Variation in Biofilm-Forming Potential of Staphylococcus aureus from Clinical and Non-Clinical Sources

Introduction: Biofilm forming ability has been described as a potential marker of pathogenicity, particularly in Staphylococcus aureus. These biofilms are notable as an important contributor to virulence abilities, further aiding the producing strain in long term survival and resistance to antimicrobial agents. Regional data exploring biofilm forming ability of S. aureus from various sources is limited. This study therefore set out to explore variations in biofilm-forming potential of S. aureus from clinical and non-clinical sources.

Place and Duration of Study: Medical Microbiology Laboratory, Department of Microbiology, University of Port Harcourt, Nigeria from August to October 2019.

Methodology: Eighty five S. aureus clinical and non-clinical isolates were studied. Biofilm-forming potential was assessed using the Congo Red agar (CRA) method which describes both the presence and degree biofilm-forming potential.

Results: Majority of isolates (65.9%) did not exhibit any biofilm-forming potential using the CRA method. Biofilm-forming potential however appeared source based with 100% of non-clinical S. aureus isolates lacking biofilm-forming potential, while 58% of clinical isolates showed biofilm-forming potential. A higher proportion (65.5%) of the clinical isolates exhibiting biofilm-forming potential where associated with strong biofilm-forming potential.

Conclusion: This study reports a high association of biofilm-forming potential with S. aureus isolated from clinical rather than non-clinical settings. If this characteristic can indeed be used as a general marker of pathogenicity would however require more extensive studies.