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A CRISPR interference platform for selective downregulation of gene expression in Borrelia burgdorferi. Appl Environ Microbiol 2021; 87:AEM.02519-20. [PMID: 33257311 PMCID: PMC7851697 DOI: 10.1128/aem.02519-20] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The spirochete Borrelia burgdorferi causes Lyme disease, an increasingly prevalent infection. While previous studies have provided important insight into B. burgdorferi biology, many aspects, including basic cellular processes, remain underexplored. To help speed up the discovery process, we adapted a CRISPR interference (CRISPRi) platform for use in B. burgdorferi For efficiency and flexibility of use, we generated various CRISPRi template constructs that produce different basal and induced levels of dcas9 and carry different antibiotic resistance markers. We characterized the effectiveness of our CRISPRi platform by targeting the motility and cell morphogenesis genes flaB, mreB, rodA, and ftsI, whose native expression levels span two orders of magnitude. For all four genes, we obtained gene repression efficiencies of at least 95%. We showed by darkfield microscopy and cryo-electron tomography that flagellin (FlaB) depletion reduced the length and number of periplasmic flagella, which impaired cellular motility and resulted in cell straightening. Depletion of FtsI caused cell filamentation, implicating this protein in cell division in B. burgdorferi Finally, localized cell bulging in MreB- and RodA-depleted cells matched the locations of new peptidoglycan insertion specific to spirochetes of the Borrelia genus. These results therefore implicate MreB and RodA in the particular mode of cell wall elongation of these bacteria. Collectively, our results demonstrate the efficiency and ease of use of our B. burgdorferi CRISPRi platform, which should facilitate future genetic studies of this important pathogen.IMPORTANCE Gene function studies are facilitated by the availability of rapid and easy-to-use genetic tools. Homologous recombination-based methods traditionally used to genetically investigate gene function remain cumbersome to perform in B. burgdorferi, as they often are relatively inefficient. In comparison, our CRISPRi platform offers an easy and fast method to implement as it only requires a single plasmid transformation step and IPTG addition to obtain potent (>95%) downregulation of gene expression. To facilitate studies of various genes in wild-type and genetically modified strains, we provide over 30 CRISPRi plasmids that produce distinct levels of dcas9 expression and carry different antibiotic resistance markers. Our CRISPRi platform represents a useful and efficient complement to traditional genetic and chemical methods to study gene function in B. burgdorferi.
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Snow S, Bacon E, Bergeron J, Katzman D, Wilhelm A, Lewis O, Syangtan D, Calkins A, Archambault L, Anacker ML, Schlax PJ. Transcript decay mediated by RNase III in Borrelia burgdorferi. Biochem Biophys Res Commun 2020; 529:386-391. [PMID: 32703440 DOI: 10.1016/j.bbrc.2020.05.201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 05/26/2020] [Indexed: 11/29/2022]
Abstract
The causative agent of Lyme disease, Borrelia burgdorferi, requires shifts in gene expression to undergo its natural enzootic cycle between tick and vertebrate hosts. mRNA decay mechanisms play significant roles in governing gene expression in other bacteria, but are not yet characterized in B. burgdorferi. RNase III is an important enzyme in processing ribosomal RNA, but it also plays a role in mRNA decay in many bacteria. We compared RNA decay profiles and steady-state abundances of transcripts in wild-type Borrelia burgdorferi strain B31 and in an RNase III null (rnc-) mutant. Transcripts encoding RNA polymerase subunits (rpoA and rpoS), ribosomal proteins (rpsD, rpsK, rpsM, rplQ, and rpsO), a nuclease (pnp), a flagellar protein (flaB), and a translational regulator (bpuR) decayed more rapidly in the wild-type strain than in the slow growing rnc- mutant indicating that RNA turnover is mediated by RNase III in the bacterium that causes Lyme disease. Additionally, in wild type bacteria, RNA decay rates of rpoS, rpoN, ospA, ospC, bpuR and dbpA transcripts are only modestly affected by changes in the osmolarity.
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Affiliation(s)
- Santina Snow
- Department of Chemistry and Biochemistry, Bates College, Lewiston, ME, USA
| | - Emily Bacon
- Department of Chemistry and Biochemistry, Bates College, Lewiston, ME, USA
| | - Jennifer Bergeron
- Department of Chemistry and Biochemistry, Bates College, Lewiston, ME, USA
| | - David Katzman
- Department of Chemistry and Biochemistry, Bates College, Lewiston, ME, USA
| | - Amelia Wilhelm
- Department of Chemistry and Biochemistry, Bates College, Lewiston, ME, USA
| | - Owen Lewis
- Department of Chemistry and Biochemistry, Bates College, Lewiston, ME, USA
| | - Deepsing Syangtan
- Department of Chemistry and Biochemistry, Bates College, Lewiston, ME, USA
| | - Andrew Calkins
- Department of Chemistry and Biochemistry, Bates College, Lewiston, ME, USA
| | - Linda Archambault
- Department of Chemistry and Biochemistry, Bates College, Lewiston, ME, USA
| | - Melissa L Anacker
- Division of Biological Sciences, University of Montana, Missoula, MT, USA
| | - Paula Jean Schlax
- Department of Chemistry and Biochemistry, Bates College, Lewiston, ME, USA.
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Takacs CN, Kloos ZA, Scott M, Rosa PA, Jacobs-Wagner C. Fluorescent Proteins, Promoters, and Selectable Markers for Applications in the Lyme Disease Spirochete Borrelia burgdorferi. Appl Environ Microbiol 2018; 84:e01824-18. [PMID: 30315081 PMCID: PMC6275353 DOI: 10.1128/aem.01824-18] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 10/08/2018] [Indexed: 11/30/2022] Open
Abstract
Lyme disease is the most widely reported vector-borne disease in the United States. Its incidence is rapidly increasing, and disease symptoms can be debilitating. The need to understand the biology of the disease agent, the spirochete Borrelia burgdorferi, is thus evermore pressing. Despite important advances in B. burgdorferi genetics, the array of molecular tools available for use in this organism remains limited, especially for cell biological studies. Here, we adapt a palette of bright and mostly monomeric fluorescent proteins for versatile use and multicolor imaging in B. burgdorferi We also characterize two novel antibiotic selection markers and establish the feasibility of their use in conjunction with extant markers. Last, we describe a set of promoters of low and intermediate strengths that allow fine-tuning of gene expression levels. These molecular tools complement and expand current experimental capabilities in B. burgdorferi, which will facilitate future investigation of this important human pathogen. To showcase the usefulness of these reagents, we used them to investigate the subcellular localization of BB0323, a B. burgdorferi lipoprotein essential for survival in the host and vector environments. We show that BB0323 accumulates at the cell poles and future division sites of B. burgdorferi cells, highlighting the complex subcellular organization of this spirochete.IMPORTANCE Genetic manipulation of the Lyme disease spirochete B. burgdorferi remains cumbersome, despite significant progress in the field. The scarcity of molecular reagents available for use in this pathogen has slowed research efforts to study its unusual biology. Of interest, B. burgdorferi displays complex cellular organization features that have yet to be understood. These include an unusual morphology and a highly fragmented genome, both of which are likely to play important roles in the bacterium's transmission, infectivity, and persistence. Here, we complement and expand the array of molecular tools available for use in B. burgdorferi by generating and characterizing multiple fluorescent proteins, antibiotic selection markers, and promoters of varied strengths. These tools will facilitate investigations in this important human pathogen, as exemplified by the polar and midcell localization of the cell envelope regulator BB0323, which we uncovered using these reagents.
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Affiliation(s)
- Constantin N Takacs
- Microbial Sciences Institute, Yale West Campus, West Haven, Connecticut, USA
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut, USA
- Howard Hughes Medical Institute, Yale West Campus, West Haven, Connecticut, USA
| | - Zachary A Kloos
- Microbial Sciences Institute, Yale West Campus, West Haven, Connecticut, USA
- Microbiology Program, Yale University, New Haven, Connecticut, USA
| | - Molly Scott
- Microbial Sciences Institute, Yale West Campus, West Haven, Connecticut, USA
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut, USA
- Howard Hughes Medical Institute, Yale West Campus, West Haven, Connecticut, USA
| | - Patricia A Rosa
- Laboratory of Bacteriology, Rocky Mountain Laboratories, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Christine Jacobs-Wagner
- Microbial Sciences Institute, Yale West Campus, West Haven, Connecticut, USA
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut, USA
- Howard Hughes Medical Institute, Yale West Campus, West Haven, Connecticut, USA
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, USA
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Molodtsov V, Scharf NT, Stefan MA, Garcia GA, Murakami KS. Structural basis for rifamycin resistance of bacterial RNA polymerase by the three most clinically important RpoB mutations found in Mycobacterium tuberculosis. Mol Microbiol 2017; 103:1034-1045. [PMID: 28009073 DOI: 10.1111/mmi.13606] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/08/2016] [Indexed: 12/01/2022]
Abstract
Since 1967, Rifampin (RMP, a Rifamycin) has been used as a first line antibiotic treatment for tuberculosis (TB), and it remains the cornerstone of current short-term TB treatment. Increased occurrence of Rifamycin-resistant (RIFR ) TB, ∼41% of which results from the RpoB S531L mutation in RNA polymerase (RNAP), has become a growing problem worldwide. In this study, we determined the X-ray crystal structures of the Escherichia coli RNAPs containing the most clinically important S531L mutation and two other frequently observed RIFR mutants, RpoB D516V and RpoB H526Y. The structures reveal that the S531L mutation imparts subtle if any structural or functional impact on RNAP in the absence of RIF. However, upon RMP binding, the S531L mutant exhibits a disordering of the RIF binding interface, which effectively reduces the RMP affinity. In contrast, the H526Y mutation reshapes the RIF binding pocket, generating significant steric conflicts that essentially prevent any RIF binding. While the D516V mutant does not exhibit any such gross structural changes, certainly the electrostatic surface of the RIF binding pocket is dramatically changed, likely resulting in the decreased affinity for RIFs. Analysis of interactions of RMP with three common RIFR mutant RNAPs suggests that modifications to RMP may recover its efficacy against RIFR TB.
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Affiliation(s)
- Vadim Molodtsov
- Department of Biochemistry and Molecular Biology, The Center for RNA Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Nathan T Scharf
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, 428 Church St, Ann Arbor, MI, 48109-1065, USA
| | - Maxwell A Stefan
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, 428 Church St, Ann Arbor, MI, 48109-1065, USA
| | - George A Garcia
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, 428 Church St, Ann Arbor, MI, 48109-1065, USA
| | - Katsuhiko S Murakami
- Department of Biochemistry and Molecular Biology, The Center for RNA Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA
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Ohnishi H, Yonetani S, Matsushima S, Wada H, Takeshita K, Kuramochi D, Caldas PCDS, Campos CED, da Costa BP, Ramos JP, Mikura S, Narisawa E, Fujita A, Funayama Y, Kobashi Y, Sakakibara Y, Ishiyama Y, Takakura S, Goto H, Watanabe T. Mycobacterium kyorinense infection. Emerg Infect Dis 2013; 19:508-10. [PMID: 23750358 PMCID: PMC3647647 DOI: 10.3201/eid1903.12-0591] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Abstract
The importance of gene regulation in the enzootic cycle of Borrelia burgdorferi, the spirochete that causes Lyme disease, is well established. B. burgdorferi regulates gene expression in response to changes in environmental stimuli associated with changing hosts. In this study, we monitored mRNA decay in B. burgdorferi following transcriptional arrest with actinomycin D. The time-dependent decay of transcripts encoding RNA polymerase subunits (rpoA and rpoS), ribosomal proteins (rpsD, rpsK, rpsM, rplQ, and rpsO), a nuclease (pnp), outer surface lipoproteins (ospA and ospC), and a flagellar protein (flaB) have different profiles and indicate half-lives ranging from approximately 1 min to more than 45 min in cells cultured at 35°C. Our results provide a first step in characterizing mRNA decay in B. burgdorferi and in investigating its role in gene expression and regulation.
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Ohnishi H, Yonetani S, Matsushima S, Wada H, Takeshita K, Kuramochi D, Caldas PCDS, Campos CED, Porphirio da Costa B, Ramos JP, Mikura S, Narisawa E, Fujita A, Funayama Y, Kobashi Y, Sakakibara Y, Ishiyama Y, Takakura S, Goto H, Watanabe T. Mycobacterium kyorinenseInfection. Emerg Infect Dis 2013. [DOI: 10.3201/eid1903.120591] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Characterization of a rifampin-inactivating glycosyltransferase from a screen of environmental actinomycetes. Antimicrob Agents Chemother 2012; 56:5061-9. [PMID: 22802246 DOI: 10.1128/aac.01166-12] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Identifying and understanding the collection of all antibiotic resistance determinants presented in the global microbiota, the antibiotic resistome, provides insight into the evolution of antibiotic resistance and critical information for the development of future antimicrobials. The rifamycins are broad-spectrum antibiotics that target bacterial transcription by inhibition of RNA polymerase. Although mutational alteration of the drug target is the predominant mechanism of resistance to this family of antibiotics in the clinic, a number of diverse inactivation mechanisms have also been reported. In this report, we investigate a subset of environmental rifampin-resistant actinomycete isolates and identify a diverse collection of rifampin inactivation mechanisms. We describe a single isolate, WAC1438, capable of inactivating rifampin by glycosylation. A draft genome sequence of WAC1438 (most closely related to Streptomyces speibonae, according to a 16S rRNA gene comparison) was assembled, and the associated rifampin glycosyltransferase open reading frame, rgt1438, was identified. The role of rgt1438 in rifampin resistance was confirmed by its disruption in the bacterial chromosome, resulting in a loss of antibiotic inactivation and a 4-fold decrease in MIC. Interestingly, examination of the RNA polymerase β-subunit sequence of WAC1438 suggests that it harbors a resistant target and thus possesses dual mechanisms of rifamycin resistance. Using an in vitro assay with purified enzyme, Rgt1438 could inactivate a variety of rifamycin antibiotics with comparable steady-state kinetics constants. Our results identify rgt1438 as a rifampin resistance determinant from WAC1438 capable of inactivating an assortment of rifamycins, adding a new element to the rifampin resistome.
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Abstract
Syphilis is a multistage infectious disease that is usually transmitted through contact with active lesions of a sexual partner or from an infected pregnant woman to her fetus. Despite elimination efforts, syphilis remains endemic in many developing countries and has reemerged in several developed countries, including China, where a widespread epidemic recently occurred. In the absence of a vaccine, syphilis control is largely dependent upon identification of infected individuals and treatment of these individuals and their contacts with antibiotics. Although penicillin is still effective, clinically significant resistance to macrolides, a second-line alternative to penicillin, has emerged. Macrolide-resistant strains of Treponema pallidum are now prevalent in several developed countries. An understanding of the genetic basis of T. pallidum antibiotic resistance is essential to enable molecular surveillance. This review discusses the genetic basis of T. pallidum macrolide resistance and the potential of this spirochete to develop additional antibiotic resistance that could seriously compromise syphilis treatment and control.
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Rooney AP, Swezey JL, Friedman R, Hecht DW, Maddox CW. Analysis of core housekeeping and virulence genes reveals cryptic lineages of Clostridium perfringens that are associated with distinct disease presentations. Genetics 2006; 172:2081-92. [PMID: 16489222 PMCID: PMC1456398 DOI: 10.1534/genetics.105.054601] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Clostridium perfringens is an important human and animal pathogen that causes a number of diseases that vary in their etiology and severity. Differences between strains regarding toxin gene composition and toxin production partly explain why some strains cause radically different diseases than others. However, they do not provide a complete explanation. The purpose of this study was to determine if there is a phylogenetic component that explains the variance in C. perfringens strain virulence by assessing patterns of genetic polymorphism in genes (colA gyrA, plc, pfoS, and rplL) that form part of the core genome in 248 type A strains. We found that purifying selection plays a central role in shaping the patterns of nucleotide substitution and polymorphism in both housekeeping and virulence genes. In contrast, recombination was found to be a significant factor only for the virulence genes plc and colA and the housekeeping gene gyrA. Finally, we found that the strains grouped into five distinct evolutionary lineages that show evidence of host adaptation and the early stages of speciation. The discovery of these previously unknown lineages and their association with distinct disease presentations carries important implications for human and veterinary clostridial disease epidemiology and provides important insights into the pathways through which virulence has evolved in C. perfringens.
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Affiliation(s)
- Alejandro P Rooney
- Microbial Genomics Research Unit, National Center for Agricultural Utilization Research, U.S. Department of Agriculture--Agricultural Research Service, Peoria, Illinois 61604, USA.
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Kim H, Kim SH, Ying YH, Kim HJ, Koh YH, Kim CJ, Lee SH, Cha CY, Kook YH, Kim BJ. Mechanism of natural rifampin resistance of Streptomyces spp. Syst Appl Microbiol 2005; 28:398-404. [PMID: 16094866 DOI: 10.1016/j.syapm.2005.02.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In a previous phylogenetic study of the genus Streptomyces using the rpoB gene, N531, which stands for an aspargine residue in position 531 of RpoB instead of serine (S531), known to be associated with natural rifampin resistance in several organisms, was also observed in the RpoB of several Streptomyces species. To determine whether N531 is associated with the rifampin resistance of Streptomyces strains, we analyzed the rifampin minimum inhibitory concentrations (MICs) of 11 strains of the N531 RpoB type (putative rifampin resistant strains) and of 12 strains of the S531 RpoB type. (putative rifampin susceptible strains). In general, the N531 RpoB types showed higher MIC levels (16-128 microg/ml) than the S531 RpoB types (0-8 microg/ml). To determine the isolation frequencies of N531 RpoB types versus rifampin concentration, we applied screening methods involving different rifampin concentrations (0, 20 and 100 microg/ml) to Korean soils. Higher isolation frequencies of the N531 RpoB types were observed at the higher rifampin concentrations. In addition, during the course of this study we developed an allele specific PCR method to detect rifampin resistant Streptomyces strains. Our results strongly suggested that N531 might be involved in a major mechanism of natural rifampin resistance in strains of the genus Streptomyces.
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Affiliation(s)
- Hong Kim
- Department of Microbiology, College of Medicine, Seoul National University, 28 Yongon-dong, Chongno-gu, Seoul 110-799, Republic of Korea
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12
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Affiliation(s)
- Heinz G Floss
- Department of Chemistry, Box 351700, University of Washington, Seattle, Washington 98195-1700, USA
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Kim BJ, Kim CJ, Chun J, Koh YH, Lee SH, Hyun JW, Cha CY, Kook YH. Phylogenetic analysis of the genera Streptomyces and Kitasatospora based on partial RNA polymerase beta-subunit gene (rpoB) sequences. Int J Syst Evol Microbiol 2004; 54:593-598. [PMID: 15023980 DOI: 10.1099/ijs.0.02941-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The RNA polymerase beta-subunit genes (rpoB) of 67 Streptomyces strains, representing 57 species, five Kitasatospora strains and Micromonospora echinospora KCTC 9549 were partially sequenced using a pair of rpoB PCR primers. Among the streptomycetes, 99.7-100 % similarity within the same species and 90.2-99.3 % similarity at the interspecific level were observed by analysis of the determined rpoB sequences. The topology of the phylogenetic tree based on rpoB sequences was similar to that of 16S rDNA. The five Kitasatospora strains formed a stable monophyletic clade and a sister group to the clade comprising all Streptomyces species. Although there were several discrepancies in the details, considerable agreement was found between the results of rpoB analysis and those of numerical phenetic classification. This study demonstrates that analysis of rpoB can be used as an alternative genetic method in parallel to conventional taxonomic methods, including numerical phenetic and 16S rDNA analyses, for the phylogenetic analyses of the genera Streptomyces and Kitasatospora.
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Affiliation(s)
- Bum-Joon Kim
- Department of Microbiology, College of Medicine, Seoul National University, Seoul 110-799, Korea
| | - Chang-Jin Kim
- Korea Research Institute of Bioscience and Biotechnology, Yusung, Taejon 305-600, Korea
| | - Jongsik Chun
- School of Biological Sciences, Seoul National University, Seoul 151-742, Korea
| | - Young-Hwan Koh
- Department of Food Science and Engineering, Cheju National University, Jeju 690-756, Korea
| | - Sueng-Hyun Lee
- Department of Microbiology, College of Medicine, Konkuk University, Chungju 380-230, Korea
| | - Jin-Won Hyun
- Department of Biochemistry, College of Medicine, Cheju National University, Jeju 690-756, Korea
| | - Chang-Yong Cha
- Department of Microbiology, College of Medicine, Seoul National University, Seoul 110-799, Korea
| | - Yoon-Hoh Kook
- Department of Microbiology, College of Medicine, Seoul National University, Seoul 110-799, Korea
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Abstract
Functions of the Borrelia burgdorferi RecA protein were investigated in Escherichia coli recA null mutants. Complementation with B. burgdorferi recA increased survival of E. coli recA mutants by 3 orders of magnitude at a UV dose of 2,000 microJ/cm(2). The viability at this UV dose was about 10% that provided by the homologous recA gene. Expression of B. burgdorferi recA resulted in survival of E. coli at levels of mitomycin C that were lethal to noncomplemented hosts. B. burgdorferi RecA was as effective as E. coli RecA in mediating homologous recombination in E. coli. Furthermore, E. coli lambda phage lysogens complemented with B. burgdorferi recA produced phage even in the absence of UV irradiation. The level of phage induction was 55-fold higher than the level in cells complemented with the homologous recA gene, suggesting that B. burgdorferi RecA may possess an enhanced coprotease activity. This study indicates that B. burgdorferi RecA mediates the same functions in E. coli as the homologous E. coli protein mediates. However, the rapid loss of viability and the absence of induction in recA expression after UV irradiation in B. burgdorferi suggest that recA is not involved in the repair of UV-induced damage in B. burgdorferi. The primary role of RecA in B. burgdorferi is likely to be a role in some aspect of recombination.
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Affiliation(s)
- Dionysios Liveris
- Department of Microbiology & Immunology, New York Medical College, Valhalla, New York 10595, USA.
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Stamm LV, Bergen HL, Shangraw KA. Natural rifampin resistance in Treponema spp. correlates with presence of N531 in RpoB rif cluster i. Antimicrob Agents Chemother 2001; 45:2973-4. [PMID: 11702716 PMCID: PMC90769 DOI: 10.1128/aac.45.10.2973-2974.2001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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16
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Lee SH, Kim BJ, Kim JH, Park KH, Kim SJ, Kook YH. Differentiation of Borrelia burgdorferi sensu lato on the basis of RNA polymerase gene (rpoB) sequences. J Clin Microbiol 2000; 38:2557-62. [PMID: 10878043 PMCID: PMC86967 DOI: 10.1128/jcm.38.7.2557-2562.2000] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We determined the nucleotide sequences (329 bp) of the rpoB DNAs from 22 reference strains of Borrelia. No insertions or deletions were observed. Deduced amino acid sequences of amplified rpoB DNA comprised 109 amino acid residues (N(450) to M(558) [Escherichia coli numbering]). All amino acid sequences were identical with the exception of those of Borrelia lusitaniae PotiB2 (T(461)-->A) and B. bissettii DN127 (I(498)-->V). Each species of B. burgdorferi sensu lato was differentiated as a distinct entity in the phylogenetic tree constructed by a neighbor-joining method. B. burgdorferi sensu lato could be distinguished from B. turicatae and B. hermsii, which are associated with relapsing fever. Seventeen Korean isolates could be identified by PCR-linked direct sequencing and restriction analysis of the rpoB DNA. These results suggest that rpoB DNA is useful for identification and characterization of Borrelia. In addition, we developed the rapid species identification method using the species-specific primer sets based on rpoB gene sequences.
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Affiliation(s)
- S H Lee
- Department of Microbiology, College of Medicine, Konkuk University, Chungju, Chungchongbuk-Do 380-701, Korea
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Renesto P, Lorvellec-Guillon K, Drancourt M, Raoult D. rpoB gene analysis as a novel strategy for identification of spirochetes from the genera Borrelia, Treponema, and Leptospira. J Clin Microbiol 2000; 38:2200-3. [PMID: 10834976 PMCID: PMC86763 DOI: 10.1128/jcm.38.6.2200-2203.2000] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Spirochetes are emerging pathogens for which culture and identification are partly unresolved. In fact, 16S rRNA-based sequencing is by far the most widely used PCR methodology that is able to detect such uncultivable pathogens. However, this assay actually has some limitations linked to potential problems of contamination, which hampers diagnosis. To circumvent this, we have devised a simple PCR strategy involving targeting of the gene encoding the RNA polymerase beta subunit (rpoB), a highly conserved enzyme. The complete sequence of the Leptospira biflexa (serovar patoc) rpoB gene was determined and compared with the published sequences for Borrelia burgdorferi and Treponema pallidum. From the resulting analysis, degenerate nucleotide primers were designed and tested for their ability to amplify a portion of the rpoB gene from various spirochetes. Using two different pairs of these primers, we succeeded in obtaining specific rpoB-amplified fragments for all members of the genera Leptospira, Treponema, and Borrelia tested and no other bacteria. Our findings may have significant implications for the development of a new tool for the identification of spirochetes, especially if clinical samples are contaminated or when the infecting strain is uncultivable.
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Affiliation(s)
- P Renesto
- Unité des Rickettsies, CNRS UPRES-A 6020, Faculté de Médecine, Université de la Méditerranée, Marseille, France
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Hemmer B, Gran B, Zhao Y, Marques A, Pascal J, Tzou A, Kondo T, Cortese I, Bielekova B, Straus SE, McFarland HF, Houghten R, Simon R, Pinilla C, Martin R. Identification of candidate T-cell epitopes and molecular mimics in chronic Lyme disease. Nat Med 1999; 5:1375-82. [PMID: 10581079 DOI: 10.1038/70946] [Citation(s) in RCA: 141] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Elucidating the cellular immune response to infectious agents is a prerequisite for understanding disease pathogenesis and designing effective vaccines. In the identification of microbial T-cell epitopes, the availability of purified or recombinant bacterial proteins has been a chief limiting factor. In chronic infectious diseases such as Lyme disease, immune-mediated damage may add to the effects of direct infection by means of molecular mimicry to tissue autoantigens. Here, we describe a new method to effectively identify both microbial epitopes and candidate autoantigens. The approach combines data acquisition by positional scanning peptide combinatorial libraries and biometric data analysis by generation of scoring matrices. In a patient with chronic neuroborreliosis, we show that this strategy leads to the identification of potentially relevant T-cell targets derived from both Borrelia burgdorferi and the host. We also found that the antigen specificity of a single T-cell clone can be degenerate and yet the clone can preferentially recognize different peptides derived from the same organism, thus demonstrating that flexibility in T-cell recognition does not preclude specificity. This approach has potential applications in the identification of ligands in infectious diseases, tumors and autoimmune diseases.
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Affiliation(s)
- B Hemmer
- Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Building 10, Room 5B-16, 10 Center DR MSC 1400, Bethesda, Maryland 20892-1400, USA
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Kim BJ, Lee SH, Lyu MA, Kim SJ, Bai GH, Chae GT, Kim EC, Cha CY, Kook YH. Identification of mycobacterial species by comparative sequence analysis of the RNA polymerase gene (rpoB). J Clin Microbiol 1999; 37:1714-20. [PMID: 10325313 PMCID: PMC84932 DOI: 10.1128/jcm.37.6.1714-1720.1999] [Citation(s) in RCA: 305] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
For the differentiation and identification of mycobacterial species, the rpoB gene, encoding the beta subunit of RNA polymerase, was investigated. rpoB DNAs (342 bp) were amplified from 44 reference strains of mycobacteria and clinical isolates (107 strains) by PCR. The nucleotide sequences were directly determined (306 bp) and aligned by using the multiple alignment algorithm in the MegAlign package (DNASTAR) and the MEGA program. A phylogenetic tree was constructed by the neighbor-joining method. Comparative sequence analysis of rpoB DNAs provided the basis for species differentiation within the genus Mycobacterium. Slowly and rapidly growing groups of mycobacteria were clearly separated, and each mycobacterial species was differentiated as a distinct entity in the phylogenetic tree. Pathogenic Mycobacterium kansasii was easily differentiated from nonpathogenic M. gastri; this differentiation cannot be achieved by using 16S rRNA gene (rDNA) sequences. By being grouped into species-specific clusters with low-level sequence divergence among strains of the same species, all of the clinical isolates could be easily identified. These results suggest that comparative sequence analysis of amplified rpoB DNAs can be used efficiently to identify clinical isolates of mycobacteria in parallel with traditional culture methods and as a supplement to 16S rDNA gene analysis. Furthermore, in the case of M. tuberculosis, rifampin resistance can be simultaneously determined.
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Affiliation(s)
- B J Kim
- Department of Microbiology and Cancer Research Center, Seoul National University College of Medicine, Seoul 110-799, Korea
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Mollet C, Drancourt M, Raoult D. Determination of Coxiella burnetii rpoB sequence and its use for phylogenetic analysis. Gene X 1998; 207:97-103. [PMID: 9511749 DOI: 10.1016/s0378-1119(97)00618-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The nucleotide sequence of the rpoB, encoding the beta-subunit of RNA polymerase of the obligate intracellular bacterium Coxiella burnetii, was determined using a polymerase chain reaction amplification and direct sequencing methodology. Comparison between C. burnetii and other eubacterial rpoB sequences indicated sequence similarity ranging from 53.6% to 67.6%. Coxiella burnetii rpoB consists of 4128 base pairs with a 45.3% GC content encoding 1375 amino acids with a calculated molecular mass of 153.67 kDa. Comparison of 512 bases of the rpoB variable region I, from eight C. burnetii strains isolated from various sources, revealed fewer than four base differences, although the distribution of these did not correlate with previously determined genotypic groupings with the species. Phylogenetic analysis of C. burnetii based on comparison of its rpoB sequence with sequences available for other bacteria is consistent with those previously derived from 16S rRNA gene sequence, and indicate that C. burnetii belongs to the gamma-group of Proteobacteria. Furthermore, phylogeny inferred from comparison of RpoB, or homologous sequences including Archae, Bacteria and Eukarya, concurred with these results.
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Affiliation(s)
- C Mollet
- Unité des Rickettsies, CNRS UPRES-A 6020, Université de la Méditerranée, Marseille, France
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