Bacteriological Profile and Antimicrobial Resistance Patterns of Skin and Soft-tissue Infections: A Five-year Retrospective Study

Introduction: Skin and Soft-Tissue Infections (SSTIs) constitute a major burden of infectious diseases and are among the most common conditions encountered in clinical practice. The emergence and rapid spread of antimicrobial resistance among pathogens causing SSTIs have significantly limited therapeutic options, increasing morbidity, prolonging hospital stays, and raising healthcare costs. Periodic surveillance of the bacteriological profile and antimicrobial susceptibility patterns of pus isolates is essential to guide empirical therapy and strengthen antimicrobial stewardship in tertiary care settings. Aim: To determine the bacteriological profile and antimicrobial resistance patterns of pathogens isolated from SSTI. Materials and Methods: This retrospective observational study was conducted in the Department of Microbiology, BJ Government Medical College and Sassoon General Hospital, Pune, Maharashtra, India, from January 2020 to December 2024. Laboratory records of pus samples received were reviewed. Data extraction, compilation and analysis were performed between October 2025 and January 2026. Bacterial isolates were identified using standard microbiological techniques, and antimicrobial susceptibility was assessed by standardised antimicrobial susceptibility testing methods. The bacteriological profile, antimicrobial resistance patterns, and prevalence of Multidrug-Resistant (MDR), Extensively Drug-Resistant (XDR), Carbapenem-Resistant Enterobacterales (CRE), MethicillinResistant Staphylococcus aureus (MRSA), and ExtendedSpectrum b-Lactamase (ESBL)-producing isolates were assessed. Data were analysed using descriptive statistics and the Chi-square test for trend where applicable. A p-value<0.05 was considered statistically significant. Results: A total of 18,391 pus samples were received and wound swabs processed; 10,264 (55.8%) showed significant bacterial growth. Gram Negative Bacilli (GNB) predominated, accounting for 8,039 (78.3%) isolates, while Gram positive Cocci (GPC) constituted 2,225 (21.7%). Escherichia coli 2638 (25.7%) was the most common Gram negative isolate, followed by Klebsiella pneumoniae 2361 (23.0%) and Pseudomonas aeruginosa 1540 (15%). Among GPC, Staphylococcus aureus was predominant 1755 (17.1%). A high burden of antimicrobial resistance was observed, with 7,027 (68.4%) isolates classified as MDR and 5,071 (49.4%) as XDR. Extended-spectrum betalactamase production was noted in 4,697 (58.4%) of Gram negative isolates, and carbapenem resistance was observed in 3,085 (38.4%). Among S. aureus isolates, 1,038 (59.1%) were MRSA. Conclusion: The study demonstrated a predominance of gram negative pathogens and a high prevalence of MDR among bacteria causing SSTI. High burdens of MDR, XDR, ESBLproducing, and carbapenem-resistant organisms were observed, with statistically significant increasing trends identified for selected organisms and resistance phenotypes.