Aim: To determine the prevalence of pathogens in diabetic foot infections, in relation to parameters like Wagner's grading, duration of diabetes and healing time.
Material and methods: A group of 654 (M:F, 433:221) type 2 diabetic patients with foot ulcers were studied. Specimens like pus, wound exudate and tissue were processed for smear for Gram's staining, aerobic and anaerobic culture, and biochemical identifications.
Results: In 654 diabetic patients, 728 pathogens were isolated. Aerobic pathogens were isolated in 437 (66.8%) patients and anaerobic pathogens were isolated in 217 (33.2%). As Wagner's grading increased, the prevalence of anaerobic pathogens also increased. Neuropathy was common in diabetic patients infected with both aerobic and anaerobic pathogens. Ulcers infected with anaerobic pathogens showed a longer healing time than ulcers infected with aerobic pathogens. There was no significant difference in peripheral vascular disease (PVD) in patients selected for the study. Among aerobic pathogens, Enterobacteriaceae family (48%), Staphylococcus species (spp) (18.2%), Streptococcus spp (16.8%) and Pseudomonas spp (17%) were seen frequently. Among anaerobes Peptostreptococcus spp and Clostridium spp formed 69.4%. Gram-negative anaerobes like Bacteroides spp and Fusobacterium spp were present in 30.6%. Healing time was longer when strict aerobic pathogen Pseudomonas spp and strict anaerobic pathogens were present (136.1 +/- 28.6 and 136.4 +/- 34.7 days, respectively).
Conclusions: Diabetic foot infection is polymicrobial in nature. The healing time of wound infected with anaerobic pathogens was higher than those infected with aerobic pathogens. Anaerobic pathogens increased with the Wagner's grading. Presence of neuropathy increased the risk of foot infection.