Microbiology and antibiotic resistance of diabetes-related foot infections in Brazil: a systematic review

INTRODUCTION: Diabetic foot infections are the main cause of lower limb amputations. Knowing the microbiology of these infections is important because the most effective empirical antibiotic therapy varies by region due to differences in the prevalence of causative pathogens. This study aimed to identify the microbiological profile and antimicrobial resistance patterns of diabetes-related foot infections in Brazil. METHODOLOGY: The study followed a systematic literature review methodology. Manuscripts in the electronic databases PubMed, SciELO and VHL were searched through November 2022. Eligible studies were retrieved using the MeSH terms "diabetic foot" AND "Brazil". Two independent evaluators selected the articles. Of the 466 titles identified, 10 observational studies met the eligibility criteria. RESULTS: All 10 studies had observational design and covered 7 Federative Units of Brazil. The sample size varied between 17 and 320 cases, and hospital inpatients predominated (9 studies). Two studies performed anaerobic cultures. Among the 1,506 isolates, more than half were Gram-negative (836/55.5%) followed by Gram-positive (624/41.4%) and anaerobic bacteria (46/3.1%). The 3 most common species were Staphylococcus aureus (251), Enterococcus faecalis (112), and Pseudomonas aeruginosa (97). Forty percent (40%) of Staphylococcus aureus isolates were methicillin-resistant (MRSA). A fifth (20%) of the Pseudomonas spp isolates were resistant to carbapenems. The prevalence of extended-spectrum beta-lactamase-producing (ESBL-producing) was 43%, 33%, and 26% for K. pneumoniae, Proteus spp, and E. coli respectively. CONCLUSIONS: In Brazil, the microbiology of foot infections in persons with diabetes showed Gram-negative predominance. Staphylococcus aureus was the most frequently isolated species with a high prevalence of MRSA.