1
|
Singh RN, Sani RK. Genome-Wide Computational Prediction and Analysis of Noncoding RNAs in Oleidesulfovibrio alaskensis G20. Microorganisms 2024; 12:960. [PMID: 38792789 PMCID: PMC11124144 DOI: 10.3390/microorganisms12050960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 05/03/2024] [Accepted: 05/08/2024] [Indexed: 05/26/2024] Open
Abstract
Noncoding RNAs (ncRNAs) play key roles in the regulation of important pathways, including cellular growth, stress management, signaling, and biofilm formation. Sulfate-reducing bacteria (SRB) contribute to huge economic losses causing microbial-induced corrosion through biofilms on metal surfaces. To effectively combat the challenges posed by SRB, it is essential to understand their molecular mechanisms of biofilm formation. This study aimed to identify ncRNAs in the genome of a model SRB, Oleidesulfovibrio alaskensis G20 (OA G20). Three in silico approaches revealed genome-wide distribution of 37 ncRNAs excluding tRNAs in the OA G20. These ncRNAs belonged to 18 different Rfam families. This study identified riboswitches, sRNAs, RNP, and SRP. The analysis revealed that these ncRNAs could play key roles in the regulation of several pathways of biosynthesis and transport involved in biofilm formation by OA G20. Three sRNAs, Pseudomonas P10, Hammerhead type II, and sX4, which were found in OA G20, are rare and their roles have not been determined in SRB. These results suggest that applying various computational methods could enrich the results and lead to the discovery of additional novel ncRNAs, which could lead to understanding the "rules of life of OA G20" during biofilm formation.
Collapse
Affiliation(s)
- Ram Nageena Singh
- Department of Chemical and Biological Engineering, South Dakota Mines, Rapid City, SD 57701, USA;
- 2-Dimensional Materials for Biofilm Engineering, Science and Technology, South Dakota Mines, Rapid City, SD 57701, USA
| | - Rajesh K. Sani
- Department of Chemical and Biological Engineering, South Dakota Mines, Rapid City, SD 57701, USA;
- 2-Dimensional Materials for Biofilm Engineering, Science and Technology, South Dakota Mines, Rapid City, SD 57701, USA
- Data Driven Material Discovery Center for Bioengineering Innovation, South Dakota Mines, Rapid City, SD 57701, USA
| |
Collapse
|
2
|
Klementiev AD, Garg N, Whiteley M. Identification of a glutathione transporter in A. actinomycetemcomitans. Microbiol Spectr 2024; 12:e0351123. [PMID: 38051055 PMCID: PMC10782972 DOI: 10.1128/spectrum.03511-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 10/31/2023] [Indexed: 12/07/2023] Open
Abstract
IMPORTANCE Microbes produce a large array of extracellular molecules, which serve as signals and cues to promote polymicrobial interactions and alter the function of microbial communities. This has been particularly well studied in the human oral microbiome, where key metabolites have been shown to impact both health and disease. Here, we used an untargeted mass spectrometry approach to comprehensively assess the extracellular metabolome of the pathogen Aggregatibacter actinomycetemcomitans and the commensal Streptococcus gordonii during mono- and co-culture. We generated and made publicly available a metabolomic data set that includes hundreds of potential metabolites and leveraged this data set to identify an operon important for glutathione secretion in A. actinomycetemcomitans.
Collapse
Affiliation(s)
- Alexander D. Klementiev
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Neha Garg
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, Georgia, USA
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Marvin Whiteley
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, Georgia, USA
- Emory-Children's Cystic Fibrosis Center, Atlanta, Georgia, USA
| |
Collapse
|
3
|
Oogai Y, Nakata M. Small regulatory RNAs of oral streptococci and periodontal bacteria. JAPANESE DENTAL SCIENCE REVIEW 2021; 57:209-216. [PMID: 34745393 PMCID: PMC8551640 DOI: 10.1016/j.jdsr.2021.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 09/20/2021] [Accepted: 09/24/2021] [Indexed: 11/27/2022] Open
Abstract
Small regulatory RNAs (sRNAs) belong to a family of non-coding RNAs, and many of which regulate expression of genes via interaction with mRNA. The recent popularity of high-throughput next generation sequencers have presented abundant sRNA-related data, including sRNAs of several different oral bacterial species. Some sRNA candidates have been validated in terms of their expression and interaction with target mRNAs. Since the oral cavity is an environment constantly exposed to various stimuli, such as fluctuations in temperature and pH, and osmotic pressure, as well as changes in nutrient availability, oral bacteria require rapid control of gene expression for adaptation to such diverse conditions, while regulation via interactions of sRNAs with mRNA provides advantages for rapid adaptation. This review summarizes methods effective for identification and validation of sRNAs, as well as sRNAs identified to be associated with oral bacterial species, including cariogenic and periodontal pathogens, together with their confirmed and putative target genes.
Collapse
Affiliation(s)
- Yuichi Oogai
- Department of Oral Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, 890-8544, Japan
| | - Masanobu Nakata
- Department of Oral Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, 890-8544, Japan
| |
Collapse
|
4
|
Bhattacharjee MK, Mehta BS, Akukwe B. Maillard reaction products inhibit the periodontal pathogen Aggregatibacter actinomycetemcomitans by chelating iron. Arch Oral Biol 2020; 122:104989. [PMID: 33249361 DOI: 10.1016/j.archoralbio.2020.104989] [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: 08/09/2020] [Revised: 10/30/2020] [Accepted: 11/10/2020] [Indexed: 01/13/2023]
Abstract
OBJECTIVE To determine the mechanism of growth inhibition of Aggregatibacter actinomycetemcomitans by Maillard reaction products (MRP). DESIGN Growth and cell viabilities in the presence or absence of MRP were measured for both the rough and smooth variants of the bacteria. Effects of addition of ferrous and ferric ions on the inhibition of the bacteria by MRP were determined. RESULTS MRPs decreased the extent of complex formation of Chrome Azurol S with iron suggesting that MRPs can chelate iron effectively. The chelation causes growth inhibition of both the rough and smooth strains. At low concentrations of the inhibitor, lag time was extended by approximately 12 h while at high concentrations, cells were killed, decreasing cell viability by up to 8 orders of magnitude. Growth of both the rough and smooth strains could be restored to original level by addition of iron. For the rough strain, both ferrous and ferric ions could relieve the inhibition by MRP while for the smooth strain only ferrous ion was effective. CONCLUSION MRPs inhibit the growth of A. actinomycetemcomitans by chelating iron and the inhibition can be relieved by addition of iron.
Collapse
Affiliation(s)
| | - Binal S Mehta
- Department of Pharmacology and Toxicology, Long Island University, Brooklyn, NY, USA
| | - Bernadine Akukwe
- Department of Chemistry and Biochemistry, Long Island University, Brooklyn, NY, USA
| |
Collapse
|
5
|
Kalvari I, Argasinska J, Quinones-Olvera N, Nawrocki EP, Rivas E, Eddy SR, Bateman A, Finn RD, Petrov AI. Rfam 13.0: shifting to a genome-centric resource for non-coding RNA families. Nucleic Acids Res 2019; 46:D335-D342. [PMID: 29112718 PMCID: PMC5753348 DOI: 10.1093/nar/gkx1038] [Citation(s) in RCA: 607] [Impact Index Per Article: 121.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 10/19/2017] [Indexed: 11/13/2022] Open
Abstract
The Rfam database is a collection of RNA families in which each family is represented by a multiple sequence alignment, a consensus secondary structure, and a covariance model. In this paper we introduce Rfam release 13.0, which switches to a new genome-centric approach that annotates a non-redundant set of reference genomes with RNA families. We describe new web interface features including faceted text search and R-scape secondary structure visualizations. We discuss a new literature curation workflow and a pipeline for building families based on RNAcentral. There are 236 new families in release 13.0, bringing the total number of families to 2687. The Rfam website is http://rfam.org.
Collapse
Affiliation(s)
- Ioanna Kalvari
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Joanna Argasinska
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | | | - Eric P Nawrocki
- National Center for Biotechnology Information; National Institutes of Health; Department of Health and Human Services; Bethesda, MD 20894, USA
| | - Elena Rivas
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Sean R Eddy
- Howard Hughes Medical Institute, Harvard University, 16 Divinity Avenue, Cambridge, MA 02138, USA
| | - Alex Bateman
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Robert D Finn
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Anton I Petrov
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| |
Collapse
|
6
|
Oogai Y, Gotoh Y, Ogura Y, Kawada-Matsuo M, Hayashi T, Komatsuzawa H. Small RNA repertoires and their intraspecies variation in Aggregatibacter actinomycetemcomitans. DNA Res 2018; 25:207-215. [PMID: 29211829 PMCID: PMC5909427 DOI: 10.1093/dnares/dsx050] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 11/15/2017] [Indexed: 11/13/2022] Open
Abstract
Aggregatibacter actinomycetemcomitans is a major periodontal pathogen that has several virulence factors such as leukotoxin and cytolethal distending toxin. Although the genes responsible for virulence have been identified, little is known about their regulatory mechanisms. Small RNA (sRNA) has been recognized as an important factor for gene regulation. To identify new regulatory mechanisms via sRNA in A. actinomycetemcomitans HK1651, we performed a systematic search for sRNAs by RNA-seq and identified 90 intergenic region sRNAs and 30 antisense sRNAs. Of the 85 analysable sRNAs, we successfully detected and quantified 70 sRNAs by developing an RT-PCR system, and we identified 17 sRNAs that were differentially expressed during different growth phases. In addition, we found notable intraspecies variation in the sRNA repertoire of A. actinomycetemcomitans, thus suggesting that frequent acquisition or deletion of sRNAs occurred during the evolution of this species. The predicted target genes of the intergenic region sRNAs indicated the possibility of sRNA interaction with several virulence genes including leukotoxin and cytolethal distending toxin. Our results should serve as an important genomic and genetic basis for future studies to fully understand the regulatory network in A. actinomycetemcomitans and provide new insights into the intraspecies variation of the bacterial sRNA repertoire in bacteria.
Collapse
Affiliation(s)
- Yuichi Oogai
- Department of Oral Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1, Sakuragaoka, Kagoshima 890-8544, Japan
| | - Yasuhiro Gotoh
- Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Yoshitoshi Ogura
- Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Miki Kawada-Matsuo
- Department of Oral Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1, Sakuragaoka, Kagoshima 890-8544, Japan
| | - Tetsuya Hayashi
- Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Hitoshi Komatsuzawa
- Department of Oral Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1, Sakuragaoka, Kagoshima 890-8544, Japan
| |
Collapse
|
7
|
Ding Q, Tan KS. Himar1 Transposon for Efficient Random Mutagenesis in Aggregatibacter actinomycetemcomitans. Front Microbiol 2017; 8:1842. [PMID: 29018421 PMCID: PMC5622930 DOI: 10.3389/fmicb.2017.01842] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 09/08/2017] [Indexed: 12/14/2022] Open
Abstract
Aggregatibacter actinomycetemcomitans is the primary etiological agent of aggressive periodontal disease. Identification of novel virulence factors at the genome-wide level is hindered by lack of efficient genetic tools to perform mutagenesis in this organism. The Himar1 mariner transposon is known to yield a random distribution of insertions in an organism’s genome with requirement for only a TA dinucleotide target and is independent of host-specific factors. However, the utility of this system in A. actinomycetemcomitans is unknown. In this study, we found that Himar1 transposon mutagenesis occurs at a high frequency (×10-4), and can be universally applied to wild-type A. actinomycetemcomitans strains of serotypes a, b, and c. The Himar1 transposon inserts were stably inherited in A. actinomycetemcomitans transconjugants in the absence of antibiotics. A library of 16,000 mutant colonies of A. actinomycetemcomitans was screened for reduced biofilm formation. Mutants with transposon inserts in genes encoding pilus, putative ion transporters, multidrug resistant proteins, transcription regulators and enzymes involved in the synthesis of extracellular polymeric substance, bacterial metabolism and stress response were discovered in this screen. Our results demonstrated the utility of the Himar1 mutagenesis system as a novel genetic tool for functional genomic analysis in A. actinomycetemcomitans.
Collapse
Affiliation(s)
- Qinfeng Ding
- Faculty of Dentistry, National University of Singapore, Singapore, Singapore
| | - Kai Soo Tan
- Faculty of Dentistry, National University of Singapore, Singapore, Singapore
| |
Collapse
|
8
|
Álvarez-Fraga L, Rumbo-Feal S, Pérez A, Gómez MJ, Gayoso C, Vallejo JA, Ohneck EJ, Valle J, Actis LA, Beceiro A, Bou G, Poza M. Global assessment of small RNAs reveals a non-coding transcript involved in biofilm formation and attachment in Acinetobacter baumannii ATCC 17978. PLoS One 2017; 12:e0182084. [PMID: 28763494 PMCID: PMC5538643 DOI: 10.1371/journal.pone.0182084] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 07/12/2017] [Indexed: 12/30/2022] Open
Abstract
Many strains of Acinetobacter baumannii have been described as being able to form biofilm. Small non-coding RNAs (sRNAs) control gene expression in many regulatory circuits in bacteria. The aim of the present work was to provide a global description of the sRNAs produced both by planktonic and biofilm-associated (sessile) cells of A. baumannii ATCC 17978, and to compare the corresponding gene expression profiles to identify sRNAs molecules associated to biofilm formation and virulence. sRNA was extracted from both planktonic and sessile cells and reverse transcribed. cDNA was subjected to 454-pyrosequencing using the GS-FLX Titanium chemistry. The global analysis of the small RNA transcriptome revealed different sRNA expression patterns in planktonic and biofilm associated cells, with some of the transcripts only expressed or repressed in sessile bacteria. A total of 255 sRNAs were detected, with 185 of them differentially expressed in the different types of cells. A total of 9 sRNAs were expressed only in biofilm cells, while the expression of other 21 coding regions were repressed only in biofilm cells. Strikingly, the expression level of the sRNA 13573 was 120 times higher in biofilms than in planktonic cells, an observation that prompted us to further investigate the biological role of this non-coding transcript. Analyses of an isogenic mutant and over-expressing strains revealed that the sRNA 13573 gene is involved in biofilm formation and attachment to A549 human alveolar epithelial cells. The present work serves as a basis for future studies examining the complex regulatory network that regulate biofilm biogenesis and attachment to eukaryotic cells in A. baumannii ATCC 17978.
Collapse
Affiliation(s)
- Laura Álvarez-Fraga
- Departamento de Microbiología, Instituto de Investigación Biomédica (INIBIC), Complejo Hospitalario Universitario (CHUAC), A Coruña, Spain
| | - Soraya Rumbo-Feal
- Departamento de Microbiología, Instituto de Investigación Biomédica (INIBIC), Complejo Hospitalario Universitario (CHUAC), A Coruña, Spain
| | - Astrid Pérez
- Departamento de Microbiología, Instituto de Investigación Biomédica (INIBIC), Complejo Hospitalario Universitario (CHUAC), A Coruña, Spain
- Department of Microbiology, Miami University, Oxford, Ohio, United States of America
| | - Manuel J. Gómez
- Department of Molecular Evolution, Center for Astrobiology, INTA-CSIC, Torrejón de Ardoz, Madrid, Spain
- Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
| | - Carmen Gayoso
- Departamento de Microbiología, Instituto de Investigación Biomédica (INIBIC), Complejo Hospitalario Universitario (CHUAC), A Coruña, Spain
| | - Juan A. Vallejo
- Departamento de Microbiología, Instituto de Investigación Biomédica (INIBIC), Complejo Hospitalario Universitario (CHUAC), A Coruña, Spain
| | - Emily J. Ohneck
- Department of Microbiology, Miami University, Oxford, Ohio, United States of America
| | - Jaione Valle
- Departamento de Biofilms Microbianos, Instituto de Agrobiotecnología, Navarra, Spain
| | - Luis A. Actis
- Department of Microbiology, Miami University, Oxford, Ohio, United States of America
| | - Alejandro Beceiro
- Departamento de Microbiología, Instituto de Investigación Biomédica (INIBIC), Complejo Hospitalario Universitario (CHUAC), A Coruña, Spain
| | - Germán Bou
- Departamento de Microbiología, Instituto de Investigación Biomédica (INIBIC), Complejo Hospitalario Universitario (CHUAC), A Coruña, Spain
- * E-mail: (GB); (MP)
| | - Margarita Poza
- Departamento de Microbiología, Instituto de Investigación Biomédica (INIBIC), Complejo Hospitalario Universitario (CHUAC), A Coruña, Spain
- * E-mail: (GB); (MP)
| |
Collapse
|
9
|
Lu W, Xin Z, Shida W, Jiyao L, Xin X. [Role of small noncoding RNA in the regulation of bacterial virulence]. HUA XI KOU QIANG YI XUE ZA ZHI = HUAXI KOUQIANG YIXUE ZAZHI = WEST CHINA JOURNAL OF STOMATOLOGY 2017; 34:433-438. [PMID: 28317367 DOI: 10.7518/hxkq.2016.04.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In the long-term interaction between pathogens and host, the pathogens regulate the expression of related viru-lence genes to fit the host environment in response to the changes in the host microenvironment. Gene expression was believed to be controlled mainly at the level of transcription initiation by repressors or activators. Recent studies have revealed that small noncoding RNAs (sRNAs) are key regulators in bacterial pathogenesis. sRNA in bacteria is a noncoding RNA with length ranging from 50 to 500 nucleotides. Pathogens can sense the changes in the host environment and consequently regulate the expression of virulence genes by sRNAs. This condition promotes the ability of pathogens to survive within the host, which is beneficial to the invasion and pathogenicity of pathogens. In contrast to transcriptional factors, sRNA-mediated gene regu-lation makes rapid and sensitive responses to environmental cues. Many sRNAs involved in bacterial virulence and pathogenesis have been identified. These sRNAs are key components of coordinated regulation networks, playing important roles in regulating the expression of virulence genes at post-transcriptional level. This review aims to provide an overview on the molecular mechanisms and roles of sRNAs in the regulation of bacterial virulence.
Collapse
Affiliation(s)
- Wang Lu
- State Key Laboratory of Oral Diseases, Dept. of Operative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Zheng Xin
- State Key Laboratory of Oral Diseases, Dept. of Operative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Wang Shida
- State Key Laboratory of Oral Diseases, Dept. of General Clinic, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Li Jiyao
- State Key Laboratory of Oral Diseases, Dept. of Operative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Xu Xin
- State Key Laboratory of Oral Diseases, Dept. of Operative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| |
Collapse
|
10
|
Rossi CC, Bossé JT, Li Y, Witney AA, Gould KA, Langford PR, Bazzolli DMS. A computational strategy for the search of regulatory small RNAs in Actinobacillus pleuropneumoniae. RNA (NEW YORK, N.Y.) 2016; 22:1373-85. [PMID: 27402897 PMCID: PMC4986893 DOI: 10.1261/rna.055129.115] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 05/24/2016] [Indexed: 05/26/2023]
Abstract
Bacterial regulatory small RNAs (sRNAs) play important roles in gene regulation and are frequently connected to the expression of virulence factors in diverse bacteria. Only a few sRNAs have been described for Pasteurellaceae pathogens and no in-depth analysis of sRNAs has been described for Actinobacillus pleuropneumoniae, the causative agent of porcine pleuropneumonia, responsible for considerable losses in the swine industry. To search for sRNAs in A. pleuropneumoniae, we developed a strategy for the computational analysis of the bacterial genome by using four algorithms with different approaches, followed by experimental validation. The coding strand and expression of 17 out of 23 RNA candidates were confirmed by Northern blotting, RT-PCR, and RNA sequencing. Among them, two are likely riboswitches, three are housekeeping regulatory RNAs, two are the widely studied GcvB and 6S sRNAs, and 10 are putative novel trans-acting sRNAs, never before described for any bacteria. The latter group has several potential mRNA targets, many of which are involved with virulence, stress resistance, or metabolism, and connect the sRNAs in a complex gene regulatory network. The sRNAs identified are well conserved among the Pasteurellaceae that are evolutionarily closer to A. pleuropneumoniae and/or share the same host. Our results show that the combination of newly developed computational programs can be successfully utilized for the discovery of novel sRNAs and indicate an intricate system of gene regulation through sRNAs in A. pleuropneumoniae and in other Pasteurellaceae, thus providing clues for novel aspects of virulence that will be explored in further studies.
Collapse
Affiliation(s)
- Ciro C Rossi
- Laboratório de Genética Molecular de Micro-organismos, Departamento de Microbiologia, Instituto de Biotecnologia Aplicada à Agropecuária-BIOAGRO, Universidade Federal de Viçosa, Viçosa, 36570-900, Brazil
| | - Janine T Bossé
- Section of Paediatrics, Imperial College London, St. Mary's Campus, London W2 1PG, United Kingdom
| | - Yanwen Li
- Section of Paediatrics, Imperial College London, St. Mary's Campus, London W2 1PG, United Kingdom
| | - Adam A Witney
- Institute for Infection and Immunity, St. George's, University of London, London SW17 0RE, United Kingdom
| | - Kate A Gould
- Institute for Infection and Immunity, St. George's, University of London, London SW17 0RE, United Kingdom
| | - Paul R Langford
- Section of Paediatrics, Imperial College London, St. Mary's Campus, London W2 1PG, United Kingdom
| | - Denise M S Bazzolli
- Laboratório de Genética Molecular de Micro-organismos, Departamento de Microbiologia, Instituto de Biotecnologia Aplicada à Agropecuária-BIOAGRO, Universidade Federal de Viçosa, Viçosa, 36570-900, Brazil
| |
Collapse
|
11
|
Kreth J, Liu N, Chen Z, Merritt J. RNA regulators of host immunity and pathogen adaptive responses in the oral cavity. Microbes Infect 2015; 17:493-504. [PMID: 25790757 PMCID: PMC4485933 DOI: 10.1016/j.micinf.2015.03.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 03/05/2015] [Accepted: 03/07/2015] [Indexed: 12/15/2022]
Abstract
The recent explosion of RNA-seq studies has resulted in a newfound appreciation for the importance of riboregulatory RNAs in the posttranscriptional control of eukaryotic and prokaryotic genetic networks. The current review will explore the role of trans-riboregulatory RNAs in various adaptive responses of host and pathogen in the oral cavity.
Collapse
Affiliation(s)
- Jens Kreth
- OUHSC Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA; OUHSC College of Dentistry, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.
| | - Nan Liu
- Department of Restorative Dentistry, Oregon Health and Science University, 2730 SW Moody Ave., Portland, OR, 97201-5042, USA
| | - Zhiyun Chen
- OUHSC Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Justin Merritt
- Department of Restorative Dentistry, Oregon Health and Science University, 2730 SW Moody Ave., Portland, OR, 97201-5042, USA.
| |
Collapse
|
12
|
HrrF is the Fur-regulated small RNA in nontypeable Haemophilus influenzae. PLoS One 2014; 9:e105644. [PMID: 25157846 PMCID: PMC4144887 DOI: 10.1371/journal.pone.0105644] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 07/21/2014] [Indexed: 02/06/2023] Open
Abstract
Nontypeable Haemophilus influenzae (NTHi) are Gram-negative commensal bacteria that reside in the nasopharynx. NTHi can also cause multiple upper and lower respiratory tract diseases that include sinusitis, conjunctivitis, bronchitis, and otitis media. In numerous bacterial species the ferric uptake regulator (Fur) acts as a global regulator of iron homeostasis by negatively regulating the expression of iron uptake systems. However in NTHi strain 86-028NP and numerous other bacterial species there are multiple instances where Fur positively affects gene expression. It is known that many instances of positive regulation by Fur occur indirectly through a small RNA intermediate. However, no examples of small RNAs have been described in NTHi. Therefore we used RNA-Seq analysis to analyze the transcriptome of NTHi strain 86-028NPrpsL and an isogenic 86-028NPrpsLΔfur strain to identify Fur-regulated intergenic transcripts. From this analysis we identified HrrF, the first small RNA described in any Haemophilus species. Orthologues of this small RNA exist only among other Pasteurellaceae. Our analysis showed that HrrF is maximally expressed when iron levels are low. Additionally, Fur was shown to bind upstream of the hrrF promoter. RNA-Seq analysis was used to identify targets of HrrF which include genes whose products are involved in molybdate uptake, deoxyribonucleotide synthesis, and amino acid biosynthesis. The stability of HrrF is not dependent on the RNA chaperone Hfq. This study is the first step in an effort to investigate the role small RNAs play in altering gene expression in response to iron limitation in NTHi.
Collapse
|
13
|
Martínez LC, Vadyvaloo V. Mechanisms of post-transcriptional gene regulation in bacterial biofilms. Front Cell Infect Microbiol 2014; 4:38. [PMID: 24724055 PMCID: PMC3971182 DOI: 10.3389/fcimb.2014.00038] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 03/08/2014] [Indexed: 12/19/2022] Open
Abstract
Biofilms are characterized by a dense multicellular community of microorganisms that can be formed by the attachment of bacteria to an inert surface and to each other. The development of biofilm involves the initial attachment of planktonic bacteria to a surface, followed by replication, cell-to-cell adhesion to form microcolonies, maturation, and detachment. Mature biofilms are embedded in a self-produced extracellular polymeric matrix composed primarily of bacterial-derived exopolysaccharides, specialized proteins, adhesins, and occasionally DNA. Because the synthesis and assembly of biofilm matrix components is an exceptionally complex process, the transition between its different phases requires the coordinate expression and simultaneous regulation of many genes by complex genetic networks involving all levels of gene regulation. The finely controlled intracellular level of the chemical second messenger molecule, cyclic-di-GMP is central to the post-transcriptional mechanisms governing the switch between the motile planktonic lifestyle and the sessile biofilm forming state in many bacteria. Several other post-transcriptional regulatory mechanisms are known to dictate biofilm development and assembly and these include RNA-binding proteins, small non-coding RNAs, toxin-antitoxin systems, riboswitches, and RNases. Post-transcriptional regulation is therefore a powerful molecular mechanism employed by bacteria to rapidly adjust to the changing environment and to fine tune gene expression to the developmental needs of the cell. In this review, we discuss post-transcriptional mechanisms that influence the biofilm developmental cycle in a variety of pathogenic bacteria.
Collapse
Affiliation(s)
| | - Viveka Vadyvaloo
- Paul G. Allen School for Global Animal Health, Washington State UniversityPullman, WA, USA
| |
Collapse
|
14
|
Merritt J, Chen Z, Liu N, Kreth J. Posttranscriptional regulation of oral bacterial adaptive responses. ACTA ACUST UNITED AC 2014; 1:50-58. [PMID: 24695639 DOI: 10.1007/s40496-013-0005-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Within the past 10 years, it has become increasingly evident that posttranscriptional regulation is among the most important mechanisms used by bacteria to modulate gene expression in response to environmental perturbations. Posttranscriptional mechanisms provide a much faster response and lower energy burden compared to most transcription regulatory pathways and they have the unique advantage that they can override existing transcriptional responses once the environment changes. Because of this, virulence factor gene expression is particularly suited for posttranscriptional control, and not surprisingly, an abundance of recent evidence indicates that posttranscriptional regulators are the predominant virulence regulators of human pathogens. Typically, this involves global riboregulators that primarily serve as modulators of virulence gene translation initiation and/or mRNA stability. Surprisingly little has been reported about posttranscriptional regulatory pathways in oral bacteria, but recent results suggest that oral species are equally dependent upon posttranscriptional control of their adaptive genetic responses. In this report, we discuss the major themes in RNA-based regulation of gene expression and review the available literature related to the most commonly studied oral bacterial species.
Collapse
Affiliation(s)
- Justin Merritt
- Department of Microbiology & immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Zhiyun Chen
- Department of Microbiology & immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Nan Liu
- Department of Microbiology & immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Jens Kreth
- Department of Microbiology & immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| |
Collapse
|
15
|
Pöllänen MT, Paino A, Ihalin R. Environmental stimuli shape biofilm formation and the virulence of periodontal pathogens. Int J Mol Sci 2013; 14:17221-37. [PMID: 23965982 PMCID: PMC3759961 DOI: 10.3390/ijms140817221] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 08/02/2013] [Accepted: 08/07/2013] [Indexed: 12/31/2022] Open
Abstract
Periodontitis is a common inflammatory disease affecting the tooth-supporting structures. It is initiated by bacteria growing as a biofilm at the gingival margin, and communication of the biofilms differs in health and disease. The bacterial composition of periodontitis-associated biofilms has been well documented and is under continual investigation. However, the roles of several host response and inflammation driven environmental stimuli on biofilm formation is not well understood. This review article addresses the effects of environmental factors such as pH, temperature, cytokines, hormones, and oxidative stress on periodontal biofilm formation and bacterial virulence.
Collapse
Affiliation(s)
- Marja T. Pöllänen
- Institute of Dentistry, University of Turku, FI-20014 Turku, Finland
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +358-40-723-58-18
| | - Annamari Paino
- Department of Biochemistry and Food Chemistry, University of Turku, FI-20014 Turku, Finland; E-Mails: (A.P.); (R.I.)
| | - Riikka Ihalin
- Department of Biochemistry and Food Chemistry, University of Turku, FI-20014 Turku, Finland; E-Mails: (A.P.); (R.I.)
| |
Collapse
|
16
|
Exposure of Salmonella enterica Serovar typhimurium to a protective monoclonal IgA triggers exopolysaccharide production via a diguanylate cyclase-dependent pathway. Infect Immun 2012; 81:653-64. [PMID: 23230292 DOI: 10.1128/iai.00813-12] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Sal4 is a monoclonal polymeric IgA antibody directed against the O antigen (O-Ag) of Salmonella enterica serovar Typhimurium (S. Typhimurium), which is sufficient to protect mice against intestinal infections from S. Typhimurium. We recently reported that the exposure of S. Typhimurium to Sal4 results in the immediate loss of flagellum-based motility, in alterations to the outer membrane (OM) integrity, and in the concomitant appearance of a mucoid phenotype that is reminiscent of cells in the earliest stages of biofilm formation. We demonstrate here that prolonged (>4 h) exposure of S. Typhimurium to Sal4 at 37 °C (but not at ambient temperature [25°C]) results in measurable exopolysaccharide (EPS) accumulation and biofilm formation on both borosilicate glass surfaces and polystyrene microtiter plates. The polysaccharide produced by S. Typhimurium in response to Sal4 contains cellulose, in addition to O-Ag capsule and colanic acid. EPS production was dependent on YeaJ, a proposed inner membrane-localized diguanylate cyclase (DGC) and a known regulator of cellulose biosynthesis. An S. Typhimurium ΔyeaJ strain was unable to produce cellulose or form a biofilm in response to Sal4. Conversely, the overexpression of yeaJ in S. Typhimurium enhanced Sal4-induced biofilm formation and resulted in increased intracellular levels of cyclic dimeric guanosine monophosphate (c-di-GMP) compared to that of a wild-type control; this strongly suggests that YeaJ is indeed a functional DGC. Based on these data, we speculate that Sal4, by virtue of its ability to associate with the O-Ag and to induce OM stress, renders S. Typhimurium avirulent by triggering a c-di-GMP-dependent signaling pathway via YeaJ that leads to the suppression of bacterial motility while simultaneously stimulating EPS production.
Collapse
|