Browsing by Subject "Microbiome"
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Item 1735. The Pig Skin Commensal D. incerta Exhibits Antimicrobial Activity Against Methicillin-Resistant Staphylococcus aureus(Oxford University Press, 2022) Wei, Monica; Knight, Simon; Flowers, Laurice; Walsh, Jasmine; Grice, Elizabeth A.; Medicine, School of MedicineBackground: Methicillin-resistant Staphylococcus aureus (MRSA) infections occur commonly on skin and cause significant healthcare burden. MRSA can also stably colonize the skin and nasal passages, contributing to community spread. This colonization results in long-term interaction with the skin microbiome, which harbors a diverse community of bacteria that often use antimicrobial molecules to compete for ecologic niches. We hypothesize that the skin microbiome contains bacteria that secrete novel antimicrobial agents against MRSA. Methods: Pigs are an established model organism for skin whose microbiome is not well explored. We mined the pig skin microbiome for bacterial species that inhibited MRSA via a modified disc diffusion assay. Results: We find that the novel pig skin commensal D. incerta inhibits USA300 strain MRSA via a secreted antimicrobial protein that can be isolated from cell-free supernatant. Analysis of the D. incerta genome shows little homology to known antimicrobial genes clusters. The identity of the antimicrobial molecule and whether its antimicrobial activity persists in the context of MRSA skin infection remain unclear. We characterize the identity of this antimicrobial molecule via parallel genomic and biochemical approaches. Finally, we propose to test the ability of D. incerta to impede MRSA colonization and improve healing of MRSA-mediated skin infection, two clinically important skin conditions. Conclusion: We screened the pig skin microbiome and successfully identified bacterial inhibitors of MRSA. Preliminary data suggest that the pig skin commensal D. incerta secretes a novel antimicrobial protein. Our current efforts focus on identifying this antimicrobial molecule and investigating its therapeutic potential in animal models of skin.Item Acyloxyacyl hydrolase is a host determinant of gut microbiome-mediated pelvic pain(The American Physiological Society, 2021) Rahman-Enyart, Afrida; Yang, Wenbin; Yaggie, Ryan E.; White, Bryan A.; Welge, Michael; Auvil, Loretta; Berry, Matthew; Bushell, Colleen; Rosen, John M.; Rudick, Charles N.; Schaeffer, Anthony J.; Klumpp, David J.; Pharmacology and Toxicology, School of MedicineDysbiosis of gut microbiota is associated with many pathologies, yet host factors modulating microbiota remain unclear. Interstitial cystitis/bladder pain syndrome (IC/BPS) is a debilitating condition of chronic pelvic pain often with comorbid urinary dysfunction and anxiety/depression, and recent studies find fecal dysbiosis in patients with IC/BPS. We identified the locus encoding acyloxyacyl hydrolase, Aoah, as a modulator of pelvic pain severity in a murine IC/BPS model. AOAH-deficient mice spontaneously develop rodent correlates of pelvic pain, increased responses to induced pelvic pain models, voiding dysfunction, and anxious/depressive behaviors. Here, we report that AOAH-deficient mice exhibit dysbiosis of gastrointestinal (GI) microbiota. AOAH-deficient mice exhibit an enlarged cecum, a phenotype long associated with germ-free rodents, and a "leaky gut" phenotype. AOAH-deficient ceca showed altered gene expression consistent with inflammation, Wnt signaling, and urologic disease. 16S sequencing of stool revealed altered microbiota in AOAH-deficient mice, and GC-MS identified altered metabolomes. Cohousing AOAH-deficient mice with wild-type mice resulted in converged microbiota and altered predicted metagenomes. Cohousing also abrogated the pelvic pain phenotype of AOAH-deficient mice, which was corroborated by oral gavage of AOAH-deficient mice with stool slurry of wild-type mice. Converged microbiota also alleviated comorbid anxiety-like behavior in AOAH-deficient mice. Oral gavage of AOAH-deficient mice with anaerobes cultured from IC/BPS stool resulted in exacerbation of pelvic allodynia. Together, these data indicate that AOAH is a host determinant of normal gut microbiota, and dysbiosis associated with AOAH deficiency contributes to pelvic pain. These findings suggest that the gut microbiome is a potential therapeutic target for IC/BPS.Item Alcohol-induced gut microbial reorganization and associated overproduction of phenylacetylglutamine promotes cardiovascular disease(Springer Nature, 2024-12-30) Li, Zhen; Gu, Min; Zaparte, Aline; Fu, Xiaoming; Mahen, Kala; Mrdjen, Marko; Li, Xinmin S.; Yang, Zhihong; Ma, Jing; Thoudam, Themis; Chandler, Kristina; Hesler, Maggie; Heathers, Laura; Gorse, Kiersten; Van, Thanh Trung; Wong, David; Gibson, Aaron M.; Wang, Zeneng; Taylor, Christopher M.; Quijada, Pearl; Makarewich, Catherine A.; Hazen, Stanley L.; Liangpunsakul, Suthat; Brown, J. Mark; Lefer, David J.; Welsh, David A.; Sharp, Thomas E., III; Medicine, School of MedicineThe mechanism(s) underlying gut microbial metabolite (GMM) contribution towards alcohol-mediated cardiovascular disease (CVD) is unknown. Herein we observe elevation in circulating phenylacetylglutamine (PAGln), a known CVD-associated GMM, in individuals living with alcohol use disorder. In a male murine binge-on-chronic alcohol model, we confirm gut microbial reorganization, elevation in PAGln levels, and the presence of cardiovascular pathophysiology. Fecal microbiota transplantation from pair-/alcohol-fed mice into naïve male mice demonstrates the transmissibility of PAGln production and the CVD phenotype. Independent of alcohol exposure, pharmacological-mediated increases in PAGln elicits direct cardiac and vascular dysfunction. PAGln induced hypercontractility and altered calcium cycling in isolated cardiomyocytes providing evidence of improper relaxation which corresponds to elevated filling pressures observed in vivo. Furthermore, PAGln directly induces vascular endothelial cell activation through induction of oxidative stress leading to endothelial cell dysfunction. We thus reveal that the alcohol-induced microbial reorganization and resultant GMM elevation, specifically PAGln, directly contributes to CVD.Item Altered microbial biogeography in an innate model of colitis(Taylor & Francis, 2022) Boger-May, Antonia; Reed, Theodore; LaTorre, Diana; Ruley-Haase, Katelyn; Hoffman, Hunter; English, Lauren; Roncagli, Connor; Overstreet, Anne-Marie; Boone, David; Microbiology and Immunology, School of MedicineChanges in the spatial organization, or biogeography, of colonic microbes have been observed in human inflammatory bowel disease (IBD) and mouse models of IBD. We have developed a mouse model of IBD that occurs spontaneously and consistently in the absence of adaptive immunity. Mice expressing tumor necrosis factor-induced protein 3 (TNFAIP3) in intestinal epithelial cells (villin-TNFAIP3) develop colitis when interbred with Recombination Activating 1-deficient mice (RAG1−/−). The colitis in villin-TNFAIP3 × RAG1−/− (TRAG) mice is prevented by antibiotics, indicating a role for microbes in this innate colitis. We therefore explored the biogeography of microbes and responses to antibiotics in TRAG colitis. Laser capture microdissection and 16S rRNA sequencing revealed altered microbial populations across the transverse axis of the colon as the inner mucus layer of TRAG, but not RAG1−/−, mice was infiltrated by microbes, which included increased abundance of the classes Gammaproteobacteria and Actinobacteria. Along the longitudinal axis differences in the efficacy of antibiotics to prevent colitis were evident. Neomycin was most effective for prevention of inflammation in the cecum, while ampicillin was most effective in the proximal and distal colon. RAG1−/−, but not TRAG, mice exhibited a structured pattern of bacterial abundance with decreased Firmicutes and Proteobacteria but increased Bacteroidetes along the proximal to distal axis of the gut. TRAG mice exhibited increased relative abundance of potential pathobionts including Bifidobacterium animalis along the longitudinal axis of the gut whereas others, like Helicobacter hepaticus were increased only in the cecum. Potential beneficial organisms including Roseburia were decreased in the proximal regions of the TRAG colon, while Bifidobacterium pseudolongulum was decreased in the TRAG distal colon. Thus, the innate immune system maintains a structured, spatially organized, gut microbiome along the transverse and longitudinal axis of the gut, and disruption of this biogeography is a feature of innate immune colitis.Item Altered Tissue Specialized Pro-Resolving Mediators in Chronic Rhinosinusitis(Elsevier, 2021) Vickery, Thad W.; Armstrong, Michael; Kofonow, Jennifer M.; Robertson, Charles E.; Kroehl, Miranda E.; Reisdorph, Nichole A.; Ramakrishnan, Vijay R.; Frank, Daniel N.; Otolaryngology -- Head and Neck Surgery, School of MedicineCurrent literature implicates arachidonic acid-derived leukotrienes and prostaglandins in the pathogenesis of chronic rhinosinusitis. However, other omega-3 and omega-6 derived lipid mediators, such as specialized pro-resolving mediators (SPMs), may also be important in chronic inflammatory disorders of the upper airway. We hypothesize that SPMs differ among CRS subtypes compared to controls and in relation to sinonasal microbiota. Ethmoid sinus tissue and middle meatal swabs were collected from a convenience sample of 66 subjects, including non-CRS controls, CRS with polyps (CRSwNP), and CRS without polyps (CRSsNP). Lipid mediator pathways were analyzed by liquid chromatography/tandem mass spectrometry. Bacterial taxa were profiled in parallel by 16S rRNA gene sequencing. Resolvin D2 was elevated in both CRSwNP (p = 0.00076) and CRSsNP (p = 0.030) compared with non-CRS controls. Lipoxin A4 was significantly increased in CRSwNP compared with CRSsNP (p = 0.000033) and controls (p = 0.044). Cigarette smoking was associated with significantly lower concentrations of several 15-lipoxygenase metabolites including resolvin D1 (p = 0.0091) and resolvin D2 (p = 0.0097), compared with never-smokers. Several of the lipid compounds also correlated with components of the sinonasal mucosal microbiota, including bacterial pathogens such as Pseudomonas aeruginosa. These data suggest that dysfunctional lipid mediator pathways in CRS extend beyond the traditional descriptions of leukotrienes and prostaglandins and include SPMs. Furthermore, dysregulated SPM signaling may contribute to persistent inflammation and bacterial colonization in CRS.Item The Application of Metabolomics to Probiotic and Prebiotic Interventions in Human Clinical Studies(MDPI, 2020-03) O’Connell, Thomas M.; Otolaryngology -- Head and Neck Surgery, School of MedicineThere is an ever-increasing appreciation for our gut microbiota that plays a crucial role in the maintenance of health, as well as the development of disease. Probiotics are live bacteria that are consumed to increase the population of beneficial bacteria and prebiotics are dietary substrates intended to promote the propagation of beneficial bacteria. In order to optimize the use of probiotics and prebiotics, a more complete biochemical understanding of the impact that these treatments have on the community and functioning of the gut microbiota is required. Nucleic acid sequencing methods can provide highly detailed information on the composition of the microbial communities but provide less information on the actual function. As bacteria impart much of their influence on the host through the production of metabolites, there is much to be learned by the application of metabolomics. The focus of this review is on the use of metabolomics in the study of probiotic and prebiotic treatments in the context of human clinical trials. Assessment of the current state of this research will help guide the design of future studies to further elucidate the biochemical mechanism by which probiotics and prebiotics function and pave the way toward more personalized applications.Item Association of Baseline Luminal Narrowing With Ileal Microbial Shifts and Gene Expression Programs and Subsequent Transmural Healing in Pediatric Crohn Disease(Oxford University Press, 2021) Ta, Allison D.; Ollberding, Nicholas J.; Karns, Rebekah; Haberman, Yael; Alazraki, Adina L.; Hercules, David; Baldassano, Robert; Markowitz, James; Heyman, Melvin B.; Kim, Sandra; Kirschner, Barbara; Shapiro, Jason M.; Noe, Joshua; Oliva-Hemker, Maria; Otley, Anthony; Pfefferkorn, Marian; Kellermayer, Richard; Snapper, Scott; Rabizadeh, Shervin; Xavier, Ramnik; Dubinsky, Marla; Hyams, Jeffrey; Kugathasan, Subra; Jegga, Anil G.; Dillman, Jonathan R.; Denson, Lee A.; Pediatrics, School of MedicineBackground: Transmural healing (TH) is associated with better long-term outcomes in Crohn disease (CD), whereas pretreatment ileal gene signatures encoding myeloid inflammatory responses and extracellular matrix production are associated with stricturing. We aimed to develop a predictive model for ileal TH and to identify ileal genes and microbes associated with baseline luminal narrowing (LN), a precursor to strictures. Materials and methods: Baseline small bowel imaging obtained in the RISK pediatric CD cohort study was graded for LN. Ileal gene expression was determined by RNASeq, and the ileal microbial community composition was characterized using 16S rRNA amplicon sequencing. Clinical, demographic, radiologic, and genomic variables were tested for association with baseline LN and future TH. Results: After controlling for ileal location, baseline ileal LN (odds ratio [OR], 0.3; 95% confidence interval [CI], 0.1-0.8), increasing serum albumin (OR, 4; 95% CI, 1.3-12.3), and anti-Saccharomyces cerevisiae antibodies IgG serology (OR, 0.97; 95% CI, 0.95-1) were associated with subsequent TH. A multivariable regression model including these factors had excellent discriminant power for TH (area under the curve, 0.86; positive predictive value, 80%; negative predictive value, 87%). Patients with baseline LN exhibited increased Enterobacteriaceae and inflammatory and extracellular matrix gene signatures, coupled with reduced levels of butyrate-producing commensals and a respiratory electron transport gene signature. Taxa including Lachnospiraceae and the genus Roseburia were associated with increased respiratory and decreased inflammatory gene signatures, and Aggregatibacter and Blautia bacteria were associated with reduced extracellular matrix gene expression. Conclusions: Pediatric patients with CD with LN at diagnosis are less likely to achieve TH. The association between specific microbiota, wound healing gene programs, and LN may suggest future therapeutic targets.Item Composition and Functional Potential of the Human Mammary Microbiota Prior to and Following Breast Tumor Diagnosis(American Society for Microbiology, 2022) Hoskinson, Courtney; Zheng, Kelly; Gabel, Jaelyn; Kump, Annie; German, Rana; Podicheti, Ram; Marino, Natascia; Stiemsma, Leah T.; Medicine, School of MedicineMicrobiota studies have reported changes in the microbial composition of the breast upon cancer development. However, results are inconsistent and limited to the later phases of cancer development (after diagnosis). We analyzed and compared the resident bacterial taxa of histologically normal breast tissue (healthy, H, n = 49) with those of tissues donated prior to (prediagnostic, PD, n = 15) and after (adjacent normal, AN, n = 49, and tumor, T, n = 46) breast cancer diagnosis (n total = 159). DNA was isolated from tissue samples and submitted for Illumina MiSeq paired-end sequencing of the V3-V4 region of the 16S gene. To infer bacterial function in breast cancer, we predicted the functional bacteriome from the 16S sequencing data using PICRUSt2. Bacterial compositional analysis revealed an intermediary taxonomic signature in the PD tissue relative to that of the H tissue, represented by shifts in Bacillaceae, Burkholderiaceae, Corynebacteriaceae, Streptococcaceae, and Staphylococcaceae. This compositional signature was enhanced in the AN and T tissues. We also identified significant metabolic reprogramming of the microbiota of the PD, AN, and T tissue compared with the H tissue. Further, preliminary correlation analysis between host transcriptome profiling and microbial taxa and genes in H and PD tissues identified altered associations between the human host and mammary microbiota in PD tissue compared with H tissue. These findings suggest that compositional shifts in bacterial abundance and metabolic reprogramming of the breast tissue microbiota are early events in breast cancer development that are potentially linked with cancer susceptibility. IMPORTANCE: The goal of this study was to determine the role of resident breast tissue bacteria in breast cancer development. We analyzed breast tissue bacteria in healthy breast tissue and breast tissue donated prior to (precancerous) and after (postcancerous) breast cancer diagnosis. Compared to healthy tissue, the precancerous and postcancerous breast tissues demonstrated differences in the amounts of breast tissue bacteria. In addition, breast tissue bacteria exhibit different functions in pre-cancerous and post-cancerous breast tissues relative to healthy tissue. These differences in function are further emphasized by altered associations of the breast tissue bacteria with gene expression in the human host prior to cancer development. Collectively, these analyses identified shifts in bacterial abundance and metabolic function (dysbiosis) prior to breast tumor diagnosis. This dysbiosis may serve as a therapeutic target in breast cancer prevention.Item Contributions of the Microbiome-Derived Metabolome for Risk Assessment and Prognostication of Pancreatic Cancer(Oxford University Press, 2024) León-Letelier, Ricardo A.; Dou, Rongzhang; Vykoukal, Jody; Yip-Schneider, Michele T.; Maitra, Anirban; Irajizad, Ehsan; Wu, Ranran; Dennison, Jennifer B.; Do, Kim-An; Zhang, Jianjun; Schmidt, C. Max; Hanash, Samir; Fahrmann, Johannes F.; Epidemiology, Richard M. Fairbanks School of Public HealthBackground: Increasing evidence implicates microbiome involvement in the development and progression of pancreatic ductal adenocarcinoma (PDAC). Studies suggest that reflux of gut or oral microbiota can lead to colonization in the pancreas, resulting in dysbiosis that culminates in release of microbial toxins and metabolites that potentiate an inflammatory response and increase susceptibility to PDAC. Moreover, microbe-derived metabolites can exert direct effector functions on precursors and cancer cells, as well as other cell types, to either promote or attenuate tumor development and modulate treatment response. Content: The occurrence of microbial metabolites in biofluids thereby enables risk assessment and prognostication of PDAC, as well as having potential for design of interception strategies. In this review, we first highlight the relevance of the microbiome for progression of precancerous lesions in the pancreas and, using liquid chromatography-mass spectrometry, provide supporting evidence that microbe-derived metabolites manifest in pancreatic cystic fluid and are associated with malignant progression of intraductal papillary mucinous neoplasm(s). We secondly summarize the biomarker potential of microbe-derived metabolite signatures for (a) identifying individuals at high risk of developing or harboring PDAC and (b) predicting response to treatment and disease outcomes. Summary: The microbiome-derived metabolome holds considerable promise for risk assessment and prognostication of PDAC.Item Diabetes mellitus promotes the nasal colonization of high virulent Staphylococcus aureus through the regulation of SaeRS two-component system(Taylor & Francis, 2023) Wang, Qichen; Nurxat, Nadira; Zhang, Lei; Liu, Yao; Wang, Yanan; Zhang, Lei; Zhao, Na; Dai, Yingxin; Jian, Ying; He, Lei; Wang, Hua; Bae, Taeok; Li, Min; Liu, Qian; Microbiology and Immunology, School of MedicineDiabetic foot infections are a common complication of diabetes. Staphylococcus aureus is frequently isolated from diabetic foot infections and commonly colonizes human nares. According to the study, the nasal microbiome analysis revealed that diabetic patients had a significantly altered nasal microbial composition and diversity. Typically, the fasting blood glucose (FBG) level had an impact on the abundance and sequence type (ST) of S. aureus in diabetic patients. We observed that highly virulent S. aureus ST7 strains were more frequently colonized in diabetic patients, especially those with poorly controlled FBG, while ST59 was dominant in healthy individuals. S. aureus ST7 strains were more resistant to human antimicrobial peptides and formed stronger biofilms than ST59 strains. Critically, S. aureus ST7 strains displayed higher virulence compared to ST59 strains in vivo. The dominance of S. aureus ST7 strains in hyperglycemic environment is due to the higher activity of the SaeRS two-component system (TCS). S. aureus ST7 strains outcompeted ST59 both in vitro, and in nasal colonization model in diabetic mice, which was abolished by the deletion of the SaeRS TCS. Our data indicated that highly virulent S. aureus strains preferentially colonize diabetic patients with poorly controlled FBG through SaeRS TCS. Detection of S. aureus colonization and elimination of colonizing S. aureus are critical in the care of diabetic patients with high FBG.