Medical Microbiology Commons^™

Habitual Sleep Duration And The Colonic Mucosa-Associated Gut Microbiota In Humans-A Pilot Study, Ritwick Agrawal, Nadim J Ajami, Sonal Malhotra, Liang Chen, Donna L White, Amir Sharafkhaneh, Kristi L Hoffman, David Y Graham, Hashem B El-Serag, Joseph F Petrosino, Li Jiao

Faculty, Staff and Students Publications

We examined the association between the colonic adherent microbiota and nocturnal sleep duration in humans. In a cross-sectional study, 63 polyp-free adults underwent a colonoscopy and donated 206 mucosal biopsies. The gut microbiota was profiled using the 16S rRNA gene sequencing targeting the V4 region. The sequence reads were processed using UPARSE and DADA2, respectively. Lifestyle factors, including sleep habits, were obtained using an interviewer-administered questionnaire. We categorized the participants into short sleepers (<6 h per night; n = 16) and normal sleepers (6–8 h per night; n = 47) based on self-reported data. Differences in bacterial biodiversity and the taxonomic relative abundance …

Identification Of Effectors Of Synergistic Lethality In Candida Albicans-Staphylococcus Aureus Polymicrobial Intra-Abdominal Infection, Olivia Adele Todd

Theses and Dissertations (ETD)

Candida albicans, an opportunistic fungal pathogen, and Staphylococcus aureus, a ubiquitous pathogenic bacterium, are among the most prevalent causes of nosocomial infections and cause severe morbidity and mortality. Moreover, they are frequently coisolated from central venous catheters and deep-seated infections, including intra-abdominal sepsis. Relatively little is known about the complex interactions and signaling events that occur between microbes and even less so how microbial “cross-talk” shapes human health and disease.

Using a murine model of polymicrobial intra-abdominal infection (IAI), we have previously shown that coinfection with C. albicans and S. aureus leads to synergistic lethality whereas monomicrobial infection is nonlethal. …

Antibiotic Tolerance And Heteroresistance: Associated Fitness Costs And Potential In Evading Antibiotic Killing, Tina H. Dao

Theses and Dissertations (ETD)

Streptococcus pneumoniae is a prominent human pathogen that causes both invasive and non-invasive diseases, such as otitis media, pneumonia, meningitis, and bacteremia. Although it is frequently an asymptomatic colonizer of the human nasopharynx, S. pneumoniae is a major cause of morbidity and mortality in the immune compromised population, young children, and the elderly. Up until the 1970s, S. pneumoniae was susceptible to almost all antibiotics. Since then, this pathogen has gained resistance to a variety of antibiotic treatments, including beta-lactams, macrolides, and fluoroquinolones.

In the first chapter, we focused on fluoroquinolone resistance in S. pneumoniae. Fluoroquinolones are one of the …

Delineating The Upc2a Regulon In Candida Glabrata, Yu Li

Theses and Dissertations (ETD)

Candida glabrata is the second most common cause of invasive candidiasis. Intrinsic resistance has greatly limited the utility of the triazole antifungal, fluconazole, in the treatment of invasive fungal infection. The transcription factor Upc2 regulates the expression of sterol biosynthesis genes in yeast. Disrupting UPC2A in C. glabrata greatly increases its susceptibility to fluconazole (FLU) in both FLU-susceptible and -resistant clinical isolates. Therefore, the Upc2A and its target genes represent a potential pathway for overcoming FLU resistance in C. glabrata. We aimed to delineate the Upc2A regulon to determine its target genes involved in FLU resistance. Transcriptome sequencing (RNA-seq) analysis …

A Novel Application Of Galleria Mellonella Larvae To Study Pathogenesis Of Rickettsia Rickettsii Infection, Jacob M. Jones

Honors College Theses

Rickettsia are obligate intracellular tick-borne bacteria that cause acute undifferentiated febrile illness accompanied by headache, malaise, myalgias, and disseminated endothelial infection. Immune responses to Rickettsia and pathogenesis of rickettsioses are not fully understood. Current work with Rickettsia is limited to vertebrate models that are strictly regulated and have low throughput. Since the innate immune system of vertebrates retains striking similarities with the immune response in insects, invertebrates are being used to study host responses to various pathogens. The purpose of this study was to evaluate if larvae of the greater wax moth Galleria mellonella (GML) can be used as an …

Streptococcus Anginosus Lung Infection And Empyema: A Case Report And Review Of The Literature, Nishita Tripathi, Kuldeep Ghosh, Anupama Raghuram

The University of Louisville Journal of Respiratory Infections

Streptococcus milleri group (SMG) also referred to as the Streptococcus anginosus group. These are Gram-positive, variable hemolysis, catalase negative, microaerophilic, non-motile facultative anaerobes which have been known to cause abscesses in humans. We report a case of empyema caused by Streptococcus anginosus in a patient with an unresolved pneumonia for over a month. In early October 2018, the patient presented to an emergency room with the complaints of shortness of air, productive cough, chills, subjective fever and weight loss for 4 weeks. A chest X-ray revealed a left lower lobe pneumonia. He was treated with 250 mg of azithromycin for …

When The Pandemic Opts For The Lockdown: Secretion System Evolution In The Cholera Bacterium, Francis J. Santoriello, Stefan Pukatzki

Publications and Research

Vibrio cholerae, the causative agent of the diarrheal disease cholera, is a microbe capable of inhabiting two different ecosystems: chitinous surfaces in brackish, estuarine waters and the epithelial lining of the human gastrointestinal tract. V. cholerae defends against competitive microorganisms with a contact-dependent, contractile killing machine called the type VI secretion system (T6SS) in each of these niches. The T6SS resembles an inverted T4 bacteriophage tail and is used to deliver toxic effector proteins into neighboring cells. Pandemic strains of V. cholerae encode a unique set of T6SS effector proteins, which may play a role in pathogenesis or pandemic …

Piglet Immunization With A Spike Subunit Vaccine Enhances Disease By Porcine Epidemic Diarrhea Virus, Jieshi Yu, Chithra Sreenivasan, Tirth Uprety, Rongyuan Gao, Chen Huang, Ella J. Lee, Steven Lawson, Julie Nelson, Jane Christopher-Hennings, Radhey S. Kaushik, Eric Nelson, Diego G. Diel, Ben M. Hause, Feng Li, Dan Wang

Maxwell H. Gluck Equine Research Center Faculty Publications

Immunization with an insect cell lysate/baculovirus mixture containing recombinant porcine epidemic diarrhea virus (PEDV) spike protein induced high levels of neutralizing antibodies in both mice and piglets. However, immunization of piglets with this vaccine resulted in enhancement of disease symptoms and virus replication in vaccine recipients exposed to PEDV challenge. Thus, these observations demonstrate a previously unrecognized challenge of PEDV vaccine research, which has important implications for coronavirus vaccine development.

Streptococcus Cristatus – An Oral Bacterium Causing A Case Of Mild Bacteremia And “Possible Endocarditis”, Camilo Guzman, Adi Zaclli, John Molinari

Medical Student Research Symposium

Streptococcus cristatus is a member of the Mitis streptococcus group. Like other members of this group, it resides in mucosal surfaces of the oral cavity but rarely causes disease. We present a case of S. cristatus bacteremia and “possible endocarditis” (per the modified Duke criteria) in a 59-year-old male suffering from end- stage cryptogenic cirrhosis. To date, it is the fifth reported case of disease caused by the microbe, and the first adult case in which S. cristatus was the sole microbe identified. Our patient had a history of dental caries and poor dentition, which were likely the source of …

Comparisons Of Oral, Intestinal, And Pancreatic Bacterial Microbiomes In Patients With Pancreatic Cancer And Other Gastrointestinal Diseases, Mei Chung, Naisi Zhao, Richard Meier, Devin C. Koestler, Guojun Wu, Erika De Castillo, Bruce J. Paster, Kevin Charpentier, Jacques Izard, Karl T. Kelsey, Dominique S. Michaud

Department of Food Science and Technology: Faculty Publications

Background: Oral microbiota is believed to play important roles in systemic diseases, including cancer. Methods: We collected oral samples (tongue, buccal, supragingival, and saliva) and pancreatic tissue or intestinal samples from 52 subjects, and characterized 16S rRNA genes using high-throughput DNA sequencing.

Results: Bray–Curtis plot showed clear separations between bacterial communities in the oral cavity and those in intestinal and pancreatic tissue samples. PERMANOVA tests indicated that bacterial communities from buccal samples were similar to supragingival and saliva samples, and pancreatic duct samples were similar to pancreatic tumor samples, but all other samples were significantly different from each …

Trypanosoma Cruzi Modulates Piwi-Interacting Rna Expression In Primary Human Cardiac Myocytes During The Early Phase Of Infection, Kayla J. Rayford, Ayorinde Cooley, Ashutosh Arun, Girish Rachakonda, Yulia Kleschenko, Fernando Villalta, Siddharth Pratap, Maria F. Lima, Pius N. Nde

Publications and Research

Trypanosoma cruzi dysregulates the gene expression profile of primary human cardiomyocytes (PHCM) during the early phase of infection through a mechanism which remains to be elucidated. The role that small non-coding RNAs (sncRNA) including PIWI-interacting RNA (piRNA) play in regulating gene expression during the early phase of infection is unknown. To understand how T. cruzi dysregulate gene expression in the heart, we challenged PHCM with T. cruzi trypomastigotes and analyzed sncRNA, especially piRNA, by RNA-sequencing. The parasite induced significant differential expression of host piRNAs, which can target and regulate the genes which are important during the early infection phase. An …

Pandemic Vibrio Cholerae Shuts Down Site-Specific Recombination To Retain An Interbacterial Defence Mechanism, Francis J. Santoriello, Lina Michel, Daniel Unterweger, Stefan Pukatzki

Publications and Research

Vibrio cholerae is an aquatic microbe that can be divided into three subtypes: harmless environmental strains, localised pathogenic strains, and pandemic strains causing global cholera outbreaks. Each type has a contact-dependent type VI secretion system (T6SS) that kills neighbouring competitors by translocating unique toxic effector proteins. Pandemic isolates possess identical effectors, indicating that T6SS effectors may affect pandemicity. Here, we show that one of the T6SS gene clusters (Aux3) exists in two states: a mobile, prophage-like element in a small subset of environmental strains, and a truncated Aux3 unique to and conserved in pandemic isolates. Environmental Aux3 can be readily …

Acute Ischemic Stroke As The Presenting Feature Of Covid-19 In The Young And Pregnant, Nermila A. Ballmick, Jiri F. Kubac, Hossein Akhondi

HCA Healthcare Journal of Medicine

Introduction: Coronavirus disease (COVID-19) is an emerging and rapidly evolving public health issue that has become globally widespread and an overwhelming pandemic. Clinical manifestations of the disease include asymptomatic carrier states, acute respiratory distress syndrome, and even multiorgan dysfunction. Here, we present a unique and rare case of an acute ischemic stroke (AIS) in an asymptomatic pregnant woman with no predisposing medical illnesses.

Discussion: An 18-year-old G2P1 African American woman at 7 weeks gestational age with no significant medical or family history presenting to the Emergency Department during the initial phases of the pandemic with complaints of new onset left …

Investigating Microbial And Host Factors That Modulate Severity Of Clostridioides Difficile Associated Disease, Armando Lerma

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Clostridioides difficile is recognized as one of the most important pathogens in hospital and community healthcare settings. The clinical outcome of infection of toxigenic C. difficile infection (CDI) ranges from asymptomatic colonization to fulminant pseudomembranous colitis and death. In recent studies, it has been suggested that a high proportion of nosocomial CDI cases are transmitted from asymptomatic carriers which might be acting as infection reservoirs. Understanding what causes the different responses to infection could lead to the development of novel prevention and treatment strategies. Although several explanations have been proposed to explain variations in susceptibility, understanding of the exact mechanisms …

Chain-Selective Isotopic Labeling Of The Heterodimeric Type Iii Secretion Chaperone, Scc4:Scc1, Reveals The Total Structural Rearrangement Of The Chlamydia Trachomatis Bi-Functional Protein, Scc4, Thilini O. Ukwaththage, Samantha M. Keane, Li Shen, Megan A. Macnaughtan

School of Medicine Faculty Publications

Scc4 is an unusual bi-functional protein from Chlamydia trachomatis (CT) that functions as a type III secretion system (T3SS) chaperone and an RNA polymerase (RNAP)-binding protein. Both functions require interactions with protein partners during specific stages of the CT developmental cycle. As a T3SS chaperone, Scc4 binds Scc1 during the late stage of development to form a heterodimer complex, which chaperones the essential virulence effector, CopN. During the early-middle stage of development, Scc4 regulates T3SS gene expression by binding the σ66-containing RNAP holoenzyme. In order to study the structure and association mechanism of the Scc4:Scc1 T3SS chaperone complex using nuclear …

Tumor Somatic Mutations Also Existing As Germline Polymorphisms May Help To Identify Functional Snps From Genome-Wide Association Studies, Ivan P Gorlov, Xiangjun Xia, Spiridon Tsavachidis, Olga Y Gorlova, Christopher I Amos

Faculty, Staff and Students Publications

We hypothesized that a joint analysis of cancer risk-associated single-nucleotide polymorphism (SNP) and somatic mutations in tumor samples can predict functional and potentially causal SNPs from GWASs. We used mutations reported in the Catalog of Somatic Mutations in Cancer (COSMIC). Confirmed somatic mutations were subdivided into two groups: (1) mutations reported as SNPs, which we call mutational/SNPs and (2) somatic mutations that are not reported as SNPs, which we call mutational/noSNPs. It is generally accepted that the number of times a somatic mutation is reported in COSMIC correlates with its selective advantage to tumors, with more frequently reported mutations being …

Plasmodium Impairs Antibacterial Innate Immunity To Systemic Infections In Part Through Hemozoin-Bound Bioactive Molecules., Christopher Lynn Harding

Electronic Theses and Dissertations

Despite efforts to decrease the global health burden of malaria, infections with Plasmodium species continue to cause over 200 million episodes of malaria each year which resulted in 405,000 deaths in 2018 [1]. One complication of malaria is increased susceptibility to invasive bacterial infections. Plasmodium infections impair host immunity to non-Typhoid Salmonella (NTS) through activities of heme oxygenase I (HO-I) )-induced release of immature granulocytes and myeloid cell-derived IL-10. Yet, it is not known if these mechanisms are specific to NTS. We show here, that Plasmodium yoelii 17XNL (Py) infected mice had impaired clearance of systemic Listeria monocytogenes (Lm) during …

Development, Expansion And Role Of Myeloid-Derived Suppressor Cells In Post-Sepsis Immune Suppression, Tuqa Alkhateeb

Electronic Theses and Dissertations

Myeloid-derived suppressor cells (MDSCs) numbers increase significantly in sepsis and are associated with high mortality rates. These myeloid cell precursors promote immunosuppression, especially in the late (post sepsis) stage. However, the mechanisms that underlie MDSC expansion and programming are not completely understood. To investigate these mechanisms, we used a cecal-ligation and puncture (CLP) mouse model of polymicrobial sepsis that progresses from an early/acute proinflammatory phase to a late/chronic immunosuppressive phase. Previous studies in our laboratory showed that microRNA (miR)-21 and miR-181b elevate levels of the transcription factor nuclear factor 1 (NFI-A) that promotes MDSC expansion. We report here that miR-21 …

The Inhibitory Effects Of An Antimicrobial Gel On The Staphylococcus Species, Mara Trinkle

Undergraduate Honors Theses

The prevalence of antibiotic resistant bacteria has made the choices for topical treatments for patients who experience burns wounds extremely limited. The Staphylococcus genus is naturally occurring in and on the human body but can become harmful once it enters the bloodstream. A novel antimicrobial gel has been shown by our laboratory to inhibit both the planktonic growth and biofilm formation of Staphylococcus aureus in previous studies. The antimicrobial gel is made of seven natural compounds including antioxidants (vitamin C and E). We wanted to examine the effects of the antimicrobial gel on numerous other Staphylococcal species because it is …

Thrombospondin-1 Plays An Essential Role In Yes-Associated Protein Nuclear Translocation During The Early Phase Of Trypanosoma Cruzi Infection In Heart Endothelial Cells, Ashutosh Arun, Kayla J. Rayford, Ayorinde Cooley, Girish Rachakonda, Fernando Villalta, Siddharth Pratap, Maria F. Lima, Nader Sheibani, Pius N. Nde

Publications and Research

The protozoan parasite Trypanosoma cruzi is the causative agent of Chagas disease. This neglected tropical disease causes severe morbidity and mortality in endemic regions. About 30% of T. cruzi infected individuals will present with cardiac complications. Invasive trypomastigotes released from infected cells can be carried in the vascular endothelial system to infect neighboring and distant cells. During the process of cellular infection, the parasite induces host cells, to increase the levels of host thrombospondin-1 (TSP-1), to facilitate the process of infection. TSP-1 plays important roles in the functioning of vascular cells, including vascular endothelial cells with important implications in cardiovascular …

Convalescent Plasma In Covid-19, Ranjit S. Banwait, Joshua K. Salabei, Troy J. Fishman, Uma G. Iyer

HCA Healthcare Journal of Medicine

The recent pandemic of SARS-CoV-2, which causes novel coronavirus disease 2019 (Covid-19), has had devastating impact on a global and national scale. In order to overcome this outbreak it is imperative we find treatments that are safe and effective. To date, no definitive treatment is available that can curtail the spread of this viral syndrome. Convalescent plasma (CP) is one such option that has repeatedly served as an important tool in treatment of various bacterial and viral infections, especially in the setting of no specific antimicrobial or vaccination against an infectious disease. Herein, we review the history of CP, prior …

Similac Special Care And Elecare Cause Neonatal Gut Injury In Mice, Karishma Rao, Heather L. Menden, Wei Yu, Inamul Haque, Susana Chavez-Bueno, Alain C. Cuna, Shahid Umar, Venkatesh Sampath

Research Days

No abstract provided.

How Can We Stop Cancer?, Joseph R. Current

The Review: A Journal of Undergraduate Student Research

Cancer is a disease that humans have been struggling to combat for centuries. It originates from the accumulation of several mutations over the life of a cell that causes it to evade cell death and multiply rapidly. It can affect any tissue in the body and can spread to other parts of the body through metastasis. Cancer comes in numerous shapes and sizes with different levels of aggression, growth speeds, and health risks. Many treatments for cancer exist today, three of the most popular being surgery, chemotherapy, and radiation therapy, which can be used in combinations with other treatments to …

Gut Pathophysiology In Mouse Models Of Social Behavior Deficits, Kyla Scott

Undergraduate Honors Theses

Autism spectrum disorders (ASD) encompass neurodevelopment disorders characterized by atypical patterns of development that impact multiple areas of functioning beginning in early childhood. The etiology of ASD is unknown and there are currently no preventative treatment options. Gastrointestinal symptoms are commonly associated comorbidities. The microbiota-gut-brain axis is a multidirectional communication chain that connects the central and enteric nervous system that relates brain function to peripheral intestinal functions. Changes within this axis have been postulated in ASD. For example, the “leaky gut theory” proposes that chronic inflammation is linked to alterations in the bacterial profiles of the gut microbiome and subsequent …

Molecular Mechanisms Of Antimicrobial Resistance In Multi-Drug Resistant Enterococci, Ayesha Khan

Dissertations and Theses (Open Access)

Antibiotic resistance is a major global public health threat. Enterococci are recalcitrant, nosocomial pathogens that can be intrinsically resistant to valuable antibiotics, like beta-lactams, or evolve resistance to all existing antimicrobials. The LiaFSR system regulates resistance to cell membrane (CM) stressors like daptomycin (DAP), a front-line drug for multi-drug resistant infections. DAP resistance (DAP-R) in E. faecalis is mediated by CM phospholipid alterations. Emergence of DAP-R often leads to b-lactam resensitization, a phenomenon called the seesaw effect. The molecular mechanism of DAP-R and the seesaw effect are unknown. Here we show that LiaX is a surface exposed protein whose C-terminal …

How Immune T-Cell Augmentation Can Help Prevent Covid-19: A Possible Nutritional Solution Using Ketogenic Lifestyle, Ravi K. Kamepalli Md,Fidsa,Cwsp

The University of Louisville Journal of Respiratory Infections

No abstract provided.

Association Between Sulfur-Metabolizing Bacterial Communities In Stool And Risk Of Distal Colorectal Cancer In Men, Long H. Nguyen, Wenjie Ma, Dong D. Wang, Yin Cao, Himel Mallick, Teklu K. Gerbaba, Jason Lloyd-Price, Galeb Abu-Ali, A. Brantley Hall, Daniel Sikavi, David A. Drew, Raaj S. Mehta, Cesar Arze, Amit D. Joshi, Yan Yan, Tobyn Branck, Casey Dulong, Kerry L. Ivey, Shuji Ogino, Eric B. Rimm, Mingyang Song, Wendy S. Garrett, Jacques Izard, Cutis Huttenhower, Andrew T. Chan

Department of Food Science and Technology: Faculty Publications

Background and aims: Sulfur-metabolizing microbes, which convert dietary sources of sulfur into genotoxic hydrogen sulfide (H₂S), have been associated with development of colorectal cancer (CRC). We identified a dietary pattern associated with sulfur-metabolizing bacteria in stool and then investigated its association with risk of incident CRC using data from a large prospective study of men.

Methods: We collected data from 51,529 men enrolled in the Health Professionals Follow-up Study since 1986 to determine the association between sulfur-metabolizing bacteria in stool and risk of CRC over 26 years of follow-up. First, in a subcohort of 307 healthy men, we …

A Decerebrating Female: A Rare Presentation Of Acute Disseminated Encephalomyelitis Due To Measles, Natasha Del Rio, Yordan Orive, Andres Sobrado, Ruben Cabrera, Ilde Manuel Lee, Troy Hoang, Sherard Lacaille, Ricardo Garcia-Rivera, Robert Hernandez

Internal Medicine

No abstract provided.

The Interplay Of The Oral-Gut Microbiome With Chronic Inflammation In Rheumatoid Arthritis And Crohn's Disease, Anuradha Rampersaud

Mako: NSU Undergraduate Student Journal

Abstract

Rheumatoid Arthritis (RA) and Crohn’s Disease (CD) are both chronic inflammatory diseases that share developmental and treatment similarities. RA’s symptoms include swelling, stiffness, and pain in synovial joints, corresponding with bone and cartilage destruction. CD’s symptoms include abdominal pain, bowel obstruction, bloating, diarrhea, and fever. The purpose of this literature review was to investigate the links between these two diseases and propose future treatment and prevention targets. Current treatment for RA and CD aims to suppress inflammation by targeting its mediators. However, this review noted that there should be greater focus on resolving inflammation. Both diseases are characterized by …

Cryptococcal Antigen Testing In An Integrated Medical System: Eastern Wisconsin, Marianne Klumph, Brian Hoeynck, Dennis J. Baumgardner

Journal of Patient-Centered Research and Reviews

Cryptococcosis is a serious environmentally acquired endemic fungal infection commonly associated with immunocompromised hosts. Little is known regarding frequency or distribution in Wisconsin. We explored the geodemographic and clinical features of patients tested with cryptococcal antigen tests (CrAg) — previously shown to be >90% sensitive and >90% specific — within a large health care system located in eastern Wisconsin. To examine this, we retrospectively analyzed 1465 CrAg tests on 1211 unique patients (female: 50.2%; white race: 73.9%; mean age: 53.7 ± 16.5 years). At least one CrAg result was positive in 23 of 1211 patients (1.9%). From these, 21 of …