Resuscitation of bacterial biofilm by sunlight : effects on different enteropathogenic bacteria

Abstract

Bangladesh encounters seasonal cholera endemics biannually. Vibrio cholerae and Shiga toxin- producing Escherichia coli (STEC) is responsible for cholera and similar diarrheal disease outbreaks. Biofilms go through a cycle of formation and degradation influenced by various environmental conditions, and it is this degradation that contributes to increased numbers of planktonic bacteria in water bodies. In this study, the effect of sunlight on resuscitation of bacterial biofilm was investigated. Biofilm of Vibrio cholerae, three strains, and STEC were subjected to sunlight exposure during wet season, June to August. The results demonstrate that degradation of biofilm during these seasons, considered the off-season, occurs but is insignificant when compared to summer season, considered the peak season of bacterial infection. This can indicate that sunlight is a significant factor in biofilm resuscitation and seasonal outbreaks of bacterial diseases. Including these seasonal results, around the year data has been obtained for this study. However, replication would lead to a more insightful conclusion.