Biofilm Forming Potential of Escherichia coli from Various Sources

Majority of bacterial communities exist as biofilms and these contribute to the survival of the bacteria. Biofilm development has been associated with protection from adverse environmental conditions and resistance to harmful agents. Generally, however data on biofilm-forming potential of bacteria in Nigeria is sparse. This study was therefore aimed at analyzing variations in biofilm-forming potential of Escherichia coli from various sources in Port Harcourt, Nigeria. Previously characterized clinical (30) and non-clinical (30) E. coli isolates were assessed for their biofilm-forming potential using the Congo Red agar method and variations in this potential determined as weak, moderate or strong. Majority of isolates (67%) had the potential to form biofilms but only 40% of isolates exhibiting biofilm-forming potential were from clinical sources. Isolates exhibited variable degrees of biofilm-forming potential, with only non-clinical isolates exhibiting strong potential. Majority of both clinical and non-clinical isolates (68.7% and 88% respectively) exhibited moderate biofilm-forming potential. The higher occurrence of E. coli exhibiting biofilm-forming potential among non-clinical isolates possibly reflects the essential role biofilms play in the survival of bacteria in nature, but not in infection cases. This study reports on a high level association between the isolates and biofilm production and highlights differences in the abilities of biofilm production between clinical and non-clinical isolates.