Medical Microbiology Commons^™

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.

Identifying Determinants Of Target Specificity In Two Related Bacterial Peptide Toxins, Andrew D. Holmes

Honors Thesis

Toxin-antitoxin (TA) systems were originally identified as two-component systems ensuring the stable inheritance of plasmids in bacterial populations. Recently, they have been identified on bacterial chromosomes where their functions remain mostly undefined. The par locus of E. faecalis plasmid pAD1 (par_pAD1) was the first TA system defined in a Gram-positive bacterium and a homolog encoded on the E. faecalis chromosome (par_EF0409) was later described. Related loci numbering in the hundreds have been identified throughout Gram-positive bacteria based on homology to the toxin of the system, Fst, and similarities in genetic organization and regulation. Despite …

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 …

Transcriptomic Responses To Coaggregation Between Oral Bacteria, V R Mutha Naresh

Student Works (2020-2029)

Cell-cell interactions between genetically distinct oral bacteria form macroscopic clumps known as coaggregates. These interactions, termed coaggregation contribute to the formation of highly structured multispecies communities in oral cavity, known as oral biofilms. Individual species also compete and collaborate with other neighboring species through metabolic interactions allowing growth of other species by coaggregation. This study involves the mixing of selected pairs of oral bacteria to form coaggregates and quantifying differential gene expression levels in each pair in comparison with mono-species coaggregation. The dual RNA-Seq approach made it possible to see how bacteria respond to one another leading to different metabolic …

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.

Biological Sex Influences Susceptibility To Acinetobacter Baumannii Pneumonia In Mice, Sílvia Pires, Adeline Peignier, Jeremy Seto, Davida S. Smyth, Dane Parker

Publications and Research

Acinetobacter baumannii (A. baumannii) is an extremely versatile multidrug-resistant pathogen with a very high mortality rate; therefore, it has become crucial to understand the host response during its infection. Given the importance of mice for modeling infection and their role in preclinical drug development, equal emphasis should be placed on the use of both sexes. Through our studies using a murine model of acute pneumonia with A. baumannii, we observed that female mice were more susceptible to infection. Likewise, treatment of male mice with estradiol increased their susceptibility to infection. Analysis of the airway compartment revealed enhanced inflammation and reduced …

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 …

Discovery Of A Bacterial Peptide As A Modulator Of Glp-1 And Metabolic Disease, Catherine Tomaro-Duchesneau, Stephanie L Levalley, Daniel Roeth, Liang Sun, Frank T Horrigan, Markus Kalkum, Joseph M Hyser, Robert A Britton

Faculty, Staff and Students Publications

Early work in rodents highlighted the gut microbiota's importance in metabolic disease, including Type II Diabetes Mellitus (T2DM) and obesity. Glucagon-like peptide-1 (GLP-1), an incretin secreted by L-cells lining the gastrointestinal epithelium, has important functions: promoting insulin secretion, insulin sensitivity, and β-cell mass, while inhibiting gastric emptying and appetite. We set out to identify microbial strains with GLP-1 stimulatory activity as potential metabolic disease therapeutics. Over 1500 human-derived strains were isolated from healthy individuals and screened for GLP-1 modulation by incubating bacterial cell-free supernatants with NCI H716 L-cells. Approximately 45 strains capable of increasing GLP-1 were discovered. All GLP-1 positive …

Approaches To Overcome Flow Cytometry Limitations In The Analysis Of Cells From Veterinary Relevant Species, Julia Hunka, John T. Riley, Gudrun F. Debes

Department of Microbiology and Immunology Faculty Papers

BACKGROUND: Flow cytometry is a powerful tool for the multiparameter analysis of leukocyte subsets on the single cell level. Recent advances have greatly increased the number of fluorochrome-labeled antibodies in flow cytometry. In particular, an increase in available fluorochromes with distinct excitation and emission spectra combined with novel multicolor flow cytometers with several lasers have enhanced the generation of multidimensional expression data for leukocytes and other cell types. However, these advances have mainly benefited the analysis of human or mouse cell samples given the lack of reagents for most animal species. The flow cytometric analysis of important veterinary, agricultural, wildlife, …

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 …

Prevalence Of The Hypervirulent Nap1/Bi/027 Strain Of C. Difficile In Southwestern Virginia And Risk Factors Associated With Infection, Andrew O. Hanna, Anthony Baffoe-Bonnie, Shikha Vasudeva

Graduate Medical Education (GME) Resident and Fellow Research Day Posters

C. difficile infection (CDI) incidence has increased over the last several decades. The BI/NAP1/027 ribotype was discovered in 2005 and has since been responsible for multiple outbreaks in the US and Canada. This subtype of C. Difficile is known to be more virulent in vivo and produce more severe disease. Limited regional data of the prevalence of this ribotype is available, which could help guide treatment. Using infection control data from a large regional hospital and a VA medical center, this study documented the prevalence of the 027 ribotype in Southwest Virginia. Patients were included if they were tested at …

Neutrophils Are Mediators Of Metastatic Prostate Cancer Progression In Bone, Diane L. Costanzo-Garvey, Tyler Keeley, Adam J. Case, Gabrielle F. Watson, Massar Alsamraae, Yangsheng Yu, Kaihong Su, Cortney E. Heim, Tammy Kielian, Colm Morrissey, Jeremy S Frieling, Leah M. Cook

Journal Articles: Pathology and Microbiology

Bone metastatic prostate cancer (BM-PCa) significantly reduces overall patient survival and is currently incurable. Current standard immunotherapy showed promising results for PCa patients with metastatic, but less advanced, disease (i.e., fewer than 20 bone lesions) suggesting that PCa growth in bone contributes to response to immunotherapy. We found that: (1) PCa stimulates recruitment of neutrophils, the most abundant immune cell in bone, and (2) that neutrophils heavily infiltrate regions of prostate tumor in bone of BM-PCa patients. Based on these findings, we examined the impact of direct neutrophil-prostate cancer interactions on prostate cancer growth. Bone marrow neutrophils directly induced apoptosis …

Tlr2 And Caspase-1 Signaling Are Critical For Bacterial Containment But Not Clearance During Craniotomy-Associated Biofilm Infection, Amy L. Aldrich, Cortney E. Heim, Wen Shi, Rachel W. Fallet, Bin Duan, Tammy Kielian

Journal Articles: Pathology and Microbiology

BACKGROUND: A craniotomy is required to access the brain for tumor resection or epilepsy treatment, and despite precautionary measures, infectious complications occur at a frequency of 1-3%. Approximately half of craniotomy infections are caused by Staphylococcus aureus (S. aureus) that forms a biofilm on the bone flap, which is recalcitrant to antibiotics. Our prior work in a mouse model of S. aureus craniotomy infection revealed a critical role for myeloid differentiation factor 88 (MyD88) in bacterial containment and pro-inflammatory mediator production. Since numerous receptors utilize MyD88 as a signaling adaptor, the current study examined the importance of Toll-like receptor 2 …

Monocyte Metabolic Reprogramming Promotes Pro-Inflammatory Activity And Staphylococcus Aureus Biofilm Clearance, Kelsey J. Yamada, Cortney E. Heim, Xinyuan Xi, Kuldeep S. Attri, Dezhen Wang, Wenting Zhang, Pankaj K. Singh, Tatiana K. Bronich, Tammy Kielian

Journal Articles: Pathology and Microbiology

Biofilm-associated prosthetic joint infections (PJIs) cause significant morbidity due to their recalcitrance to immune-mediated clearance and antibiotics, with Staphylococcus aureus (S. aureus) among the most prevalent pathogens. We previously demonstrated that S. aureus biofilm-associated monocytes are polarized to an anti-inflammatory phenotype and the adoptive transfer of pro-inflammatory macrophages attenuated biofilm burden, highlighting the critical role of monocyte/macrophage inflammatory status in dictating biofilm persistence. The inflammatory properties of leukocytes are linked to their metabolic state, and here we demonstrate that biofilm-associated monocytes exhibit a metabolic bias favoring oxidative phosphorylation (OxPhos) and less aerobic glycolysis to facilitate their anti-inflammatory activity and biofilm …

Stochastic Expression Of Sae-Dependent Virulence Genes During Staphylococcus Aureus Biofilm Development Is Dependent On Saes, Elizabeth A. Delmain, Derek E. Moormeier, Jennifer L. Endres, Rebecca E. Hodges, Marat R. Sadykov, Alexander R. Horswill, Kenneth W. Bayles

Journal Articles: Pathology and Microbiology

The intricate process of biofilm formation in the human pathogen Staphylococcus aureus involves distinct stages during which a complex mixture of matrix molecules is produced and modified throughout the developmental cycle. Early in biofilm development, a subpopulation of cells detaches from its substrate in an event termed “exodus” that is mediated by SaePQRS-dependent stochastic expression of a secreted staphylococcal nuclease, which degrades extracellular DNA within the matrix, causing the release of cells and subsequently allowing for the formation of metabolically heterogenous microcolonies. Since the SaePQRS regulatory system is involved in the transcriptional control of multiple S. aureus virulence factors, the …

Fluorescent Sensor Arrays Can Predict And Quantify The Composition Of Multicomponent Bacterial Samples, Denis Svechkarev, Marat Sadykov, Lucas J. Houser, Kenneth W. Bayles, Aaron M. Mohs

Journal Articles: Pathology and Microbiology

Fast and reliable identification of infectious disease agents is among the most important challenges for the healthcare system. The discrimination of individual components of mixed infections represents a particularly difficult task. In the current study we further expand the functionality of a ratiometric sensor array technology based on small-molecule environmentally-sensitive organic dyes, which can be successfully applied for the analysis of mixed bacterial samples. Using pattern recognition methods and data from pure bacterial species, we demonstrate that this approach can be used to quantify the composition of mixtures, as well as to predict their components with the accuracy of ~80% …

An Integrated Computational And Experimental Study To Investigate Staphylococcus Aureus Metabolism, Mohammad Mazharul Islam, Vinai Chittezham Thomas, Matthew Van Beek, Jong-Sam Ahn, Abdulelah A. Alqarzaee, Chunyi Zhou, Paul D. Fey, Kenneth W. Bayles, Rajib Saha

Journal Articles: Pathology and Microbiology

Staphylococcus aureus is a metabolically versatile pathogen that colonizes nearly all organs of the human body. A detailed and comprehensive knowledge of staphylococcal metabolism is essential to understand its pathogenesis. To this end, we have reconstructed and experimentally validated an updated and enhanced genome-scale metabolic model of S. aureus USA300_FPR3757. The model combined genome annotation data, reaction stoichiometry, and regulation information from biochemical databases and previous strain-specific models. Reactions in the model were checked and fixed to ensure chemical balance and thermodynamic consistency. To further refine the model, growth assessment of 1920 nonessential mutants from the Nebraska Transposon Mutant Library …

Alteration Of The Gut Microbiome In Normal And Overweight School Children From Selangor With Lactobacillus Fermented Milk Administration, Narcisse Joseph, Jonathan B. Clayton, Susan L. Hoops, Carter A. Linhardt, Amalia Mohd Hashim, Barakatun Nisak Mohd Yusof, Suresh Kumar, Syafinaz Amin Nordin

Food for Health: Publications

Childhood obesity is a serious public health problem worldwide. Perturbations in the gut microbiota composition have been associated with the development of obesity in both children and adults. Probiotics, on the other hand, are proven to restore the composition of the gut microbiome which helps reduce the development of obesity. However, data on the effect of probiotics on gut microbiota and its association with childhood obesity is limited. This study aims to determine the effect of probiotics supplement intervention on gut microbiota profiles in obese and normal-weight children. A total of 37 children, 17 normal weight, and 20 overweight school …

Stool Microbiome, Ph And Short/Branched Chain Fatty Acids In Infants Receiving Extensively Hydrolyzed Formula, Amino Acid Formula, Or Human Milk Through Two Months Of Age, Car Reen Kok, Bradford Brabec, Maciej Chichlowski, Cheryl L. Harris, Nancy Moore, Jennifer L. Wampler, Jon Vanderhoof, Devin Rose, Robert Hutkins

Food for Health: Publications

CRISPR–Cas is an anti-viral mechanism of prokaryotes that has been widely adopted for genome editing. To make CRISPR–Cas genome editing more controllable and safer to use, anti-CRISPR proteins have been recently exploited to prevent excessive/prolonged Cas nuclease cleavage. Anti-CRISPR (Acr) proteins are encoded by (pro)phages/(pro)viruses, and have the ability to inhibit their host’s CRISPR–Cas systems. We have built an online database AcrDB (http://bcb.unl.edu/AcrDB) by scanning ∼19 000 genomes of prokaryotes and viruses with AcrFinder, a recently developed AcrAca (Acr-associated regulator) operon prediction program. Proteins in Acr-Aca operons were further processed by two machine learning-based programs (AcRanker and PaCRISPR) to obtain …

First-Time Characterization Of Viable But Non-Culturable Proteus Mirabilis: Induction And Resuscitation, Reham Wasfi, G. R. Abdellatif, H. M. Elshishtawy, Hossam M. Ashour

USF St. Petersburg Campus Faculty Publications

Pathogenic bacteria can enter into a viable but non-culturable (VBNC) state under unfavourable conditions. Proteus mirabilis is responsible for dire clinical consequences including septicaemia, urinary tract infections and pneumonia, but is not a species previously known to enter VBNC state. We suggested that stress-induced P. mirabilis can enter a VBNC state in which it retains virulence. P. mirabilis isolates were incubated in extreme osmotic pressure, starvation, low temperature and low pH to induce a VBNC state. Resuscitation was induced by temperature upshift and inoculation in tryptone soy broth with Tween 20 and brain heart infusion broth. Cellular ultrastructure and gene …

Assessing Embalmer Exposure To Bioaerosols And The Associated Health Risk, Geneviève Marchand, Loïc Wingert, Stéphane Hallé, Maximilien Debia

Rapports de recherche scientifique

Plusieurs manipulations réalisées sur les corps des défunts par les thanatopracteurs produisent des bioaérosols qui peuvent contenir des agents pathogènes infectieux. La ventilation générale est souvent le seul moyen utilisé dans les laboratoires de thanatopraxie pour maîtriser les bioaérosols. Toutefois, il n’y a pas de recommandations précises pour sa mise en application. De plus, peu d'études abordent les expositions professionnelles aux bioaérosols dans le domaine de la thanatopraxie tant quantitativement (niveau d’exposition) que qualitativement (identification et classification selon les groupes de risque). L’objectif de cette étude était d’évaluer l’exposition des thanatopracteurs aux bioaérosols afin d’apprécier les risques potentiels sur leur …

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. …

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 …

Tick-Borne Infections In New Hampshire: An Evaluation Of The Diagnostic Process In A Local Patient Population, Katherine Anderson

Honors Theses and Capstones

Overall, approximately 95 percent of reported cases of vector-borne disease were associated with ticks, making these the most medically important group of arthropods in the United States.¹ Despite the prevalence of tick-borne infections, the process for the diagnosis of this condition is not well studied. This study aims to analyze data from a pool of 100 patients who underwent testing for tick-borne disease in the same institution in Dover, New Hampshire during the most recent peak tick season of 2019. Information utilized in this study included: patient age, sex, location of testing (inpatient versus outpatient), diagnostic testing methods used …

Corpus Cavernosum Abscess Secondary To Traumatic Perforation Of Urethral Diverticulum, Thomas C. Gore, Anna Schepcoff, Domenick Sorresso

West Florida Division GME Research Day 2020

A corpus cavernosum abscess is a rare condition. Usual etiologies include penile injection of erectile dysfunction medications or illicit drugs, priapism, sexually transmitted infections, and trauma; however, there have been reported cases of idiopathic etiology. The most common causative organisms include Staphylococcus aureus, Streptococci, and Bacteroides [1]. Diagnosis is typically made clinically and through imaging (computed tomography [CT] and ultrasound). The first-line treatment is the use of intravenous (IV) antibiotics and surgical drainage. More conservative treatment, however, includes aspiration in conjunction with IV antibiotics [2-3]. Urethral diverticulum (UD) is the formation of a saccular outpouching of the urethral lumen. Symptoms …

Aging Induces B Cell Defects And Decreased Antibody Responses To Influenza Infection And Vaccination, Daniela Frasca, Bonnie B. Blomberg

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Background: Aging is characterized by a progressive decline in the capacity of the immune system to fight influenza virus infection and to respond to vaccination. Among the several factors involved, in addition to increased frailty and high-risk conditions, the age-associated decrease in cellular and humoral immune responses plays a relevant role. This is in large part due to inflammaging, the chronic low-grade inflammatory status of the elderly, associated with intrinsic inflammation of the immune cells and decreased immune function.

Results: Aging is usually associated with reduced influenza virus-specific and influenza vaccine-specific antibody responses but some elderly individuals with higher pre-exposure …