Temperature influences commensal-pathogen dynamics in a nasal epithelial cell co-culture model.

Chronic rhinosinusitis (CRS) is an inflammatory disease of the paranasal sinuses, and microbial dysbiosis associated with CRS is thought to be a key driver of host inflammation that contributes to disease progression. is a common upper respiratory tract (URT) pathobiont associated with higher carriage rates in CRS populations, where -secreted toxins can be identified in CRS tissues. Although many genera of bacteria colonize the URT, few account for the majority of sequencing reads.

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.

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 .

The role of nitrogen-responsive regulators in controlling inorganic polyphosphate synthesis in .

Inorganic polyphosphate (polyP) is synthesized by bacteria under stressful environmental conditions and acts by a variety of mechanisms to promote cell survival. While the kinase that synthesizes polyP (PPK, encoded by the gene) is well known, transcription is not activated by environmental stress and little is understood about how environmental stress signals lead to polyP accumulation. Previous work has shown that the transcriptional regulators DksA, RpoN (σ) and RpoE (σ) positively regulate polyP production, but not transcription, in .

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.

Streptococcus pneumoniae Binds to Host Lactate Dehydrogenase via PspA and PspC To Enhance Virulence.

Pneumococcal surface protein A (PspA) and pneumococcal surface protein C (PspC, also called CbpA) are major virulence factors of (). These surface-exposed choline-binding proteins (CBPs) function independently to inhibit opsonization, neutralize antimicrobial factors, or serve as adhesins. PspA and PspC both carry a proline-rich domain (PRD) whose role, other than serving as a flexible connector between the N-terminal and C-terminal domains, was up to this point unknown.

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.