An oral commensal attenuates -induced airway inflammation and modulates nitrite flux in respiratory epithelium.

Respiratory infections are a leading cause of morbidity and mortality in people with cystic fibrosis (CF). These infections are polymicrobial in nature with overt pathogens and other colonizing microbes present. Microbiome data have indicated that the presence of oral commensal bacteria in the lungs is correlated with improved outcomes.

Commensal colonization reduces burden and subsequent airway damage.

dominates the complex polymicrobial cystic fibrosis (CF) airway and is a leading cause of death in persons with CF. Interestingly, oral streptococcal colonization has been associated with stable CF lung function. The most abundant streptococcal species found in stable patients, , has been shown to downregulate pro-inflammatory cytokines in multiple colonization models.

Oral Commensal Streptococci: Gatekeepers of the Oral Cavity.

Oral commensal streptococci are primary colonizers of the oral cavity. These streptococci produce many adhesins, metabolites, and antimicrobials that modulate microbial succession and diversity within the oral cavity. Often, oral commensal streptococci antagonize cariogenic and periodontal pathogens such as Streptococcus mutans and Porphyromonas gingivalis, respectively.

A Commensal Streptococcus Dysregulates the Nitrosative Stress Response.

Chronic infections in the cystic fibrosis (CF) airway are composed of both pathogenic and commensal bacteria. However, chronic infections are the leading cause of lung deterioration in individuals with CF. Interestingly, oral commensals can translocate to the CF lung and their presence is associated with improved lung function, presumably due to their ability to antagonize .

Pseudomonas aeruginosa polysaccharide Psl supports airway microbial community development.

Pseudomonas aeruginosa dominates the complex polymicrobial cystic fibrosis (CF) airway and is a leading cause of death in persons with CF. Oral streptococcal colonization has been associated with stable CF lung function. However, no studies have demonstrated how Streptococcus salivarius, the most abundant streptococcal species found in individuals with stable CF lung disease, potentially improves lung function or becomes incorporated into the CF airway biofilm.

Nitrite Triggers Reprogramming of the Oral Polymicrobial Metabolome by a Commensal Streptococcus.

Commensal streptococci regulate health and homeostasis within oral polymicrobial communities. Remarkably, high salivary nitrite concentrations have also been associated with improved health in the oral cavity. We previously demonstrated that nitrite assists hydrogen peroxide-producing oral commensal streptococci in regulating homeostasis the generation of reactive nitrogen species (RNS), which have antimicrobial activity on oral pathogens.

Disruption of Streptococcus mutans and Candida albicans synergy by a commensal streptococcus.

Polymicrobial interactions in dental plaque play a significant role in dysbiosis and homeostasis in the oral cavity. In early childhood caries, Streptococcus mutans and Candida albicans are often co-isolated from carious lesions and associated with increased disease severity. Studies have demonstrated that metabolic and glucan-dependent synergism between C.

Effects of on Microglial-Derived Extracellular Vesicle Biogenesis and Composition.

The packaging of molecular constituents inside extracellular vesicles (EVs) allows them to participate in intercellular communication and the transfer of biological molecules, however the role of EVs during bacterial infection is poorly understood. The goal of this study was to examine the effects of ( infection on the biogenesis and composition of EVs derived from the mouse microglia cell line, BV-2. BV-2 cells were cultured in exosome-free media and infected with 0, 1.

A commensal streptococcus hijacks a Pseudomonas aeruginosa exopolysaccharide to promote biofilm formation.

Pseudomonas aeruginosa causes devastating chronic pulmonary infections in cystic fibrosis (CF) patients. Although the CF airway is inhabited by diverse species of microorganisms interlaced within a biofilm, many studies focus on the sole contribution of P. aeruginosa pathogenesis in CF morbidity.

Fine-tuned production of hydrogen peroxide promotes biofilm formation of Streptococcus parasanguinis by a pathogenic cohabitant Aggregatibacter actinomycetemcomitans.

Balanced bacterial biofilm communities help to maintain host health. Disturbance of such balance can lead to bacterial dysbiosis and pathogenesis. However, complex and dynamic bacterial interactions within the biofilm communities are poorly understood.

Nitrite reductase is critical for Pseudomonas aeruginosa survival during co-infection with the oral commensal Streptococcus parasanguinis.

Pseudomonas aeruginosa is the major aetiological agent of chronic pulmonary infections in cystic fibrosis (CF) patients. However, recent evidence suggests that the polymicrobial community of the CF lung may also harbour oral streptococci, and colonization by these micro-organisms may have a negative impact on P. aeruginosa within the CF lung.

Oral streptococci and nitrite-mediated interference of Pseudomonas aeruginosa.

The oral cavity harbors a diverse community of microbes that are physiologically unique. Oral microbes that exist in this polymicrobial environment can be pathogenic or beneficial to the host. Numerous oral microbes contribute to the formation of dental caries and periodontitis; however, there is little understanding of the role these microbes play in systemic infections.

Influence of RpoN on isocitrate lyase activity in Pseudomonas aeruginosa.

Pseudomonas aeruginosa is the major aetiological agent of chronic pulmonary infections in patients with cystic fibrosis (CF). The metabolic pathways utilized by P. aeruginosa during these infections, which can persist for decades, are poorly understood.