Microbiology Commons^™

Spatial Structure Of Germination And Seed-Associated Fungi In Tropical Pioneer Seeds, Daniela Varon Garcia

USF Tampa Graduate Theses and Dissertations

Negative density-dependent regulation is the process by which host-specific natural enemies reduce the survival of seeds and seedlings of conspecifics near adult trees, favoring heterospecific recruitment, and ultimately increasing local diversity. Negative density-dependent regulation by fungal pathogens has been consistently reported to promote plant diversity in the tropics, even though they tend to be multi-host and host-specificity is rarely reported. Nevertheless, evidence suggests that host-generalist fungi can have host-specific effects that produce disproportionate negative effects on some plant species but not others, promoting regional diversity. However, such studies have not tested for both host-specificity and distance-dependent effects in fully replicated …

Acetate-Encapsulated Linolenic Acid Liposomes Reduce Sars-Cov-2 And Rsv Infection, Andrew R. Mcgill

USF Tampa Graduate Theses and Dissertations

Coronavirus disease-19 (COVID-19), caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), is an ongoing pandemic-endemic. In the United States, it remains the third leading cause of death in 2022. SARS-CoV-2, an RNA virus, has a genome prone to rapid mutation, generating variant species capable of resisting therapies and vaccination efforts. However, it has been estimated that more than 40% of SARS-CoV-2 infections may be asymptomatic, which calls into question any biological differences between the asymptomatic and afflicted groups. Additionally, Respiratory Syncytial Virus (RSV) is the most significant cause of bronchiolitis and asthma in neonates, with an increasing burden on the …

Dcaf14 Regulates Cdt2 To Promote Set8-Dependent Replication Fork Protection, Neysha Tirado-Class, Caitlin Hathaway, Anthony Nelligan, Huzefa Dungrawala

Molecular Biosciences Faculty Publications

DDB1- and CUL4-associated factors (DCAFs) CDT2 and DCAF14 are substrate receptors for Cullin4–RING E3 ubiquitin ligase (CRL4) complexes. CDT2 is responsible for PCNA-coupled proteolysis of substrates CDT1, p21, and SET8 during S-phase of cell cycle. DCAF14 functions at stalled replication forks to promote genome stability, but the mechanism is unknown. We find that DCAF14 mediates replication fork protection by regulating CRL4CDT2 activity. Absence of DCAF14 causes increased proteasomal degradation of CDT2 substrates. When forks are challenged with replication stress, increased CDT2 function causes stalled fork collapse and impairs fork recovery in DCAF14-deficient conditions. We further show that stalled fork protection …

Otud5 Limits Replication Fork Instability By Organizing Chromatin Remodelers, Angelo De Vivo, Hongseon Song, Yujin Lee, Neysha Tirado-Class, Anthony Sanchez, Sandy D. Westerheide, Huzefa Dungrawala, Younghoon Kee

Molecular Biosciences Faculty Publications

Proper regulation of replication fork progression is important for genomic maintenance. Subverting the transcription-induced conflicts is crucial in preserving the integrity of replication forks. Various chromatin remodelers, such as histone chaperone and histone deacetylases are known to modulate replication stress, but how these factors are organized or collaborate are not well understood. Here we found a new role of the OTUD5 deubiquitinase in limiting replication stress. We found that OTUD5 is recruited to replication forks, and its depletion causes replication fork stress. Through its C-terminal disordered tail, OTUD5 assembles a complex containing FACT, HDAC1 and HDAC2 at replication forks. A …

The Identification Of Two M20b Family Peptidases Required For Full Virulence In Staphylococcus Aureus, Nathanial James Torres, Devon Rizzo, Maria A. Reinberg, Mary-Elizabeth Jobson, Brendan C. Totzke, Jessica K. Jackson, Wenqi Yu, Lindsey Neil Shaw

Molecular Biosciences Faculty Publications

We have previously demonstrated that deletion of an intracellular leucine aminopeptidase results in attenuated virulence of S. aureus. Herein we explore the role of 10 other aminopeptidases in S. aureus pathogenesis. Using a human blood survival assay we identified mutations in two enzymes from the M20B family (PepT1 and PepT2) as having markedly decreased survival compared to the parent. We further reveal that pepT1, pepT2 and pepT1/2 mutant strains are impaired in their ability to resist phagocytosis by, and engender survival within, human macrophages. Using a co-infection model of murine sepsis, we demonstrate impairment of dissemination and survival …

Algae And Cyanobacteria In The Aphotic Habitats Of Veternica Cave (Medvednica Mt., Croatia) And Selected Caves Of The Dinaric Karst (South-Eastern Europe), Najla Baković, Tanja Pipan, Robert Baković, Roman Ozimec, Josip Rubinić, Renata Matoničkin Kepčija

International Journal of Speleology

Microphototrophs (algae and cyanobacteria) in karst environments have been intensively studied in aquatic epigean habitats. In recent decades knowledge about the communities inhabiting cave entrances and lampenflora has grown substantially, but the data about the communities in aphotic cave zone are scarce. This study aimed to investigate spatio-temporal presence of microphototrophs in the aphotic zone of Veternica Cave (Mt. Medvednica karst) and to present additional preliminary data from 22 caves of the Dinaric karst. The data were collected over ten years, in parallel with research on cave phagotrophic protists. In addition to the remains of microphototrophs, living algae and cyanobacteria …

Anthropogenic Fecal Pollution Affects Microbial Water Quality And Multidrug Resistance In Tropical Aquatic Environments, Adriana González-Fernández

USF Tampa Graduate Theses and Dissertations

Although an often-overlooked issue, fecal pollution at recreational beaches should concerneveryone. Worldwide more than 80% of wastewater is discharged into rivers or the ocean without any treatment. Untreated and inefficiently treated wastewater can introduce diseasecausing microorganisms into the aquatic environment. Fecal-borne pathogens can also originate in animal waste, and humans can be exposed to these pathogens from poorly managed animal feces that make their way into the aquatic environment. Exposure to waterborne pathogens in recreational waters is a public health hazard, as it facilitates the transmission of waterborne illness, and surface waters serve as natural reservoirs of antibiotic resistant bacteria …

To Be Or Not To Be: A Tale Of Staphylococcal Gpsb, Lauren R. Hammond

USF Tampa Graduate Theses and Dissertations

There are two big drivers motivating studies into bacterial cell division. The first is a desire to understand life around us. One of the defining characteristics of life is the ability for a cell to grow and divide, and without in-depth knowledge of this process, we cannot truly understand the complexities that allow for life on this planet. The second motivator is to identify new drug targets in the ongoing fight against antimicrobial resistance. Many infectious organisms have become resistant to commonly used antibiotics, and the bacterial cell division machinery is a largely untapped essential process with many potential therapeutic …

Lord Of The Z-Rings: Uncovering The Role Of Mraz And Ftsl In Bacillus Subtilis Cell Division, Maria Louise White

USF Tampa Graduate Theses and Dissertations

Cell division is a complex and highly orchestrated process that requires careful coordination. The process of cell division in prokaryotes primarily occurs via binary fission, where one mother cell becomes two genetically identically and equally sized daughter cells. In most bacteria a key protein, FtsZ, forms a FtsZ ring (Z-ring) to mark the division site and recruit proteins involved in cytokinesis. Whilst much has been learned about the contents and assembly of the divisome in model organisms such as Escherichia coli and Bacillus subtilis factors governing the regulation of divisome are much more poorly understood. …

Assessing The Human-Health Risk Of Exposure To Pathogens From Beach Sands, Javier Federico Gallard-Góngora

USF Tampa Graduate Theses and Dissertations

Fecal contamination at recreational beaches impacts the health of beachgoers, through the introduction of disease-causing microorganisms, and the well-being of communities dependent on income from recreational beach activities. Beach ecosystems are also impacted by sewage through the introduction of nutrients that can cause abnormal increases in autochthonous microorganisms which can impact the population of larger organisms in the ecosystem. Fecal contamination is introduced into sand via untreated sewage, direct deposition of human feces into sand, runoff, and deposition of animal feces into sand. The introduction of fecal contamination into sand exposes individuals to pathogens (disease causing microorganisms) which can result …

Seroprevalence Of Sars-Cov-2 Antibodies, The Gut Microbiome, And Peripherally Circulating Cytokines In Pregnant Hispanic Females, Tina Susanna Mutka

USF Tampa Graduate Theses and Dissertations

Pregnant Hispanic females have been disproportionately impacted by SARS-CoV-2 andhave experienced high rates of asymptomatic or mildly symptomatic, unrecognized infection. Acute SARS-CoV-2 infection has been associated with gut microbiome changes and altered peripherally circulating cytokine levels in symptomatic, non-pregnant individuals.

This study investigated the seroprevalence of anti-SARS-CoV-2 IgG antibodies in a sample of pregnant Hispanic females (n = 197). A sub-sample of SARS-CoV-2 seropositive and seronegative pregnant Hispanic females were followed across pregnancy and their bacterial gut microbiome was characterized, and cytokine levels measured to investigate relationships between SARS-CoV-2 serostatus, the gut microbiome, and peripherally circulating cytokine levels across pregnancy. …

Antibiotic-Resistant Escherichia Coli And EnterococcusSpp. In Sand And Water At Tampa Bay Beaches, Jennifer K. Sabater

USF Tampa Graduate Theses and Dissertations

As antibiotic resistance in the environment continues to rise there is an increased concern that infections may become harder to treat as bacteria acquire genes for multidrug resistance. Recreational beach waters in the Tampa Bay area are routinely monitored by the Florida Department of Environmental Protection for the presence of fecal indicator bacteria (FIB) such as Escherichia coli and enterococci. Exceedances of beach action values (BAV) 235 CFU/100 mL (E. coli) and 70 CFU/100 mL (enterococci) indicate the presence of fecal contamination which is associated with an increased risk of disease for beachgoers. Antibiotic-resistant E. coli and Enterococcus spp. have …

Antimicrobial Activity Of Zinc Oxide Nanoparticles Compared To Silver Nanoparticles Administered Towards Methicillin-Resistant Staphylococcus Aureus Biofilms, Kevin Núño

USF Tampa Graduate Theses and Dissertations

Zinc oxide nanoparticles (ZnO NPs), silver nanoparticles (AgNPs), and chitosan nanoparticles have strong antibacterial activity as a broad-spectrum antibiotic against multi-drug resistant (MDR) bacteria. MDR bacteria have a mechanism that increases antibiotic resistance through biofilm formations. MDR methicillin-resistant Staphylococcus aureus BAA-1720 was chosen for an in vitro assessment to calculate the biofilm reduction rate and the median effective dose (ED50) by performing biofilm quantification. Dynamic light scattering was chosen to determine the physiochemical characteristics of ZnO NPs, silver nanoparticles (AgNPs), and chitosan NPs. Transmission electron microscopy was conducted to verify each treatment’s physiochemical characteristics. Antimicrobial susceptibility testing of broad-spectrum and …

Phip Variants Associated With Chung–Jansen Syndrome Disrupt Replication Fork Stability And Genome Integrity, Neysha Tirado-Class, Caitlin Hathaway, Wendy K. Chung, Huzefa Dungrawala

Molecular Biosciences Faculty Publications

Chung–Jansen syndrome (CJS) is a rare, autosomal dominant disorder characterized by developmental delay, intellectual disability/cognitive impairment, behavioral challenges, obesity, and dysmorphic features. CJS is associated with heterozygous variants in PHIP (Pleckstrin-Homology Interacting Protein), a gene that encodes one of several substrate receptors for Cullin4-RING (CRL4) E3 ubiquitin ligase complex. Full-length PHIP, also called DCAF14, was recently identified to function as a replication stress response protein. Herein, we report the identification of two PHIP missense variants identified by exome sequencing in unrelated individuals with CJS. The variants p.D488V and p.E963G occur in different functional elements of DCAF14-WD40 repeat domain and pleckstrin …

Sequence Properties Of An Intramolecular Interaction That Inhibits P53 Dna Binding, Emily Gregory, Gary W. Daughdrill

Molecular Biosciences Faculty Publications

An intramolecular interaction between the p53 transactivation and DNA binding domains inhibits DNA binding. To study this autoinhibition, we used a fragment of p53, referred to as ND WT, containing the N-terminal transactivation domains (TAD1 and TAD2), a proline rich region (PRR), and the DNA binding domain (DBD). We mutated acidic, nonpolar, and aromatic amino acids in TAD2 to disrupt the interaction with DBD and measured the effects on DNA binding affinity at different ionic strengths using fluorescence anisotropy. We observed a large increase in DNA binding affinity for the mutants consistent with reduced autoinhibition. The ΔΔG between DBD and …

Monitoring Photosynthetic Activity Using In Vivo Chlorophyll A Fluorescence In Microalgae And Cyanobacteria Biofilms In The Nerja Cave (Malaga, Spain), Yolanda Del Rosal, Juan Muñoz-Fernández, Paula S.M. Celis-Plá, Mariona Hernández-Mariné, Félix Álvarez-Gómez, Salvador Merino, Félix L. Figueroa

International Journal of Speleology

The characterization of the most common photosynthetic biofilms in the Nerja Cave by the continuous monitoring of the in vivo chlorophyll a (Chl a) fluorescence and the incorporation of the irradiance as a new environmental variable related to previous studies in the cave, have allowed us to improve our knowledge about the photosynthetic pattern of the biofilms of the cave. Effective quantum yield (ΔF/F_m′) and relative electron transport rate (rETR) were determined during periods of the light, whereas the maximal quantum yield (F_v /F_m) was determined during dark periods. Increases in …

Multifaceted Approach To Understanding Acinetobacter Baumannii Biofilm Formation And Drug Resistance, Jessie L. Allen

USF Tampa Graduate Theses and Dissertations

Acinetobacter baumannii is a multi-drug resistant nosocomial pathogen known for causing wound related- and respiratory-infections. It is currently on the WHO’s list of critical pathogens due to its broadly drug resistant nature and the constant appearance of pan-resistant isolates. A majority of the infections caused by this organism are biofilm associated, however there is limited existing knowledge regarding the mechanisms used to engage in this multicellular lifestyle. As such, we set out to explore the factors influencing this behavior using an 10,000+ isolate transposon mutant library of A. baumannii strain AB5075. Of the strains tested, 6.45% demonstrated some level of …

Unraveling The Role Of Novel G5 Peptidase Family Proteins In Virulence And Cell Envelope Biogenesis Of Staphylococcus Aureus, Stephanie M. Marroquin

USF Tampa Graduate Theses and Dissertations

Virulence factors and the bacterial cell envelope are two important components in S. aureus pathogenesis and survival. More importantly, understanding the regulation of these cellular processes is crucial to further understanding and combating this successful pathogen. To date, numerous factors have been identified as playing a role in the regulation of Agr activity in S. aureus, including transcription factors, antisense RNAs, and host elements. Herein we investigate the product of SAUSA300_1984 (termed MroQ), a transmembrane G5 peptidase family protein, as a novel effector of this system. Using a USA300 mroQ mutant we observed a drastic reduction in proteolysis, hemolysis, and …

Microbial Dark Matter: Culturing The Uncultured In Search Of Novel Chemotaxonomy, Sarah J. Kennedy

USF Tampa Graduate Theses and Dissertations

Although <1% of environmental isolates can be cultured, insights into the culturable fraction refine future techniques to unlock the cryptic biodiversity. This cryptic biodiversity is omnipresent within culture-independent surveys of environmental bacterial populations. Subsequently, these elusive organisms are termed “microbial dark matter” due to the intrigue surrounding their potential taxonomic and biosynthetic impacts. To this end of investigating bacterial-specific dark matter, we employed high-throughput culturing techniques to examine Gulf of Mexico sediments and sponges for chemotaxonomically important bacteria. Through stepwise implementation of permissive and selective recovery techniques, we succeeded in recovering over 150 unique bacterial isolates. We observed several isolates that pose as chemotaxonomically interesting, including several strains that belong to critical bioremediation taxa. In addition to these biotechnological-amenable isolates, we have also succeeded in culturing taxa historically attributed with antibacterial discoveries. One such isolate was a previously sponge-associated organism belonging to the rarely cultured Verrucosispora genus. Through extensive comparative genomics, we identified it as a novel species and subsequently named it Verrucosispora sioxanthis sp. nov. with the published genome serving as a resource for continued microbial dark matter investigations. Following continued passaging of the organism, we observed improved growth, biomass, and liquid growth dispersal within each increasingly sub-passaged generation of the isolate. As such, the laboratory attenuation, or domestication, of the organism warranted in-depth whole genomic analyses to generate insight into the increased laboratory sustainability. Through phenotypically-guided bioinformatics, we determined that the domestication was mediated through genome-wide selective pseudo- or non-pseudogenization of genes. As the previously sponge-associated organism evolved with the selection pressures of the static laboratory, we demonstrate that isolate effectively underwent genomic atrophy to resolve into a largely stable, sustainable laboratory-domesticated strain. Collectively, our chemotaxonomic discovery pipeline expands on the culturable bacterial biodiversity and ultimately provides a previously uncultured model organism for initial forays into resolving the microbial dark matter knowledge gap.

Investigation Of An Alternative Protocol For The Production Of Sars-Cov-2 Antigenic Proteins, Nichole Ninaltowski

USF Tampa Graduate Theses and Dissertations

With the COVID-19 pandemic showing no signs of slowing down, large-scale antigenic protein production is still needed for surveillance using serologic assays. From screening to vaccines to biotherapeutics, being able to produce the proteins for these assays is essential; however, the current gold standard method for producing SARS-CoV-2 spike proteins is prohibitively expensive for most research groups.

Alternative methods of transfecting mammalian cells to produce recombinant proteins that are relatively inexpensive have been used for years. Unlike the expensive, commercially available lipid-based methods, other established methods such as polyethyleneimine (PEI), are considerably easier, and cheaper to meet the needs of …

A Functional Characterization Of The Omega (Ω) Subunit Of Rna Polymerase In Staphylococcus Aureus, Shrushti B. Patil

USF Tampa Graduate Theses and Dissertations

In bacteria, RNA polymerase (RNAP) is a well-characterized and highly conserved multi-subunit enzyme complex responsible for transcription of DNA into RNA. The ω subunit (rpoZ/RpoZ), one of the smaller accessory subunits of RNAP, is often overlooked and under-studied, however, particularly in Gram-positive species. We have previously shown that deleting ω impacts the integrity of RNA polymerase in S. aureus, especially the β' subunit, and alters preference of the core enzyme for sigma factors, skewing heavily towards σB instead of the housekeeping σ factor. Consequently, this causes deregulation of myriad transcriptional processes, strongly rewiring gene expression circuits, and ultimately impairing the …

Transcriptomic And Functional Investigation Of Bacterial Biofilm Formation, Brooke R. Nemec

USF Tampa Graduate Theses and Dissertations

Staphylococcus aureus and Acinetobacter baumannii are two highly successful human pathogens, which have adopted very different, but effective survival strategies. The success of S. aureus is attributed to the tight regulation of an arsenal of virulence factors. Conversely, A. baumannii lacks what would be considered traditional virulence factors and, instead, has developed a high tolerance for environmental stress, which allows it to persist in unforgiving environments, including nosocomial settings and the human body. One common characteristic of these two organisms is their proclivity for biofilm formation. Herein, we discuss the diverse mechanisms governing biofilm formation for A. baumannii and S. …

Exploring Prokaryotic And Viral Communities Within Florida’S Freshwater Springs, Kema Saydoon Malki

USF Tampa Graduate Theses and Dissertations

Florida’s freshwater springs serve as a crucial ecosystem for the state, having both ecological and economic importance. Springs occur where there is an opening where aquifers discharge groundwater. Florida’s springs are fed by the Floridan aquifer system (FAS), which underlies the entire state and extends into several neighboring states. The FAS provides potable water to over 10 million people. The constant flow of groundwater through the springs feeds major river systems and creates unique freshwater systems that support numerous plants and animals. The combination of natural beauty and charismatic fauna attract tourism and generate millions of dollars in revenue for …

Development And Validation Of An Isothermal Amplification Assay For Eastern Equine Encephalitis Virus, Mikayla D. Maddison

USF Tampa Graduate Theses and Dissertations

Eastern Equine Encephalitis virus (EEEV) is a neurotrophic alphavirus for which there is no effective treatment or vaccine for humans. Periodic outbreaks in the Eastern United States represent an ongoing public health problem; Florida serves as the reservoir for EEEV for the rest of the country. Reverse transcription-polymerase chain reaction (RT-PCR) is the current gold standard for molecular diagnostic testing of the presence of EEEV in vectors. However, RT-PCR is technically complex and can be difficult for mosquito control districts to utilize. In order to provide a simple, cost-effective alternative for mosquito surveillance and control, a novel one step reverse …

Microbially-Mediated Carbonate Dissolution And Precipitation; Towards A Protocol For Ex-Situ, Cave-Analogue Cultivation Experiments, Vanessa E. Johnston, Andrea Martín-Pérez, Sara Skok, Janez Mulec

International Journal of Speleology

Subterranean calcite dissolution and precipitation are often considered as strictly geochemical processes. The active involvement of microbes in these processes is commonly underestimated in the literature due to general oligotrophic conditions in caves, except in particular cave conditions, such as sulfidic caves and moonmilk deposits, where the presence of microbes likely plays a key role in mineral deposition. Here, we study the possible involvement of microbes from Postojna Cave, Slovenia, in carbonate dissolution (litholysis) and precipitation (lithogenesis). Microbes were sampled from small pools below hydrologically diverse drip sites and incubated on polished limestone tablets at 10 and 20°C for 2 …

Microbiological Study In A Gneissic Cave From Sri Lanka, With Special Focus On Potential Antimicrobial Activities, Ethige Isuru P. Silva, Pathmakumara Jayasingha, Saman Senanayake, Anura Dandeniya, Dona Helani Munasinghe

International Journal of Speleology

The emergence of antibiotic resistance is a global health crisis, thus the search for novel antimicrobial compounds has become a continuous necessity. Underexplored and extreme environments, such as cave ecosystems, have been identified as a promising potential source for the discovery of novel microorganisms with novel antimicrobial compounds (AMC). This study presents the first cave microbiological investigation in Sri Lanka, with a special preference for bioprospecting of novel AMC. The cave sediment characterization demonstrated the presence of close to strong acidic conditions (pH 3.1 – 3.3) and thus indicates the possibility of isolating acidophilic microorganisms. Eight cave wall/ceiling fungal strains …

Novel Co2 Transporters From Autotrophic Bacteria From Extreme Environments, Sarah E. Schmid

USF Tampa Graduate Theses and Dissertations

Autotrophic organisms are responsible for introducing carbon into food webs. These organisms take up dissolved inorganic carbon (DIC) and use it as their major carbon source, converting it to biomass using a variety of carbon fixing pathways (e.g., the Calvin-Benson-Bassham cycle). In nature, DIC concentrations can be low or temporally heterogeneous, so autotrophic organisms adapt with CO2 concentrating mechanisms (CCMs) to facilitate the acquisition and fixation of this dissolved gas. CCMs consist of membrane-spanning DIC transporters, which elevate intracellular DIC concentrations, which in turn are harvested by carboxysomes, proteinaceous microcompartments that contain the carboxylase Ribulose-1,5-bisphosphate carboxylase-oxygenase (RubisCO) and carbonic anhydrase. …

Tracking The Subcellular Localization Of Surface Proteins In Staphylococcus Aureus By Immunofluorescence Microscopy, Salvatore J. Scaffidi, Mac A. Shebes, Wenqi Yu

Molecular Biosciences Faculty Publications

Surface proteins of Staphylococcus aureus and other Gram-positive bacteria play essential roles in bacterial colonization and host-microbe interactions. Surface protein precursors containing a YSIRK/GXXS signal peptide are translocated across the septal membrane at mid-cell, anchored to the cell wall peptidoglycan at the cross-wall compartment, and presented on the new hemispheres of the daughter cells following cell division. After several generations of cell division, these surface proteins will eventually cover the entire cell surface. To understand how these proteins travel from the bacterial cytoplasm to the cell surface, we describe a series of immunofluorescence microscopy protocols designed to detect the stepwise …

Dcaf14 Promotes Stalled Fork Stability To Maintain Genome Integrity, Arik Townsend, Gabriella Lora, Justin Engel, Neysha Tirado-Class, Huzefa Dungrawala

Molecular Biosciences Faculty Publications

No abstract provided.

Environmental Influences On Expression Of Virulence- And Survival-Associated Genes And Epigenetic Modifications Of Dna In Vibrio Vulnificus, James W. Conrad

USF Tampa Graduate Theses and Dissertations

Vibrio vulnificus is an autochthonous inhabitant of warm, brackish coastal waters and is an opportunistic pathogen that causes the highest mortality of all seafood-related illnesses (1). These fatal infections are generally caused by the clinically-associated vcgC/16S rRNA type B genotypes within the biotype I group (2–5). However, the reasons for the heightened infectiousness of the clinically-associated strains over environmentally-associated ones remains elusive, as no unique clinically-associated virulence genes have been identified through genomic sequencing or other strategies. DNA methylation may contribute to regulation of virulence by affecting gene transcription, and was investigated in the highly virulent V. vulnificus strain CMCP6. …