|LADELY, SCOTT - Food Safety Inspection Service (FSIS)|
|Meinersmann, Richard - Rick|
|Line, John - Eric|
|OAKLEY, BRIAN - Former ARS Employee|
|Cox, Nelson - Nac|
Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/21/2016
Publication Date: 11/1/2016
Citation: Berrang, M.E., Ladely, S.R., Meinersmann, R.J., Line, J.E., Oakley, B., Cox Jr, N.A. 2016. Variation in Campylobacter multilocus sequence subtypes from chickens as detected on three plating media. Journal of Food Protection. 79(11):1986-1989.
Interpretive Summary: Campylobacter is a human pathogen that is associated with chicken and chicken meat products. It is important to know the Campylobacter status of a flock of broilers on the farm and in the slaughter/processing plant. There are multiple methods and growth media used to culture Campylobacter. It is unclear if different media select for different subtypes of Campylobacter. This represents a potential for a bias in type of Campylobacter detected depending on the growth medium that a laboratory may choose. We tested three different types of growth media (Campy-Cefx agar, Campy-Line agar and RF Campylobacter jejuni/coli agar) to detect Campylobacter from chicken gut and carcass rinse samples collected in a commercial slaughterer plant. Campylobacter detected on each medium were subtyped using a molecular method that compared the DNA sequence in multiple genes. We found that there was minimal differences and that for the most part, all three types of growth media allowed detection of the same types of Campylobacter. These data are useful to researchers, commercial laboratories, regulators, and poultry processors as they can use any one of these media to culture Campylobacter and be confident that they are detecting the same subtype regardless of the growth medium used.
Technical Abstract: The objective of this study was to compare subtypes of Campylobacter jejuni and coli detected on three discreet selective Campylobacter plating media to determine if different media select for different subtypes. Fifty ceca and fifty carcasses (n=100, representing 50 flocks) were collected from the evisceration line in a commercial broiler processing plant. Campylobacter were cultured and isolated from cecal contents and carcass rinses on Campy-Cefex, Campy Line and RF Campylobacter jejuni/coli agars. In cases where a positive was found on all three media, one colony of the most prevalent colonial morphology on each medium was selected. Isolates were analyzed by full genome sequencing and multi-locus sequence typing; sequence types were assigned according to Pubmlst. A total of 49 samples were positive for Campylobacter on all three media. Forty samples had only C. jejuni; 3 had only C. coli and both were detected in 6 samples. Approximately 71% of samples had the same Campylobacter subtype on all three media. Significantly fewer (26%, P<0.01) samples had one medium with a different subtype than the other two. When multiple subtypes were detected, the medium with the odd subtype was Campy-Cefex 6 times, Campy-Line 4 times and RF Campylobacter jejuni/coli 6 times. In only one sample were three different subtypes detected. In most cases, all three plating media allowed detection of the same subtype of Campylobacter from complex naturally contaminated chicken related samples.