Pathogenic Microbiology Commons^™

A High-Fat/High-Protein, Atkins-Type Diet Exacerbates Clostridioides (Clostridium) Difficile Infection In Mice, Whereas A High-Carbohydrate Diet Protects, Chrisabelle C. Mefferd, Shrikant S. Bhute, Jacqueline R. Phan, Jacob V. Villarama, Dung M. Do, Stephanie Alarcia, Ernesto Abel-Santos, Brian P. Hedlund

Chemistry and Biochemistry Faculty Research

Clostridioides difficile (formerly Clostridium difficile) infection (CDI) can result from the disruption of the resident gut microbiota. Western diets and popular weight-loss diets drive large changes in the gut microbiome; however, the literature is conflicted with regard to the effect of diet on CDI. Using the hypervirulent strain C. difficile R20291 (RT027) in a mouse model of antibiotic-induced CDI, we assessed disease outcome and microbial community dynamics in mice fed two high-fat diets in comparison with a high-carbohydrate diet and a standard rodent diet. The two high-fat diets exacerbated CDI, with a high-fat/high-protein, Atkins-like diet leading to severe CDI and …

The Regulation Of The Icsp Promoter Of Shigella Flexneri By Ryhb, Lia A. Africa, Helen J. Wing

Undergraduate Research Opportunities Program (UROP)

Iron is an essential element in the metabolism of many organisms, including bacteria. In many pathogenic bacteria, the levels of iron present trigger the expression of many virulence genes. In Shigella, a gram-negative bacterium that causes dysentery in humans, the expression of a small regulatory RNA, ryhB, is blocked in the presence of iron. Studies have revealed that ryhB represses virB, a global regulator of virulence genes in Shigella.

The icsP gene is under the direct control of VirB. icsP encodes an outer membrane protease that cleaves a protein necessary for the actin tail assembly of Shigella in vitro. In …

An Evaluation Of Methicillin Resistant Staphylococcus Aureus Survival On Five Environmental Surfaces Under Two Different Humidities, With And Without The Addition Of Bovine Serum Albumin, Courtney Ann Coughenour

UNLV Theses, Dissertations, Professional Papers, and Capstones

The spread of antibiotic resistant bacteria is a major public health concern, as they result in greater healthcare costs and increased morbidity and mortality rates. Methicillin resistant Staphylococcus aureus (MRSA) is one organism of particular concern, with the number of infections increasing in epidemic proportion. Bacterial surface contamination with MRSA is significant, as it may serve as a reservoir for transmission and have negative health implications. The purpose of this study was to evaluate survival of MRSA on five environmental surface materials; glass, wood, vinyl, plastic, and cloth. The effect of relative humidity (RH) and bovine serum albumin (BSA) were …

The Regulation Of The Icsp Promoter Of Shigella Flexneri By The Virulence Factor Virb, Maria Castellanos, Dustin Harrison, Helen Wing

Undergraduate Research Opportunities Program (UROP)

Shigella flexneri is a pathogenic bacterium that causes severe dysentery in humans commonly known as shigellosis. Shigella encodes an outer membrane protease called IcsP. The regulation of icsP expression is under direct control of a transcriptional factor called VirB, which controls the expression of many virulence genes in Shigella. Previous work has shown through deletion analysis of the icsP promoter region that sequences as far as 1368 base pairs upstream of the transcription starting site are important for the regulation of the icsP gene by VirB. However, it is still unclear whether VirB activation requires sequences within the icsP promoter …