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 …

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 Publications

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 …

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 Publications

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 …

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 …

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.