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Articles 1 - 4 of 4
Full-Text Articles in Pathogenic Microbiology
Molecular Mechanisms Underlying Mucosal Attachment And Colonization By Clostridioides Difficile, Ben Sidner
Molecular Mechanisms Underlying Mucosal Attachment And Colonization By Clostridioides Difficile, Ben Sidner
Department of Food Science and Technology: Dissertations, Theses, and Student Research
Clostridioides difficile is a Gram-positive, spore-forming, anaerobic bacterium which causes gastrointestinal disease and is a leading cause of nosocomial infections. Although infection typically occurs following antibiotic therapy, in recent years there has been an increase in infections which are not preceded by antibiotic use. Additionally, community-associated infections and rates of disease recurrence have increased. While it is understood that a healthy gastrointestinal microbiota provides protection against infection, the molecular mechanisms which underly C. difficile's ability to colonize and persist in the gut are mostly unknown. Building on work from others that suggests C. difficile associates with the outer mucus …
The Group A Streptococci Bacteriocins Facilitate A Competitive Advantage During Nasopharyngeal Infection, Lana Estafanos
The Group A Streptococci Bacteriocins Facilitate A Competitive Advantage During Nasopharyngeal Infection, Lana Estafanos
Electronic Thesis and Dissertation Repository
Pathogenic streptococci have evolved specific systems to eliminate bacterial competitors within their biological niche. In microbial environments, niche competition is often driven by the production of short antimicrobial peptides called bacteriocins; this provides a mechanism by which Streptococcus pyogenes may compete for ecological stability and establish infection. Recent findings from our laboratory have identified two novel Class IIb bacteriocin systems – Streptococcus pyogenes bacteriocin (Spb) JK and MN in the M18 serotype S. pyogenes strain MGAS8232 – that may contribute to nasopharyngeal infection. Here, we show that galactose and CO2 are distinct regulatory cues which induce antimicrobial activity. Under …
Colonization Of Intestinal Pathogen Changes The Gut Microbiota, Kaitlyn Shondelmyer
Colonization Of Intestinal Pathogen Changes The Gut Microbiota, Kaitlyn Shondelmyer
Senior Honors Theses
Enterohemorrhagic Escherechia coli is a serious human pathogen causing bloody diarrhea and hemolytic uremic syndrome. It is difficult to study in animal models, but pathogenesis may be modeled in mice with the similar murine pathogen, Citrobacter rodentium. C. rodentium does not cause disease in streptomycin-treated mice, suggesting that it is competition with other facultative anaerobes that triggers pathogenesis. Streptomycin-treated mice were co-colonized with C. rodentium and a commensal E. coli strain. The intestinal microbiota of each group was observed over a 15-day period using quantitative PCR. Colon weights were also measured over the same period. Results indicate that the …
Changes To The Equine Hindgut Microflora In Response To Antibiotic Challenge, Brittany E. Harlow
Changes To The Equine Hindgut Microflora In Response To Antibiotic Challenge, Brittany E. Harlow
Theses and Dissertations--Animal and Food Sciences
Antibiotics are important to equine medicine, but can cause detrimental side-effects including reduced feed intake, allergic reactions, and diarrhea. Antibiotic-associated diarrhea (AAD) is attributed to disruption of the hindgut microflora, permitting proliferation of pathogenic microbes. The objectives were to evaluate the effects of antibiotics on beneficial fecal bacteria, AAD-associated pathogens, microbial species richness and fermentation. Horses were assigned to treatment groups: control (no antibiotics, n=6), trimethoprim-sulfadiazine (oral, n=6), or sodium ceftiofur (IM, n=6). Fecal samples were taken during adaptation (3 wk), antibiotic challenge (1 wk), and withdrawal (1 wk). Fecal cellulolytics decreased by >99% during challenge and did not recover …