Spectrum and prevalence of fungal infections in diabetic foot wounds and the role of fluconazole in diabetic foot wound healing

Abstract

Diabetes is now a worldwide epidemic. India is one the WHO member countries with highest number of people with diabetes. The elevated serum glucose levels associated with diabetes mellitus alter host immune responses, resulting in a well-documented increase in the predisposition to infectious processes. Common sites of serious infection associated with DM include the head and neck, biliary tract, and urinary tract, as well as the skin, soft tissue, and bony structures of the feet in particular. Lower extremity wound infections are found to be the most common causes for increased mortality and morbidity of diabetic patients worldwide. It is reported that 85% of lower limb amputations are preceded by microbial infections. Currently clinical practice, only antibiotics are administered for managing a wound. The possibility of fungal infections as well as mixed microbial infections is overlooked. The prevalence rate and spectrum of fungi infecting deep tissues of diabetic lower limb wounds (DLWs) has not been previously studied. 518 (382 male and 136 female) consecutive Type-2 diabetic patients hospitalized due to infected lower limb wounds were enlisted in this study. Deep tissue (approximately 0.5 X 0.5 cm size) taken per-operatively from wound bed and was cultured for fungi. Fungal prevalence was found in 27.2 % (141/518) of the study population. Candida parapsilosis (25.5%), Candida tropicalis (22.7%), Trichosporon asahii (12.8%), Candida albicans (10.6%) and Aspergillus species (5.0%) were the most predominant fungal isolates. 17.7% of the fungal isolates were resistant to itraconazole, 6.9% to amphotericin b, 6.9% to voriconazole, 3.9% to fluconazole and 1.5% to flucytosine respectively. About 79.7% (413/518) population had bacterial infection in deep tissue. The predominant isolates were Enterococcus faecalis (14.1%), Staphylococcus aureus (12.2%) and Pseudomonas aeruginosa (10.8%). Mixed fungal and bacterial infections were seen in 21.4% of patients, while 5.8% had only fungal infection..