Pathogenic Microbiology Commons^™

Acinetobacter Baumannii - The Perfect Pathogen, Jesse Guzik, Myrna Rezcallah, Alexcia Zeller, Kaite Mattson

Research and Scholarship Symposium Posters

Acinetobacter was discovered in 1911 by Martinus Beijerinck. Acinetobacter baumannii didn't receive its scientific name until 1986. A. baumannii is now commonly referred to as "Iraqibacter" due to a rise in infections among US military personnel returning from Iraq and Afghanistan. After the Iraq War began in 2003, the frequency of cases began to rise, especially among patients in intensive care units. Patients using ventilators, catheters, have postoperative wounds, stay in the hospital for an extended period of time, or are immunocompromised are at a considerably higher risk of getting A. baumannii. Because of its large number of virulence …

Functional Analysis Of Legionella Pneumophila Effector Protein, Shreya Neupane

Masters Theses & Specialist Projects

Legionella pneumophila is a gram-negative bacterium that causes Legionnaire’s disease (a severe form of pneumonia) in humans. L. pneumophila can cause infection by utilizing its Type IV secretion system, a protein secretion system that transports proteins from the bacterial cytosol into the infected macrophage. Effectors released from the Type Iv secretion system allow L. pneumophila to create a safe environment to survive, replicate and cause infection. One such effector, RavQ, inhibits cell proliferation of mammalian HEK 293T cells and localizes to the cell’s nucleus, leading us to hypothesize that RavQ interferes with cellular activity in the nucleus. To detect its …

Resolving The Repression Pathway Of Virulence Gene Hila In Salmonella, Alexandra King, Lon Chubiz Phd, Brenda Pratte, Lauren Daugherty

Undergraduate Research Symposium

Salmonella is a relatively abundant, virulent species of bacteria that is most known for spreading gastrointestinal diseases through food. These illnesses result in approximately 1.35 million infections, including over 25,000 hospitalizations each year, in the U.S. alone (CDC.gov). As antibiotic resistance becomes an increasingly urgent public health problem, the importance of developing alternative treatment methods is only becoming more crucial. One of the genes responsible for this virulence is known as hilA. HilA is the main transcriptional regulator of Salmonella Pathogenicity Island-1 gene (UniProt). SPI-1 plays an important role in the invasion of Salmonella into epithelial cells. The proteins encoded …

Eskape Pathogens: The Clinical Prevalence And Molecular Mechanisms Of Antibiotic Resistance, Anusha Attre

Honors Scholar Theses

The ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) are the leading cause of all nosocomial, or healthcare-associated (HAI), infections (Navidinia, 2016). The purpose of this research study is to determine the burden of ESKAPE infections on healthcare and study the antibiotic resistance in these high-risk pathogens to provide direction for researchers to develop new antimicrobial innovations to reduce ESKAPE infectivity and improve patient outcomes. To study the burden of ESKAPE infections, this review analyzes the current statistics explaining the clinical prevalence of each pathogen in causing HAIs. Additionally, each pathogen is …

Sars-Cov-2 Reveals That Chimeric Agents Are The Bioweapons Of The Future, Rachel Craig

Senior Honors Theses

Bioweapons programs have existed since their development during the Cold War. These biowarfare programs initially utilized naturally occurring pathogens capable of infecting crops, livestock populations, and human populations. Anthrax is a widely exploited bioagent responsible for attacks ranging from the Germans’ deployment in World War I to the mailing of anthrax through the postal service in attempts on U.S. senators’ lives. With the development of genetic manipulations, the Soviet Union began modifying anthrax to resist detection and treatment. With the continued advancement of science and technology, a new bioagent has entered the scene – the man-made chimeric virus. Chimeric viruses …

The Coxsackievirus And Adenovirus Receptor Has A Short Half-Life In Epithelial Cells, Poornima Kotha Lakshmi Narayan, James M. Readler, Mahmoud S. Alghamri, Trisha L. Brockman, Ray Yan, Priyanka Sharma, Vladislav Snitsarev, Katherine J.D.A Excoffon, Abimbola O. Kolawole

Department of Biology Faculty Scholarship and Creative Works

The coxsackievirus and adenovirus receptor (CAR) is an essential cellular protein that is involved in cell adhesion, cell signaling, and viral infection. The 8-exon encoded isoform (CAREx8) resides at the apical surface of polarized epithelia, where it is accessible as a receptor for adenovirus entering the airway lumen. Given its pivotal role in viral infection, it is a target for antiviral strategies. To understand the regulation of CAREx8 and determine the feasibility of receptor down regulation, the half-life of total and apical localized CAREx8 was determined and correlated with adenovirus transduction. Total and apical CAREx8 has a relatively short half-life …

Editorial: Pathogens, Pathobionts, And Autoimmunity, Linda A. Spatz, Gregg J. Silverman, Judith A. James

Publications and Research

No abstract provided.

Mara Repression Of Virulence Gene Hila In Salmonella, Alexandra King, Lauren Daugherty, Lon Chubiz Phd

Undergraduate Research Symposium

Salmonella is a bacteria most commonly known for causing the eponymous food-related illness. Due to their rapid reproduction rate and their ability to be propogated and maintained in a lab setting, they are commonly used in lab studies so that we can better understand how Salmonella causes disease in organisms that are more difficult to study. One area of interest is analyzing how Salmonella controls expression of the mechanisms that actually cause disease, called virulence traits, in response to the environment. In this study, antibiotic stress was used to analyze virulence gene expression. MarA is a gene that regulates ampicillin …

Draft Genome Sequences Of 13 Vibrio Cholerae Strains From The Rio Grande Delta, Jeffrey W. Turner, Jorge Duran-Gonzalez, David A. Laughlin, Daniel Unterweger, David Silva, Boris Ermolinsky, Stefan Pukatzki, Daniele Provenzano

Publications and Research

Vibrio cholerae is the etiologic agent of cholera, an acute and often fatal diarrheal disease that affects millions globally. We report the draft genome sequences of 13 non-O1/O139 V. cholerae strains isolated from the Rio Grande Delta in Texas. These genomes will aid future analyses of environmental serovars.

Sickness Behaviors Across Vertebrate Taxa: Proximate And Ultimate Mechanisms, Patricia C. Lopes, Susannah S. French, Douglas C. Woodhams, Sandra A. Binning

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

There is nothing like a pandemic to get the world thinking about how infectious diseases affect individual behavior. In this respect, sick animals can behave in ways that are dramatically different from healthy animals: altered social interactions and changes to patterns of eating and drinking are all hallmarks of sickness. As a result, behavioral changes associated with inflammatory responses (i.e. sickness behaviors) have important implications for disease spread by affecting contacts with others and with common resources, including water and/or sleeping sites. In this Review, we summarize the behavioral modifications, including changes to thermoregulatory behaviors, known to occur in vertebrates …

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

Publications and Research

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

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

Publications and Research

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

Aspergillus Niger Decreases Bioavailability Of Arsenic(V) Via Biotransformation Of Manganese Oxide Into Biogenic Oxalate Minerals, Bence Farkas, Marek Kolenčík, Miroslav Hain, Edmund Dobročka, Gabriela Kratošová, Marek Bujdoš, Huan Feng, Yang Deng, Qian Yu, Ramakanth Illa, B. Ratna Sunil, Hyunjung Kim, Peter Matúš, Martin Urík

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The aim of this work was to evaluate the transformation of manganese oxide (hausmannite) by microscopic filamentous fungus Aspergillus niger and the effects of the transformation on mobility and bioavailability of arsenic. Our results showed that the A. niger strain CBS 140837 greatly affected the stability of hausmannite and induced its transformation into biogenic crystals of manganese oxalates—falottaite and lindbergite. The transformation was enabled by fungal acidolysis of hausmannite and subsequent release of manganese ions into the culture medium. While almost 45% of manganese was bioextracted, the arsenic content in manganese precipitates increased throughout the 25-day static cultivation of fungus. …

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

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

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

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 …

Investigation Of Rapid Diagnostic Tests For Characterization Of Mycobacterium Avium Complex (Mac) From Various Isolates And Identification Of Virulence Factors Of Porcine Reproductive And Respiratory Syndrome Virus (Prrsv) In Vitro, Claudia Antonika

UCARE Research Products

Chapter 1

Mycobacterium avium complex (MAC) has become one of the major problems in public health and livestock. Members of MAC, such as M. avium subsp paratuberculosis (MAP) and M. avium subsp hominissuis (MAH), are responsible for many opportunistic infections and the loss of livestock. MAP is economically significant to the beef and dairy industries because it is the etiologic agent of Johnes’s disease, a chronic and fatal enteritis in ruminants. Tracing the infection sources of MAC could be difficult since it infects many types of hosts in the natural environment. Furthermore, there is less information known about MAP pathogenicity …

Histidine-Triad Hydrolases Provide Resistance To Peptide-Nucleotide Antibiotics., Eldar Yagmurov, Darya Tsibulskaya, Alexey Livenskyi, Marina Serebryakova, Yury I Wolf, Sergei Borukhov, Konstantin Severinov, Svetlana Dubiley

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

The Escherichia coli microcin C (McC) and related compounds are potent Trojan horse peptide-nucleotide antibiotics. The peptide part facilitates transport into sensitive cells. Inside the cell, the peptide part is degraded by nonspecific peptidases releasing an aspartamide-adenylate containing a phosphoramide bond. This nonhydrolyzable compound inhibits aspartyl-tRNA synthetase. In addition to the efficient export of McC outside the producing cells, special mechanisms have evolved to avoid self-toxicity caused by the degradation of the peptide part inside the producers. Here, we report that histidine-triad (HIT) hydrolases encoded in biosynthetic clusters of some McC homologs or by standalone genes confer resistance to McC-like …

A High-Fat/High-Protein, Atkins-Type Diet Exacerbates Clostridioides (Clostridium) Difficile Infection In Mice, Whereas A High-Carbohydrate Diet Protects, Chrisabelle C. Mefferd, Shrikant S. Bhute, Jacqueline R. Phan, Jacob V. Villarama, Dung M. Do, Stephanie Alarcia, Ernesto Abel-Santos, Brian P. Hedlund

Chemistry and Biochemistry Faculty Research

Clostridioides difficile (formerly Clostridium difficile) infection (CDI) can result from the disruption of the resident gut microbiota. Western diets and popular weight-loss diets drive large changes in the gut microbiome; however, the literature is conflicted with regard to the effect of diet on CDI. Using the hypervirulent strain C. difficile R20291 (RT027) in a mouse model of antibiotic-induced CDI, we assessed disease outcome and microbial community dynamics in mice fed two high-fat diets in comparison with a high-carbohydrate diet and a standard rodent diet. The two high-fat diets exacerbated CDI, with a high-fat/high-protein, Atkins-like diet leading to severe CDI and …

A Rapid Viability And Drug‑Susceptibility Assay Utilizing Mycobacteriophage As An Indicator Of Drug Susceptibilities Of Anti‑Tb Drugs Against Mycobacterium Smegmatis Mc2 155, Gillian Catherine Crowley, Jim O'Mahony, Aidan Coffey, Riona G. Sayers, Paul D. Cotter

Department of Biological Sciences Publications

Background: A rapid in-house TM4 mycobacteriophage-based assay, to identify multidrug resistance against various anti-tuberculosis drugs, using the fast-growing Mycobacterium smegmatis mc² 155 in a microtiter plate format was evaluated, based on phage viability assays. Methods: A variety of parameters were optimized before the study including the minimum incubation time for the drugs, phage and M. smegmatis mc² 155 to be in contact. An increase in phage numbers over 2 h was indicative that M. smegmatis mc² 155 is resistant to the drugs under investigation, however when phage numbers remained static, M. smegmatis mc² 155 found to …

Triatomines: Trypanosomatids, Bacteria, And Viruses Potential Vectors? [Review], Caroline Barreto Vieira, Yanna Reis Praça, Kaio Luís Da Silva Bentes, Paula Beatriz Santiago, Sofia Marcelino Martins Silva, Gabriel Dos Santos Silva, Flávia Nader Motta, Izabela Marques Dorado Bastos, Jaime Martins De Santana, Carla Nunes De Araújo

Harold W. Manter Laboratory: Library Materials

Triatominae bugs are the vectors of Chagas disease, a major concern to public health especially in Latin America, where vector-borne Chagas disease has undergone resurgence due mainly to diminished triatomine control in many endemic municipalities. Although the majority of Triatominae species occurs in the Americas, species belonging to the genus Linshcosteus occur in India, and species belonging to the Triatoma rubrofasciata complex have been also identified in Africa, the Middle East, South-East Asia, and in the Western Pacific. Not all of Triatominae species have been found to be infected with Trypanosoma cruzi, but the possibility of establishing vector transmission …

Green Tea Polyphenol Epigallocatechin-3-Gallate-Stearate Inhibits The Growth Of Streptococcus Mutans: A Promising New Approach In Caries Prevention, Amy Lynn Melok, Lee Lee, Siti Ayuni Mohamed Yussof, Tinchun Chu

Department of Biology Faculty Scholarship and Creative Works

Streptococcus mutans (S. mutans) is the main etiological bacteria present in the oral cavity that leads to dental caries. All of the S. mutans in the oral cavity form biofilms that adhere to the surfaces of teeth. Dental caries are infections facilitated by the development of biofilm. An esterified derivative of epigallocatechin-3-gallate (EGCG), epigallocatechin-3-gallate-stearate (EGCG-S), was used in this study to assess its ability to inhibit the growth and biofilm formation of S. mutans. The effect of EGCG-S on bacterial growth was evaluated with colony forming units (CFU) and log reduction; biofilm formation was qualitatively determined by Congo red assay, …

Arthropod Transcriptional Activator Protein-1 (Ap-1) Aids Tick-Rickettsial Pathogen Survival In The Cold, Supreet Khanal, Vikas Taank, John F. Anderson, Hameeda Sultana, Girish Neelakanta

Biological Sciences Faculty Publications

Ixodes scapularis ticks transmit several pathogens to humans including rickettsial bacterium, Anaplasma phagocytophilum. Here, we report that A. phagocytophilum uses tick transcriptional activator protein-1 (AP-1) as a molecular switch in the regulation of arthropod antifreeze gene, iafgp. RNAi-mediated silencing of ap-1 expression significantly affected iafgp gene expression and A. phagocytophilum burden in ticks upon acquisition from the murine host. Gel shift assays provide evidence that both the bacterium and AP-1 influences iafgp promoter and expression. The luciferase assays revealed that a region of approximately 700 bp upstream of the antifreeze gene is sufficient for AP-1 binding to promote …

Novel Role Of Pseudomonas Aeruginosa Lptd Operon, Sundar Pandey

FIU Electronic Theses and Dissertations

Pseudomonas aeruginosais an opportunistic pathogen that infects cystic fibrosis (CF) patients contributing to their high morbidity and mortality. P. aeruginosaundergoes a phenotypic conversion in the CF lung, from nonmucoid to mucoid, by constitutively producing a polysaccharide called alginate. These mucoid strains often revert to nonmucoid in vitrodue to second-site suppressor mutations. We hypothesized that mapping these mutations would lead to the identification of novel genes involved in alginate production. In a previous study, a mucoid strain, PDO300 (PAOmucA22), was used to isolate suppressors of alginate phenotype (sap). One of the uncharacterized nonmucoid revertants, …

Rapid Identification And Typing Of Mycobacterium Avium Complex Using Matrix Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry (Maldi-Tof) Library And Biomarker Based Approaches., Claudia Antonika, John Dustin Loy, Raul Barletta, Michael Collins

UCARE Research Products

Bacteria associated with the Mycobacterium avium complex (MAC) cause significant problems in animal agriculture and cause large economic losses and morbidity of livestock. Two clinically important subspecies of M. avium are M.avium ssp paratuberculosis (MAP) and M. avium ssp hominissuis (MAH). MAP is the etiologic agent of Johne’s disease, a chronic and fatal enteritis in ruminants, that has been linked to Crohn’s disease in humans.1 MAH has zoonotic potential as it is one of the leading causes of secondary infections in AIDS patients. Identification of M. avium in clinical samples is challenging as they have overlapping host ranges and clinical …

Fluorescence-Reported Allelic Exchange Mutagenesis Reveals A Role For Chlamydia Trachomatis Tmea In Invasion That Is Independent Of Host Ahnak, M. J. Mckuen, Konrad E. Mueller, Y. S. Bae, Kenneth A. Fields

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Development of approaches to genetically manipulate Chlamydia is fostering important advances in understanding pathogenesis. Fluorescence-reported allelic exchange mutagenesis (FRAEM) now enables the complete deletion of specific genes in C. trachomatis L2. We have leveraged this technology to delete the coding sequences for a known type III effector. The evidence provided here indicates that CT694/CTL0063 is a virulence protein involved in chlamydial invasion. Based on our findings, we designate the gene product corresponding to ct694-ctl0063 translocated membrane-associated effector A (TmeA). Deletion of tmeA did not impact development of intracellular chlamydiae. However, the absence of TmeA manifested as a decrease in infectivity …

Quorum Sensing Signals Produced By Heterotrophic Bacteria In Black Band Disease (Bbd) Of Corals And Their Potential Role In Bbd Pathogenesis, Chinmayee D. Bhedi

FIU Electronic Theses and Dissertations

Black band disease (BBD) of corals is a temperature dependent, highly virulent, polymicrobial disease affecting reef-building corals globally. The microbial consortium of BBD is primarily comprised of functional physiological groups that include photosynthetic cyanobacteria, sulfate reducers, sulfide oxidizers and a vast repertoire of heterotrophic bacteria. Quorum sensing (QS), the cell-density dependent communication phenomenon in bacteria, is known to induce expression of genes for a variety of virulence factors in diseases worldwide. Microbes capable of QS release signals such as acyl homoserine lactones (AHLs) and autoinducer-2 (AI-2), which coordinate microbial interaction. The focus of the present study was to investigate the …

Phenomenological And Molecular Basis Of The Cnidarian Immune System, Tanya Brown

FIU Electronic Theses and Dissertations

Coral reefs are one of the most diverse ecosystems on the planet due partially to the habitat structure provided by corals. Corals are long lived organisms that can live for hundreds of years and as a result growth of many species is very slow. As a result of this, recovery of corals from disease outbreaks is very slow and difficult and therefore the ecosystem is deteriorating rapidly. Due to this increase in disease and its detrimental effect on coral reefs, it has become imperative to study how corals respond to disease outbreaks. The response of the coral to pathogens is …

Borrelia Burgdorferi-Specific Iga In Lyme Disease, Christina D'Arco, Raymond Dattwyler, Paul Arnaboldi

NYMC Faculty Publications

The laboratory diagnosis of Lyme disease is currently dependent on the detection of IgM and IgG antibodies against Borrelia burgdorferi, the causative agent of the disease. The significance of serum IgA against B. burgdorferi remains unclear. The production of intrathecal IgA has been noted in patients with the late Lyme disease manifestation, neuroborreliosis, but production of antigen-specific IgA during early disease has not been evaluated. In the current study, we assessed serum IgA binding to the B. burgdorferi peptide antigens, C6, the target of the FDA-cleared C6 EIA, and FlaB(211-223)-modVlsE(275-291), a peptide containing a Borrelia flagellin epitope linked to a …

Comparative Genomic Analysis Of Two Serotype 1/2b Listeria Monocytogenes Isolates From Analogous Environmental Niches Demonstrates The Influence Of Hypervariable Hotspots In Defining Pathogenesis, Aidan Casey, Kieran Jordan, Aidan Coffey, Edward M. Fox, Olivia Mcauliffe

Department of Biological Sciences Publications

The vast majority of clinical human listeriosis cases are caused by serotype 1/2a, 1/2b, 1/2c, and 4b isolates of Listeria monocytogenes. The ability of L. monocytogenes to establish a systemic listeriosis infection within a host organism relies on a combination of genes that are involved in cell recognition, internalization, evasion of host defenses, and in vitro survival and growth. Recently, whole genome sequencing and comparative genomic analysis have proven to be powerful tools for the identification of these virulence-associated genes in L. monocytogenes. In this study, two serotype 1/2b strains of L. monocytogenes with analogous isolation sources, but …

Elucidating The Role Of Mifs-Mifr Two-Component System In Regulating Pseudomonas Aeruginosa Pathogenicity, Gorakh Digambar Tatke

FIU Electronic Theses and Dissertations

Pseudomonas aeruginosa is a Gram-negative, metabolically versatile, opportunistic pathogen that exhibits a multitude of virulence factors, and is extraordinarily resistant to a gamut of clinically significant antibiotics. This ability is in part mediated by two-component systems (TCS) that play a crucial role in regulating virulence mechanisms, metabolism and antibiotic resistance. Our sequence analysis of the P. aeruginosa PAO1 genome revealed the presence of two open reading frames, mifS and mifR, which encodes putative TCS proteins, a histidine sensor kinase MifS and a response regulator MifR, respectively. This two-gene operon was found immediately upstream of the poxAB operon, where poxB encodes …