SLR - July 2022 - Andrew Fischer, DPM
Reference: Macdonald KE, Boeckh S, Stacey HJ, Jones JD. The microbiology of diabetic foot infections: a meta-analysis. BMC Infect Dis. 2021 Aug 9;21(1):770. doi: 10.1186/s12879-021-06516-7. PMID: 34372789; PMCID: PMC8351150.Level of Evidence: II
Scientific Literature Review
Reviewed by: Andrew E Fischer, DPM
Residency Program: Hennepin Healthcare, Minneapolis, MN
Podiatric Relevance:
Diabetic limb salvage can be a large portion of the podiatric surgeon’s practice. The increasing prevalence of diabetes indicates that this will continue to be a relevant field to be well versed in. Poorly controlled diabetes can predispose patients to foot ulcers which leaves them at risk of developing an infection. Familiarity with the microbiome of a diabetic foot ulceration is helpful when choosing treatment choices for the diabetic foot from antimicrobial therapy to advanced biologics.
Methods:
This meta-analysis was performed using a search of four electronic databases from the year 1980 through the year 2019. Inclusion criteria for studies included a diagnosis of diabetes mellitus and a diabetic foot infection, primary microbiological culture results, each patient had at least on microbiologic sample, microbiological prevalence data had to be presented in full, the study was published in the English language, and the studies had to contain data for 10 or more patients. If there were any discrepancies in summary values and raw data, the studies were excluded.
Results:
A total of 112 studies were eligible for inclusion criteria. These included 76 prospective studies, 33 retrospective studies, and 3 clinical trials tested only for aerobic bacteria. The 112 studies contained microbiological prevalence data for 16,159 patients, of which 14,445 (89.4 percent) were positive for microbial growth. The three most frequently identified organisms were Staphylococcus aureus, Pseudomonas spp. and E. coli. The proportion of methicillin resistant staphylococcus aureus among these isolates was 18.0 perent. The authors also assessed the correlation between average income and infectious organism and found that there was a higher occurrence of gram-negative organisms among lower income populations and a higher occurrence of gram-positive organisms among higher income populations.
Conclusions:
As expected, the microbiology of diabetic foot infections is diverse. Globally, S. aureus is the organism most identified in diabetic foot infections, with MRSA representing 18.0 percent of S. aureus. There is a correlation between Gross National Income and diabetic foot microbiology. This may represent variations in sanitation. Knowledge of the microbiology of diabetic foot infections will help direct the development of novel therapeutics and appropriate antimicrobial therapy.