Genetic Characterization of Methicillin-Resistant Staphylococcus aureus Isolated From Diabetic Foot Ulcers in a Tertiary Care Hospital in Mysuru, South India

Background Diabetic foot ulcers (DFUs) are common complications in diabetes patients, often leading to sepsis and leg amputation. Methicillin-resistant Staphylococcus aureus (MRSA) infections in DFUs pose challenges due to methicillin resistance with and genes. This study aims to assess the prevalence of MRSA in clinical isolates from DFUs, analyze the antibiogram of MRSA isolates, and detect the presence of the and genes among MRSA isolates. Methodology The isolated colonies were identified and antimicrobial susceptibility was performed using the Vitek-2 Compact system. Methicillin resistance was also confirmed through the disc diffusion method. Confirmed methicillin-resistant isolates were subjected to real-time polymerase chain reaction (RT-PCR) to detect and genes. Results A total of 474 purulent samples from DFUs yielded 541 distinct isolates, comprising 201 gram-positive and 340 gram-negative organisms. Among the gram-positive organisms, species predominated, with 79 isolates, 34 of which were methicillin-resistant. All MRSA isolates (100%) were sensitive to tetracycline, linezolid, teicoplanin, and vancomycin, and 94% were sensitive to cotrimoxazole but least susceptible to ciprofloxacin and levofloxacin. RT-PCR confirmed the presence of genes in all 34 isolates and genes in three isolates. Conclusions The presence of in all 34 MRSA isolates underscores consistent methicillin resistance. The co-occurrence of and in three isolates hints at genetic diversity. Two MRSA isolates positive for were isolated from rural patients involved in farming and animal husbandry, suggesting an occupational risk. The third patient was from a non-rural area, indicating potential alternative transmission pathways warranting further investigation.