Parasitology Commons^™

Increased Neural Activity In The Bed Nucleus Of The Stria Terminalis Of Uninfected Canaries After Observation Of Infected Conspecifics, Madeleine Chang, Sophia Santangelo, Devon Comito, Bennett Hardy, Patricia C. Lopes

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Recent evidence suggests that the immune system may be upregulated in anticipation of pathogen exposure, yet the neural mechanisms that respond to and signal impending infection risk remain poorly understood. We investigated neural responses to infection risk in uninfected hosts observing infected conspecifics, using the canary (Serinus canaria domestica)—Mycoplasma gallisepticum host–parasite system. We focused on five brain regions of interest, comprising three nodes of the social decision-making network—preoptic area, bed nucleus of the stria terminalis (BNST) and hippocampus—a stress modulatory region (paraventricular nucleus) and a visual processing region (nucleus rotundus). After 1 h of observing infected canaries, …

Tick Lipocalin Triggers Mammalian Igfbp-3-Mediated Apoptosis In Macrophages And Keratinocytes, Krittika Nandy, P. P. Mahesh, Lichao Liu, Daniel E. Sonenshine, Hameeda Sultana, Girish Neelakanta

Biological Sciences Faculty Publications

Ticks secrete several molecules, including lipocalins, in their saliva during blood feeding on a vertebrate host. In this study, we provide novel evidence on the role of Ornithodoros turicata americanus tick lipocalin (Otlip) in modulating cytokine expression and in triggering apoptosis in mammalian macrophages and keratinocytes. The cytokine array analysis revealed significantly increased secretion of insulin-like growth factor-binding protein 3 (IGFBP3) from murine macrophage cell line upon treatment with recombinant Otlip protein (rGST-Otlip) when compared to the secretion noted from cells treated with a control protein (rGST). Similar observation with cytokine protein array analysis was noted when murine macrophages were …

Monoclonal Antibodies Targeting Candida Disrupt Biofilms And Inhibit Growth Across Global Clinical Isolates, Jonothan Rosario-Colon, Karen Eberle, Hong Xin

School of Graduate Studies Faculty Publications

Candida species are a major cause of severe fungal infections, particularly in immunocompromised individuals and hospitalized patients. Among these, Candida auris stands out as an emerging “superbug”, responsible for life-threatening bloodstream infections with mortality rates up to 60%. This multidrug-resistant, hospital-acquired pathogen has been declared a serious global health threat, complicating effective treatment and increasing mortality risks. Our research has identified universal monoclonal antibodies (mAbs) targeting Candida albicans cell wall epitopes, which are highly homologous to those in other pathogenic Candida species, including C. auris. Passive transfer of mAbs—C3.1 (anti-β-1,2-mannotriose) and 9F2 (anti-phosphoglycerate kinase 1)—significantly extended survival and improved fungal …

Mechanisms Of Behavioral Change In Hosts Of Toxoplasma Gondii: A Review, Olivia Grimsley

Senior Honors Theses

The parasite Toxoplasma gondii is a highly ubiquitous parasite that latently infects an estimated 33% percent of the global population. Toxoplasmosis is of obvious clinical significance due to the extremely high risks to the unborn who contract it congenitally. Less attention has been given to a more subtle aspect of latent infection, which is the behavioral alterations that are commonly experienced by those who contract the parasite. Infected individuals commonly display a variety of altered behaviors, such as increased aggression and risk-seeking behaviors, depression, higher tendency towards suicide and self-directed violence, a loss of fear response, and a greatly increased …

Characterization Of Vaccine-Enhanced Humoral Immune Responses Against Emergent Sars-Cov-2 Variants In A Convalescent Cohort, Jared Sheehan, Amber J. Trauth, Michael E. Hagensee, Alistair J. Ramsay

School of Graduate Studies Faculty Publications

Vaccination of COVID-19–convalescent individuals may generate ‘hybrid’ immunity of enhanced magnitude, durability, and cross-reactive breadth. Our primary goal was to characterize hybrid antibody (Ab) responses in a patient cohort infected with ancestral Wuhan-Hu-1 virus and vaccinated between 6 and 10 months later with the Wuhan-Hu-1–based BNT162b2 mRNA vaccine. We were particularly interested in determining the efficacy of neutralizing Ab responses against subsequently emergent SARS-CoV-2 variants. Sera collected at 3-monthly intervals over a period of 12 months were analyzed by ELISA for SARS-CoV-2 RBD–specific Ab responses, and also for neutralizing Ab activity using pseudovirus-based neutralization assays. We found that convalescent RBD-reactive …

Rwanda's Natural Remedies: A Fresh Look At The Fight Against Malaria, Leandre Nsabimana Ndisanze

Pomona Senior Theses

Malaria remains one of the most devastating parasitic diseases globally, disproportionately affecting sub-Saharan Africa, where Rwanda continues to face high transmission rates and rising resistance to conventional interventions. Despite decades of control efforts, the emergence of drug-resistant Plasmodium falciparum and insecticide-resistant Anopheles mosquitoes threatens to reverse recent gains. This research responds to the urgent need for sustainable and culturally relevant alternatives by exploring the therapeutic potential of Rwandan traditional medicinal plants. These indigenous remedies, long used by local healers, offer an underexplored reservoir of bioactive compounds that may provide the basis for novel antimalarial drugs.

The central hypothesis of this …

Novel Therapuetic Approaches For Chagas Disease, Juan Carlos Silva

Open Access Theses & Dissertations

Chagas disease (CD) is caused by the hemoflagellate protozoan Trypanosoma cruzi. This disease is considered one of the 20 neglected tropical diseases (NTD), and it is estimated that 6 to 8 million people worldwide are diagnosed with CD. In the United States, Chagas infection is not reported in all states; however, most reported CD cases are chronic infections. Chagas infection is characterized by two phases: an acute and a chronic phase. Until this present moment, no prophylactic or therapeutic human vaccine is available. However, in a recent study in a murine model, our group showed that the synthetic 20-merpeptide (DAENPGGEVFNDNKKGLSRV) …

Multiple Factors Regulate The Expression Of Sufcdsub In Streptococcus Mutans, Kassapa Ellepola, Lauren C. Guillot, Bradley Comeaux, Yiran Han, Jessica K. Kajfasz, Jacob P. Bitoun, Grace Spatafora, Jose A. Lemos, Zezhang T. Wen

School of Dentistry Faculty Publications

Introduction: The sufCDSUB gene cluster, encoding the sole iron-sulfur (Fe-S) cluster assembly system in S. mutans, was recently shown to be up-regulated in response to oxidative stressors and Fe limitation. Methods: In this study, luciferase reporter fusion assays, electrophoretic gel mobility shift assays (EMSA) and in vitro transcription assays (IVT) were used to dissect the cis- and trans-acting factors that regulate the expression of sufCDSUB. Results and discussion: Results showed deletion of perR, for the only Fur-family transcriptional regulator in S. mutans, resulted in > 5-fold increases in luciferase activity under the control of the sufCDSUB promoter (P < 0.01), as compared to the parent strain, UA159 when the reporter strains were grown in medium with no supplemental iron. Site-directed mutagenesis of a PerR-box in the promoter region led to elevation of the reporter activity by >1.6-fold (P < 0.01). In an EMSA, recombinant PerR (rPerR) was shown to bind to the cognate sufCDSUB promoter leading to mobility retardation. On the other hand, the reporter activity was increased by > 84-fold …

Limosilactobacillus Reuteri Ameliorates Maternal Separation Stress In Newborn Mice And Alters Subsequent Adult Behaviour, Z. M. Saleh, B. Okeugo, V. R. Venna, F. W. Blixt, V. A. Quaicoe, E. S. Park, S. Giorgberidze, Meng Luo, Christopher M. Taylor, J. M. Rhoads, Y. Liu

School of Medicine Faculty Publications

Maternal separation (MS) in mice results in behavioral deficits and gut microbiota dysbiosis that all persist into adulthood. Limosilactobacillus reuteri DSM 17938 modulates gut microbiota, alters systemic metabolites, and facilitates immune regulation. To assess the effect of DSM 17938 on biochemical and behavioural stress-associated changes, newborn mice were exposed to unpredictable MS (MSU) daily from day 7 to day 20 of life, with intragastric administration of DSM 17938 or PBS as control. Body weight, brain levels of cholecystokinin (CCK), glial fibrillary acidic protein (GFAP), corticosterone, and stool microbiota were assessed at day 21. Behaviour tests including Y-maze (YMT), Tail Suspension …

High Fat, High Sucrose Diet Promotes Increased Expression Of Ace2 Receptor In The Siv-Infected Host: Implications For Sars-Cov-2 Infection, Elizabeth C. Delery, Danielle E. Levitt, Angela M. Amedee, Patricia E. Molina, Liz Simon

School of Graduate Studies Faculty Publications

Introduction: People with pre-existing conditions, including metabolic comorbidities, are at greater risk for complications of SARS-CoV-2 infection and expression of machinery required for viral entry into host cells may be a contributing factor. This study tested the hypothesis that high fat, high sucrose diet (HFSD) and alcohol use increase expression of angiotensin converting enzyme 2 (ACE2) receptor and transmembrane serine protease 2 (TMPRSS2) in tissues isolated from simian immunodeficiency virus (SIV) infected macaques, the most clinically relevant model for the study of HIV. Methods: Biospecimens obtained from a longitudinal study of SIV-infected, antiretroviral therapy (ART)-treated female rhesus macaques (Macaca mulatta) …

Characterization Of High-Risk-Other Human Papillomavirus Genotypes In Papanicolaou Tests, High-Grade Squamous Intraepithelial Lesions, And Cervical Cancer, Caitlin E. Witt, Elizabeth F. Sutton, Ashley M. Stansbury, Ashley N. Winters, Luke C. Konur, Meng Luo, Jennifer E. Cameron, Beverly Ogden

School of Medicine Faculty Publications

Background: The objective of this study was to determine the human papillomavirus (HPV) genotypes of high-risk-other HPV Papanicolaou (Pap) tests and of biopsy tissues from patients with high-grade squamous intraepithelial lesion (HGSIL) or cervical cancer. High-risk-other HPV status was determined with the cobas HPV Test (Roche Diagnostics, North America) that identifies 12 high-risk, non-16/18 HPV genotypes. We hypothesized that we would find genotypes of HPV in our population that are not covered by the 9-valent HPV vaccine. Methods: For this retrospective cohort study, we randomly selected 50 high-risk-other HPV Pap test samples from 2018 from our pathology department registries for …

Adaptative Survival Of Aspergillus Fumigatus To Echinocandins Arises From Cell Wall Remodeling Beyond Β−1,3-Glucan Synthesis Inhibition, Malitha C. Dickwella Widanage, Isha Gautam, Daipayan Sarkar, Frederic Mentink-Vigier, Josh V. Vermaas, Shi You Ding, Andrew S. Lipton, Thierry Fontaine, Jean Paul Latgé, Ping Wang, Tuo Wang

School of Graduate Studies Faculty Publications

Antifungal echinocandins inhibit the biosynthesis of β−1,3-glucan, a major and essential polysaccharide component of the fungal cell wall. However, the efficacy of echinocandins against the pathogen Aspergillus fumigatus is limited. Here, we use solid-state nuclear magnetic resonance (ssNMR) and other techniques to show that echinocandins induce dynamic changes in the assembly of mobile and rigid polymers within the A. fumigatus cell wall. The reduction of β−1,3-glucan induced by echinocandins is accompanied by a concurrent increase in levels of chitin, chitosan, and highly polymorphic α−1,3-glucans, whose physical association with chitin maintains cell wall integrity and modulates water permeability. The rearrangement of …

Morgs3 Functions In Intracellular Reactive Oxygen Species Perception-Integrated Camp Signaling To Promote Appressorium Formation In Magnaporthe Oryzae, Ruiming Zhang, Xinyu Liu, Jiayun Xu, Chen Chen, Zhaoxuan Tang, Chengtong Wu, Xinyue Li, Lei Su, Muxing Liu, Leiyun Yang, Gang Li, Haifeng Zhang, Ping Wang, Zhengguang Zhang

School of Graduate Studies Faculty Publications

Regulator of G-protein signaling (RGS) proteins exhibit GTPase-accelerating protein activities to govern G-protein function. In the rice blast fungus Magnaporthe oryzae, there is a family of at least eight RGS and RGS-like proteins (MoRgs1 to MoRgs8), each exhibiting distinct or shared functions in the growth, appressorium formation, and pathogenicity. MoRgs3 recently emerged as one of the crucial regulators that senses intracellular oxidation during appressorium formation. To explore this unique regulatory mechanism of MoRgs3, we identified the nucleoside diphosphate kinase MoNdk1 that interacts with MoRgs3. MoNdk1 phosphorylates MoRgs3 under induced intracellular reactive oxygen species levels, and MoRgs3 phosphorylation is required for …

Standard Rodent Diets Differentially Impact Alcohol Consumption, Preference, And Gut Microbiome Diversity, Aline Zaparte, Evan Dore, Selby White, Franciely Paliarin, Cameron Gabriel, Katherine Copenhaver, Samhita Basavanhalli, Emily Garcia, Rishith Vaddavalli, Meng Luo, Christopher M. Taylor, David Allen Welsh, Rajani Maiya

School of Graduate Studies Faculty Publications

Alcohol use disorder (AUD) is a complex and widespread disease with limited pharmacotherapies. Preclinical animal models of AUD use a variety of voluntary alcohol consumption procedures to recapitulate different phases of AUD, including binge alcohol consumption and dependence. However, voluntary alcohol consumption in mice is widely variable, making it difficult to reproduce results across labs. Accumulating evidence indicates that different brands of commercially available rodent chow can profoundly influence alcohol intake. In this study, we investigated the effects of three commercially available and widely used rodent diet formulations on alcohol consumption and preference in C57BL/6 J mice using the 24 …

Serine Deamination By Human Serine Racemase Synergizes With Antibiotics To Curtail The Replication Of Chlamydia Trachomatis, Patricia D. Mott, Arnold H. Zea, Jamiya Lewis, Oygul Mirzalieva, Ashok A. Aiyar

School of Medicine Faculty Publications

The obligate intracellular bacterium, Chlamydia trachomatis, has evolved to depend on its human host for many metabolites, including most amino acids and three of the four nucleotides. Given this, it is not surprising that depletion of a single amino acid in the host cell growth medium blocks chlamydial replication. Paradoxically, supra-normal levels of some amino acids also block productive replication of Chlamydia. Here, we have determined how elevated serine levels, generated by exogenous supplementation, impede chlamydial inclusion development and reduce the generation of infectious progeny. Our findings reveal that human serine racemase, which is broadly expressed in multiple tissues, potentiates …

Gut Microbial Dysbiosis Differs In Two Distinct Cachectic Tumor-Bearing Models Consuming The Same Diet, Lauri O. Byerley, Brittany Lorenzen, Hsiao Man Chang, William G. Hartman, Michael J. Keenan, Ryan Page, Meng Luo, Scot E. Dowd, Christopher M. Taylor

School of Medicine Faculty Publications

The impact of cancer cachexia on the colonic microbiota is poorly characterized. This study assessed the effect of two cachectic-producing tumor types on the gut microbiota to determine if a similar dysbiosis could be found. In addition, it was determined if a diet containing an immunonutrient-rich food (walnuts) known to promote the growth of probiotic bacteria in the colon could alter the dysbiosis and slow cachexia. Male Fisher 344 rats were randomly assigned to a semi-purified diet with or without walnuts. Then, within each diet group, rats were further assigned randomly to a treatment group: tumor-bearing ad libitum fed (TB), …

Momkk1 And Moatg1 Dichotomously Regulating Autophagy And Pathogenicity Through Moatg9 Phosphorylation In Magnaporthe Oryzae, Yun Kong, Pusheng Guo, Jiayun Xu, Jiaxu Li, Miao Wu, Ziqi Zhang, Yifan Wang, Xinyu Liu, Leiyun Yang, Muxing Liu, Haifeng Zhang, Ping Wang, Zhengguang Zhang

School of Medicine Faculty Publications

Autophagy is a central biodegradation pathway critical in eliminating intracellular cargo to maintain cellular homeostasis and improve stress resistance. At the same time, the key component of the mitogen-activated protein kinase cascade regulating cell wall integrity signaling MoMkk1 has an essential role in the autophagy of the rice blast fungus Magnaporthe oryzae. Still, the mechanism of how MoMkk1 regulates autophagy is unclear. Interestingly, we found that MoMkk1 regulates the autophagy protein MoAtg9 through phosphorylation. MoAtg9 is a transmembrane protein subjected to phosphorylation by autophagy-related protein kinase MoAtg1. Here, we provide evidence demonstrating that MoMkk1-dependent MoAtg9 phosphorylation is required for phospholipid …

Tailoring T Fh Profiles Enhances Antibody Persistence To A Clade C Hiv-1 Vaccine In Rhesus Macaques, Anil Verma, Chase E. Hawes, Sonny R. Elizaldi, Justin C. Smith, Dhivyaa Rajasundaram, Gabriel Kristian Pedersen, Xiaoying Shen, La Tonya D. Williams, Georgia D. Tomaras, Pamela A. Kozlowski, Rama R. Amara, Smita S. Iyer

School of Medicine Faculty Publications

CD4 T follicular helper cells (Tfh) are essential for establishing serological memory and have distinct helper attributes that impact both the quantity and quality of the antibody response. Insights into Tfh subsets that promote antibody persistence and functional capacity can critically inform vaccine design. Based on the Tfh profiles evoked by the live attenuated measles virus vaccine, renowned for its ability to establish durable humoral immunity, we investigated the potential of a Tfh1/17 recall response during the boost phase to enhance persistence of HIV-1 Envelope (Env) antibodies in rhesus macaques. Using a DNA-prime encoding gp160 antigen and Tfh polarizing cytokines …

Probiotic Limosilactobacillus Reuteri Dsm 17938 Changes Foxp3 Deficiency-Induced Dyslipidemia And Chronic Hepatitis In Mice, Erini Nessim Kostandy, Ji Ho Suh, Xiangjun Tian, Beanna Okeugo, Erin Rubin, Sara Shirai, Meng Luo, Christopher M. Taylor, Kang Ho Kim, J. Marc Rhoads, Yuying Liu

School of Medicine Faculty Publications

The probiotic Limosilactobacillus reuteri DSM 17938 produces anti-inflammatory effects in scurfy (SF) mice, a model characterized by immune dysregulation, polyendocrinopathy, enteropathy, and X-linked inheritance (called IPEX syndrome in humans), caused by regulatory T cell (Treg) deficiency and is due to a Foxp3 gene mutation. Considering the pivotal role of lipids in autoimmune inflammatory processes, we investigated alterations in the relative abundance of lipid profiles in SF mice (± treatment with DSM 17938) compared to normal WT mice. We also examined the correlation between plasma lipids and gut microbiota and circulating inflammatory markers. We noted a significant upregulation of plasma lipids …

Microbial Interactions Among Gardnerella, Prevotella And Fannyhessea Prior To Incident Bacterial Vaginosis: Protocol For A Prospective, Observational Study, Christina A. Muzny, Jacob H. Elnaggar, Lúcia G.V. Sousa, Ângela Lima, Kristal J. Aaron, Isaac C. Eastlund, Keonte J. Graves, Chaoling Dong, Olivia T. Van Gerwen, Meng Luo, Ashutosh Tamhane, Dustin Long, Nuno Cerca, Christopher M. Taylor

School of Graduate Studies Faculty Publications

Introduction The aetiology of bacterial vaginosis (BV), a biofilm-associated vaginal infection, remains unknown. Epidemiologic data suggest that it is sexually transmitted. BV is characterised by loss of lactic acid-producing lactobacilli and an increase in facultative and strict anaerobic bacteria. Gardnerella spp are present in 95%–100% of cases; Gardnerella vaginalis has been found to be more virulent than other BV-associated bacteria (BVAB) in vitro. However, G. vaginalis is found in women with normal vaginal microbiota and colonisation is not sufficient for BV development. We hypothesise that Gardnerella spp initiate BV biofilm formation, but incident BV (iBV) requires incorporation of other key …

Autophagy And Cell Wall Integrity Pathways Coordinately Regulate The Development And Pathogenicity Through Moatg4 Phosphorylation In Magnaporthe Oryzae, Pusheng Guo, Yurong Wang, Jiayun Xu, Zhixiang Yang, Ziqi Zhang, Jinyi Qian, Jiexiong Hu, Ziyi Yin, Leiyun Yang, Muxing Liu, Xinyu Liu, Gang Li, Haifeng Zhang, Ryan Rumsey, Ping Wang, Zhengguang Zhang

School of Medicine Faculty Publications

Autophagy and Cell wall integrity (CWI) signaling are critical stress-responsive processes during fungal infection of host plants. In the rice blast fungus Magnaporthe oryzae, autophagy-related (ATG) proteins phosphorylate CWI kinases to regulate virulence; however, how autophagy interplays with CWI signaling to coordinate such regulation remains unknown. Here, we have identified the phosphorylation of ATG protein MoAtg4 as an important process in the coordination between autophagy and CWI in M. oryzae. The ATG kinase MoAtg1 phosphorylates MoAtg4 to inhibit the deconjugation and recycling of the key ATG protein MoAtg8. At the same time, MoMkk1, a core kinase of CWI, also phosphorylates …

Targeted Repression Of Topa By Crispri Reveals A Critical Function For Balanced Dna Topoisomerase I Activity In The Chlamydia Trachomatis Developmental Cycle, Li Shen, Leiqiong Gao, Abigail R. Swoboda, Scot P. Ouellette

School of Medicine Faculty Publications

Chlamydia trachomatis is an obligate intracellular bacterium that is responsible for the most prevalent bacterial sexually transmitted infection. Changes in DNA topology in this pathogen have been linked to its pathogenicity-associated developmental cycle. Here, evidence is provided that the balanced activity of DNA topoisomerases contributes to controlling Chlamydia developmental processes. Utilizing catalytically inactivated Cas12 (dCas12)-based clustered regularly interspaced short palindromic repeats interference (CRISPRi) technology, we demonstrate targeted knockdown of chromosomal topA transcription in C. trachomatis without detected toxicity of dCas12. Repression of topA impaired the developmental cycle of C. trachomatis mostly through disruption of its differentiation from a replicative form …

Interplay Between Acetylation And Ubiquitination Of Imitation Switch Chromatin Remodeler Isw1 Confers Multidrug Resistance In Cryptococcus Neoformans, Yang Meng, Yue Ni, Zhuoran Li, Tianhang Jiang, Tianshu Sun, Yanjian Li, Xindi Gao, Hailong Li, Chenhao Suo, Chao Li, Sheng Yang, Tian Lan, Guojian Liao, Tongbao Liu, Ping Wang, Chen Ding

School of Medicine Faculty Publications

Cryptococcus neoformans poses a threat to human health, but anticryptococcal therapy is hampered by the emergence of drug resistance, whose underlying mechanisms remain poorly understood. Herein, we discovered that Isw1, an imitation switch chromatin remodeling ATPase, functions as a master modulator of genes responsible for in vivo and in vitro multidrug resistance in C. neoformans. Cells with the disrupted ISW1 gene exhibited profound resistance to multiple antifungal drugs. Mass spectrometry analysis revealed that Isw1 is both acetylated and ubiquitinated, suggesting that an interplay between these two modification events exists to govern Isw1 function. Mutagenesis studies of acetylation and ubiquitination sites …

Genital Tract Infections, The Vaginal Microbiome And Gestational Age At Birth Among Pregnant Women In South Africa: A Cohort Study Protocol, Ranjana M.S. Gigi, Mandisa M. Mdingi, Hyunsul Jung, Shantelle Claassen-Weitz, Lukas Bütikofer, Jeffrey D. Klausner, Christina A. Muzny, Christopher M. Taylor, Janneke H.H.M. Van De Wijgert, Remco P.H. Peters, Nicola Low

School of Medicine Faculty Publications

Introduction Preterm birth complications are the most common cause of death in children under 5 years. The presence of multiple microorganisms and genital tract inflammation could be the common mechanism driving early onset of labour. South Africa has high levels of preterm birth, genital tract infections and HIV infection among pregnant women. We plan to investigate associations between the presence of multiple lower genital tract microorganisms in pregnancy and gestational age at birth. Methods and analysis This cohort study enrols around 600 pregnant women at one public healthcare facility in East London, South Africa. Eligible women are ≥18 years and …

Association Of Chlamydia Trachomatis Burden With The Vaginal Microbiota, Bacterial Vaginosis, And Metronidazole Treatment, Caleb M. Ardizzone, Christopher M. Taylor, Evelyn Toh, Rebecca A. Lillis, Jacob H. Elnaggar, John W. Lammons, Patricia Dehon Mott, Emily L. Duffy, Li Shen, Alison J. Quayle

School of Graduate Studies Faculty Publications

Bacterial vaginosis (BV), a dysbiosis of the vaginal microbiota, is a common coinfection with Chlamydia trachomatis (Ct), and BV-associated bacteria (BVAB) and their products have been implicated in aiding Ct evade natural immunity. Here, we determined if a non-optimal vaginal microbiota was associated with a higher genital Ct burden and if metronidazole, a standard treatment for BV, would reduce Ct burden or aid in natural clearance of Ct infection. Cervicovaginal samples were collected from women at enrollment and, if testing positive for Ct infection, at a follow-up visit approximately one week later. Cervical Ct burden was assessed by inclusion forming …

Methionine Biosynthesis Enzyme Momet2 Is Required For Rice Blast Fungus Pathogenicity By Promoting Virulence Gene Expression Via Reducing 5mc Modification, Huimin Li, Pengcheng Mo, Jun Zhang, Zhuoer Xie, Xinyu Liu, Han Chen, Leiyun Yang, Muxing Liu, Haifeng Zhang, Ping Wang, Zhengguang Zhang

School of Medicine Faculty Publications

The emergence of fungicide resistance severely threatens crop production by limiting the availability and application of established fungicides. Therefore, it is urgent to identify new fungicidal targets for controlling plant diseases. Here, we characterized the function of a conserved homoserine O-acetyltransferase (HOA) from the rice blast fungus Magnaporthe oryzae that could serve as the candidate antifungal target. Deletion of the MoMET2 and MoCYS2 genes encoding HOAs perturbed the biosynthesis of methionine and S-adenyl methionine, a methyl group donor for epigenetic modifications, and severely attenuated the development and virulence of M. oryzae. The ΔMomet2 mutant is significantly increased in 5-methylcytosine (5mC) …

Investigating Novel Chemotherapeutics Against The Parasite Toxoplasma Gondii, Braydon Dreher

Theses/Capstones/Creative Projects

Toxoplasma gondii, an intracellular protozoan, is a globally prevalent parasite due to the infectivity of T. gondii with nearly 2.5 billion people affected worldwide. Toxoplasma gondii can cause toxoplasmosis, which is a disease acquired through the consumption of undercooked meat or found in the feces of felines, and often leads to profound neuropathology and potentially death. Currently, acute toxoplasmosis is treated with pyrimethamine and sulfadiazine, which is a combination of an antiprotozoal and a sulfonamide. This combination of drugs directly targets the acute stage of infection but has failed to eliminate or impact the chronic carriage of bradyzoites while …

Impact Of Testosterone Use On The Vaginal Microbiota Of Transgender Men, Including Susceptibility To Bacterial Vaginosis: Study Protocol For A Prospective, Observational Study, Christina A. Muzny, Olivia T. Van Gerwen, Julia A. Schroeder, Emma Sophia Kay-Duncan, Krishmita Siwakoti, Kristal J. Aaron, Isaac C. Eastlund, Keonte J. Graves, Jacob H. Elnaggar, Ashutosh Tamhane, Dustin Long, Nicholas Van Wagoner, Evelyn Toh, Christopher M. Taylor

School of Graduate Studies Faculty Publications

Introduction The effect of testosterone (T) therapy on the vaginal microbiota of transgender men (TGM) is not well characterised, although one cross-sectional study comparing the vaginal microbiota of cisgender women to TGM on T≥1 year found that, in 71% of the TGM, the vaginal microbiota was less likely to be Lactobacillus-dominated and more likely to be enriched with >30 other bacterial species, many associated with bacterial vaginosis (BV). This prospective study aims to investigate changes in the composition of the vaginal microbiota over time in TGM who retain their natal genitalia (ie, vagina) and initiate T. In addition, we will …

Infection And Transmission Determinants Of Flea-Borne Rickettsioses, Hanna J. Laukaitis

Graduate Theses and Dissertations (2019 - present)

The genus Rickettsia is comprised of Gram-negative, obligate intracellular bacteria that are spread by hematophagous arthropods. Elucidating the factors conferring rickettsial virulence has perplexed investigators for decades, complicated by the lack of efficient genetic tools necessary to uncover rickettsial- and vector-specific factors contributing to persistence. The advent of transposon mutagenesis has enabled the field to make vast developments in uncovering novel rickettsial mechanisms utilized in various host backgrounds. Thus, the aim of this study was to generate Rickettsia felis transposon mutants and characterize novel phenotypes associated with genetic disruption in an arthropod background. Distribution of rickettsiae is reliant on the …

Solid-State Nmr Analysis Of Unlabeled Fungal Cell Walls From Aspergillus And Candida Species, Liyanage D. Fernando, Malitha C. Dickwella Widanage, S. Chandra Shekar, Frederic Mentink-Vigier, Ping Wang, Sungsool Wi, Tuo Wang

School of Medicine Faculty Publications

Fungal infections cause high mortality in immunocompromised individuals, which has emerged as a significant threat to human health. The efforts devoted to the development of antifungal agents targeting the cell wall polysaccharides have been hindered by our incomplete picture of the assembly and remodeling of fungal cell walls. High-resolution solid-state nuclear magnetic resonance (ss NMR) studies have substantially revised our understanding of the polymorphic structure of polysaccharides and the nanoscale organization of cell walls in Aspergillus fumigatus and multiple other fungi. However, this approach requires 13C/15N-enrichment of the sample being studied, severely restricting its application. Here we employ the dynamic …