Biofilm Production Potential of Serovars Isolated from Chickens in North West Province, South Africa.

Bacterial biofilms have recently gained considerable interest in the food production and medical industries due to their ability to resist destruction by disinfectants and other antimicrobials. Biofilms are extracellular polymer matrices that may enhance the survival of pathogens even when exposed to environmental stress. The effect of incubation temperatures (25°C, 37°C, and 40°C) and serotype on biofilm-forming potentials was evaluated. Previously typed serotypes (55) isolated from the gut of chickens were accessed for biofilms formation using a standard assay. Typhimurium ATCC 14028 and Enteritidis ATCC 13076 (positive controls), (internal control) and un-inoculated Luria Bertani (LB) broth (negative control) were used. The isolates formed no biofilm (11.86-13.56%), weak (11.86-45.76%), moderate (18.64-20.34%), strong biofilms (23.73-54.24%) across the various temperatures investigated. Serotypes, Heidelberg and Weltevreden were the strongest biofilm formers at temperatures (25°C, 37°C, and 40°C, respectively). The potential of a large proportion (80%) of serotypes to form biofilms increased with increasing incubation temperatures but decreased at 40°C. Findings indicate that average temperature favours biofilm formation by serotypes. However, the influence of incubation temperature on biofilm formation was greater when compared to serotype. A positive correlation exists between biofilm formed at 25°C, 37°C and 40°C ( ≥ 0.01). The ability of species to form biofilms at 25°C and 37°C suggests that these serotypes may present severe challenges to food-processing and hospital facilities.