Necessity of Tissue Culture from Clinically Uninfected Wounds in Diabetic Patients

Background: The Infectious Diseases Society of America Clinical Practice Guidelines recommends not culturing specimens from patients with diabetes who do not show clinical signs or symptoms of local inflammation. However, in diabetic patients the local or systemic inflammatory response is commonly reduced, even in severely infected cases, owing to poor immune response. This study aimed to investigate the clinical significance of tissue cultures in patients with diabetic ulcers without clinical signs of infection. Methods: This study included 248 of 1,346 patients who had diabetic foot ulcers but did not exhibit any signs or symptoms of infection in our hospital. Tissue culture results were classified as either negative, positive culture in soft tissue or positive culture in bone. Wound healing outcomes were divided into two categories: healed without amputation or healed with amputation. Results: A significant difference existed between the negative culture and bone culture-positive groups. Patients who had a positive bone culture result were 2.1 times more likely to require amputation than those who had negative culture results. Moreover, the rate of amputation was higher in bone culture-positive patients than in soft tissue culture-positive patients. Conclusion: Our study showed that tissue culture may be required for patients with diabetic ulcers even if they do not exhibit any signs or symptoms of inflammation.