Submitted to: Germplasm Release
Publication Type: Germplasm Release
Publication Acceptance Date: February 17, 2009
Publication Date: February 17, 2009
Citation: Cox Jr, N.A., Richardson, L.J., Berrang, M.E., Cray, P.J., Buhr, R.J. 2009. Notice of release of a Campylobacter coli resistant to high concentrations of gentamicin. Germplasm Release. Technical Abstract: The Agricultural Research Service of the United States Department of Agriculture announces the release of a Campylobacter coli strain resistant to high levels of gentamicin to be used as a marker organism in research studies. Campylobacter inoculation studies are limited without a suitable marker strain. Campylobacter strains (n=2,073) were obtained from poultry carcass rinses through the National Antimicrobial Resistant Monitoring System (NARMS) and evaluated for resistance to gentamicin. A C. coli strain was found resistant to gentamicin at > 32 µg/ml. Gentamicin was incorporated into media (Campy-cefex, Brucella, and blood agar) from 0 to 1,000 µg/ml and the upper level of gentamicin resistance determined. The C. coli strain’s upper level of growth on Campy-cefex plates, blood agar plates, and brucella agar plates was 400 µg/ml, 300 µg/ml, and 200 µg/ml, respectively. Ceca and post-pick carcass rinses were obtained and streaked onto Campy-cefex agar at the above gentamicin levels to evaluate background microflora exclusion. Campy-cefex agar containing gentamicin at 100 µg/ml prevented from the ceca and reduced from the rinse background microflora. The C. coli strain was orally or intracloacally inoculated into chicks. At 1, 3, and 6 wks-of-age, inoculated broilers were removed and several tissue types sampled for the presence of the marker strain. At 6 wks-of-age, 10 additional non-inoculated pen-mates were sampled. The C. coli strain colonized chicks, disseminated to body tissues, colonized pen-mates and persisted throughout a six week grow-out. The C. coli strain’s unique characteristic, being resistant to high levels of gentamicin allows for a marker which can be used in a wide range of Campylobacter research projects. The strain is currently being used by other scientists as an effective marker organism in several research studies.