Oral Presentation Australian Society for Microbiology Annual Scientific Meeting 2014

Do Campylobacter biofilms contribute to their survival in the environment? (#54)

Amy HT Teh 1 , Gary A Dykes 2
  1. School of Science, Monash University, Bandar Sunway, Selangor, Malaysia
  2. School of Chemistry, Monash University, Clayton, Victoria, Australia

Thermophilic Campylobacter, specifically Campylobacter jejuni and Campylobacter coli, are among the most frequent causes of bacterial gastrointestinal food-borne infection. These species are part of the normal flora of the gastrointestinal tract of food animals, including poultry which is regarded as the primary source of human Campylobacter infections. The survival and persistence of Campylobacter in food processing environments is a significant risk which contributes to the spread of these pathogens through the food chain. Compared to other food-borne pathogens Campylobacter are fastidious in their growth requirements and are susceptible to environmental stressors. Biofilm formation has been suggested to play a significant role in Campylobacter survival in the food production and processing environment. In a recent study we investigated the influence of prior mode of growth (planktonic or sessile), temperature (37°C and 42°C) and nutrient conditions (nutrient broth and Muller-Hinton broth) on biofilm formation by eight C. jejuni strains on different abiotic surfaces (stainless steel, glass and polystyrene). The hydrophobicity and auto-aggregation of, and presence of virulence genes in, the strains were also determined. The results showed that cells previously grown in sessile culture produced more biofilm (p<0.05) as compared to their planktonic counterparts. Growth at different temperatures did not affect biofilm formation (p>0.05), but it was higher in lower nutrient media (p<0.05). The C. jejuni strains formed biofilms on abiotic surfaces with the highest amount formed on glass, followed by polystyrene and then stainless steel. Notably, none of the strains demonstrated strong, complex or structured biofilm formation. We have previously demonstrated that Campylobacter attach well to abiotic surfaces even when in a viable-but-non-culturable state. Our data, and that in the literature, suggest that simple attachment to, and persistence on surfaces and in existing biofilms of other species, are more likely to contribute to Campylobacter survival in the environment than biofilm formation per se.