Bacteriological study of diabetic foot ulcers.

Bacteriological study of 61 patients with diabetic gangrene or non-gangrenous foot ulcers was undertaken to determine the pattern of infection and antimicrobial susceptibility with a view to suggest optimal antibiotic therapy for these patients. Gangrenous ulcers showed a higher frequency of mixed infection; the predominant organisms being enterococci, Proteus sp., Pseudomonas sp. and Klebsiella sp. Infected non-gangrenous ulcers showed Staph. pyogenes, and beta haemolytic Streptococcus as single organism in 12 patients. Anaerobes were more frequently isolated in gangrenous lesions than in non-gangrenous ulcers. Antimicrobial susceptibility showed that gram positive organisms were sensitive to co-trimoxazole, cephaloridine, ampicillin and penicillin. Gram negative aerobic bacilli were sensitive to gentamycin, chloramphenicol, cotrimoxazole and streptomycin. Anaerobes were sensitive to chloramphenicol, clindamycin and metronidazole. Antibiotics of choice for gangrenous lesions with spreading infection and septicaemia are a combination of gentamycin, ampicillin and metronidazole as an adjuvant to surgical treatment.