Emerging Multidrug-resistance in Surgical Site Infections: Bacteriological Profile and Antimicrobial Susceptibility Patterns in a Tertiary Care Hospital in Andhra Pradesh

Surgical site infections (SSIs) are a frequent cause of postoperative morbidity and mortality, leading to prolonged hospital stays, increased healthcare costs, and additional antibiotic use. The rising occurrence of infections caused by multidrug-resistant (MDR) organisms further complicates management. Continuous hospital-acquired infection (HAI) surveillance, adherence to infection prevention protocols, and timely surgical prophylaxis play a critical role in SSI prevention. This study aimed to determine the prevalence of SSIs in a tertiary care teaching hospital, identify the bacterial pathogens, evaluate their antimicrobial resistance patterns, and emphasize the need for targeted preventive strategies. A retrospective analysis was conducted in the Department of Microbiology, NRI General Hospital, Andhra Pradesh, India, over a two-year period (August 2023-July 2025). Postoperative patients with suspected SSIs were evaluated, and specimens were collected under aseptic precautions. Microbiological identification and antimicrobial susceptibility testing were performed using standard protocols and the VITEK 2 Compact system, following CLSI guidelines. Isolates were screened for methicillin resistance, extended-spectrum β-lactamase (ESBL) production, carbapenem resistance, and multidrug-resistance. Out of 21,952 surgeries, 50 culture-positive SSI cases were identified (0.23%). The majority occurred in the 21-40 year age group (56%) and in females (68%). Obstetrics and Gynecology accounted for most infections (58%), predominantly after emergency surgeries. The leading organism was Escherichia coli (40%), followed by Klebsiella spp. (26%) and Pseudomonas aeruginosa (12%). Resistance patterns revealed MRSA (4%), MDR (8%), ESBL producers (14%), and carbapenem resistance (14%). E. coli showed high susceptibility to tigecycline (90%) and amikacin (80%), while Klebsiella spp. and Pseudomonas spp. isolates responded best to tigecycline and carbapenems, respectively. Although SSI prevalence was low, infections were concentrated in emergency obstetric procedures and mainly caused by Gram-negative bacilli. The detection of ESBL and carbapenem-resistant strains emphasizes the need for robust infection control, antimicrobial stewardship and timely prophylactic measures to reduce SSI risk and improve outcomes.