Purpose: 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.
Methods: Fifty ceca and fifty carcasses (n=100) 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 Campy agars. In cases where a positive was found on all three media, one colony of the most prevalent type on each medium was selected. Isolates were analyzed by full genome sequencing and multilocus sequence typing; sequence types were assigned according to Pubmlst.
Results: A total of 49 samples were positive for Campylobacter on all three media. Forty samples had only C. jejuni; 2 had only C. coli and both were detected in 7 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 two subtypes were detected, the medium with the odd subtype was Campy Cefex 5 times, Campy Line 3 times and RF Campy 5 times. In only one sample were three different subtypes detected.
Significance: In most cases, all three plating media allowed detection of the same subtype of Campylobacter from complex naturally contaminated chicken related samples.