Presence of Campylobacter in the respiratory tract of broiler carcasses before and after commercial scalding

Campylobacter could be detected in the thoraco-abdominal cavity of broiler carcasses even if they were carefully eviscerated by hand with no evidence of intestinal rupture or leakage. If Campylobacter is present in the air sacs, which are unavoidably torn during evisceration, it could contaminate the thoraco-abdominal cavity of the eviscerated carcass. This study was done to determine if Campylobacter contamination is present in the respiratory tract of broilers prior to evisceration. Whole carcass rinses and respiratory tract washes were done on broiler carcasses collected at a commercial processing plant just before and just after scalding. Samples were cultured for presence and numbers of Campylobacter, Escherichia coli, coliforms, and total aerobic bacteria. Campylobacter isolates were subtyped by sequencing the short variable region of the flaA gene. The same subtypes of Campylobacter were detected in whole carcass rinse samples as in respiratory tract wash samples from individual broilers. Furthermore, the same numbers and subtypes of Campylobacter were recovered from respiratory tracts of carcasses collected before scalding and those collected after scalding. However, respiratory tracts of carcasses after scalding had higher numbers of E. coli, coliforms, and total aerobic bacteria than those tested before scalding. Although some bacterial counts were higher in the respiratory tracts of carcasses after scalding, Campylobacter counts were not. It appears that Campylobacter is present in the respiratory tracts of broilers as they enter processing, and contamination may be due to airborne bacteria during production or transport.