Submitted to: Applied and Environmental Microbiology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 4/5/2006
Publication Date: 9/1/2006
Citation: Callicott, K., Fridriksdottir, V., Reiersen, J., Lowman, R., Bisaillon, J., Gunnarsson, E., Berndtson, E., Hiett, K.L., Needleman, D.S., Stern, N.J. 2006. Lack of evidence for verticle transmission of campylobacter spp. in chickens. Applied and Environmental Microbiology. 72(9):5794-5798. Interpretive Summary: We examined evidence from our Iceland studies for vertical, or egg-borne, transmission of Campylobacter in chickens. When offspring were examined for Campylobacter, there was no evidence for its presence in the fluff remaining in the hatching cabinets (when tested by molecular methods) or in the birds themselves (tested by culture) while they were housed in a quarantine rearing facility, through the age of 8 weeks. When the offspring birds were moved from quarantine to non-biosecure housing, the flocks became positive for Campylobacter, but genetically, there was no match found between the Campylobacter found in the hens that produced the eggs and their offspring. Because the offspring flocks were comprised of 159,745 birds, the lack of any evidence for vertical transmission indicates that if it is occurring, vertical transmission is a rare and insignificant source for flock colonization. This work has strong implications for on-farm control of Campylobacter.
Technical Abstract: Campylobacter jejuni is a major cause of bacterial foodborne infection in the industrial world. There is evidence that C. jejuni are present in eggs and hatchery fluff, opening the possibility for vertical transmission from hens to progeny. Poultry operations in Iceland provide an excellent opportunity to study this possibility, as breeding flocks are established solely from eggs imported from grandparent flocks in Sweden. This leaves limited opportunity for grandparents and their progeny to share isolates through horizontal transmission. No evidence of Campylobacter was found by PCR in any of the 18 quarantine hatchery fluff samples examined, and no Campylobacter were found in the parent birds through 8 weeks, while they were still in quarantine rearing facilities. Twenty-eight alleles were observed among the 239 isolates studied. While 4 alleles were found in both Sweden and Iceland, in no case was the same allele found both in a particular grandparent flock and its progeny. We could find no evidence for vertical transmission from the Swedish grandparent flocks to the 159,745 Icelandic parents. If vertical transmission is occurring, it is not a significant source for the contamination of chicken flocks with Campylobacter spp.