Investigation Of Biofilm Formation And Presence Of IcaA/D Genes In Staphylococcal Isolates

Abstract

Background: Biofilm formation in staphylococci is critical due to its role in antibiotic resistance and persistence in clinical settings. Biofilms enhance bacterial survival by conferring resistance to drugs and facilitating evasion of the host's immunological systems.  Aim: This study focused on assessing biofilm formation in clinical Staphylococcus isolates and examining the presence of icaA/D genes to gain insights into their role in infection severity and persistence.  Methods: This cross-sectional study analyzed 109 staphylococcal isolates (41 Staphylococcus aureus and 68 Staphylococcus epidermidis) obtained from a variety of clinical specimens between 2022 and 2023 in the Department of Microbiology at Integral Institute of Medical Science & Research, Lucknow.  Slime production was assessed phenotypically using Congo red agar, and genotypic analysis for the presence of icaA/D genes was performed via PCR with specific primers under standardized conditions. Statistical analysis including chi-square tests were used to compare biofilm production rates between the two species.  Results: Out of the 41 S. aureus isolates, 60.97% (25/41) demonstrated biofilm production using the CRA method. In contrast, 88.23% (60/68) of the S. epidermidis isolates were biofilm producers, a significantly higher rate (p < 0.05). The icaA/D genes were detected in 68.3% of the S. aureus isolates and in 88.23% of the S. epidermidis isolates. A positive correlation was observed between slime production and the presence of icaA/D genes (p < 0.05).  Conclusion: The high incidence of biofilm production in clinically isolated staphylococci highlights the need for enhanced infection control measures.  Strategies such as the use of biofilm-disrupting agents and rigorous sterilization protocols should be prioritized to reduce biofilm formation on healthcare devices and clinical settings, thus limiting infection risks and the spread of antibiotic-resistant strains.