The following is a summary of “16S rRNA seq-identified Corynebacterium promotes pyroptosis to aggravate diabetic foot ulcer,” published in the April 2024 issue of Infectious Disease by Zheng et al.

Researchers conducted a retrospective study identifying factors influencing wound healing in diabetic foot ulcers (DFU) caused by bacterial infection.

They selected DFU patients meeting the criteria and meticulously recorded clinical data. Pus exudate from foot wounds and venous blood were collected for biochemical analysis, with bacterial flora distribution analyzed using 16S rRNA sequencing. Statistical analysis was conducted to correlate DFU with pathogenic variables, pyroptosis, and immunity. The effects of key bacteria on inflammation, proliferation, apoptosis, and pyroptosis of polymorphonuclear leukocytes were investigated using ELISA, CCK-8, flow cytometry, RT-qPCR, and western blot.

The results showed a positive correlation between Wagner score and levels of inflammatory factors, along with high CD3⁺, CD4⁺, and low CD8⁺ levels in DFU patients with elevated Wagner scores. Corynebacterium constituted a significant portion of DFU cases, as determined through alpha and beta diversity and species composition analyses. Analysis using logistic regression and Pearson correlation demonstrated that mixed bacterial infections worsened foot ulcers, with bacterial count closely associated with inflammatory factors (PCT, PRT), immune cells (CD8⁺), and pyroptosis-related proteins (GSDMD, NLRP3). In vitro, Corynebacterium inhibits cell proliferation but increases inflammation (TNF-α, PCT, CRP), apoptosis, and pyroptosis (IL-1β, LDH, IL-18, GSDMD, NLRP3, caspase-3).

Investigators concluded that mixed bacterial infections dominated by Corynebacterium exacerbate DFU progression through inflammation, apoptosis, and pyroptosis, thereby inhibiting DFU healing.

Source: bmcinfectdis.biomedcentral.com/articles/10.1186/s12879-024-09235-x