|Watts, D. D.|
Submitted to: Livestock Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/18/2013
Publication Date: 1/16/2014
Citation: Pao, S., Hagen, B., Kim, C., Wildeus, S., Ettinger, M., Wilson, M., Watts, D., Whitley, N., Porto Fett, A.C., Schwarz, J., Ren, S., Long, W., Li, H., Luchansky, J.B. 2014. Prevalence and molecular analyses of Campylobacter jejuni and Salmonella spp. in co-grazing small ruminants and wild-living birds. Livestock Science. 160:163-171. Interpretive Summary: Wild-birds are potential sources of enteric disease infections in farm animals and, in turn, for humans. This study was designed to evaluate the potential pathways and control of foodborne pathogen transmission between wild-birds and farm animals. At two farms, on a total of 14 one-acre, fenced pastures, fecal samples from birds, goats, and sheep, as well as water samples, were tested every two weeks in May-June and October-November for two years. The samples were analyzed for the presence of Salmonella and Campylobacter using standard techniques. From small ruminants and captured wild birds, respectively, 2880 and 440 fecal samples were collected for pathogen detection. Campylobacter spp. were found in 5.0 and 8.2% of the fecal samples from small ruminants and wild birds, respectively. C. jejuni was isolated from 86 and 97% of corresponding positive samples. Salmonella spp. were only found in 0.9% of feces from small ruminants and 0.2% of wild birds. Note, neither pathogen was found in any water samples. By using the tools of molecular biology it was also shown that isolates of Campylobacter and Salmonella recovered from wild birds were different from otherwise similar isolates recovered from sheep and goats. These data do confirm, however, that wild birds are carriers of foodborne pathogens and, as such, may serve as a vehicle for their transmission to humans.
Technical Abstract: A total of 689 co-grazing small ruminants along with 446 wild-living birds were tested during two springs and autumns under two management systems at two Mid-Atlantic locations (~187 km in aerial distance) of the U.S. Fecal shedding of Campylobacter jejuni and Salmonella were, respectively, detected in 9.3% and 3.5% of small ruminants and in 7.4% and 0.2% of wild-living birds. Sheep had a significantly higher prevalence of C. jejuni and Salmonella of isolated strains revealed geographic specificity and genomic diversity of both pathogens from small ruminants. However, C. jejuni strains with indistinguishable PFGE profiles were isolated from one Rock Dove and two European Starlings caught at separate locations. Matching strain profiles were not found between small ruminants and wild-living birds. This study found that sheep pose a greater risk than goats in C. jejuni and Salmonella contamination at co-grazing small ruminant farms. Wild-living birds also are potential carriers of foodborne pathogens.