DOCSLIB.ORG

CRISPR-Cas3 of Salmonella Upregulates Bacterial Biofilm

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
CRISPR-Cas3 of Salmonella Upregulates Bacterial Biofilm pathogens Article CRISPR-cas3 of Salmonella Upregulates Bacterial Biofilm Formation and Virulence to Host Cells by Targeting Quorum-Sensing Systems Luqing Cui 1,2, Xiangru Wang 1 , Deyu Huang 3, Yue Zhao 1, Jiawei Feng 1, Qirong Lu 3, Qinqin Pu 2, Yulian Wang 3, Guyue Cheng 3, Min Wu 2,* and Menghong Dai 1,* 1 The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan 430070, China; [email protected] (L.C.); [email protected] (X.W.); [email protected] (Y.Z.); [email protected] (J.F.) 2 Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58203, USA; [email protected] 3 MOA Key Laboratory of Food Safety Evaluation/National Reference Laboratory of Veterinary Drug Residue (HZAU), Huazhong Agricultural University, Wuhan 430070, China; [email protected] (D.H.); [email protected] (Q.L.); [email protected] (Y.W.); [email protected] (G.C.) * Correspondence: [email protected] (M.W.); [email protected] (M.D.); Tel.: +1-701-777-4875 (M.W.); +86-027-8767-2232 (M.D.); Fax: +1-701-777-2382 (M.W.); +86-027-8767-2232 (M.D.) Received: 8 December 2019; Accepted: 7 January 2020; Published: 10 January 2020 Abstract: Salmonella is recognized as one of the most common microbial pathogens worldwide. The bacterium contains the clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated (Cas) systems, providing adaptive immunity against invading foreign nucleic acids. Previous studies suggested that certain bacteria employ the Cas proteins of CRISPR-Cas systems to target their own genes, which also alters the virulence during invasion of mammals. However, whether CRISPR-Cas systems in Salmonella have similar functions during bacterial invasion of host cells remains unknown. Here, we systematically analyzed the genes that are regulated by Cas3 in a type I-E CRISPR-Cas system and the virulence changes due to the deletion of cas3 in Salmonella enterica serovar Enteritidis. Compared to the cas3 gene wild-type (cas3 WT) Salmonella strain, cas3 deletion upregulated the lsrFGBE genes in lsr (luxS regulated) operon related to quorum sensing (QS) and downregulated biofilm-forming-related genes and Salmonella pathogenicity island 1 (SPI-1) genes related to the type three secretion system (T3SS). Consistently, the biofilm formation ability was downregulated in the cas3 deletion mutant (Dcas3). The bacterial invasive and intracellular capacity of Dcas3 to host cells was also reduced, thereby increasing the survival of infected host cells and live chickens. By the transcriptome-wide screen (RNA-Seq), we found that the cas3 gene impacts a series of genes related to QS, the flagellum, and SPI-1-T3SS system, thereby altering the virulence phenotypes. As QS SPI-1-T3SS and CRISPR-Cas systems are widely distributed in the bacteria kingdom, our findings extend our understanding of virulence regulation and pathogenicity in mammalian hosts for Salmonella and potentially other bacteria. Keywords: type I-E CRISPR-Cas system; cas3; Salmonella virulence; RNA-Seq; quorum sensing; biofilm formation; SPI-1-T3SS 1. Introduction Salmonella is a significant pathogen for humans and animals. It not only causes a variety of diseases in livestock and poultry but also causes food poisoning in humans [1]. Among the foods that cause Pathogens 2020, 9, 53; doi:10.3390/pathogens9010053 www.mdpi.com/journal/pathogens Pathogens 2020, 9, x FOR PEER REVIEW 2 of 20 1. Introduction Pathogens 2020, 9, 53 2 of 20 Salmonella is a significant pathogen for humans and animals. It not only causes a variety of diseases in livestock and poultry but also causes food poisoning in humans [1]. Among the foods that causeSalmonella Salmonellapoisoning, poisoning, more thanmore 90% than are 90% meat are and meat other and animal other animal products products [2,3]. It [2,3]. is a highly It is a diversehighly diversespecies comprisingspecies comprising of two species of two divided species into divided six subspecies into six andsubspecies over 2500 and serovars over 2500 [4]. Statistics serovars show [4]. Statisticsthat Salmonella show entericathat Salmonellaserovar Enteritidis enterica serovar (S. Enteritidis), EnteritidisS. Choleraesuis,(S. Enteritidis), and S.S. Choleraesuis,Typhimurium and are theS. Typhimuriummajor pathogenic are the bacteria major that pathogenic contaminate bacteria animal that products contaminate and animal cause human productsSalmonella and causepoisoning. human SalmonellaThese bacteria poisoning. cause significant These bacteria harm tocause human significant health and harm livestock to human development health [ 5].and In thislivestock study, developmentthe Salmonella [5].strain In this SE211 study, serotype the Salmonella is identified strain asSE211S. Enteritidis, serotype is one identified of the as dominant S. Enteritidis, serotypes. one ofSE211 the dominant is characterized serotypes. as a SE211 highly is pathogeniccharacterizedSalmonella as a highlyharboring pathogenic a type Salmonella I-E clustered harboring interspaced a type I-Eshort clustered palindromic interspaced repeats short (CRISPR)-CRISPR-associated palindromic repeats (CRISPR)-CRISPR-associ (Cas) system. Theated system (Cas) comprises system. The two systemmajor molecularcomprises constituents:two major molecular A set of constituents:cas genes and A CRISPR set of cas arrays genes (Figure and CRISPR1). CRISPR arrays arrays (Figure have 1). CRISPRbeen widely arrays used have in been the serotyping widely used of inSalmonella the serotypingaccording of Salmonella to the variety according in the to spacers the variety [6,7], in and the it spacerswas shown [6,7], thatand theit was results shown from that CRISPR the results typing from had CRISPR a good typing correspondence had a good correspondence with whole genome with wholesequence genome typing sequence [8,9]. Furthermore, typing [8,9]. CRISPR-multi-virulence-locus Furthermore, CRISPR-multi-v sequenceirulence-locus typing (MVLST) sequence has typing been (MVLST)frequently has used been to subtypefrequentlySalmonella used toserovars subtype [ 10Salmonella,11]. The conservedserovars [10,11]. genetic The organization conserved of genetic the cas organizationgenes in some of Salmonellathe cas genesserovars in some is consistentSalmonella withserovars its biological is consistent function with its in biological these bacteria function [12–14 in]. theseIn addition, bacteria some [12–14]. reports In addi foundtion, that some in reportsS. Typhi, found this systemthat in S. consists Typhi, ofthis five system transcriptional consists of units, five transcriptionalincluding two messengerunits, including ribonucleic two messenger acids (CRISPR-cas ribonucleicand acidscas3), (CRISPR-cas one sense ribonucleic and cas3), acidone (sensescse2), ribonucleicand two antisense acid (scse2 RNAs), and (ascse2-1 two antisenseand ascas2-1 RNAs)[ 15(ascse2-1]. and ascas2-1) [15]. FigureFigure 1. 1. SchematicSchematic of of the the SalmonellaSalmonella typetype I-E I-E clustered clustered interspaced interspaced short short palindromic palindromic repeats repeats (CRISPR)-CRISPR-associated(CRISPR)-CRISPR-associated (Cas) (Cas) operon. operon. SalmonellaSalmonella hashas two two CRISPR CRISPR loci, loci, CRISPR1 CRISPR1 and and CRISPR2, CRISPR2, bothboth encoded encoded on on the the minus minus strand. strand. There There are are eight eight cascas genesgenes that that are are located located upstream upstream of of CRISPR1, CRISPR1, shownshown as as colored colored boxed boxed arrows. arrows. Type Type I I system system signature signature gene, gene, cas3cas3,, is is shown shown (red). (red). The The cas1cas1 andand cas2cas2 genesgenes are universal, andand presentpresent in in all all CRISPR-Cas CRISPR-Cas systems systems (orange). (orange). The The remaining remainingcas genescas genes are typeare typeI-E-dependent I-E-dependent (green). (green). The CRISPR The CRISPR locus compriseslocus comprises a leader a regionleader and region repeats and (black repeats cross (black lines) cross that lines)are separated that are separated by unique by spacers unique (vertical spacers colored(vertical lines). colored crRNA lines). (CRISPR crRNA (C RNA)RISPR consists RNA) consists of a spacer of aflanked spacer byflanked partial by repeats. partial repeats. CRISPR array and cas genes are broadly present in the genomes of prokaryotic organisms, such as CRISPR array and cas genes are broadly present in the genomes of prokaryotic organisms, such bacteria and archaea. CRISPR-Cas is a prokaryotic immune system that confers resistance to foreign as bacteria and archaea. CRISPR-Cas is a prokaryotic immune system that confers resistance to genetic elements, such as those present within plasmids and phages [16–18] that provide a form of foreign genetic elements, such as those present within plasmids and phages [16–18] that provide a acquired immunity. crRNA (CRISPR RNA), which harbors the spacer sequence, helps Cas proteins form of acquired immunity. crRNA (CRISPR RNA), which harbors the spacer sequence, helps Cas recognize and cut the DNA of foreign pathogens [19], and RNA-guided Cas proteins can also cleave proteins recognize and cut the DNA of foreign pathogens [19], and RNA-guided Cas proteins can invading RNA [20], for example, type III-A CRISPR-Cas Csm complex of Thermus thermophilus target also cleave invading RNA [20], for example, type III-A CRISPR-Cas Csm complex of Thermus
Load more

Recommended publications
  • Helicobacter Pylori Infection Causes Characteristic DNA Damage Patterns in Human Cells
    Report Helicobacter pylori Infection Causes Characteristic DNA Damage Patterns in Human Cells Graphical Abstract Authors Max Koeppel, Fernando Garcia-Alcalde, Frithjof Glowinski, Philipp Schlaermann, Thomas F. Meyer Correspondence [email protected] In Brief The gastric pathogen H. pylori can cause cancer in humans by compromising the genomic integrity of infected cells. Koeppel et al. show that infection affects the DNA damage response and reveal a DNA damage pattern reminiscent of genomic aberrations found in gastric tumors. Highlights Accession Numbers d H. pylori impairs the DNA repair response in normal human GSE55699 epithelial cells d Distinct genomic regions show increased susceptibility to H. pylori-induced damage d DNA damage accumulates in telomere-proximal, actively transcribed regions d Susceptible genomic regions overlap with gastric cancer genomic aberrations Koeppel et al., 2015, Cell Reports 11, 1703–1713 June 23, 2015 ª2015 The Authors http://dx.doi.org/10.1016/j.celrep.2015.05.030 Cell Reports Report Helicobacter pylori Infection Causes Characteristic DNA Damage Patterns in Human Cells Max Koeppel,1 Fernando Garcia-Alcalde,1 Frithjof Glowinski,1 Philipp Schlaermann,1 and Thomas F. Meyer1,* 1Department of Molecular Biology, Max Planck Institute for Infection Biology, Charite´ platz 1, 10117 Berlin, Germany *Correspondence: [email protected] http://dx.doi.org/10.1016/j.celrep.2015.05.030 This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). SUMMARY (Jenks et al., 2003; Touati et al., 2003). This process has been linked to reduced expression of mismatch repair genes (Kim Infection with the human pathogen Helicobacter et al., 2002) and increased expression of activation-induced cyti- pylori (H.
    [Show full text]
  • Analysis and Construction of Pathogenicity Island Regulatory Pathways in Salmonella Enterica Serovar Typhi
    Journal of Integrative Bioinformatics, 7(1):145, 2010 http://journal.imbio.de Analysis and construction of pathogenicity island regulatory pathways in Salmonella enterica serovar Typhi Su Yean Ong1 *, Fui Ling Ng1, Siti Suriawati Badai1, Anton Yuryev2, Maqsudul Alam1 1 Centre for Chemical Biology, Universiti Sains Malaysia, 1st Floor, Block B, No. 10, Persiaran Bukit Jambul, 11900 Bayan Lepas, Pulau Pinang, Malaysia 2 Ariadne Genomics Inc., 9430 Key West Avenue, Suite 113, Rockville, MD 20850, USA [email protected], [email protected], [email protected], [email protected], [email protected] Summary Signal transduction through protein-protein interactions and protein modifications are the main mechanisms controlling many biological processes. Here we described the (http://creativecommons.org/licenses/by-nc-nd/3.0/). implementation of MedScan information extraction technology and Pathway Studio software (Ariadne Genomics Inc.) to create a Salmonella specific molecular interaction License database. Using the database, we have constructed several signal transduction pathways in Salmonella enterica serovar Typhi which causes Typhoid Fever, a major health threat especially in developing countries. S. Typhi has several pathogenicity islands that control Unported rapid switching between different phenotypes including adhesion and colonization, 3.0 invasion, intracellular survival, proliferation, and biofilm formation in response to environmental changes. Understanding of the detailed mechanism for S. Typhi survival in host cells is necessary for development of efficient detection and treatment of this pathogen. The constructed pathways were validated using publically available gene expression microarray data for Salmonella. Bioinformatics. 1 Introduction Integrative S. Typhi is able to survive a variety of harsh conditions and defense mechanisms existing in of the human gastrointestinal tract.
    [Show full text]
  • Identification of a Pathogenicity Island, Which Contains Genes For
    Proc. Natl. Acad. Sci. USA Vol. 96, pp. 10875–10880, September 1999 Microbiology Identification of a pathogenicity island, which contains genes for virulence and avirulence, on a large native plasmid in the bean pathogen Pseudomonas syringae pathovar phaseolicola (plant disease resistance͞hypersensitive reaction͞signal transduction) ROBERT W. JACKSON*, EVANGELOS ATHANASSOPOULOS†‡,GEORGE TSIAMIS†‡,JOHN W. MANSFIELD†§,ANE SESMA¶, ʈ DAWN L. ARNOLD*, MARJORIE J. GIBBON*, JESUS MURILLO¶,JOHN D. TAYLOR , AND ALAN VIVIAN* *Department of Biological and Biomedical Sciences, University of the West of England, Coldharbor Lane, Bristol BS16 1QY, United Kingdom; †Department of Biological Sciences, Wye College, Wye, Ashford, Kent TN25 5AH, United Kingdom; ¶Escuela Te´cnica Superior de Ingenieros Agro´nomos, Universidad Pu´blica de Navarra, 31006 Pamplona, Spain; and ʈHorticulture Research International, Wellesbourne, Warwick CV35 9EF, United Kingdom Communicated by Noel T. Keen, University of California, Riverside, CA, July 7, 1999 (received for review April 2, 1999) ABSTRACT The 154-kb plasmid was cured from race 7 Certain avr genes, although recognized by their ability to strain 1449B of the phytopathogen Pseudomonas syringae pv. activate plant defenses (the HR), also may have a role in phaseolicola (Pph). Cured strains lost virulence toward bean, pathogenicity in the absence of the interacting R gene in the causing the hypersensitive reaction in previously susceptible host plant. In some cases there is a clear, qualitative effect on cultivars. Restoration of virulence was achieved by complemen- pathogenicity of mutations in avr genes, as with avrBs2 in tation with cosmid clones spanning a 30-kb region of the plasmid certain races of Xanthomonas campestris pv. vesicatoria in that contained previously identified avirulence (avr) genes avrD, pepper and avrRpm1 in P.
    [Show full text]
  • The Role of Integrating Conjugative Elements in Helicobacter Pylori: a Review Langgeng Agung Waskito1,2, Jeng Yih-Wu3 and Yoshio Yamaoka1,4,5*
    Waskito et al. Journal of Biomedical Science (2018) 25:86 https://doi.org/10.1186/s12929-018-0489-2 REVIEW Open Access The role of integrating conjugative elements in Helicobacter pylori: a review Langgeng Agung Waskito1,2, Jeng Yih-Wu3 and Yoshio Yamaoka1,4,5* Abstract The genome of Helicobacter pylori contains many putative genes, including a genetic region known as the Integrating Conjugative Elements of H. pylori type four secretion system (ICEHptfs). This genetic regions were originally termed as “plasticity zones/regions” due to the great genetic diversity between the original two H. pylori whole genome sequences. Upon analysis of additional genome sequences, the regions were reported to be extremely common within the genome of H. pylori. Moreover, these regions were also considered conserved rather than genetically plastic and were believed to act as mobile genetic elements transferred via conjugation. Although ICEHptfs(s) are highly conserved, these regions display great allele diversity, especially on ICEHptfs4, with three different subtypes: ICEHptfs4a, 4b, and 4c. ICEHptfs were also reported to contain a novel type 4 secretion system (T4SS) with both epidemiological and in vitro infection model studies highlighting that this novel T4SS functions primarily as a virulence factor. However, there is currently no information regarding the structure, the genes responsible for forming the T4SS, and the interaction between this T4SS and other virulence genes. Unlike the cag pathogenicity island (PAI), which contains CagA, a gene found to be essential for H. pylori virulence, these novel T4SSs have not yet been reported to contain genes that contribute significant effects to the entire system.
    [Show full text]
  • Cag, a Pathogenicity Island of Helicobacter Pylori, Encodes Type I
    Proc. Natl. Acad. Sci. USA Vol. 93, pp. 14648–14653, December 1996 Genetics cag, a pathogenicity island of Helicobacter pylori, encodes type I-specific and disease-associated virulence factors (secretionyinsertion sequenceyinflammationyevolution) STEFANO CENSINI,CHRISTINA LANGE,ZHAOYING XIANG*, JEAN E. CRABTREE†,PAOLO GHIARA, MARK BORODOVSKY‡,RINO RAPPUOLI, AND ANTONELLO COVACCI§ Immunobiological Research Institute of Siena, Chiron Vaccines, Via Fiorentina 1, 53100 Siena, Italy Communicated by Stanley Falkow, Stanford University School of Medicine, Stanford, CA, October 9, 1996 (received for review June 14, 1996) ABSTRACT cagA, a gene that codes for an immunodom- Genetic analysis shows that the cagA gene is present only in inant antigen, is present only in Helicobacter pylori strains that type I strains, while the vacA gene is present in both types (4). are associated with severe forms of gastroduodenal disease An active toxin is produced only by type I strains; however, the (type I strains). We found that the genetic locus that contains linkage between CagA and VacA expression is not yet clear cagA (cag) is part of a 40-kb DNA insertion that likely was since the cagA and vacA genes are located more than 300 kb acquired horizontally and integrated into the chromosomal apart on the chromosome of the H. pylori NCTC 11638 (11). glutamate racemase gene. This pathogenicity island is flanked Moreover, it has been shown that inactivation of the cagA gene by direct repeats of 31 bp. In some strains, cag is split into a has no consequence on expression of VacA or on the ability to right segment (cagI) and a left segment (cagII) by a novel induce IL-8 (12–14).
    [Show full text]
  • CAG PATHOGENICITY ISLAND of Helicobacter Pylori and ITS ASSOCIATION to PRENEOPLASTIC LESIONS and GASTRIC CANCER
    Artículo de Revisión Cristancho Liévano, F.; Trujillo Gama, E.; Bravo Hernández, M.M.: cagPAI Helicobacter pylori CAG PATHOGENICITY ISLAND OF Helicobacter pylori AND ITS ASSOCIATION TO PRENEOPLASTIC LESIONS AND GASTRIC CANCER EL ISLOTE DE PATOGENICIDAD CAG DE Helicobacter pylori Y SU ASOCIACIÓN CON LESIONES PRENEOPLÁSICAS Y CÁNCER GÁSTRICO Felipe Cristancho Liévano1, Esperanza Trujillo Gama2, María Mercedes Bravo Hernández3 1Biólogo, Grupo de Investigación en Biología del Cáncer. Instituto Nacional de Cancerología, Calle 1 No. 9-85, Bogotá, D.C., Colombia, e-mail: [email protected], https://orcid.org/0000-0002-2652-6372; 2Química, M.Sc., Grupo de Investi- gación en Biología del Cáncer. Instituto Nacional de Cancerología, Calle 1 No. 9-85, Bogotá, D.C., Colombia, e-mail: estrujil- [email protected]; 3Microbióloga, M.Sc., Grupo de Investigación en Biología del Cáncer. Instituto Nacional de Cancerología, Calle 1 No. 9-85, Bogotá, D.C., Colombia, e-mail: [email protected], https://orcid.org/0000-0002-6472-8362 Rev. U.D.C.A Act. & Div. Cient. 21(2): 309-318, Julio-Diciembre, 2018 https://doi.org/10.31910/rudca.v21.n2.2018.972 Open access article published by Revista U.D.C.A Actualidad & Divulgación Científica under a Creative Commons CC BY-NC 4.0 International License ABSTRACT población mundial. Los efectos patológicos ocasionados por la infección con H. pylori dependen, en buena parte, Gastric cancer is one of the main causes of death by cancer de un sistema de secreción tipo IV, codificado en el islote in the world and the infection with Helicobacter pylori is de patogenicidad cag (cagPAI).
    [Show full text]
  • Genome Sequencing and Analysis of Salmonella Enterica Subsp. Enterica Serovar Stanley UPM
    Genome sequencing and analysis of Salmonella enterica subsp. enterica serovar Stanley UPM 517: Insights on its virulence-associated elements and their potentials as vaccine candidates Khalidah Syahirah Ashari1, Najwa Syahirah Roslan2, Abdul Rahman Omar2,3, Mohd Hair Bejo2,3, Aini Ideris2,4 and Nurulfiza Mat Isa1,2 1 Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia 2 Institute of Bioscience, Universiti Putra Malaysia, Serdang, Selangor, Malaysia 3 Department of Veterinary Pathology and Microbiology, Faculty of Veterinary Medicine, Universiti Putra Malaysia, Serdang, Selangor, Malaysia 4 Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, Serdang, Selangor, Malaysia ABSTRACT Salmonella enterica subsp. enterica serovar Stanley (S. Stanley) is a pathogen that contaminates food, and is related to Salmonella outbreaks in a variety of hosts such as humans and farm animals through products like dairy items and vegetables. Despite the fact that several vaccines of Salmonella strains had been constructed, none of them were developed according to serovar Stanley up to this day. This study presents results of genome sequencing and analysis on our S. Stanley UPM 517 strain taken from fecal swabs of 21-day-old healthy commercial chickens in Perak, Malaysia and used Salmonella enterica subsp. enterica serovar Typhimurium LT2 (S. Typhimurium LT2) as a reference to be compared with. First, sequencing and Submitted 2 August 2018 assembling of the Salmonella Stanley UPM 517 genome into a contiguous form were Accepted 5 April 2019 done. The work was then continued with scaffolding and gap filling. Annotation and Published 28 June 2019 alignment of the draft genome was performed with S.
    [Show full text]
  • An Analysis of Outer Inflammatory Protein a in Cag Pathogenicity Island Negative and Positive Strains of Helicobacter Pylori
    W&M ScholarWorks Undergraduate Honors Theses Theses, Dissertations, & Master Projects 4-2017 An Analysis of Outer Inflammatory Protein A in cag Pathogenicity Island Negative and Positive Strains of Helicobacter pylori Danielle N. Horridge College of William and Mary Follow this and additional works at: https://scholarworks.wm.edu/honorstheses Part of the Bacteriology Commons, and the Pathogenic Microbiology Commons Recommended Citation Horridge, Danielle N., "An Analysis of Outer Inflammatory Protein A in cag Pathogenicity Island Negative and Positive Strains of Helicobacter pylori" (2017). Undergraduate Honors Theses. Paper 1126. https://scholarworks.wm.edu/honorstheses/1126 This Honors Thesis is brought to you for free and open access by the Theses, Dissertations, & Master Projects at W&M ScholarWorks. It has been accepted for inclusion in Undergraduate Honors Theses by an authorized administrator of W&M ScholarWorks. For more information, please contact [email protected]. An Analysis of Outer Inflammatory Protein A in cag Pathogenicity Island Negative and Positive Strains of Helicobacter pylori Danielle N. Horridge1 1- The College of William & Mary, Williamsburg, VA 23187 A thesis submitted in partial fulfillment of the requirements of the degree of Bachelor of Science with Honors in Biology from The College of William & Mary in Virginia. Williamsburg, Virginia May 2017 © Copyright by Danielle N. Horridge 2017 Abstract OipA, outer inflammatory protein A, is an outer membrane protein virulence factor of the gastric pathogen Helicobacter pylori. oipA expression is regulated by phase variation at a CT dinucleotide repeat located within the 5’ end of the gene, such that the gene is alternatively in- frame (Phase On) or out-of-frame (Phase Off).
    [Show full text]
  • CRISPR-Based Screening of Genomic Island Excision Events in Bacteria
    CRISPR-based screening of genomic island excision events in bacteria Kurt Sellea,b, Todd R. Klaenhammera,b,1, and Rodolphe Barrangoua,1 aDepartment of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, NC 27695; and bFunctional Genomics Graduate Program, North Carolina State University, Raleigh, NC 27695 Contributed by Todd R. Klaenhammer, May 19, 2015 (sent for review September 22, 2014) Genomic analysis of Streptococcus thermophilus revealed that RNAs (crRNAs) that guide Cas proteins for sequence-specific mobile genetic elements (MGEs) likely contributed to gene acqui- recognition and cleavage of target DNA complementary to the sition and loss during evolutionary adaptation to milk. Clustered spacer (7). CRISPR-Cas technology has applications in strain regularly interspaced short palindromic repeats–CRISPR-associated typing and detection (8–10), exploitation of natural/engineered genes (CRISPR-Cas), the adaptive immune system in bacteria, limits immunity against mobile genetic elements (11), programmable genetic diversity by targeting MGEs including bacteriophages, genome editing in diverse backgrounds (12), transcriptional con- transposons, and plasmids. CRISPR-Cas systems are widespread trol (13, 14), and manipulation of microbial populations in defined in streptococci, suggesting that the interplay between CRISPR- consortia (15). Cas systems and MGEs is one of the driving forces governing Although sequence features corresponding to CRISPR arrays genome homeostasis in this genus. To investigate the genetic out- were described previously in multiple organisms (16, 17), Strep- in comes resulting from CRISPR-Cas targeting of integrated MGEs, tococcus thermophilus was the first microbe in which the roles silico prediction revealed four genomic islands without essential of specific cas genes and CRISPR-array components were elu- genes in lengths from 8 to 102 kbp, totaling 7% of the genome.
    [Show full text]
  • Identification of Pathogenic Islands Using Comparative Genomics Based Tools
    Identification of Pathogenic Islands using Comparative Genomics Based Tools Author’s Note Every year I take my bioscience students on a field trip to the University of Florida’s campus in Gainesville. The students tour research labs, talk with graduate students, and get to perform a laboratory experiment on campus. It is the highlight of their year! During our field trip in November of 2012, we happened to have some down time between activities. I had noticed a flyer for an open lecture titled “From tRNA to protein modification: Linking gene function by comparative genomics” by Dr. Valérie de Crécy-Lagard. I didn’t know how much my students or myself would get out of it, but we went for it. It was there that I first met Valérie, an insanely energetic woman with enough enthusiasm about her research topic to fill an ocean. As a teacher, I recognized that comparative genomics and bioinformatics would be important to my students who chose to continue their education in the field of bioscience. My educational experience with CPET had provided me with a superficial background knowledge of comparative genomics and its importance as a research tool. During the lecture, Valérie mentioned a workshop that she was giving over the summer and afterwards I approached her for more information. She was more than happy to chat about it and told me I could email her. So I did. The response I got stated that the course was intensive and they were not sure I had the ‘necessary training in biochemistry and bioinformatics to participate’.
    [Show full text]
  • Investigating Genetic (IN)Compatibility Between Temperate Phages and CRISPR-CAS Systems in Staphylococcus Aureus Gregory W
    Rockefeller University Digital Commons @ RU Student Theses and Dissertations 2018 Investigating Genetic (IN)Compatibility Between Temperate Phages and CRISPR-CAS Systems in Staphylococcus Aureus Gregory W. Goldberg Follow this and additional works at: https://digitalcommons.rockefeller.edu/ student_theses_and_dissertations Part of the Life Sciences Commons INVESTIGATING GENETIC (IN)COMPATIBILITY BETWEEN TEMPERATE PHAGES AND CRISPR-CAS SYSTEMS IN STAPHYLOCOCCUS AUREUS A Thesis Presented to the Faculty of The Rockefeller University in Partial Fulfillment of the Requirements for the degree of Doctor of Philosophy by Gregory W. Goldberg June 2018 © Copyright by Gregory W. Goldberg 2018 INVESTIGATING GENETIC (IN)COMPATIBILITY BETWEEN TEMPERATE PHAGES AND CRISPR-CAS SYSTEMS IN STAPHYLOCOCCUS AUREUS Gregory W. Goldberg, Ph.D. The Rockefeller University 2018 Prokaryotic organisms employ various mechanisms for defending against parasitism by viruses and other mobile genetic elements. One form of defense comprises the adaptive immune systems derived from clustered, regularly interspaced, short palindromic repeat (CRISPR) loci and CRISPR-associated (cas) genes. CRISPR-Cas immune systems enable the acquisition of heritable resistance to specific mobile genetic elements on the basis of nucleic acid sequence recognition, but do not necessarily discriminate between target elements which are burdensome and those which are beneficial. My thesis is concerned with the consequences of CRISPR-Cas immunity directed at a particular breed of bacterial DNA viruses,
    [Show full text]
  • Identification of a Pathogenicity Island, Which Contains Genes For
    Proc. Natl. Acad. Sci. USA Vol. 96, pp. 10875–10880, September 1999 Microbiology Identification of a pathogenicity island, which contains genes for virulence and avirulence, on a large native plasmid in the bean pathogen Pseudomonas syringae pathovar phaseolicola (plant disease resistance͞hypersensitive reaction͞signal transduction) ROBERT W. JACKSON*, EVANGELOS ATHANASSOPOULOS†‡,GEORGE TSIAMIS†‡,JOHN W. MANSFIELD†§,ANE SESMA¶, ʈ DAWN L. ARNOLD*, MARJORIE J. GIBBON*, JESUS MURILLO¶,JOHN D. TAYLOR , AND ALAN VIVIAN* *Department of Biological and Biomedical Sciences, University of the West of England, Coldharbor Lane, Bristol BS16 1QY, United Kingdom; †Department of Biological Sciences, Wye College, Wye, Ashford, Kent TN25 5AH, United Kingdom; ¶Escuela Te´cnica Superior de Ingenieros Agro´nomos, Universidad Pu´blica de Navarra, 31006 Pamplona, Spain; and ʈHorticulture Research International, Wellesbourne, Warwick CV35 9EF, United Kingdom Communicated by Noel T. Keen, University of California, Riverside, CA, July 7, 1999 (received for review April 2, 1999) ABSTRACT The 154-kb plasmid was cured from race 7 Certain avr genes, although recognized by their ability to strain 1449B of the phytopathogen Pseudomonas syringae pv. activate plant defenses (the HR), also may have a role in phaseolicola (Pph). Cured strains lost virulence toward bean, pathogenicity in the absence of the interacting R gene in the causing the hypersensitive reaction in previously susceptible host plant. In some cases there is a clear, qualitative effect on cultivars. Restoration of virulence was achieved by complemen- pathogenicity of mutations in avr genes, as with avrBs2 in tation with cosmid clones spanning a 30-kb region of the plasmid certain races of Xanthomonas campestris pv. vesicatoria in that contained previously identified avirulence (avr) genes avrD, pepper and avrRpm1 in P.
    [Show full text]