Microbiology Commons^™

Single-Cell Rna Sequencing Deconvolutes The In Vivo Heterogeneity Of Human Bone Marrow-Derived Mesenchymal Stem Cells, Zun Wang, Xiaohua Li, Junxiao Yang, Yun Gong, Huixi Zhang, Xiang Qiu, Ying Liu, Cui Zhou, Yu Chen, Jonathan Greenbaum, Liang Cheng, Yihe Hu, Jie Xie, Xucheng Yang, Yusheng Li, Martin R. Schiller

Life Sciences Faculty Research

Bone marrow-derived mesenchymal stem cells (BM-MSCs) are multipotent stromal cells that have a critical role in the maintenance of skeletal tissues such as bone, cartilage, and the fat in bone marrow. In addition to providing microenvironmental support for hematopoietic processes, BM-MSCs can differentiate into various mesodermal lineages including osteoblast/osteocyte, chondrocyte, and adipocyte that are crucial for bone metabolism. While BM-MSCs have high cell-to-cell heterogeneity in gene expression, the cell subtypes that contribute to this heterogeneity in vivo in humans have not been characterized. To investigate the transcriptional diversity of BM-MSCs, we applied single-cell RNA sequencing (scRNA-seq) on freshly isolated CD271+ …

Microcystis Sp. Co-Producing Microcystin And Saxitoxin From Songkhla Lake Basin, Thailand, Ampapan Naknaen, Waraporn Ratsameepakai, Oramas Suttinun, Yaowapa Sukpondma, Eakalak Khan, Rattanaruji Pomwised

Civil and Environmental Engineering and Construction Faculty Research

The Songkhla Lake Basin (SLB) located in Southern Thailand, has been increasingly polluted by urban and industrial wastewater, while the lake water has been intensively used. Here, we aimed to investigate cyanobacteria and cyanotoxins in the SLB. Ten cyanobacteria isolates were identified as Microcystis genus based on16S rDNA analysis. All isolates harbored microcystin genes, while five of them carried saxitoxin genes. On day 15 of culturing, the specific growth rate and Chl-a content were 0.2–0.3 per day and 4 µg/mL. The total extracellular polymeric substances (EPS) content was 0.37–0.49 µg/mL. The concentration of soluble EPS (sEPS) was 2 times higher …

Analysis Of 316 Omnitrophota (Op3) Genomes Reveals A Diverse And Ubiquitous Candidate Phylum Of Putative Syntrophs, Predators, And Free-Living Nanobacteria Encoding Giant Open-Reading Frames., Cale O. Seymour

UNLV Theses, Dissertations, Professional Papers, and Capstones

Candidate bacterial phylum Omnitrophota has never been isolated and is poorly understood. In this study, we explored the genomics, phylogeny, taxonomy, distribution, cell size, and predicted physiology of Omnitrophota based on 316 genomes. Phylogenomic concordance identified seven classes accommodating 144 species. Calibration of genome-based taxonomy to ribosomal SSU profiling revealed most Omnitrophota classes are prevalent in the Earth Microbiome Dataset, particularly in soils and sediments. Fluorescence-activated cell sorting and differential size filtration experiments showed ultra-small (<400 >nm) cells are common across the phylum, as are parasitism-related genes, including a conserved tight adherence (Tad) complex and ATP/ADP translocase. However, nucleotide and …

Comparative Genomics Reveals Thermal Adaptation And A High Metabolic Diversity In “Candidatus Bathyarchaeia”, Yan-Ling Qi, Paul N. Evans, Yu-Xian Li, Yang-Zhi Rao, Yan-Ni Qu, Sha Tan, Jian-Yu Jiao, Ya-Ting Chen, Brian P. Hedlund, Wen-Sheng Shu, Zheng-Shuang Hua, Wen Jun Li

Life Sciences Faculty Research

"Candidatus Bathyarchaeia"is a phylogenetically diverse and widely distributed lineage often in high abundance in anoxic submarine sediments; however, their evolution and ecological roles in terrestrial geothermal habitats are poorly understood. In the present study, 35 Ca. Bathyarchaeia metagenome-assembled genomes (MAGs) were recovered from hot spring sediments in Tibet and Yunnan, China. Phylogenetic analysis revealed all MAGs of Ca. Bathyarchaeia can be classified into 7 orders and 15 families. Among them, 4 families have been first discovered in the present study, significantly expanding the known diversity of Ca. Bathyarchaeia. Comparative genomics demonstrated Ca. Bathyarchaeia MAGs from thermal habitats to encode a …

Non-B Dna-Forming Motifs Promote Mfd-Dependent Stationary-Phase Mutagenesis In Bacillus Subtilis, Tatiana Ermi, Carmen Vallin, Ana Gabriela Regalado García, Moises Bravo, Ismaray Fernandez Cordero, Holly Anne Martin, Mario Pedraza-Reyes, Eduardo Robleto

Life Sciences Faculty Research

Transcription-induced mutagenic mechanisms limit genetic changes to times when expression happens and to coding DNA. It has been hypothesized that intrinsic sequences that have the potential to form alternate DNA structures, such as non-B DNA structures, influence these mechanisms. Non-B DNA structures are promoted by transcription and induce genome instability in eukaryotic cells, but their impact in bacterial genomes is less known. Here, we investigated if G4 DNA-and hairpin-forming motifs influence stationary-phase mutagenesis in Bacillus subtilis. We developed a system to measure the influence of non-B DNA on B. subtilis stationary-phase mutagenesis by deleting the wild-type argF at its chromosomal …

Microbial Screening Reveals Oral Site-Specific Locations Of The Periodontal Pathogen Selenomonas Noxia, Jaydene Mcdaniel, Steven Mcdaniel, Beanca Jhanine Samiano, Matthew Marrujo, Karl Kingsley, Katherine M. Howard

Dental Medicine Faculty Research

Introduction: Selenomonas noxia (SN) is an important periodontal pathogen, associated with gingivitis and periodontitis. Many studies have found associations between SN and indicators of poor health outcomes, such as smoking, low socioeconomic status and obesity. However, less is known about the prevalence of this organism and more specifically about other oral site-specific locations that may harbor this organism. Methods: Using an existing patient repository (n = 47) of DNA isolated from saliva and other oral sites (n = 235), including the dorsum of the tongue, lower lingual incisor, upper buccal molar and gingival crevicular fluid (GCF), molecular screening for SN …

Genomics, Exometabolomics, And Metabolic Probing Reveal Conserved Proteolytic Metabolism Of Thermoflexus Hugenholtzii And Three Candidate Species From China And Japan, Scott C. Thomas, Devon Payne, Kevin O. Tamadonfar, Cale O. Seymour, Jian Yu Jiao, Senthil K. Murugapiran, Dengxun Lai, Rebecca Lau, Benjamin P. Bowen, Leslie P. Silva, Katherine B. Louie, Marcel Huntemann, Alicia Clum, Alex Spunde, Manoj Pillay, Krishnaveni Palaniappan, Neha Varghese, Natalia Mikhailova, I. Min Chen, Dimitrios Stamatis, T. B.K. Reddy, Ronan O’Malley, Chris Daum, Nicole Shapiro, Natalia Ivanova, Nikos C. Kyrpides, Tanja Woyke, Emiley Eloe-Fadrosh, Trinity L. Hamilton, Paul Dijkstra, Brian P. Hedlund

Life Sciences Faculty Research

Thermoflexus hugenholtzii JAD2 , the only cultured representative of the Chloroflexota order Thermoflexales, is abundant in Great Boiling Spring (GBS), NV, United States, and close relatives inhabit geothermal systems globally. However, no defined medium exists for T. hugenholtzii JAD2 and no single carbon source is known to support its growth, leaving key knowledge gaps in its metabolism and nutritional needs. Here, we report comparative genomic analysis of the draft genome of T. hugenholtzii JAD2 and eight closely related metagenome-assembled genomes (MAGs) from geothermal sites in China, Japan, and the United States, representing “Candidatus Thermoflexus japonica,” “Candidatus Thermoflexus tengchongensis,” and “Candidatus …

Comparing The Incidence And Prevalence Of Oral Microbial Pathogens Selenomonas Noxia And Streptococcus Mitis Within The Unlv-Sdm Clinical Patient Population, Namgu Kim

UNLV Theses, Dissertations, Professional Papers, and Capstones

Introduction: Selenomonas noxia (SN) is a gram-negative, anaerobic bacteria, which contributes to development and progression of periodontal disease. Some evidence now suggests Streptococcus mitis (SM), a gram-positive, facultative bacterium contributing to the etiology of dental caries and periodontal disease, may also influence the prevalence of SN within subgingival complexes. Based upon the overall lack of prevalence data, the objective of this study was to evaluate presence of SN and SM using qPCR among saliva samples taken from pediatric, adult, and orthodontic dental school clinics.

Methods: This study involved a retrospective analysis of previously collected saliva samples from an existing biologic …

Genomic Analysis Of Paenibacillus Larvae Bacteriophages, Casey Stamereilers

UNLV Theses, Dissertations, Professional Papers, and Capstones

American Foulbrood is the most destructive bacterial infection of the honeybee (Apis mellifera) and is caused by the Gram-positive, spore forming bacterium Paenibacillus larvae. Current treatment methods rely on antibiotics, but antibiotics treatments are experiencing a reduction in efficacy due to the recent rise in antibiotic resistant strains of P. larvae. This has been a major catalyst for exploration of alternative treatment methods. Phage therapy is an alternative treatment method that uses viruses that exclusively infect bacteria, known as bacteriophages (phages), to combat bacterial infections. Several experimental studies have shown that phages P. larvae phages are effective at lysing P. …

Implications Of The Evolutionary Past On The Activities Of Virb: A Key Transcriptional Regulator Of Virulence Genes In Shigella Flexneri, Jillian Nicole Socea

UNLV Theses, Dissertations, Professional Papers, and Capstones

Shigella species are bacterial agents that are the leading cause of diarrheal diseases, the second leading cause of child mortality worldwide. One key protein in Shigella is VirB, a transcriptional regulator of virulence genes that is essential for pathogenicity. VirB functions to antagonize H-NS, a histone-like nucleoid structuring protein that silences many genes found on the large virulence plasmid (pINV). The interplay between H-NS, the silencer, and VirB, the anti-silencer, is fundamental for Shigella virulence. Furthermore, this mechanism of gene regulation appears widespread in many bacteria including other enteric pathogens.

The goal of my dissertation was to explore the activities …

The Anti-Sigma Factor Muca Is Required For Viability In Pseudomonas Aeruginosa, Melissa C. Schofield, Daniela Q. Rodriguez, Amanda A. Kidman, Erin K. Cassin, Lia A. Michaels, Elizabeth A. Campbell, Peter A. Jorth, Boo Shan Tseng

Teaching and Learning Faculty Research

During decades-long infections in the cystic fibrosis (CF) airway, Pseudomonas aeruginosa undergoes selection. One bacterial genetic adaptation often observed in CF isolates is mucA mutations. MucA inhibits the sigma factor AlgU. Mutations in mucA lead to AlgU misregulation, resulting in a mucoid phenotype that is associated with poor CF disease outcomes. Due to its ability to be mutated, mucA is assumed to be dispensable for bacterial viability. Here we show that, paradoxically, a portion of mucA is essential in P. aeruginosa. We demonstrate that mucA is no longer required in a strain lacking algU, that mucA alleles encoding for proteins …

A Novel Jumbo Phage Phima05 Inhibits Harmful Microcystis Sp., Ampapan Naknaen, Oramas Suttinun, Komwit Surachat, Eakalak Khan, Rattanaruji Pomwised

Civil and Environmental Engineering and Construction Faculty Research

Microcystis poses a concern because of its potential contribution to eutrophication and production of microcystins (MCs). Phage treatment has been proposed as a novel biocontrol method for Microcystis. Here, we isolated a lytic cyanophage named PhiMa05 with high efficiency against MCs-producing Microcystis strains. Its burst size was large, with approximately 127 phage particles/infected cell, a short latent period (1 day), and high stability to broad salinity, pH and temperature ranges. The PhiMa05 structure was composed of an icosahedral capsid (100 nm) and tail (120 nm), suggesting that the PhiMa05 belongs to the Myoviridae family. PhiMa05 inhibited both planktonic and aggregated …

Bacterial Cyclic Diguanylate Signaling Networks Sense Temperature, Henrik Almblad, Trevor E. Randall, Fanny Liu, Katherine Leblanc, Ryan A. Groves, Weerayuth Kittichotirat, Geoffrey L. Winsor, Nicolas Fournier, Emily Au, Julie Groizeleau, Jacquelyn D. Rich, Yuefei Lou, Elise Granton, Laura K. Jennings, Larissa A. Singletary, Tara M.L. Winstone, Nathan M. Good, Roger E. Bumgarner, Michael F. Hynes, Manu Singh, Maria Silvina Stietz, Fiona S.L. Brinkman, Ayush Kumar, Ann Karen Cornelia Brassinga, Matthew R. Parsek, Boo Shan Tseng, Ian A. Lewis, Bryan G. Yipp, Justin L. Maccallum, Joe Jonathan Harrison

Life Sciences Faculty Research

Many bacteria use the second messenger cyclic diguanylate (c-di-GMP) to control motility, biofilm production and virulence. Here, we identify a thermosensory diguanylate cyclase (TdcA) that modulates temperature-dependent motility, biofilm development and virulence in the opportunistic pathogen Pseudomonas aeruginosa. TdcA synthesizes c-di-GMP with catalytic rates that increase more than a hundred-fold over a ten-degree Celsius change. Analyses using protein chimeras indicate that heat-sensing is mediated by a thermosensitive Per-Arnt-SIM (PAS) domain. TdcA homologs are widespread in sequence databases, and a distantly related, heterologously expressed homolog from the Betaproteobacteria order Gallionellales also displayed thermosensitive diguanylate cyclase activity. We propose, therefore, that thermotransduction …

Characterization Of Crispr Spacer And Protospacer Sequences In Paenibacillus Larvae And Its Bacteriophages, Casey Stamereilers, Simon Wong, Philippos K. Tsourkas

Life Sciences Faculty Research

The bacterium Paenibacillus larvae is the causative agent of American foulbrood, the most devastating bacterial disease of honeybees. Because P. larvae is antibiotic resistant, phages that infect it are currently used as alternative treatments. However, the acquisition by P. larvae of CRISPR spacer sequences from the phages could be an obstacle to treatment efforts. We searched nine complete genomes of P. larvae strains and identified 714 CRISPR spacer sequences, of which 384 are unique. Of the four epidemiologically important P. larvae strains, three of these have fewer than 20 spacers, while one strain has over 150 spacers. Of the 384 …

Rasagiline Effects On Glucose Metabolism, Cognition, And Tau In Alzheimer’S Dementia, Dawn C. Matthews, Aaron Ritter, Ronald G. Thomas, Randolph D. Andrews, Ana S. Lukic, Carolyn Revta, Jefferson W. Kinney, Babak Tousi, James B. Leverenz, Howard Fillit, Kate Zhong, Howard H. Feldman, Jeffrey Cummings

Integrated Health Sciences Faculty Research

Background: A Phase II proof of concept (POC) randomized clinical trial was conducted to evaluate the effects of rasagiline, a monoamine oxidase B (MAO-B) inhibitor approved for Parkinson disease, in mild to moderate Alzheimer's disease (AD). The primary objective was to determine if 1 mg of rasagiline daily for 24 weeks is associated with improved regional brain metabolism (fluorodeoxyglucose–positron emission tomography [FDG-PET]) compared to placebo. Secondary objectives included measurement of effects on tau PET and evaluation of directional consistency of clinical end points. Methods: This was a double-blind, parallel group, placebo-controlled, community-based, three-site trial of 50 participants randomized 1:1 to …

Transcriptional Coupling And Repair Of 8-Oxog Activate A Reca-Dependent Checkpoint That Controls The Onset Of Sporulation In Bacillus Subtilis, Valeria P. Suárez, Lissett E. Martínez, Hilda C. Leyva-Sánchez, Luz I. Valenzuela-García, Reyna Lara-Martínez, Luis F. Jiménez-García, Norma Ramírez-Ramírez, Armando Obregon-Herrera, Mayra Cuéllar-Cruz, Eduardo A. Robleto, Mario Pedraza-Reyes

Life Sciences Faculty Research

© 2021, The Author(s). During sporulation Bacillus subtilis Mfd couples transcription to nucleotide excision repair (NER) to eliminate DNA distorting lesions. Here, we report a significant decline in sporulation following Mfd disruption, which was manifested in the absence of external DNA-damage suggesting that spontaneous lesions activate the function of Mfd for an efficient sporogenesis. Accordingly, a dramatic decline in sporulation efficiency took place in a B. subtilis strain lacking Mfd and the repair/prevention guanine oxidized (GO) system (hereafter, the ∆GO system), composed by YtkD, MutM and MutY. Furthermore, the simultaneous absence of Mfd and the GO system, (i) sensitized sporulating …

Mfd Affects Global Transcription And The Physiology Of Stressed Bacillus Subtilis Cells, Holly Anne Martin, Anitha Sundararajan, Tatiana S. Ermi, Robert Heron, Jason Gonzales, Kaiden Lee, Diana Anguiano-Mendez, Faye Schilkey, Mario Pedraza-Reyes, Eduardo A. Robleto

Life Sciences Faculty Research

© Copyright © 2021 Martin, Sundararajan, Ermi, Heron, Gonzales, Lee, Anguiano-Mendez, Schilkey, Pedraza-Reyes and Robleto. For several decades, Mfd has been studied as the bacterial transcription-coupled repair factor. However, recent observations indicate that this factor influences cell functions beyond DNA repair. Our lab recently described a role for Mfd in disulfide stress that was independent of its function in nucleotide excision repair and base excision repair. Because reports showed that Mfd influenced transcription of single genes, we investigated the global differences in transcription in wild-type and mfd mutant growth-limited cells in the presence and absence of diamide. Surprisingly, we found …

Pressure Effects On Sulfur‐Oxidizing Activity Of Thiobacillus Thioparus, Jorge R. Osman, Hervé Cardon, Gilles Montagnac, Aude Picard, Isabelle Daniel

Life Sciences Faculty Research

Carbon capture and storage technologies are crucial for reducing carbon emission from power plants as a response to global climate change. The CarbFix project (Iceland) aims at examining the geochemical response of injected CO2 into subsurface reservoirs. The potential role of the subsurface biosphere has been little investigated up to now. Here, we used Thiobacillus thioparus that became abundant at the CarbFix1 pilot site after injection of CO2 and purified geothermal gases in basaltic aquifer at 400–800 m depth (4–8 MPa). The capacity of T. thioparus to produce sulfate, through oxidation of thiosulfate, was measured by Raman spectroscopy as a …

Complete Genome Sequence Of Strain Ss-5, A Magnetotactic Gammaproteobacterium Isolated From The Salton Sea, A Shallow, Saline, Endorheic Rift Lake Located On The San Andreas Fault In California, Denis Trubitsyn, Caroline L. Monteil, Corey Geurink, Viviana Morillo Lopez, Luiz Gonzaga Paula De Almeida, Ana Tereza Ribeiro De Vasconcelos, Fernanda Abreu, Dennis A. Bazylinski, Christopher T. Lefevre

Life Sciences Faculty Research

© 2021 American Society for Microbiology. All rights reserved. We report the 3.7-Mb genome sequence of strain SS-5, a magnetotactic, sulfur-oxidizing rod and member of the family Chromatiaceae of the class Gammaproteobacteria, which biomineralizes membrane-bound, elongated, prismatic octahedral, magnetite nanocrystals. This genome sequence brings further diversity for understanding the origin and evolution of magnetotaxis and magnetosome biomineralization.

Microbial Dark Matter Coming To Light: Challenges And Opportunities, Jian Yu Jiao, Lan Liu, Zheng Shuang Hua, Bao Zhu Fang, En Min Zhou, Nimaichand Salam, Brian P. Hedlund, Wen Jun Li

Life Sciences Faculty Research

Microbes are the most abundant and diverse cellular life forms on Earth and colonize a wide range of environmental niches. However, more than 99% of bacterial and archaeal species have not been obtained in pure culture [1] and we have only glimpsed the surface of this mysterious microbial world. This is so-called Microbial Dark Matter (MDM): the enormous diversity of yet-uncultivated microbes that microbiologists can only study by using cultivation-independent techniques. Recently, a number of international projects have dramatically increased our understanding of the extent and distribution of microbial diversity, including the Global Catalogue of Microorganisms (GCM), the Genomic Encyclopedia …

A Genomic Catalog Of Earth’S Microbiomes, Brian Hedlund, More Than 200 Other International Authors

Life Sciences Faculty Research

The reconstruction of bacterial and archaeal genomes from shotgun metagenomes has enabled insights into the ecology and evolution of environmental and host-associated microbiomes. Here we applied this approach to >10,000 metagenomes collected from diverse habitats covering all of Earth’s continents and oceans, including metagenomes from human and animal hosts, engineered environments, and natural and agricultural soils, to capture extant microbial, metabolic and functional potential. This comprehensive catalog includes 52,515 metagenome-assembled genomes representing 12,556 novel candidate species-level operational taxonomic units spanning 135 phyla. The catalog expands the known phylogenetic diversity of bacteria and archaea by 44% and is broadly available for …

Expanding Magnetic Organelle Biogenesis In The Domain Bacteria, Wei Lin, Wensi Zhang, Greig A. Paterson, Qiyun Zhu, Xiang Zhao, Rob Knight, Dennis A. Bazylinski, Andrew P. Roberts, Yongxin Pan

Life Sciences Faculty Research

Background: The discovery of membrane-enclosed, metabolically functional organelles in Bacteria has transformed our understanding of the subcellular complexity of prokaryotic cells. Biomineralization of magnetic nanoparticles within magnetosomes by magnetotactic bacteria (MTB) is a fascinating example of prokaryotic organelles. Magnetosomes, as nano-sized magnetic sensors in MTB, facilitate cell navigation along the local geomagnetic field, a behaviour referred to as magnetotaxis or microbial magnetoreception. Recent discovery of novel MTB outside the traditionally recognized taxonomic lineages suggests that MTB diversity across the domain Bacteria are considerably underestimated, which limits understanding of the taxonomic distribution and evolutionary origin of magnetosome organelle biogenesis. Results: Here, …

Complete Genome Sequences Of Cluster P1 And Cluster C1 Mycobacterium Smegmatis Phages Jung And Ronan, Richard Van, William Nie, Feruz Abdela, Bardia Eivazi, Dolores Kickbusch, Michael Finkle, Cody Cris, Matthew Rubinstein, Baylor Akavan, Mahdeed Raja, Jessica Vergara, Wilson Andrade, Abimael Barajas, Jocelyn Sanchez, Maria Duenas, Kurt Regner, Christy Strong, Philippos K. Tsourkas, Jay Barilla

Life Sciences Faculty Research

We present the complete genome sequences of Mycobacterium smegmatis phages Jung and Ronan, isolated from soil in Las Vegas, Nevada. The phages were isolated and annotated by students enrolled in a course for undergraduate research experience (CURE). Jung is a cluster P1 mycobacteriophage, while Ronan is in cluster C1.

Transcriptional Control Of Virulence Genes In The Bacterial Pathogen Shigella Flexneri, Joy Asami Mckenna

UNLV Theses, Dissertations, Professional Papers, and Capstones

Shigella species, the causal agents of bacillary dysentery, use a type III secretion system (T3SS) to inject two waves of virulence proteins, known as effectors, into the human colonic epithelium to subvert host cell machinery. Transcriptional regulation of these virulence genes is controlled by the three-tiered VirF/VirB/MxiE signaling cascade. Of these, VirB has the largest regulon (~50 genes); however, VirB regulatory properties are poorly understood. To date, VirB is known to function to counter or 'anti-silence' transcriptional silencing mediated by the histone-like nucleoid structuring protein H-NS. To better understand VirB regulation, my colleagues and I chose to better define the …

Effect Of Botulinum Toxin Injection On Asymmetric Lower Face And Chin Deviation, Dongwook Kim, Ju-Hyun Park, Vittorio Favero, James Mah, Young-Soo Jung, Seong Taek Kim

Dental Medicine Faculty Research

The purpose of this study was to compare the efficacy of botulinum toxin (BoNT) in masseter muscle reduction depending on the amount of chin deviation. Exploring distinctive effects of BoNT relative to the characteristics of facial asymmetry will aid in planning and predicting treatment outcomes. Sixteen adult volunteers were classified into two groups according to the degree of menton deviation observed in posteroanterior cephalograms. Eight had a menton deviation of 3 mm or more and the other eight had less than 3 mm. A total of 25 Units of BoNT was injected into the unilateral masseter muscle of the prominent …

Microbiome Shifts Associated With The Introduction Of Wild Atlantic Horseshoe Crabs (Limulus Polyphemus) Into A Touch-Tank Exhibit, Ariel D. Friel, Sean A. Neiswenter, Cale O. Seymour, Lauren Rose Bali, Ginger Mcnamara, Fabian Leija, Jack Jewell, Brian P. Hedlund

Life Sciences Faculty Research

The Atlantic horseshoe crab (Limulus polyphemus) is a common marine aquarium species and model organism for research. There is potential monetary and conservation value in developing a stable captive population of horseshoe crabs, however, one major impediment to achieving captivity is a lack of knowledge regarding captive diseases. We utilized 16S rRNA gene amplicon sequencing to track changes in the microbiomes of four body locations in three wild-caught (tracked over 14 months in captivity) and three tank-acclimated (>2 years in captivity) adult L. polyphemus in a touch tank at Shark Reef Aquarium at Mandalay Bay in Las Vegas, NV. …

Roadmap For Naming Uncultivated Archaea And Bacteria, Alison E. Murray, John Freudenstein, Simonetta Gribaldo, Roland Hatzenpichler, Philip Hugenholtz, Peter Kämpfer, Konstantinos T. Konstantinidis, Christopher E. Lane, R. Thane Papke, Donovan H. Parks, Ramon Rossello-Mora, Matthew B. Stott, Cameron Thrash, Stephanus N. Venter, William B. Whitman, Silvia G. Acinas, Rudolf I. Amann, Karthik Anantharaman, Jean Armengaud, Brett J. Baker, Roman A. Barco, Helge B. Bode, Eric S. Boyd, Carrie L. Brady, Paul Carini, Patrick S. G. Chain, Daniel R. Colman, Kristen M. Deangelis, Maria Asuncion De Los Rios, Paulina Estrada-De Los Santos, Christopher A. Dunlop

Life Sciences Faculty Research

The assembly of single-amplified genomes (SAGs) and metagenome-assembled genomes (MAGs) has led to a surge in genome-based discoveries of members affiliated with Archaea and Bacteria, bringing with it a need to develop guidelines for nomenclature of uncultivated microorganisms. The International Code of Nomenclature of Prokaryotes (ICNP) only recognizes cultures as ‘type material’, thereby preventing the naming of uncultivated organisms. In this Consensus Statement, we propose two potential paths to solve this nomenclatural conundrum. One option is the adoption of previously proposed modifications to the ICNP to recognize DNA sequences as acceptable type material; the other option creates a nomenclatural code …

The Gut Microbiome And Its Potential Role In Paradoxical Anaerobism In Pupfishes Of The Mojave Desert, Brian Hedlund

Life Sciences Faculty Research

Background: Pupfishes frequently enter paradoxical anaerobism in response to endogenously produced or exogenously supplied ethanol in a dose-dependent manner. To decipher the role of the gut microbiota in ethanol-associated paradoxical anaerobism, gut microbial communities were depleted using a cocktail of antibiotics and profiled using 16S rRNA gene sequencing. Results: Compared to the control group (n = 12), microbiota-depleted fish (n = 12) spent more time in paradoxical anaerobism. Our analysis indicated that the bacterial phyla Proteobacteria, Fusobacteria, Bacteroidetes, Firmicutes, Actinobacteria, Patescibacteria, and Dependentiae dominated the pupfish gut, which is consistent with other fish gut microbiota. Although the gut microbial communities …

Oral Localization Of Scardovia Wiggsiae, Graydon Ramos Carr

UNLV Theses, Dissertations, Professional Papers, and Capstones

Early childhood caries is one of the most prevalent diseases in the United States among children. The formation of caries is a complex, multifactorial process that is still being studied. Researchers have thought for years that Streptococcus mutans was the primary causative agent of early childhood caries. The recent discovery of a novel cariogenic pathogen, Scardovia wiggsiae and its significant contribution to the etiology of early childhood caries has led oral health researchers to re-evaluate this microorganism and its link to this disease. While there have been several projects undertaken within the University of Nevada, Las Vegas School of Dental …

The Influence Of G4 Dna Structures On Stationary Phase Mutagenesis In Bacillus Subtilis, Tatiana Ermi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Until the late 1980’s it was widely understood that bacterial variance emerges randomly during growth. Research that followed has convincingly shown evidence for mutations arising in non-growing conditions, a phenomenon known as stationary-phase mutagenesis. In Bacillus subtilis, an elegant mutagenic mechanism has been elucidated in non-growing cells that biases mutations to transcribed regions of a subpopulation. One interesting possibility is that mutations can be further biased to hotspots within genes through alternate DNA structures known as non-B DNA. Non-B DNA have been linked to genomic instability and disease in humans, lesser is known about its role in bacteria. Here we …