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Pathogenic Microbiology Commons

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Pseudomonas Aeruginosa Cleaves The Decoding Center Of Caenorhabditis Elegans Ribosomes, Alejandro Vasquez-Rifo, Emiliano P. Ricci, Victor R. Ambros 2020 University of Massachusetts Medical School

Pseudomonas Aeruginosa Cleaves The Decoding Center Of Caenorhabditis Elegans Ribosomes, Alejandro Vasquez-Rifo, Emiliano P. Ricci, Victor R. Ambros

Open Access Publications by UMMS Authors

Pathogens such as Pseudomonas aeruginosa advantageously modify animal host physiology, for example, by inhibiting host protein synthesis. Translational inhibition of insects and mammalian hosts by P. aeruginosa utilizes the well-known exotoxin A effector. However, for the infection of Caenorhabditis elegans by P. aeruginosa, the precise pathways and mechanism(s) of translational inhibition are not well understood. We found that upon exposure to P. aeruginosa PA14, C. elegans undergoes a rapid loss of intact ribosomes accompanied by the accumulation of ribosomes cleaved at helix 69 (H69) of the 26S ribosomal RNA (rRNA), a key part of ribosome decoding center. H69 cleavage ...


Bacteremia And Endocarditis, Steven C. Hatch 2020 University of Massachusetts Medical School

Bacteremia And Endocarditis, Steven C. Hatch

PEER Liberia Project

This presentation provides an overview of the pathogens that cause bacteremia and endocarditis. Manifestations, pathology and treatment are discussed. The goals of the presentation are: Consider major pathogens that cause bacteremia and endocarditis in both adults and children; Discuss pathogenesis; Review clinical manifestations; Discuss basic treatment strategies; and Highlight useful sources of information.


Increasing Antibiotic Resistance In Shigella Bacteria In The United States, William J. Pharr 2020 Georgia College and State University

Increasing Antibiotic Resistance In Shigella Bacteria In The United States, William J. Pharr

The Corinthian

Shigella bacteria cause half a million infections, 6,000 hospitalizations, and 70 deaths annually in the United States. These bacteria are of particular concern due to their high survivability, low infectious dose, and high adaptability. Cases of shigellosis from Shigella sonnei are becoming a more prevalent issue in the U.S. as the bacteria continues to develop higher resistance to today’s strongest antibiotics. Much of this resistance is connected to the exchange of genes between strains of Shigella due to insertion sequences (IS), intercontinental travel, and men who have sex with men (MSM). As a result of increased resistance ...


Investigating Microbial And Host Factors That Modulate Severity Of Clostridioides Difficile Associated Disease, Armando Lerma 2020 University of Nebraska-Lincoln

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

Dissertations, Theses, & Student Research in Food Science and Technology

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 ...


Evaluation Of Semi-Quantitative Compared To Quantitative Cultures Of Tracheal Aspirates For The Yield Of Culturable Respiratory Pathogens - A Cross-Sectional Study, Salima Rattani, Joveria Farooqi, Ghazala Jabeen, Saeeda Chandio, Qaiser Kash, Aijaz Khan, Kauser Jabeen 2020 Aga Khan University

Evaluation Of Semi-Quantitative Compared To Quantitative Cultures Of Tracheal Aspirates For The Yield Of Culturable Respiratory Pathogens - A Cross-Sectional Study, Salima Rattani, Joveria Farooqi, Ghazala Jabeen, Saeeda Chandio, Qaiser Kash, Aijaz Khan, Kauser Jabeen

Department of Pathology and Laboratory Medicine

Background: Diagnosis of lower respiratory tract infections (LRTI) depends on the presence of clinical, radiological and microbiological findings. Endotracheal suction aspirate (ETSA) is the commonest respiratory sample sent for culture from intubated patients. Very few studies have compared quantitative and semi-quantitative processing of ETSA cultures for LRTI diagnosis. We determined the diagnostic accuracy of quantitative and semi-quantitative ETSA culture for LRTI diagnosis, agreement between the quantitative and semi quantitative culture techniques and the yield of respiratory pathogens with both methods.
Methods: This was a cross-sectional study conducted at the Aga Khan University clinical laboratory, Karachi, Pakistan. One hundred and seventy-eight ...


A Natural Polymorphism Of Mycobacterium Tuberculosis In The Esxh Gene Disrupts Immunodomination By The Tb10.4-Specific Cd8 T Cell Response, Rujapak Sutiwisesak, Nathan D. Hicks, Shayla Boyce, Kenan C. Murphy, Kadamba Papavinasasundaram, Stephen M. Carpenter, Julie Boucau, Neelambari Joshi, Sylvie Le Gall, Sarah M. Fortune, Christopher M. Sassetti, Samuel M. Behar 2020 University of Massachusetts Medical School

A Natural Polymorphism Of Mycobacterium Tuberculosis In The Esxh Gene Disrupts Immunodomination By The Tb10.4-Specific Cd8 T Cell Response, Rujapak Sutiwisesak, Nathan D. Hicks, Shayla Boyce, Kenan C. Murphy, Kadamba Papavinasasundaram, Stephen M. Carpenter, Julie Boucau, Neelambari Joshi, Sylvie Le Gall, Sarah M. Fortune, Christopher M. Sassetti, Samuel M. Behar

Open Access Publications by UMMS Authors

CD8 T cells provide limited protection against Mycobacterium tuberculosis (Mtb) infection in the mouse model. As Mtb causes chronic infection in mice and humans, we hypothesize that Mtb impairs T cell responses as an immune evasion strategy. TB10.4 is an immunodominant antigen in people, nonhuman primates, and mice, which is encoded by the esxH gene. In C57BL/6 mice, 30-50% of pulmonary CD8 T cells recognize the TB10.44-11 epitope. However, TB10.4-specific CD8 T cells fail to recognize Mtb-infected macrophages. We speculate that Mtb elicits immunodominant CD8 T cell responses to antigens that are inefficiently presented by infected ...


Immunometabolism In Caenorhabditis Elegans, Sarah M. Anderson, Read Pukkila-Worley 2020 University of Massachusetts Medical School

Immunometabolism In Caenorhabditis Elegans, Sarah M. Anderson, Read Pukkila-Worley

Open Access Publications by UMMS Authors

Here, we discuss 5 concepts that have emerged in studies of metabolic and immune interactions in C. elegans. The major emerging theme is that the immune response and the ability to survive pathogen infection is heavily influenced by pathogen-induced changes in host metabolism.


Microbial Diversity In The Sawmill Environment: Implications On The Health Of Sawmill Workers And Merchants, Nigeria, Ebere J. Okafor-Elenwo EJ, Odaro S. Imade Os, Osazee E. Izevbuwa EO 2020 Igbinedion university okada

Microbial Diversity In The Sawmill Environment: Implications On The Health Of Sawmill Workers And Merchants, Nigeria, Ebere J. Okafor-Elenwo Ej, Odaro S. Imade Os, Osazee E. Izevbuwa Eo

Journal of Bioresource Management

There is an increasingly high suspicion of occupational health diseases amongst workers in sawmill factories. Hence this study aimed to determine the microbial diversity in some sawmill factories in Okada, Edo State, Nigeria to evaluate potential implications of the factory’s processing area on the health of the workers and wood merchants. Bacteria and fungi count in the bioaerosols within the processing area of each factory was performed with the passive air sampling technique. While in the sawdust samples, microbial counts were carried out with the pour plate technique. Identification of the microbes was performed with macroscopic and microscopic examinations ...


Antibody Responses In Covid-19 Patients, Shuying Liu, Shan Lu 2020 SL Consulting

Antibody Responses In Covid-19 Patients, Shuying Liu, Shan Lu

COVID-19 Publications by UMMS Authors

Measuring virus-specific antibody responses to emerging pathogens is a well-established and highly useful tool to diagnose such infections, understand interactions between the immune system and pathogens, and provide potential clues for the development of vaccines or therapeutic agents against such pathogens. Since the beginning of 2020, the discovery of SARS-CoV-2 as the emerging virus responsible for the COVID-19 pandemic has provided new insight into the complexity of antibody responses to this dangerous virus. The current review aims to sort out diverse and sometimes seemingly confusing findings to put together a cohesive understanding on the profile of antibody responses elicited in ...


Contributions Of Ifn-Gamma And Granulysin To The Clearance Of Plasmodium Yoelii Blood Stage, Natalia Satchiko Hojo-Souza, Patrick Orestes de Azevedo, Julia Teixeira de Castro, Andrea Teixeira-Carvalho, Judy Lieberman, Caroline Junqueira, Ricardo T. Gazzinelli 2020 Oswaldo Cruz Foundation

Contributions Of Ifn-Gamma And Granulysin To The Clearance Of Plasmodium Yoelii Blood Stage, Natalia Satchiko Hojo-Souza, Patrick Orestes De Azevedo, Julia Teixeira De Castro, Andrea Teixeira-Carvalho, Judy Lieberman, Caroline Junqueira, Ricardo T. Gazzinelli

Open Access Publications by UMMS Authors

P. vivax-infected Retics (iRetics) express human leukocyte antigen class I (HLA-I), are recognized by CD8+ T cells and killed by granulysin (GNLY) and granzymes. However, how Plasmodium infection induces MHC-I expression on Retics is unknown. In addition, whether GNLY helps control Plasmodium infection in vivo has not been studied. Here, we examine these questions using rodent infection with the P. yoelii 17XNL strain, which has tropism for Retics. Infection with P. yoelii caused extramedullary erythropoiesis, reticulocytosis and expansion of CD8+CD44+CD62L- IFN-gamma-producing T cells that form immune synapses with iRetics. We now provide evidence that MHC-I expression by iRetic ...


Did You Wash Your Caving Suit? Cavers’ Role In The Potential Spread Of Pseudogymnoascus Destructans, The Causative Agent Of White-Nose Disease, Violeta Zhelyazkova, Antonia Hubancheva, Georgi Radoslavov, Nia Toshkova, Sebastien J. Puechmaille 2020 National Museum of Natural History, Bulgarian Academy of Sciences

Did You Wash Your Caving Suit? Cavers’ Role In The Potential Spread Of Pseudogymnoascus Destructans, The Causative Agent Of White-Nose Disease, Violeta Zhelyazkova, Antonia Hubancheva, Georgi Radoslavov, Nia Toshkova, Sebastien J. Puechmaille

International Journal of Speleology

White-Nose Disease (WND) has killed millions of hibernating bats in the US and Canada. Its causative agent, the fungus Pseudogymnoascus destructans was introduced to North America, but is native to Europe and Asia, where it is not associated with mass mortality. Although it is nearly impossible to eradicate an emerging wildlife disease, research on P. destructans spread mechanisms can aid in prevention of new introductions and development of better environmental management strategies. It is of particular importance to quantify the potential role of people visiting caves (cavers, tourists, bat researchers, etc.) whom inadvertently move P. destructans spores between sites, and ...


Antibacterial Fusion Proteins Enhance Moraxella Catarrhalis Killing, Maisem Laabei, Lucie Colineau, Serena Bettoni, Karolina Maziarz, David Ermert, Kristian Riesbeck, Sanjay Ram, Anna M. Blom 2020 Lund University

Antibacterial Fusion Proteins Enhance Moraxella Catarrhalis Killing, Maisem Laabei, Lucie Colineau, Serena Bettoni, Karolina Maziarz, David Ermert, Kristian Riesbeck, Sanjay Ram, Anna M. Blom

Open Access Publications by UMMS Authors

Moraxella catarrhalis is a human-specific commensal of the respiratory tract and an opportunistic pathogen. It is one of the leading cause of otitis media in children and of acute exacerbations in patients with chronic obstructive pulmonary disease, resulting in significant morbidity and economic burden. Vaccines and new immunotherapeutic strategies to treat this emerging pathogen are needed. Complement is a key component of innate immunity that mediates the detection, response, and subsequent elimination of invading pathogens. Many pathogens including M. catarrhalis have evolved complement evasion mechanisms, which include the binding of human complement inhibitors such as C4b-binding protein (C4BP) and Factor ...


Isolation, Enumeration And Antibiotic Profiling Of Vibrio Vulnificus And V. Parahaemolyticus From Coastal Virginia, Stanley Peyton 2020 James Madison University

Isolation, Enumeration And Antibiotic Profiling Of Vibrio Vulnificus And V. Parahaemolyticus From Coastal Virginia, Stanley Peyton

Masters Theses, 2020-current

Vibrio vulnificus and V. parahaemolyticus are gram-negative, halophilic bacteria that reside in estuarine waters and are associated with infections in humans. These bacteria can cause gastroenteritis through their presence in raw fish and shellfish consumed by humans. V. vulnificus can also produce wound infections leading to severe septicemia, and in some cases, death if not treated promptly. With increasing incidence of infections due to these two organisms, research efforts have focused on potential reservoirs and environmental conditions that can increase human exposure to, and infection, with these species of bacteria. This study was conducted in order to examine the role ...


How Does Molecular Biology Help To Identify Plant Disease?, Madina Akramova 2020 Syracuse University

How Does Molecular Biology Help To Identify Plant Disease?, Madina Akramova

English Language Institute

This study examines a process of plant disease diagnostics in light of a particular method of molecular biology - polymerase chain reaction.


Repression Of Tick Microrna-133 Induces Organic Anion Transporting Polypeptide Expression Critical For Anaplasma Phagocytophilumsurvival In The Vector And Transmission To The Vertebrate Host, Ellango Ramasamy, Vikas Taank, John F. Anderson, Hameeda Sultana, Girish Neelakanta 2020 Old Dominion University

Repression Of Tick Microrna-133 Induces Organic Anion Transporting Polypeptide Expression Critical For Anaplasma Phagocytophilumsurvival In The Vector And Transmission To The Vertebrate Host, Ellango Ramasamy, Vikas Taank, John F. Anderson, Hameeda Sultana, Girish Neelakanta

Biological Sciences Faculty Publications

The microRNAs (miRNAs) are important regulators of gene expression. In this study, we provide evidence for the first time to show that rickettsial pathogen Anaplasma phagocytophilum infection results in the down-regulation of tick microRNA-133 (miR-133), to induce Ixodes scapularis organic anion transporting polypeptide (isoatp4056) gene expression critical for this bacterial survival in the vector and for its transmission to the vertebrate host. Transfection studies with recombinant constructs containing transcriptional fusions confirmed binding of miR-133 to isoatp4056 mRNA. Treatment with miR-133 inhibitor resulted in increased bacterial burden and isoatp4056 expression in ticks and tick cells. In contrast, treatment with miR-133 mimic ...


Plant Defensin Antibacterial Mode Of Action Against Pseudomonas Species, Andrew E. Sathoff, Shawn Lewenza, Deborah A. Samac 2020 Dakota State University

Plant Defensin Antibacterial Mode Of Action Against Pseudomonas Species, Andrew E. Sathoff, Shawn Lewenza, Deborah A. Samac

Faculty Research & Publications

Background: Though many plant defensins exhibit antibacterial activity, little is known about their antibacterial mode of action (MOA). Antimicrobial peptides with a characterized MOA induce the expression of multiple bacterial outer membrane modifications, which are required for resistance to these membrane-targeting peptides. Mini-Tn5- lux mutant strains of Pseudomonas aeruginosa with Tn insertions disrupting outer membrane protective modifications were assessed for sensitivity against plant defensin peptides. These transcriptional lux reporter strains were also evaluated for lux gene expression in response to sublethal plant defensin exposure. Also, a plant pathogen, Pseudomonas syringae pv. syringae was modified through transposon mutagenesis to create ...


Cd11chi Monocyte-Derived Macrophages Are A Major Cellular Compartment Infected By Mycobacterium Tuberculosis, Jinhee Lee, Shayla Boyce, Jennifer Powers, Christina E. Baer, Christopher M. Sassetti, Samuel M. Behar 2020 University of Massachusetts Medical School

Cd11chi Monocyte-Derived Macrophages Are A Major Cellular Compartment Infected By Mycobacterium Tuberculosis, Jinhee Lee, Shayla Boyce, Jennifer Powers, Christina E. Baer, Christopher M. Sassetti, Samuel M. Behar

Open Access Publications by UMMS Authors

During tuberculosis, lung myeloid cells have two opposing roles: they are an intracellular niche occupied by Mycobacterium tuberculosis, and they restrict bacterial replication. Lung myeloid cells from mice infected with yellow-fluorescent protein expressing M. tuberculosis were analyzed by flow cytometry and transcriptional profiling to identify the cell types infected and their response to infection. CD14, CD38, and Abca1 were expressed more highly by infected alveolar macrophages and CD11cHi monocyte-derived cells compared to uninfected cells. CD14, CD38, and Abca1 "triple positive" (TP) cells had not only the highest infection rates and bacterial loads, but also a strong interferon-gamma signature and nitric ...


Contributions Of Gyra And Parc Mutations And Qnrs2 Acquisition To Ciprofloxacin Resistance In Aeromonas Veronii Hm21, Daniel J. Silverstein 2020 University of Connecticut

Contributions Of Gyra And Parc Mutations And Qnrs2 Acquisition To Ciprofloxacin Resistance In Aeromonas Veronii Hm21, Daniel J. Silverstein

Honors Scholar Theses

In recent years, ciprofloxacin resistant (CpR) Aeromonas veronii and A. hydrophila strains have been isolated from the wounds of patients receiving leech therapy. Genome comparisons of these CpR isolates revealed the presence of chromosomal mutations in gyrA and parC as well as the gain of qnrS2 on either a large, 34 kb, conjugatable, low-copy plasmid, pAv42, or on a small, 6.8 kb, high-copy plasmid, pAh1471. The minimum inhibitory concentration, MIC, for Cp of these clinical isolates ranged from 1 to ≥32 µg/mL and some harbored a qnrS2 containing plasmid. We wanted to assess the contributions of these factors ...


Gp41-Targeted Antibodies Restore Infectivity Of A Fusion-Deficient Hiv-1 Envelope Glycoprotein, Vinita R. Joshi, Ruchi M. Newman, Melissa L. Pack, Karen A. Power, James B. Munro, Ken Okawa, Navid Madani, Joseph G. Sodroski, Aaron G. Schmidt, Todd M. Allen 2020 Harvard Medical School

Gp41-Targeted Antibodies Restore Infectivity Of A Fusion-Deficient Hiv-1 Envelope Glycoprotein, Vinita R. Joshi, Ruchi M. Newman, Melissa L. Pack, Karen A. Power, James B. Munro, Ken Okawa, Navid Madani, Joseph G. Sodroski, Aaron G. Schmidt, Todd M. Allen

Open Access Publications by UMMS Authors

The HIV-1 envelope glycoprotein (Env) mediates viral entry via conformational changes associated with binding the cell surface receptor (CD4) and coreceptor (CCR5/CXCR4), resulting in subsequent fusion of the viral and cellular membranes. While the gp120 Env surface subunit has been extensively studied for its role in viral entry and evasion of the host immune response, the gp41 transmembrane glycoprotein and its role in natural infection are less well characterized. Here, we identified a primary HIV-1 Env variant that consistently supports >300% increased viral infectivity in the presence of autologous or heterologous HIV-positive plasma. However, in the absence of HIV-positive ...


Insights Into The Chlamydial Niche: The Dynamic Roles Of Inclusion Membrane (Inc) Proteins In Chlamydia Trachomatis Development, Macy G. Wood 2020 University of Nebraska Medical Center

Insights Into The Chlamydial Niche: The Dynamic Roles Of Inclusion Membrane (Inc) Proteins In Chlamydia Trachomatis Development, Macy G. Wood

Theses & Dissertations

Chlamydia trachomatis (Ctr) is the leading cause of bacterial sexually transmitted infections. Ctr, an obligate intracellular bacterium, develops within a membrane-bound vacuole called an inclusion. The inclusion membrane is modified by chlamydial inclusion membrane (Inc) proteins, the functions of which are poorly characterized. Bacterial two-hybrid analyses found some Incs (e.g., IncF) interacted with numerous Incs while others (e.g., IncA) did not. We hypothesize that some Incs organize the inclusion through Inc-Inc interactions whereas other Incs promote chlamydial-host interactions by binding eukaryotic proteins. To test our hypothesis, we implemented the ascorbate peroxidase proximity labeling system (APEX2), which labels proximal ...


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