Central Carbon Metabolism, Sodium-Motive Electron Transfer, and Ammonium Formation by the Vaginal Pathogen Prevotella bivia

An Eleven-Year Retrospective Survey of Anaerobic Bloodstream Infection in Adults in a General Hospital

Objective

During conditions accompanied by the disruption of normal mucosal barriers, anaerobic bacteria, which a part of normal human mucosal microflora, may cause various infections. In this study, clinical features of anaerobic bloodstream infections (BSI) in a general hospital in China were investigated.

Methods

Patients with anaerobic BSI were retrospectively enrolled between 2012 and 2022. Demographic data, clinical manifestations, antibiotic treatments, and disease outcomes were analyzed.

Results

In total, 391 anaerobic bacterial strains were isolated from 381 patients aged older than 11 years of age. Given that medical records of 47 patients were missing, 334 patients were included in the clinical investigation. Patients with anaerobic BSI included in the study were predominantly older than 50 years of age. Intra-abdominal infections were the most common source of anaerobic BSI (59%), followed by those of the female genital tract (10.2%) and lower respiratory tract (7.2%). Among the isolates, Bacteroides and Clostridium spp. were the most frequently isolated anaerobes. Most of the patients received antibiotic therapy. The crude mortality was 4.5%.

Conclusion

The detection rate of anaerobic BSI in Ningxia, China, remained relatively stable from 2012 to 2022. These results provide a reference for the diagnosis and empirical treatment of anaerobic BSI in this region of China. Continuous mul-ticenter studies should be conducted to monitor the incidence of anaerobic BSI and drug resistance of anaerobic isolates to improve the treatment outcomes of patients.

Prevotella, a dominant bacterium in young people with stage Ⅲ periodontitis, related to the arachidonic acid metabolism pathway

OBJECTS

As periodontitis progresses, the oral microbiome changes dynamically. The aim of this study is to evaluate the dominant bacteria of adults with stage III periodontitis and investigate potential pathways related to the dominant bacteria.

MATERIALS AND METHODS

16S rRNA sequencing was carried out to detect the differences in the oral microbiome between adult with stage Ⅰ and stage Ⅲ periodontitis and find the dominant bacteria in each group. The inhibitor of the predominant pathway for stage Ⅲ periodontitis was used to investigate the role of the dominant bacteria in periodontitis in vivo and in vitro.

RESULTS

There was no significant difference in the α-diversity between the two groups. The results of β-diversity showed that the samples were divided into different groups according to the stage of periodontitis. The dominant bacteria in youths with stage Ⅲ periodontitis was Prevotella and may be related to the arachidonic acid metabolism pathway. Administration of SKF-86002 suppressed the expression of inflammation mediators in vivo and vitro.

CONCLUSIONS

Prevotella was the one dominant bacteria in young people with stage Ⅲ periodontitis and was related to the arachidonic acid metabolism pathway.

Functionality of the Na+-translocating NADH:quinone oxidoreductase and quinol:fumarate reductase from Prevotella bryantii inferred from homology modeling

Members of the family Prevotellaceae are Gram-negative, obligate anaerobic bacteria found in animal and human microbiota. In Prevotella bryantii, the Na+-translocating NADH:quinone oxidoreductase (NQR) and quinol:fumarate reductase (QFR) interact using menaquinone as electron carrier, catalyzing NADH:fumarate oxidoreduction. P. bryantii NQR establishes a sodium-motive force, whereas P. bryantii QFR does not contribute to membrane energization. To elucidate the possible mode of function, we present 3D structural models of NQR and QFR from P. bryantii to predict cofactor-binding sites, electron transfer routes and interaction with substrates. Molecular docking reveals the proposed mode of menaquinone binding to the quinone site of subunit NqrB of P. bryantii NQR. A comparison of the 3D model of P. bryantii QFR with experimentally determined structures suggests alternative pathways for transmembrane proton transport in this type of QFR. Our findings are relevant for NADH-dependent succinate formation in anaerobic bacteria which operate both NQR and QFR.

Molecular Advances in Microbial Metabolism

Climate change, global pollution due to plastics, greenhouse gasses, or heavy metals among other pollutants, as well as limited natural sources due to unsustainable lifestyles and consumption patterns, are revealing the need for more research to understand ecosystems, biodiversity, and global concerns from the microscale to the macroscale [...].

Nuclear Magnetic Resonance Metabolomics of Symbioses between Bacterial Vaginosis-Associated Bacteria

Bacterial vaginosis (BV) is the most common vaginal infection for women of childbearing age. Although 50% of women with BV do not have any symptoms, it approximately doubles the risk of catching a sexually transmitted infection and also increases the risk of preterm delivery in pregnant women.