Culture and metagenomics as bacterial identification methods in patients with diabetic foot ulcers: a systematic review

Background: Diabetic foot osteomyelitis (DFO) is a serious complication of infected ulcers in a diabetic patient. The identification of the infecting microorganisms is generally by culture, which causes a bias. Recently, metagenomics has been used for microbial identification. Aim: To systematically review the scientific literature related to DFO in the last 10 years to evaluate if culture and metagenomics are complementary. Material and Methods: To carry out the systematic review, PRISMA and Rayyan were used for the selection of studies, using three databases, using the keywords diabetes, osteomyelitis, culture and microbiome. Articles in English or Spanish were included, containing information related to bacterial identification in DFO. Characteristics of the technique, patients and frequency of bacterial appearance were collected. Results: Twenty six articles were included, 19 used culture and 7 metagenomics. The patients were predominantly men (68%), with an average age of 61 years, 83% had type 2 diabetes and comorbidities, mainly vascular and neuropathy. The Families with the highest frequency of appearance using the culture technique were Enterobacteriaceae (29.3%) and Staphylococcaceae(28.3%) and with metagenomics Peptoniphilaceae (22.1%) and Staphylococcaceae (9.4%). Peptoniphilaceae were not identified in culture, although they were frequently identified by metagenomics. Methicillinresistant Staphylococcus aureus, regularly identified by culture, was not identified using metagenomics. Conclusions: Comparing results, there is a certain complementarity between microbiological culture and sequencing to identify bacteria present in DFO.