few studies have been carried out on commercial meat turkeys. This study was aimed at assessing the occurrence of thermophilic Campylobacter spp., their genetic diversity and the trend of the infection during the whole production cycle of 3 turkey flocks from different farms in Northern Italy. Flocks were monitored from the housing of day-old poults to slaughter time by collecting samples (meconium and cloacal swabs) at weekly intervals up to the recovery of Campylobacter spp., and then twice a month. A conventional culture method and a multiplex PCR assay were used for Campylobacter detection and identification. A subset of isolates was genetically characterized by RAPD-PCR and flaA-SVR sequencing. Although at different times, all flocks became colonized by C. jejuni and/or C. coli, which persisted throughout the whole production cycle. Overall, 9 RAPD types and 14 flaA-SVR types were detected, with differences in their distribution among flocks and sampling times. Moreover, changes in Campylobacter genotypes colonizing turkeys were observed over time within each flock. These findings suggest that Italian commercial turkeys might be widely colonized by different genotypes of C. jejuni and C. coli and differences in the distribution and epidemiological dynamics of these microorganisms might occur among flocks.