Medical Microbiology Commons^™

Deciphering The Microbial Fingerprint Of Covid-19: A Multi-Layered Exploration Of The Oral And Gut Microbiome Dysbiosis, Iman Mostafa Sultan

Theses and Dissertations

The impact of SARS-CoV-2 infection on the human microbiome remains a dynamic and intricate puzzle. This study delves deeper into this mystery by revisiting the oral and gut microbial compositions of 53 COVID-19 patients before and after viral clearance, alongside comparisons to 76 healthy individuals. Through a comparative lens, we have emploed two distinct differential abundance methods – DeSeq2 and ANCOM – while drawing upon the thorough SILVA database encompassing the full-length 16S rRNA gene. The analysis underscores the crucial role of a diverse methodological choir in microbiome research. In certain instances, the congruence between DeSeq2 and ANCOM may exhibit …

Role Of Histone Deacetylase (Hdac) In Epithelial To Mesenchymal Transition (Emt) In A Human Cholangiocyte Model Of Ischemic Cholangiopathy, Priyanshi Pragnesh Parikh

Theses and Dissertations

Organ transplants are a vital intervention for many diseases that result in end stage organ failure. Currently, the donation pool is not meeting the demands of the transplant list. Expanding this pool to include donation after cardiac death (DCD) is highly sought-after. However, the use of DCD livers can lead to increased odds of graft failure and ischemic cholangiopathy. The loss of epithelialization and fibrosis that occurs during ischemic cholangiopathy is characteristic of these cells undergoing epithelial-to-mesenchymal transition (EMT). The biological changes the cell experiences enhance migratory capacity, invasiveness, and increased resistance to apoptosis. Our earlier studies have shown differential …

Prediction Of The Vaginal Microbiome Using Urine Samples, Christopher R. Diachok

Theses and Dissertations

The vaginal microbiome is associated with women’s health, including but not limited to the pathogenesis of bacterial vaginosis, adverse pregnancy outcomes including preterm birth and sexually transmitted infections. However, there has been very limited research on the urinary microbiome and its relationship to the vaginal microbiome. We sought to predict the vaginal microbiome profile using clean catch urine samples from the same person. Here, paired vaginal and urine samples were collected and sequenced by 16S ribosomal RNA sequencing. Alpha and beta diversity analysis showed that there was no significant difference between the paired vaginal and urine microbiomes. In fact, a …

Modeling Gardnerella Host-Pathogen Interaction: Characterization Of Vaginolysin And The Opacity Phenotype, Erin M. Garcia

Theses and Dissertations

Bacterial vaginosis (BV) describes a dysbiotic state of the vaginal mucosa, during which the dominance by beneficial lactobacilli species is lost, the vaginal pH increases, and the flora comprising the vaginal microbiome becomes more diverse. Bacterial taxa associated with this dysbiotic state interact to form a dense polymicrobial biofilm on the surface of the vaginal epithelium. This shift in the vaginal microflora is clinically important, even when symptoms are not noted, as women with BV are at increased risk for acquisition of other sexually transmitted infections, including HIV, and are more than two times as likely to experience preterm birth. …

Inhibition Of Cancer Stem Cells By Glycosaminoglycan Mimetics, Connor P. O'Hara

Theses and Dissertations

Connor O’Hara July 29, 2019

Inhibition of Cancer Stem Cells by Glycosaminoglycan Mimetics

In the United States cancer is the second leading cause of death, with colorectal cancer (CRC) being the third deadliest cancer and expected to cause over 51,000 fatalities in 2019 alone.¹ The current standard of care for CRC depends largely on the staging, location, and presence of metastasis.² As the tumor grows and invades nearby lymph tissue and blood vessels, CRC has the opportunity to invade not only nearby tissue but also metastasize into the liver and lung (most commonly).³ The 5-year survival rate …

Conjugated Bile Acid And Sphingosine 1-Phosophate Prompt Cholangiocarcinoma Cell Growth Via Releasing Exosomes, Waad A. Alruwaili

Theses and Dissertations

Cholangiocarcinoma (CCA) is a fatal primary malignancy that is formed in the bile ducts. Cancer-associated myofibroblasts play a crucial role in CCA proliferation and invasion. Furthermore, there is a growing interest in the role of the exosome in the interaction between the cancer-associated myofibroblasts and cholangiocarcinoma which lead to CCA growth. However how cholangiocarcinoma-derived exosome affect the cancer-associated myofibroblasts in the tumor microenvironment remain unknown. In this study, we examined whether exosome produced by cholangiocarcinoma could involve in the prompt of CCA cells growth by regulation of myofibroblast. We found that cholangiocarcinoma-derived exosome could prompt elevated α-smooth muscle actin and …

A Systems Biology Approach For Predicting Essential Genes And Deciphering Their Dynamics Under Stress In Streptococcus Sanguinis, Fadi El-Rami

Theses and Dissertations

Infectious diseases are the top leading cause of death worldwide. Identifying essential genes, genes indispensable for survival, has been proven indispensable in defining new therapeutic targets against pathogens, major elements of the minimal set genome to be harnessed in synthetic biology, and determinants of evolutionary relationships of phylogenetically distant species. Thus, essentiality studies promise valuable revenues that can decipher much of biological complexities.

Taking advantage of the available microbial sequences and the essentiality studies conducted in various microbial models, we proposed a framework for the prediction of essential genes based on our experimentally verified knowledge of the pathways involved in …

Emerging Pathogens In Cystic Fibrosis Patients At Virginia Commonwealth University Medical Center (Vcumc), Emily M. Hill

Theses and Dissertations

Cystic fibrosis (CF) is an autosomal recessive disorder affecting 70,000 individuals worldwide. This disease is characterized by the buildup of mucus in the airways leading to chronic lung infections resulting in pulmonary failure and death in 95% of CF patients. Routine surveillance of CF pathogens using traditional microbiology culture guides management and treatment of CF patients. Molecular profiling studies have revealed emerging pathogens that may play a role in CF lung disease by either directly causing infection or upregulating the virulence factors of classic CF pathogens, such as P. aeruginosa; however, routine CF culture protocols have not been modified …

Drug And Vaccine Development For Neisseria Gonorrhoeaea, Devin R. Cash

Theses and Dissertations

Neisseria gonorrhoeae, the causative agent of the STI gonorrhea, is not preventable by vaccination and is rapidly developing resistance to antibiotics. One important strategy for gonococcal survival in the host is iron acquisition in the face of nutritional immunity. To overcome iron limitation, the gonococcus expresses TonB dependent transporters (TdTs), outer membrane proteins that facilitate nutrient acquisition. Of the TdTs, the transferrin (Tf), lactoferrin (Lf), and hemoglobin (Hb) receptors hijack iron directly from host proteins, and studies have already shown that the Tf receptor is essential for the initiation of human infection. Given that the TdTs are virulence factors, …

Characterization Of Complement Evasion Of The Periopathogen, Treponema Denticola, Daniel Patrick Miller

Theses and Dissertations

Periodontitis is a polymicrobially-induced, chronic inflammatory disease of the tissues that support and surround the tooth. While greater than 500 organisms are found in dental plaque, Treponema denticola is one of only a few species associated with disease. It has been hypothesized that oral bacteria disrupt host homeostasis through manipulation of the innate immune system. In this study, we examine the impact of binding and subsequent cleavage of factor H, a complement regulator, by T. denticola in the evasion and subversion of complement. The molecular interaction between the sole FH-binding protein, FhbB, and FH was detailed by x-ray crystallography, site-directed …