Bacteriology and Antimicrobial Resistance Patterns in Organisms in Surgical Site Infections in a Tertiary Care Hospital

Introduction: Surgical site infections (SSIs) are a major healthcare challenge, driven by diverse bacterial pathogens with complex resistance patterns. The rise of multidrug-resistant organisms, such as MRSA and resistant Gram-negative bacteria, necessitates ongoing surveillance and tailored antibiotic therapy. This study evaluates the bacteriology and antimicrobial resistance in SSIs to guide effective treatment and prevention strategies. Methods: This cross-sectional study, conducted at Government Medical College, Anantapuram from January to December 2023, assessed SSIs in patients over 15 years old. Wound samples were cultured and tested for antimicrobial susceptibility using standard methods. Statistical analysis was performed using SPSS version 22.0, with significance set at p<0.05. Results: The study included 200 patients, with 54% female. Culture positivity rates were 29% in males and 37% in females, with no significant difference. Diabetes mellitus (16%) and anemia (13.5%) were common risk factors. Among isolates, 43.18% were Gram-positive cocci (GPC) and 56.81% Gram-negative bacilli (GNB). GPC showed highest susceptibility to Vancomycin and GNB to Meropenem. A total of 132 multidrug-resistant strains were identified, with 43% being GNB and 31.8% GPC. Conclusion: This study reveals a high prevalence of multidrug-resistant organisms in postoperative wound infections, notably MRSA and Gram-negative bacteria like Klebsiella pneumoniae. Vancomycin effectively treated all S. aureus isolates, while GNB showed high susceptibility to imipenem, amikacin, and piperacillin-tazobactam, despite some imipenem resistance. Continuous surveillance and tailored therapy are crucial.