A Clinicomicrobiological Study of Necrotising Fasciitis from A Tertiary Care Centre

Abstract Introduction: Necrotising fasciitis (NF) is a rapidly progressive and potentially fatal soft tissue infection marked by widespread necrosis of fascia and subcutaneous tissue. Early diagnosis, aggressive surgical debridement, and appropriate antimicrobial therapy are crucial for survival. This prospective study was conducted to evaluate the clinical presentation, microbiological profile, and antibiotic resistance patterns in patients with NF at a tertiary care hospital in South India. Methods: A prospective observational study was conducted from May 2024 to May 2025 at K R Hospital, Mysore. Sixty clinically diagnosed NF patients were included based on specific diagnostic criteria. Wound swabs or tissue samples were collected post-debridement and processed using standard microbiological techniques. Bacterial identification and antibiotic susceptibility testing were performed per CLSI guidelines. Patient demographics, comorbidities, and risk factors were analysed using SPSS version 25. Results: The majority of patients were males (70%) and aged 50–80 years. All patients were diabetic, and common comorbidities included liver disease (25%) and alcohol use (23.3%). Clinical presentation was consistent across all cases with pain, oedema, vesicles/bullae, and woody hard texture. Polymicrobial infections were predominant (66%), with Escherichia coli (26%), Pseudomonas spp. (22%), and Proteus spp. (21%) being the most common isolates. High resistance was observed to cephalosporins and fluoroquinolones across isolates. Carbapenem sensitivity was moderate (≤44% in E. coli), while piperacillin-tazobactam showed the highest sensitivity for Pseudomonas spp. (82%). Among gram-positive organisms, MRSA and MRCONS showed complete resistance to beta-lactams but retained sensitivity to doxycycline and linezolid. Conclusion: Necrotising Fasciitis in this region presents predominantly as polymicrobial infections in older diabetic males. Gram-negative bacteria were the major pathogens, exhibiting significant multidrug resistance, especially against cephalosporins and carbapenems. These findings underscore the necessity of early culture-based diagnosis and tailored antimicrobial therapy. Continuous monitoring of resistance trends is critical to improve outcomes and guide empiric treatment protocols.