Butyricimonas faecihominis and Eubacterium callanderi mixed bloodstream infection after appendicular peritonitis

Causal effects of gut microbiota on sepsis and sepsis-related death: insights from genome-wide Mendelian randomization, single-cell RNA, bulk RNA sequencing, and network pharmacology

BACKGROUND

Gut microbiota alterations have been implicated in sepsis and related infectious diseases, but the causal relationship and underlying mechanisms remain unclear.

METHODS

We evaluated the association between gut microbiota composition and sepsis using two-sample Mendelian randomization (MR) analysis based on published genome-wide association study (GWAS) summary statistics. Sensitivity analyses were conducted to validate the robustness of the results. Reverse MR analysis and integration of GWAS and expression quantitative trait loci (eQTL) data were performed to identify potential genes and therapeutic targets.

RESULTS

Our analysis identified 11 causal bacterial taxa associated with sepsis, with increased abundance of six taxa showing positive causal relationships. Ten taxa had causal effects on the 28-day survival outcome of septic patients, with increased abundance of six taxa showing positive associations. Sensitivity analyses confirmed the robustness of these associations. Reverse MR analysis did not provide evidence of reverse causality. Integration of GWAS and eQTL data revealed 76 genes passing the summary data-based Mendelian randomization (SMR) test. Differential expression of these genes was observed between sepsis patients and healthy individuals. These genes represent potential therapeutic targets for sepsis. Molecular docking analysis predicted potential drug-target interactions, further supporting their therapeutic potential.

CONCLUSION

Our study provides insights for the development of personalized treatment strategies for sepsis and offers preliminary candidate targets and drugs for future drug development.

Valid and accepted novel bacterial taxa derived from human clinical specimens and taxonomic revisions published in 2022

Although some nomenclature changes have caused consternation among clinical microbiologists, the discovery of novel taxa and improving classification of existing groups of organisms is exciting and adds to our understanding of microbial pathogenesis. In this mini-review, we present an in-depth summary of novel taxonomic designations and revisions to prokaryotic taxonomy that were published in 2022. Henceforth, these bacteriology taxonomic summaries will appear annually. Several of the novel Gram-positive organisms have been associated with disease, namely, the Corynebacterium kroppenstedtii-like organisms Corynebacterium parakroppenstedtii sp. nov. and Corynebacterium pseudokroppenstedtii sp. nov. A newly described Streptococcus species, Streptococcus toyakuensis sp. nov., is noteworthy for exhibiting multi-drug resistance. Among the novel Gram-negative pathogens, Vibrio paracholerae sp. nov. stands out as an organism associated with diarrhea and sepsis and has probably been co-circulating with pandemic Vibrio cholerae for decades. Many new anaerobic organisms have been described in this past year largely from genetic assessments of gastrointestinal microbiome collections. With respect to revised taxa, as discussed in previous reviews, the genus Bacillus continues to undergo further division into additional genera and reassignment of existing species into them. Reassignment of two subspecies of Fusobacterium nucleatum to species designations (Fusobacterium animalis sp. nov. and Fusobacterium vincentii sp. nov.) is also noteworthy. As was typical of previous reviews, literature updates for selected clinically relevant organisms discovered between 2017 and 2021 have been included.