B-239. The Variability of Campylobacter jejuni and Campylobacter coli Biofilms Is both Strain and Growth Media Dependant

N. W. Gunther, IV;
USDA-ARS, Wyndmoor, PA.

Biofilm formation by Campylobacter jejuni and Campylobacter coli varies significantly from strain to strain. Under the same growth conditions some strains of C. jejuni and C. coli form biofilms while other strains do not. Additionally, formation of biofilms in Campylobacter appears to be medium dependent. This inconsistency makes it difficult to determine if the ability to form biofilms contributes significantly to Campylobacter’s potential as a pathogen. In this study, we observed the biofilm forming ability of 17 different C. jejuni strains and 10 C. coli strains that were derived from environmental or clinical sources. These strains included four genetically-matched clinical and environmental strain pairs that were isolated from human cases of campylobacteriosis and the chicken production lot associated with the case of human illness. No clear relationship was observed between the source of the strain and its ability to form biofilms on glass coupons in broth cultures. This included the matched-strain pairs where only one of the four pairs demonstrated a significant difference (P<0.05) based on the site of collection. Subsequently, the Campylobacter strains were grown in four different broth formulations to determine which medium components might affect the production of biofilms. The presence of 0.09M NaCl positively influenced biofilm formation in 5 of the 17 C. jejuni and 3 of the 10 C. coli strains. Finally, a broad range of NaCl concentrations (0 to 2%) was investigated to determine the optimal concentration for biofilm formation in Campylobacter strains previously shown to be positively influenced by NaCl. Variable biofilm formation in campylobacter and the effect of medium components on biofilm formation support the importance of using a defined and relevant medium for making comparisons among Campylobacter strains and investigating the importance of biofilm formation for the persistence of these organisms in food-related environments.