Poultry are considered a major source for
campylobacteriosis in humans. A total of 1866 Campylobacter
spp. isolates collected through the poultry processing chain from four flocks
were typed using flaA-restriction fragment length polymorphism to
measure the impact of processing on the genotypes present. Temporally related
human clinical isolates (n=497) were also typed. Isolates were obtained from
chicken carcase rinses obtained from chickens collected before scalding, after
scalding, before immersion chilling, after immersion chilling and after
packaging as well as from individual caecal samples. A total of 32 genotypes
comprising at least four isolates each were recognised. Simpson’s Index of
Diversity (D) was calculated for each
sampling site within each flock, for each flock as a whole and for the clinical
isolates. From caecal collection to after packaging samples the D value did not change in two flocks,
decreased in one flock and increased in the fourth flock. Non-caecal related
genotypes were isolated from the end of processing in three flocks. Dominant
genotypes occurred in each flock but their constitutive percentages changed
through processing. There were 23 overlapping genotypes between clinical and
chicken isolates. A total of seven of the 30 genotypes isolated from clinical
samples were not found in chicken samples. Only two genotypes found in poultry
were not isolated from clinical samples. This study suggests that Campylobacter genotypes from the external surface of the chicken may play an
important role in the representation of genotypes at the end of processing.
This study confirms that poultry are a source of campylobacteriosis in the
Australian population although other sources may contribute.