Genotypic and phenotypic diversity within three Campylobacter populations isolated from broiler ceca and carcasses.

The main aim of this study was to trace Campylobacter subtypes colonizing Italian broilers and carcasses in and between flocks. Overall, 209 Campylobacter isolates were collected from ceca (n = 94) and carcasses (n = 115) of broilers belonging to 3 different flocks reared in the same farm during subsequent rotations and processed in the same slaughterhouse. All isolates were identified by multiplex polymerase chain reaction and genotyped by amplified fragment length polymorphism. Furthermore, 166 out of 209 strains were phenotyped by antimicrobial resistance profile (R-type). The results of genetic and phenotypic characterization showed that (1) multiple Campylobacter species and subtypes can colonize the same broiler and carcass; (2) common Campylobacter subtypes in ceca and carcasses seem to be rare; and (3) carryover of Campylobacter subtypes between broiler flocks in the same house rarely occurs. The outcomes of this study should be taken into account for setting of isolate collection during epidemiological investigations to check sources and transmission routs of Campylobacter in broilers and poultry products.