MICROBIOLOGICAL PROFILE OF SURGICAL SITE INFECTIONS FOLLOWING LOWER EXTREMITY AMPUTATION IN PATIENTS WITH TYPE 2...

To characterise the microbiological profile of surgical site infections (SSI) following lower extremity amputation in patients with Type 2 diabetes mellitus and to determine the incidence of SSI and associated perioperative risk factors.

A single-centre, prospective observational cohort study enrolled 76 consecutive diabetic patients undergoing above-knee (AKA) or below-knee amputation (BKA) from May 2024 to December 2025. SSI was defined and classified per Centers for Disease Control and Prevention (CDC) criteria over a 30-day postoperative period. Wound cultures were obtained from all infected wounds. Preoperative parameters, including HbA1c, serum albumin, total leucocyte count, haematocrit, BMI, Doppler vascular assessment, and sepsis status, were analysed using the Chi-square test and independent-samples t-test.

The overall SSI incidence was 39.5% (n = 30). Culture positivity was confirmed in all 30 infected wounds, yielding 30 isolates. Gram-negative organisms predominated, accounting for 66.7% (20/30) of isolates. Escherichia coli was the most prevalent isolate (46.7%, 14/30), followed by Staphylococcus aureus and Klebsiella pneumoniae (13.3% each, 4/30), Enterobacter species (6.7%, 2/30), and Streptococcus species (6.7%, 2/30), with the remaining 13.3% (4/30) comprising other bacterial species not further speciated in this analysis (none fungal or polymicrobial). Deep SSI (30.9%, 21/68) predominated over superficial SSI (10.3%, 7/68) among BKA patients. SSI was associated with significantly prolonged postoperative stay (11.3 ± 7.3 vs. 7.09 ± 3.6 days; p = 0.001) and revision surgery in 56.7% (17/30) of cases.

The Gram-negative predominant microbiological profile, with E. coli as the leading isolate, distinguishes this local epidemiological diabetic cohort from Western series and has direct implications for empirical antibiotic selection. Standard first-generation cephalosporin prophylaxis may be inadequate; broader-spectrum coverage should be considered in deep or severe SSI.