Publications by authors named "Ryan C Hunter"

Article Synopsis
  • This study investigates how chronic lung diseases influence the development of chronic lung allograft dysfunction (CLAD) in lung transplant recipients, focusing on the molecular and microbial changes in their bronchoalveolar lavage fluid (BALF).
  • Researchers analyzed BALF samples from 195 lung transplant patients over 10 years using advanced sequencing and metabolomics techniques, revealing significant differences in microbiome and metabolome profiles based on the underlying lung disease.
  • Results show that specific microbial species like Pseudomonas in cystic fibrosis and unique metabolites in alpha-1-antitrypsin disease correlate with CLAD development, suggesting that tailored treatment strategies could improve long-term outcomes for lung transplant patients.
View Article and Find Full Text PDF

Bacterial resistance to antibiotics is a rapidly increasing threat to human health. New strategies to combat resistant organisms are desperately needed. One potential avenue is targeting two-component systems, which are the main bacterial signal transduction pathways used to regulate development, metabolism, virulence, and antibiotic resistance.

View Article and Find Full Text PDF
Article Synopsis
  • Commensal anaerobic bacteria can have similar levels to harmful pathogens in chronic respiratory infections, influencing how pathogens behave by competing for resources and producing toxic byproducts.
  • The study highlights how short chain fatty acids (SCFAs) like propionate and butyrate disrupt important fatty acid metabolism, leading to reduced bacterial growth and higher sensitivity to antibiotics.
  • These metabolic changes suggest that the composition of the airway microbiome, along with the metabolites they generate, can directly affect which pathogens thrive, indicating that combining SCFAs with traditional antibiotics could enhance treatment effectiveness.
View Article and Find Full Text PDF

Predicting evolution in microbial communities is critical for problems from human health to global nutrient cycling. Understanding how species interactions impact the distribution of fitness effects for a focal population would enhance our ability to predict evolution. Specifically, does the type of ecological interaction, such as mutualism or competition, change the average effect of a mutation (i.

View Article and Find Full Text PDF

Immigration to a highly industrialized nation has been associated with metabolic disease and simultaneous shifts in microbiota composition, but the underlying mechanisms are challenging to test in human studies. Here, we conducted a pilot study to assess the differential effects of human gut microbiota collected from the United States (US) and rural Thailand on the murine gut mucosa and immune system. Colonization of germ-free mice with microbiota from US individuals resulted in an increased accumulation of innate-like CD8 T cells in the small intestine lamina propria and intra-epithelial compartments when compared to colonization with microbiota from Thai individuals.

View Article and Find Full Text PDF

Background: Stent encrustation with debris and mucostasis is a significant cause of airway injury and comorbidity, leading to ~25% of stent exchanges (1-3). Previous work from our group has shown that the experimental coating can reduce mucous adhesion in bench testing and demonstrated a signal for reducing airway injury and mucostasis in a feasibility study.

Objectives: The aim of this study is to continue our inquiry in a randomized, single-blinded multi-animal trial to investigate the degree of airway injury and mucostasis using silicone stents with and without this specialized coating.

View Article and Find Full Text PDF

Organic acids (short chain fatty acids, amino acids, etc.) are common metabolic byproducts of commensal bacteria of the gut and oral cavity in addition to microbiota associated with chronic infections of the airways, skin, and soft tissues. A ubiquitous characteristic of these body sites in which mucus-rich secretions often accumulate in excess, is the presence of mucins; high molecular weight (HMW), glycosylated proteins that decorate the surfaces of non-keratinized epithelia.

View Article and Find Full Text PDF

Predicting evolution in microbial communities is critical for problems from human health to global nutrient cycling. Understanding how species interactions impact the distribution of fitness effects for a focal population would enhance our ability to predict evolution. Specifically, it would be useful to know if the type of ecological interaction, such as mutualism or competition, changes the average effect of a mutation (i.

View Article and Find Full Text PDF

Bacterial resistance to antibiotics is a rapidly increasing threat to human health. New strategies to combat resistant organisms are desperately needed. One potential avenue is targeting two-component systems, which are the main bacterial signal transduction pathways used to regulate development, metabolism, virulence, and antibiotic resistance.

View Article and Find Full Text PDF

is associated with resilient nosocomial infections, with bacteraemia, pneumonia and chronic cystic fibrosis lung infection being the most common clinical presentations. Innate multi-drug resistance and a suite of virulence factors select for infection during long-term antibiotic therapy, contributing to its persistence, treatment recalcitrance, association with poor clinical outcomes and emergence as a problematic pathogen. Horizontal gene transfer and maintenance of large genomes underpin the resilience and cosmopolitan lifestyle of , and complicate its phylogenetic characterization.

View Article and Find Full Text PDF

Different effector arms of the immune system are optimized to protect from different classes of pathogens. In some cases, pathogens manipulate the host immune system to promote the wrong type of effector response-a phenomenon known as immune deviation. Typically, immune deviation helps pathogens to avoid destructive immune responses.

View Article and Find Full Text PDF
Article Synopsis
  • Influenza A viruses (IAV) can lead to serious health issues in humans, causing systemic inflammation and damage to the intestines during respiratory infections.
  • During active IAV infection, tuft cells in the small intestine increase, but this increase doesn't improve health outcomes, as baseline tuft cell numbers return after the viral clearance.
  • The changes in tuft cell and innate lymphoid cell (ILC) populations in the intestines during IAV infection may reveal new insights into how such infections can affect people with underlying health issues.
View Article and Find Full Text PDF

Chronic rhinosinusitis (CRS) is characterized by immune dysfunction, mucus hypersecretion, and persistent infection of the paranasal sinuses. While Staphylococcus aureus is a primary CRS pathogen, recent sequence-based surveys have found increased relative abundances of anaerobic bacteria, suggesting that S. aureus may experience altered metabolic landscapes in CRS relative to healthy airways.

View Article and Find Full Text PDF

Emerging viruses threaten global health, but few experimental models can characterize the virus and host factors necessary for within- and cross-species transmission. Here, we leverage a model whereby pet store mice or rats-which harbor natural rodent pathogens-are cohoused with laboratory mice. This "dirty" mouse model offers a platform for studying acute transmission of viruses between and within hosts via natural mechanisms.

View Article and Find Full Text PDF

We report the draft genome sequence of Scheffersomyces spartinae ARV011, which was isolated from the Great Sippewissett Marsh in Falmouth, Massachusetts. Sequencing was performed using the Illumina NovaSeq 6000 platform, yielding 7,598,030 read pairs 250 bp in length. This resulted in a total draft genome size of 12,132,557 bp.

View Article and Find Full Text PDF

Staphylococcus aureus is associated with the development of persistent and severe inflammatory diseases of the upper airways. Yet, S. aureus is also carried asymptomatically in the sinonasal cavity of ∼50% of healthy adults.

View Article and Find Full Text PDF

Chronic rhinosinusitis (CRS) affects nearly all individuals with cystic fibrosis (CF) and is thought to serve as a reservoir for microbiota that subsequently colonize the lung. To better understand the microbial ecology of CRS, we generated a 16S rRNA gene sequencing profile of sinus mucus from CF-CRS patients. We show that CF-CRS sinuses harbor bacterial diversity not entirely captured by clinical culture.

View Article and Find Full Text PDF

The human airway epithelium is the initial site of SARS-CoV-2 infection. We used flow cytometry and single cell RNA-sequencing to understand how the heterogeneity of this diverse cell population contributes to elements of viral tropism and pathogenesis, antiviral immunity, and treatment response to remdesivir. We found that, while a variety of epithelial cell types are susceptible to infection, ciliated cells are the predominant cell target of SARS-CoV-2.

View Article and Find Full Text PDF

Mucin glycoproteins confer robust protection against infection by regulating bacterial behavior and virulence gene expression, but the mechanistic bases are poorly understood. New work implicates glycan-based signaling through a carbohydrate-binding sensor kinase in mediating pathogen behavior at the mucosal interface.

View Article and Find Full Text PDF

The human airway epithelium is the initial site of SARS-CoV-2 infection. We used flow cytometry and single cell RNA-sequencing to understand how the heterogeneity of this diverse cell population contributes to elements of viral tropism and pathogenesis, antiviral immunity, and treatment response to remdesivir. We found that, while a variety of epithelial cell types are susceptible to infection, ciliated cells are the predominant cell target of SARS-CoV-2.

View Article and Find Full Text PDF

Chronic rhinosinusitis (CRS) is characterized by complex bacterial infections with persistent inflammation. Based on our rabbit model of sinusitis, blockage of sinus ostia generated a shift in microbiota to a predominance of mucin degrading microbes (MDM) with acute inflammation at 2 weeks. This was followed by conversion to chronic sinus inflammation at 3 months with a robust increase in pathogenic bacteria (e.

View Article and Find Full Text PDF

Culture-independent studies of cystic fibrosis lung microbiota have provided few mechanistic insights into the polymicrobial basis of disease. Deciphering the specific contributions of individual taxa to CF pathogenesis requires comprehensive understanding of their ecophysiology at the site of infection. We hypothesize that only a subset of CF microbiota are translationally active and that these activities vary between subjects.

View Article and Find Full Text PDF

Background: Despite availability of ceftolozane-tazobactam (C/T) and ceftazidime-avibactam (CZA) for several years, the individual spectrum of activity of each agent may not be widely known. We compared the activity of C/T and CZA against convenience samples of 119 extended-spectrum β-lactamase (ESBL)-producing Enterobacterales and 60 β-lactam-resistant Pseudomonas aeruginosa clinical isolates collected from three U.S.

View Article and Find Full Text PDF

A critical limitation in the management of chronic polymicrobial infections is the lack of correlation between antibiotic susceptibility testing (AST) and patient responses to therapy. Underlying this disconnect is our inability to accurately recapitulate the environment and complex polymicrobial communities However, emerging evidence suggests that, if modeled and tested accurately, interspecies relationships can be exploited by conventional antibiotics predicted to be ineffective by standard AST. As an example, under conditions where relies on cocolonizing organisms for nutrients (i.

View Article and Find Full Text PDF

Chronic rhinosinusitis (CRS) is persistent inflammation and/or infection of the nasal cavity and paranasal sinuses. Recent advancements in culture-independent molecular techniques have enhanced understanding of interactions between sinus microbiota and upper airway microenvironment. The dysbiosis hypothesis-alteration of microbiota associated with perturbation of the local ecological landscape-is suggested as a mechanism involved in CRS pathogenesis.

View Article and Find Full Text PDF