Medical Microbiology Commons^™

Typhlitis In A Neutropenic Patient, Alice He Bs, Wern Lynn Ng Md, Lay She Ng Md, Si Yuan Khor Md, Chandi Garg Md

Tower Health Research Day

No abstract provided.

Lncrna Impact On Regorafenib Resistance In Colorectal Cancer, Ricardo Pequeno Bracho, Kyle Doxtater, Dennis Kwabiah, Yamile Abuchard Anaya, Sophia Leslie, Mohammad Shabir Hussain, Manish Tripathi

Research Symposium

Cancer metastasis is one of the deadliest aspects of the disease, with about 90% of all cancer-related deaths due to its development at different sites within the body. Colorectal cancer (CRC) is the second leading cause of cancer mortality in the United States, with 40-50% of all patients developing metastasis at some point during their fight with the disease. With the approval of Regorafenib for treating metastatic colorectal cancer, steps have been taken to combat metastasis in colorectal cancer. A vital aspect of the development of metastasis is the development of resistance to first-line chemotherapy. Regorafenib is an oral small-molecule …

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 …

Targeted Treatment For Kras12d For Pdac Treatment, Ana Bulnes, Orlando Garcia, Poornima Devi Shaji, Melissa Elizondo, Swathi Holla, Nirnoy Dan, Anupam Dhasmana, Shabnam Malik, Murali Yallapu, Stephen Behrman

Research Symposium

Introduction: Cellular stress is known to function in synergistic cooperation with oncogenic mutations during tumorigenesis to drive cancer progression. Oncogenic RAS is a strong inducer of a variety of pro-tumorigenic cellular stresses, and also enhances the ability of cells to tolerate these stresses through multiple mechanisms that leads to resistance to chemotherapy and to therapies that target the RAS pathway. Pancreatic Ductal Adenocarcinoma (PDAC) patients exhibit extremely poor prognosis. KRAS mutation on codon-12 is present in 70–95% of PDAC cases and it drives stress-adaptive mechanisms, PDAC growth and progression. Galectin-1 (Gal-1) is present in both PDAC and stromal cells, being …

Studying The Molecular Mechanism Of Hepatocellular Carcinoma, Shabnam Malik, Mohammed Sikander, S. Mishra, Daniel Zubieta, S. K. Jain, Deepshikha Pande Katare, Meena Jaggi, Subhash Chauhan

Research Symposium

Background: Hepatocellular carcinoma (HCC) has a poor prognosis due to ineffective therapeutic modality and lack of early diagnostic marker. Accumulating studies have shown that elevated expression of mucin 13 as potential oncogene and predictive biomarker for various cancer. However, very little is known about its expression and function for development and progression of HCC.

Objective: To investigate mucin 13 expression in chemically induced hepatocellular carcinoma model.

Methodology: Diethyl nitrosamine (DEN) and 2-Acetylaminofluorene (2-AAF) induced method was employed for the development of hepatocellular carcinoma in Male Wistar rats. Serum and tissues were collected at regular intervals of time and routinely validated …

Rare Case Of Mycobacterium Avium Complex Peritonitis In A Patient With Multiple Myeloma Undergoing Peritoneal Dialysis, Sacide S. Ozgur, Nida Ansari, Dhruv Patel, Ryan Rahman, Raymond Shih

Journal of Community Hospital Internal Medicine Perspectives

Mycobacterium avium complex (MAC) infections can present as a variety of severe diseases. While it has a predilection for immunocompromised patients such as those with Human immunodeficiency virus (HIV), it can also affect immunocompetent patients as well. One of the rare yet severe diseases that MAC infections can present is MAC peritonitis. Often hard to distinguish from other causes of peritonitis, high clinical suspicion should be maintained for those who are susceptible. Here we present an 85-year-old female with a past medical history of end-stage renal disease on peritoneal dialysis who presented with nausea and vomiting. She was found to …

Metabolism Shapes Immune Responses To Staphylococcus Aureus., Prabhakar Arumugam, Tammy Kielian

Journal Articles: Pathology and Microbiology

BACKGROUND: Staphylococcus aureus (S. aureus) is a common cause of hospital- and community-acquired infections that can result in various clinical manifestations ranging from mild to severe disease. The bacterium utilizes different combinations of virulence factors and biofilm formation to establish a successful infection, and the emergence of methicillin- and vancomycin-resistant strains introduces additional challenges for infection management and treatment.

SUMMARY: Metabolic programming of immune cells regulates the balance of energy requirements for activation and dictates pro- versus anti-inflammatory function. Recent investigations into metabolic adaptations of leukocytes and S. aureus during infection indicate that metabolic crosstalk plays a crucial role in …

Metabolic Diversity Of Human Macrophages: Potential Influence On Staphylococcus Aureus Intracellular Survival, Blake P. Bertrand, Dhananjay Shinde, Vinai C. Thomas, Marvin Whiteley, Carolyn B. Ibberson, Tammy Kielian

Journal Articles: Pathology and Microbiology

Staphylococcus aureus is a leading cause of medical device-associated biofilm infections. This is influenced by the ability of S. aureus biofilm to evade the host immune response, which is partially driven by the anti-inflammatory cytokine interleukin-10 (IL-10). Here, we show that treatment of human monocyte-derived macrophages (HMDMs) with IL-10 enhanced biofilm formation, suggesting that macrophage anti-inflammatory programming likely plays an important role during the transition from planktonic to biofilm growth. To identify S. aureus genes that were important for intracellular survival in HMDMs and how this was affected by IL-10, transposon sequencing was performed. The size of the S. aureus …

Elucidating Granulocytic Myeloid-Derived Suppressor Cell Heterogeneity During Staphylococcus Aureus Biofilm Infection, Blake P. Bertrand, Cortney E. Heim, Scott A. Koepsell, Tammy Kielian

Journal Articles: Pathology and Microbiology

Myeloid-derived suppressor cells (MDSCs) are pathologically activated immature myeloid cells with immunosuppressive activity that expand during chronic inflammation, such as cancer and prosthetic joint infection (PJI). Myeloid-derived suppressor cells can be broadly separated into 2 populations based on surface marker expression and function: monocytic myeloid-derived suppressor cells (M-MDSCs) and granulocytic myeloid-derived suppressor cells (G-MDSCs). Granulocytic myeloid-derived suppressor cells are the most abundant leukocyte infiltrate during PJI; however, how this population is maintained in vivo and cellular heterogeneity is currently unknown. In this study, we identified a previously unknown population of Ly6G+Ly6C+F4/80+MHCII+ MDSCs during PJI that displayed immunosuppressive properties ex vivo. …

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 …

Sutterella And Its Metabolic Pathways Positively Correlate With Vaccine-Elicited Antibody Responses In Infant Rhesus Macaques, Danting Jiang, Ria Goswami, Maria Dennis, Holly Heimsath, Pamela A. Kozlowski, Amir Ardeshir, Koen K.A. Van Rompay, Kristina De Paris, Sallie R. Permar, Neeraj K. Surana

School of Graduate Studies Faculty Publications

Introduction: It is becoming clearer that the microbiota helps drive responses to vaccines; however, little is known about the underlying mechanism. In this study, we aimed to identify microbial features that are associated with vaccine immunogenicity in infant rhesus macaques. Methods: We analyzed 16S rRNA gene sequencing data of 215 fecal samples collected at multiple timepoints from 64 nursery-reared infant macaques that received various HIV vaccine regimens. PERMANOVA tests were performed to determine factors affecting composition of the gut microbiota throughout the first eight months of life in these monkeys. We used DESeq2 to identify differentially abundant bacterial taxa, PICRUSt2 …

Investigating The Microbiome Of The Eye And The Potential Of Probiotic Use In Optometry, Rachel Hartgerink

Theses/Capstones/Creative Projects

While the eye was once considered free of resident bacteria due to its efficient immunity mechanisms, recent studies have determined that most healthy eyes contain a variety of microbiota. Many studies have been aimed at classifying bacteria that are part of the core microbiome of the eye and the conditions under which they differ. As with gut health, a dysbiosis of ocular bacteria could correlate to disease, which presents the idea of treatment with probiotics to help regulate the microbiota of the eye. This study utilized growth assays to determine a common probiotic’s effect on bacteria that can be found …

The Implications Of Ferroptosis In Antibiotic Resistance, Marysol Hohl

Senior Honors Theses

Bacterial infections in the United States are becoming increasingly resistant to existing antibiotic treatments. Due to projected increases in resistance and the recent decrease in novel antibacterials, experts have determined that the United States is in the “post-antibiotic era.” The scientific community has failed to resolve resistance despite the continual discovery of new antibiotic compounds. In the past decade, a novel form of cell death called ferroptosis has been implicated in antibiotic treatment by employing the use of nanotechnology. This literature review will describe the problem of bacterial resistance and demonstrate how current research is pioneering a new age of …

Dynamics Of Serum-Neutralizing Antibody Responses In Vaccinees Through Multiple Doses Of The Bnt162b2 Vaccine, Jared Sheehan, Caleb M. Ardizzone, Mayank Khanna, Amber J. Trauth, Michael E. Hagensee, Alistair J. Ramsay

School of Graduate Studies Faculty Publications

SARS-CoV-2 mRNA vaccines are administered as effective prophylactic measures for reducing virus transmission rates and disease severity. To enhance the durability of post-vaccination immunity and combat SARS-CoV-2 variants, boosters have been administered to two-dose vaccinees. However, long-term humoral responses following booster vaccination are not well characterized. A 16-member cohort of healthy SARS-CoV-2 naïve participants were enrolled in this study during a three-dose BNT162b2 vaccine series. Serum samples were collected from vaccinees over 420 days and screened for antigen (Ag)-specific antibody titers, IgG subclass distribution, and neutralizing antibody (nAb) responses. Vaccine boosting restored peak Ag-specific titers with sustained α-RBD IgG and …

How Irish Medical Scientists Can Assist In The Improved Diagnosis Of Disease - Infectious Mononucleosis (Im) A Case In Point, Patrick Naughton

ORBioM (Open Research BioSciences Meeting)

The Epstein-Barr Virus (EBV) or human herpesvirus 4 (HHV-4) is the sole etiologic agent of the acute illness in humans described either as infectious mononucleosis (IM), or glandular fever. IM is a self-limiting disease with various but transient symptoms which include fever, fatigue, malaise, sore throat, swollen lymph glands (particularly of the neck), swollen liver and spleen. Diagnosis relies on clear, timely and informative laboratory test results. Patients with primary IM infection often present on investigation with a well-documented population of atypical/plasmacytoid lymphocytes. The qualitative detection of heterophile antibodies (HAs) is also a useful aid in the diagnosis of primary …

In Vivo Treatment With Insulin-Like Growth Factor 1 Reduces Ccr5 Expression On Vaccine-Induced Activated Cd4+ T-Cells, Massimiliano Bissa, Veronica Galli, Luca Schifanella, Monica Vaccari, Mohammad Arif Rahman, Giacomo Gorini, Nicolò Binello, Sarkis Sarkis, Anna Gutowska, Isabela Silva De Castro, Melvin N. Doster, Ramona Moles, Guido Ferrari, Xiaoying Shen, Georgia D. Tomaras, David C. Montefiori, Kombo F. N’Guessan, Dominic Paquin-Proulx, Pamela A. Kozlowski, David J. Venzon, Hyoyoung Choo-Wosoba, Matthew W. Breed, Joshua Kramer, Genoveffa Franchini

School of Graduate Studies Faculty Publications

At the heart of the DNA/ALVAC/gp120/alum vaccine’s efficacy in the absence of neutralizing antibodies is a delicate balance of pro- and anti-inflammatory immune responses that effectively decreases the risk of SIVmac251 acquisition in macaques. Vaccine efficacy is linked to antibodies recognizing the V2 helical conformation, DC-10 tolerogenic dendritic cells eliciting the clearance of apoptotic cells via efferocytosis, and CCR5 downregulation on vaccine-induced gut homing CD4+ cells. RAS activation is also linked to vaccine efficacy, which prompted the testing of IGF-1, a potent inducer of RAS activation with vaccination. We found that IGF-1 changed the hierarchy of V1/V2 epitope recognition and …

Tumor-Resident Lactobacillus Iners Confer Chemoradiation Resistance Through Lactate-Induced Metabolic Rewiring, Lauren E. Colbert, Molly B. El Alam, Rui Wang, Tatiana Karpinets, David Lo, Erica J. Lynn, Timothy A. Harris, Jacob H. Elnaggar, Kyoko Yoshida-Court, Katarina Tomasic, Julianna K. Bronk, Julie Sammouri, Ananta V. Yanamandra, Adilene V. Olvera, Lily G. Carlin, Travis Sims, Andrea Y. Delgado Medrano, Tatiana Cisneros Napravnik, Madison O'Hara, Daniel Lin, Chike O. Abana, Hannah X. Li, Patricia J. Eifel, Anuja Jhingran, Melissa Joyner, Lilie Lin, Lois M. Ramondetta, Andrew M. Futreal

School of Medicine Faculty Publications

Tumor microbiota can produce active metabolites that affect cancer and immune cell signaling, metabolism, and proliferation. Here, we explore tumor and gut microbiome features that affect chemoradiation response in patients with cervical cancer using a combined approach of deep microbiome sequencing, targeted bacterial culture, and in vitro assays. We identify that an obligate L-lactate-producing lactic acid bacterium found in tumors, Lactobacillus iners, is associated with decreased survival in patients, induces chemotherapy and radiation resistance in cervical cancer cells, and leads to metabolic rewiring, or alterations in multiple metabolic pathways, in tumors. Genomically similar L-lactate-producing lactic acid bacteria commensal to other …