Microbiology of superficial and deep tissues in infected diabetic gangrene.

In the current study, it is shown that, in the lesions of diabetic gangrene, there are usually mixed flora of two or more organisms. The organisms isolated from the presenting lesion may only partially reflect the organisms found in the deep tissues. Of the 58 cultures from the deep tissues, 11 of the isolates were anaerobes, but those anaerobes were never isolated as a pure culture. Bacterial synergism probably plays a role in infected diabetic gangrene. Maximizing the reduction of systemic infection and local cellulitis by elevation and appropriate antibiotic therapy results in improved wound healing in amputations of the lower extremities in patients with diabetic gangrene. However, apparent from this study, antibiotic therapy does not eradicate the organisms in the deep tissue, and surgical procedures are usually required for definitive treatment. Material from the surgically removed infected tissue should always be cultured for identification of existing organisms. When indicated, appropriate adjustment of antibiotic therapy, based upon these findings, should be prescribed.