Detection of Biofilm Production and Antibiotic Susceptibility Pattern of Staphylococci from Various Clinical Specimens at a Tertiary Care Hospital

Background: Staphylococci are among the most common causes of healthcare-associated infections. Biofilm formation is an important virulence factor that contributes to antimicrobial resistance, persistence of infection, and treatment failure, particularly in methicillin-resistant strains. Objectives: To determine the prevalence of biofilm production among clinical isolates of Staphylococcus aureus and coagulase-negative staphylococci (CoNS) and to study their antimicrobial susceptibility patterns with special reference to methicillin resistance. Materials and Methods: A prospective study was conducted over a period of 18 months in a tertiary care hospital. A total of 150 clinically significant Staphylococcal isolates obtained from various clinical specimens were identified using standard microbiological methods. Antimicrobial susceptibility testing was performed by the Kirby–Bauer disk diffusion method as per CLSI guidelines. Methicillin resistance was detected using the cefoxitin disc. Biofilm production was assessed by the tissue culture plate (TCP) method. Results: Of the 150 isolates, 87 (58%) were Staphylococcus aureus and 63 (42%) were CoNS. Methicillin resistance was observed in 86 (57.3%) isolates, with MRSA accounting for 57.5% of S. aureus. Biofilm production was detected in 69 (46%) isolates, comprising 10 (6.7%) strong and 59 (39.3%) moderate biofilm producers. Biofilm production was significantly higher among methicillin-resistant isolates (70.9%) compared to methicillin-sensitive isolates (12.5%) (p < 0.002). Biofilm-producing isolates showed higher resistance to commonly used antibiotics such as penicillin, erythromycin, ciprofloxacin, and cotrimoxazole. All isolates were susceptible to vancomycin and linezolid. Conclusion: Biofilm production is common among clinical Staphylococcal isolates and is strongly associated with methicillin resistance and multidrug resistance. Routine detection of biofilm formation along with antimicrobial susceptibility testing is essential for effective management of Staphylococcal infections and for strengthening infection control practices in hospital settings.