Background: Leprosy continues to be an important public health concern in India, and chronic ulcers remain one of its most disabling complications. Secondary bacterial and fungal infections are frequent in these ulcers, contributing to delayed wound healing, recurrence, and disability. Limited regional data exists from Northern Karnataka regarding the microbiological spectrum of these infections and their impact on ulcer healing.

Objectives: To study the spectrum of bacterial and fungal infections in leprosy patients with ulcers and to evaluate their influence on ulcer healing outcomes.

Methods: A prospective observational study was conducted in the Department of Microbiology, in collaboration with the Department of Dermatology, Venereology & Leprosy, M. R. Medical College and Basaveshwar Teaching and General Hospital, Kalaburagi, from January to June 2025. A total of 100 leprosy patients with ulcerative lesions were enrolled. Ulcer samples were subjected to bacterial culture, antibiotic susceptibility testing (CLSI 2024 guidelines), and fungal culture. Patients were followed up for eight weeks to assess healing. Statistical analysis was performed using SPSS v26, with p < 0.05 considered significant.

Results: Pseudomonas aeruginosa (33.8%) and Staphylococcus aureus (28.7%) were the predominant bacterial isolates, while Candida albicans (46.7%) was the most common fungal isolate. Gram-negative bacilli showed high resistance to cephalosporins and fluoroquinolones but retained sensitivity to carbapenems and piperacillin-tazobactam. S. aureus isolates were uniformly sensitive to vancomycin and linezolid, though methicillin resistance was noted. Ulcers without infection healed in a mean of 4.2 weeks, whereas those with bacterial, fungal, and mixed infections required 7.1, 6.8, and 9.3 weeks, respectively. Mixed infections had the poorest outcomes, with only 50% achieving complete healing (p < 0.05).

Conclusion: Secondary bacterial and fungal infections significantly delay ulcer healing in leprosy patients, with mixed infections having the worst prognosis. Routine microbiological evaluation, including fungal studies, along with targeted antimicrobial therapy, is essential for improving healing outcomes and preventing disability in leprosy.