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Whiley D, Jolley K, Blanchard A, Coffey T, Leigh J. A core genome multi-locus sequence typing scheme for Streptococcus uberis: an evolution in typing a genetically diverse pathogen. Microb Genom 2024; 10. [PMID: 38512314 DOI: 10.1099/mgen.0.001225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2024] Open
Abstract
Streptococcus uberis is a globally endemic and poorly controlled cause of bovine mastitis impacting the sustainability of the modern dairy industry. A core genome was derived from 579 newly sequenced S. uberis isolates, along with 305 publicly available genome sequences of S. uberis isolated from 11 countries around the world and used to develop a core genome multi-locus sequence typing (cgMLST) scheme. The S. uberis core genome comprised 1475 genes, and these were used to identify 1447 curated loci that were indexed into the cgMLST scheme. This was able to type 1012 of 1037 (>97 %) isolates used and differentiated the associated sequences into 932 discrete core genome sequence types (cgSTs). Analysis of the phylogenetic relationships of cgSTs revealed no clear clustering of isolates based on metadata such as disease status or year of isolation. Geographical clustering of cgSTs was limited to identification of a UK-centric clade, but cgSTs from UK isolates were also dispersed with those originating from other geographical regions across the entire phylogenetic topology. The cgMLST scheme offers a new tool for the detailed analysis of this globally important pathogen of dairy cattle. Initial analysis has re-emphasized and exemplified the genetically diverse nature of the global population of this opportunistic pathogen.
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Affiliation(s)
- Daniel Whiley
- School of Veterinary Medicine and Science, University of Nottingham, Nottingham, UK
| | - Keith Jolley
- Department of Biology, University of Oxford, Oxford, UK
| | - Adam Blanchard
- School of Veterinary Medicine and Science, University of Nottingham, Nottingham, UK
| | - Tracey Coffey
- School of Veterinary Medicine and Science, University of Nottingham, Nottingham, UK
| | - James Leigh
- School of Veterinary Medicine and Science, University of Nottingham, Nottingham, UK
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2
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Cumsille A, Serna-Cardona N, González V, Claverías F, Undabarrena A, Molina V, Salvà-Serra F, Moore ERB, Cámara B. Exploring the biosynthetic gene clusters in Brevibacterium: a comparative genomic analysis of diversity and distribution. BMC Genomics 2023; 24:622. [PMID: 37858045 PMCID: PMC10588199 DOI: 10.1186/s12864-023-09694-7] [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: 06/11/2023] [Accepted: 09/21/2023] [Indexed: 10/21/2023] Open
Abstract
Exploring Brevibacterium strains from various ecosystems may lead to the discovery of new antibiotic-producing strains. Brevibacterium sp. H-BE7, a strain isolated from marine sediments from Northern Patagonia, Chile, had its genome sequenced to study the biosynthetic potential to produce novel natural products within the Brevibacterium genus. The genome sequences of 98 Brevibacterium strains, including strain H-BE7, were selected for a genomic analysis. A phylogenomic cladogram was generated, which divided the Brevibacterium strains into four major clades. A total of 25 strains are potentially unique new species according to Average Nucleotide Identity (ANIb) values. These strains were isolated from various environments, emphasizing the importance of exploring diverse ecosystems to discover the full diversity of Brevibacterium. Pangenome analysis of Brevibacterium strains revealed that only 2.5% of gene clusters are included within the core genome, and most gene clusters occur either as singletons or as cloud genes present in less than ten strains. Brevibacterium strains from various phylogenomic clades exhibit diverse BGCs. Specific groups of BGCs show clade-specific distribution patterns, such as siderophore BGCs and carotenoid-related BGCs. A group of clade IV-A Brevibacterium strains possess a clade-specific Polyketide synthase (PKS) BGCs that connects with phenazine-related BGCs. Within the PKS BGC, five genes, including the biosynthetic PKS gene, participate in the mevalonate pathway and exhibit similarities with the phenazine A BGC. However, additional core biosynthetic phenazine genes were exclusively discovered in nine Brevibacterium strains, primarily isolated from cheese. Evaluating the antibacterial activity of strain H-BE7, it exhibited antimicrobial activity against Salmonella enterica and Listeria monocytogenes. Chemical dereplication identified bioactive compounds, such as 1-methoxyphenazine in the crude extracts of strain H-BE7, which could be responsible of the observed antibacterial activity. While strain H-BE7 lacks the core phenazine biosynthetic genes, it produces 1-methoxyphenazine, indicating the presence of an unknown biosynthetic pathway for this compound. This suggests the existence of alternative biosynthetic pathways or promiscuous enzymes within H-BE7's genome.
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Affiliation(s)
- Andrés Cumsille
- Centro de Biotecnología DAL, Universidad Técnica Federico Santa María, Valparaíso, Chile
| | - Néstor Serna-Cardona
- Centro de Biotecnología DAL, Universidad Técnica Federico Santa María, Valparaíso, Chile
| | - Valentina González
- Centro de Biotecnología DAL, Universidad Técnica Federico Santa María, Valparaíso, Chile
| | - Fernanda Claverías
- Centro de Biotecnología DAL, Universidad Técnica Federico Santa María, Valparaíso, Chile
| | - Agustina Undabarrena
- Centro de Biotecnología DAL, Universidad Técnica Federico Santa María, Valparaíso, Chile
| | - Vania Molina
- Centro de Biotecnología DAL, Universidad Técnica Federico Santa María, Valparaíso, Chile
| | - Francisco Salvà-Serra
- Department of Infectious Diseases, Institute for Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Clinical Microbiology, Region Västra Götaland and Sahlgrenska Academy, Culture Collection University of Gothenburg (CCUG), Sahlgrenska University Hospital, University of Gothenburg, Gothenburg, Sweden
- Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, Gothenburg, Sweden
| | - Edward R B Moore
- Department of Infectious Diseases, Institute for Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Clinical Microbiology, Region Västra Götaland and Sahlgrenska Academy, Culture Collection University of Gothenburg (CCUG), Sahlgrenska University Hospital, University of Gothenburg, Gothenburg, Sweden
- Microbiology, Department of Biology, University of the Balearic Islands, Palma de Mallorca, Spain
| | - Beatriz Cámara
- Centro de Biotecnología DAL, Universidad Técnica Federico Santa María, Valparaíso, Chile.
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Prichard A, Lee J, Laughlin TG, Lee A, Thomas KP, Sy AE, Spencer T, Asavavimol A, Cafferata A, Cameron M, Chiu N, Davydov D, Desai I, Diaz G, Guereca M, Hearst K, Huang L, Jacobs E, Johnson A, Kahn S, Koch R, Martinez A, Norquist M, Pau T, Prasad G, Saam K, Sandhu M, Sarabia AJ, Schumaker S, Sonin A, Uyeno A, Zhao A, Corbett KD, Pogliano K, Meyer J, Grose JH, Villa E, Dutton R, Pogliano J. Identifying the core genome of the nucleus-forming bacteriophage family and characterization of Erwinia phage RAY. Cell Rep 2023; 42:112432. [PMID: 37120812 PMCID: PMC10299810 DOI: 10.1016/j.celrep.2023.112432] [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: 12/14/2022] [Revised: 02/28/2023] [Accepted: 04/08/2023] [Indexed: 05/01/2023] Open
Abstract
We recently discovered that some bacteriophages establish a nucleus-like replication compartment (phage nucleus), but the core genes that define nucleus-based phage replication and their phylogenetic distribution were still to be determined. Here, we show that phages encoding the major phage nucleus protein chimallin share 72 conserved genes encoded within seven gene blocks. Of these, 21 core genes are unique to nucleus-forming phage, and all but one of these genes encode proteins of unknown function. We propose that these phages comprise a novel viral family we term Chimalliviridae. Fluorescence microscopy and cryoelectron tomography studies of Erwinia phage vB_EamM_RAY confirm that many of the key steps of nucleus-based replication are conserved among diverse chimalliviruses and reveal variations on this replication mechanism. This work expands our understanding of phage nucleus and PhuZ spindle diversity and function, providing a roadmap for identifying key mechanisms underlying nucleus-based phage replication.
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Affiliation(s)
- Amy Prichard
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Jina Lee
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Thomas G Laughlin
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Amber Lee
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Kyle P Thomas
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Annika E Sy
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Tara Spencer
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Aileen Asavavimol
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Allison Cafferata
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Mia Cameron
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Nicholas Chiu
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Demyan Davydov
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Isha Desai
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Gabriel Diaz
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Melissa Guereca
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Kiley Hearst
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Leyi Huang
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Emily Jacobs
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Annika Johnson
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Samuel Kahn
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Ryan Koch
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Adamari Martinez
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Meliné Norquist
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Tyler Pau
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Gino Prasad
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Katrina Saam
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Milan Sandhu
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Angel Jose Sarabia
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Siena Schumaker
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Aaron Sonin
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Ariya Uyeno
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Alison Zhao
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Kevin D Corbett
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Kit Pogliano
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Justin Meyer
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Julianne H Grose
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT 84602, USA
| | - Elizabeth Villa
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA; Howard Hughes Medical Institute, University of California San Diego, La Jolla, CA 92093, USA
| | - Rachel Dutton
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Joe Pogliano
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA.
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Evolutionary Processes Driving the Rise and Fall of Staphylococcus aureus ST239, a Dominant Hybrid Pathogen. mBio 2021; 12:e0216821. [PMID: 34903061 PMCID: PMC8669471 DOI: 10.1128/mbio.02168-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Selection plays a key role in the spread of antibiotic resistance, but the evolutionary drivers of clinically important resistant strains remain poorly understood. Here, we use genomic analyses and competition experiments to study Staphylococcus aureus ST239, a prominent MRSA strain that is thought to have been formed by large-scale recombination between ST8 and ST30. Genomic analyses allowed us to refine the hybrid model for the origin of ST239 and to date the origin of ST239 to 1920 to 1945, which predates the clinical introduction of methicillin in 1959. Although purifying selection has dominated the evolution of ST239, parallel evolution has occurred in genes involved in antibiotic resistance and virulence, suggesting that ST239 has evolved toward an increasingly pathogenic lifestyle. Crucially, ST239 isolates have low competitive fitness relative to both ST8 and ST30 isolates, supporting the idea that fitness costs have driven the demise of this once-dominant pathogen strain.
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Roszczenko-Jasińska P, Wojtyś MI, Jagusztyn-Krynicka EK. Helicobacter pylori treatment in the post-antibiotics era-searching for new drug targets. Appl Microbiol Biotechnol 2020; 104:9891-9905. [PMID: 33052519 PMCID: PMC7666284 DOI: 10.1007/s00253-020-10945-w] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 09/28/2020] [Accepted: 10/04/2020] [Indexed: 12/14/2022]
Abstract
Abstract Helicobacter pylori, a member of Epsilonproteobacteria, is a Gram-negative microaerophilic bacterium that colonizes gastric mucosa of about 50% of the human population. Although most infections caused by H. pylori are asymptomatic, the microorganism is strongly associated with serious diseases of the upper gastrointestinal tract such as chronic gastritis, peptic ulcer, duodenal ulcer, and gastric cancer, and it is classified as a group I carcinogen. The prevalence of H. pylori infections varies worldwide. The H. pylori genotype, host gene polymorphisms, and environmental factors determine the type of induced disease. Currently, the most common therapy to treat H. pylori is the first line clarithromycin–based triple therapy or a quadruple therapy replacing clarithromycin with new antibiotics. Despite the enormous recent effort to introduce new therapeutic regimens to combat this pathogen, treatment for H. pylori still fails in more than 20% of patients, mainly due to the increased prevalence of antibiotic resistant strains. In this review we present recent progress aimed at designing new anti-H. pylori strategies to combat this pathogen. Some novel therapeutic regimens will potentially be used as an extra constituent of antibiotic therapy, and others may replace current antibiotic treatments. Key points • Attempts to improve eradication rate of H. pylori infection. • Searching for new drug targets in anti-Helicobacter therapies.
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Affiliation(s)
- Paula Roszczenko-Jasińska
- Department of Bacterial Genetics, Institute of Microbiology, Faculty of Biology, Univeristy of Warsaw, Miecznikowa 1, 02-096, Warszawa, Poland
| | - Marta Ilona Wojtyś
- Department of Bacterial Genetics, Institute of Microbiology, Faculty of Biology, Univeristy of Warsaw, Miecznikowa 1, 02-096, Warszawa, Poland.,Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, Univeristy of Warsaw, Pasteura 5, 02-093, Warszawa, Poland
| | - Elżbieta K Jagusztyn-Krynicka
- Department of Bacterial Genetics, Institute of Microbiology, Faculty of Biology, Univeristy of Warsaw, Miecznikowa 1, 02-096, Warszawa, Poland.
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6
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de Sales RO, Migliorini LB, Puga R, Kocsis B, Severino P. A Core Genome Multilocus Sequence Typing Scheme for Pseudomonas aeruginosa. Front Microbiol 2020; 11:1049. [PMID: 32528447 PMCID: PMC7264379 DOI: 10.3389/fmicb.2020.01049] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 04/28/2020] [Indexed: 12/15/2022] Open
Abstract
Pseudomonas aeruginosa is a ubiquitous microorganism and an important opportunistic pathogen responsible for a broad spectrum of infections mainly in immunosuppressed and critically ill patients. Molecular investigations traditionally rely on pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). In this work we propose a core genome multilocus sequence typing (cgMLST) scheme for P. aeruginosa, a methodology that combines traditional MLST principles with whole genome sequencing data. All publicly available complete P. aeruginosa genomes, representing the diversity of this species, were used to establish a cgMLST scheme targeting 2,653 genes. The scheme was then tested using genomes available at contig, chromosome and scaffold levels. The proposed cgMLST scheme for P. aeruginosa typed over 99% (2,314/2,325) of the genomes available for this study considering at least 95% of the cgMLST target genes present. The absence of a certain number gene targets at the threshold considered for both the creation and validation steps due to low genome sequence quality is possibly the main reason for this result. The cgMLST scheme was compared with previously published whole genome single nucleotide polymorphism analysis for the characterization of the population structure of the epidemic clone ST235 and results were highly similar. In order to evaluate the typing resolution of the proposed scheme, collections of isolates belonging to two important STs associated with cystic fibrosis, ST146 and ST274, were typed using this scheme, and ST235 isolates associated with an outbreak were evaluated. Besides confirming the relatedness of all the isolates, earlier determined by MLST, the higher resolution of cgMLST denotes that it may be suitable for surveillance programs, overcoming possible shortcomings of classical MLST. The proposed scheme is publicly available at: https://github.com/BioinformaticsHIAEMolecularMicrobiology/cgMLST-Pseudomonas-aeruginosa.
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Affiliation(s)
- Romário Oliveira de Sales
- Hospital Israelita Albert Einstein, Albert Einstein Research and Education Institute, São Paulo, Brazil
| | - Letícia Busato Migliorini
- Hospital Israelita Albert Einstein, Albert Einstein Research and Education Institute, São Paulo, Brazil
| | - Renato Puga
- Hospital Israelita Albert Einstein, Albert Einstein Research and Education Institute, São Paulo, Brazil
| | - Bela Kocsis
- Institute of Medical Microbiology, Semmelweis University, Budapest, Hungary
| | - Patricia Severino
- Hospital Israelita Albert Einstein, Albert Einstein Research and Education Institute, São Paulo, Brazil
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Redfern J, Enright MC. Further understanding of Pseudomonas aeruginosa’s ability to horizontally acquire virulence: possible intervention strategies. Expert Rev Anti Infect Ther 2020; 18:539-549. [DOI: 10.1080/14787210.2020.1751610] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- James Redfern
- Department of Natural Sciences, Manchester Metropolitan University, Manchester, UK
| | - Mark C. Enright
- Department of Life Sciences, Manchester Metropolitan University, Manchester, UK
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Zhang X, Baars O, Morel FMM. Genetic, structural, and functional diversity of low and high-affinity siderophores in strains of nitrogen fixing Azotobacter chroococcum. Metallomics 2020; 11:201-212. [PMID: 30444515 DOI: 10.1039/c8mt00236c] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
To increase iron (Fe) bioavailability in surface soils, microbes secrete siderophores, chelators with widely varying Fe affinities. Strains of the soil bacterium Azotobacter chroococcum (AC), plant-growth promoting rhizobacteria used as agricultural inoculants, require high Fe concentrations for aerobic respiration and nitrogen fixation. Recently, A. chroococcum str. NCIMB 8003 was shown to synthesize three siderophore classes: (1) vibrioferrin, a low-affinity α-hydroxy carboxylate (pFe = 18.4), (2) amphibactins, high-affinity tris-hydroxamates, and (3) crochelin A, a high-affinity siderophore with mixed Fe-chelating groups (pFe = 23.9). The relevance and specific functions of these siderophores in AC strains remain unclear. We analyzed the genome and siderophores of a second AC strain, A. chroococcum str. B3, and found that it also produces vibrioferrin and amphibactins, but not crochelin A. Genome comparisons indicate that vibrioferrin production is a vertically inherited, conserved strategy for Fe uptake in A. chroococcum and other species of Azotobacter. Amphibactin and crochelin biosynthesis reflects a more complex evolutionary history, shaped by vertical gene transfer, gene gain and loss through recombination at a genomic hotspot. We found conserved patterns of low vs. high-affinity siderophore production across strains: the low-affinity vibrioferrin was produced by mildly Fe limited cultures. As cells became more severely Fe starved, vibrioferrin production decreased in favor of high-affinity amphibactins (str. B3, NCIMB 8003) and crochelin A (str. NCIMB 8003). Our results show the evolution of low and high-affinity siderophore families and conserved patterns for their production in response to Fe bioavailability in a common soil diazotroph.
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Affiliation(s)
- Xinning Zhang
- Department of Geosciences, Princeton University, USA.
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Gautreau G, Bazin A, Gachet M, Planel R, Burlot L, Dubois M, Perrin A, Médigue C, Calteau A, Cruveiller S, Matias C, Ambroise C, Rocha EPC, Vallenet D. PPanGGOLiN: Depicting microbial diversity via a partitioned pangenome graph. PLoS Comput Biol 2020; 16:e1007732. [PMID: 32191703 PMCID: PMC7108747 DOI: 10.1371/journal.pcbi.1007732] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 03/31/2020] [Accepted: 02/12/2020] [Indexed: 12/21/2022] Open
Abstract
The use of comparative genomics for functional, evolutionary, and epidemiological studies requires methods to classify gene families in terms of occurrence in a given species. These methods usually lack multivariate statistical models to infer the partitions and the optimal number of classes and don't account for genome organization. We introduce a graph structure to model pangenomes in which nodes represent gene families and edges represent genomic neighborhood. Our method, named PPanGGOLiN, partitions nodes using an Expectation-Maximization algorithm based on multivariate Bernoulli Mixture Model coupled with a Markov Random Field. This approach takes into account the topology of the graph and the presence/absence of genes in pangenomes to classify gene families into persistent, cloud, and one or several shell partitions. By analyzing the partitioned pangenome graphs of isolate genomes from 439 species and metagenome-assembled genomes from 78 species, we demonstrate that our method is effective in estimating the persistent genome. Interestingly, it shows that the shell genome is a key element to understand genome dynamics, presumably because it reflects how genes present at intermediate frequencies drive adaptation of species, and its proportion in genomes is independent of genome size. The graph-based approach proposed by PPanGGOLiN is useful to depict the overall genomic diversity of thousands of strains in a compact structure and provides an effective basis for very large scale comparative genomics. The software is freely available at https://github.com/labgem/PPanGGOLiN.
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Affiliation(s)
- Guillaume Gautreau
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, Université d’Évry, Université Paris-Saclay, CNRS, Evry, France
| | - Adelme Bazin
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, Université d’Évry, Université Paris-Saclay, CNRS, Evry, France
| | - Mathieu Gachet
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, Université d’Évry, Université Paris-Saclay, CNRS, Evry, France
| | - Rémi Planel
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, Université d’Évry, Université Paris-Saclay, CNRS, Evry, France
| | - Laura Burlot
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, Université d’Évry, Université Paris-Saclay, CNRS, Evry, France
| | - Mathieu Dubois
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, Université d’Évry, Université Paris-Saclay, CNRS, Evry, France
| | - Amandine Perrin
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, Paris, France
- Sorbonne Université, Collège doctoral, Paris, France
| | - Claudine Médigue
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, Université d’Évry, Université Paris-Saclay, CNRS, Evry, France
| | - Alexandra Calteau
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, Université d’Évry, Université Paris-Saclay, CNRS, Evry, France
| | - Stéphane Cruveiller
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, Université d’Évry, Université Paris-Saclay, CNRS, Evry, France
| | - Catherine Matias
- Laboratoire de Probabilités, Statistique et Modélisation, Sorbonne Université, Université de Paris, Centre National de la Recherche Scientifique, Paris, France
| | - Christophe Ambroise
- Laboratoire de Mathématiques et Modélisation d’Evry, UMR CNRS 8071, Université d’Evry Val d’Essonne, Evry, France
| | - Eduardo P. C. Rocha
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, Paris, France
| | - David Vallenet
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, Université d’Évry, Université Paris-Saclay, CNRS, Evry, France
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Pearce ME, Chattaway MA, Grant K, Maiden MCJ. A proposed core genome scheme for analyses of the Salmonella genus. Genomics 2020; 112:371-378. [PMID: 30905613 PMCID: PMC6978875 DOI: 10.1016/j.ygeno.2019.02.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 02/19/2019] [Accepted: 02/22/2019] [Indexed: 12/03/2022]
Abstract
The salmonellae are found in a wide range of animal hosts and many food products for human consumption. Most cases of human disease are caused by S. enterica subspecies I; however as opportunistic pathogens the other subspecies (II-VI) and S. bongori are capable of causing disease. Loci that were not consistently present in all of the species and subspecies were removed from a previously proposed core genome scheme (EBcgMLSTv2.0), the removal of these 252 loci resulted in a core genus scheme (SalmcgMLSTv1.0). SalmcgMLSTv1.0 clustered isolates from the same subspecies more rapidly and more accurately grouped isolates from different subspecies when compared with EBcgMLSTv2.0. All loci within the EBcgMLSTv2.0 scheme were present in over 98% of S. enterica subspecies I isolates and should, therefore, continue to be used for subspecies I analyses, while the SalmcgMLSTv1.0 scheme is more appropriate for cross genus investigations.
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Affiliation(s)
- Madison E Pearce
- Department of Zoology, University of Oxford, Peter Medawar Building for Pathogen Research, South Parks Road, Oxford OX1 3SY, United Kingdom; National Institute for Health Research, Health Protection Research Unit, Gastrointestinal Infections, University of Oxford, United Kingdom.
| | - Marie A Chattaway
- Public Health England, Gastrointestinal Bacteria Reference Unit, 61 Colindale Avenue, London NW9 5EQ, United Kingdom.
| | - Kathie Grant
- Public Health England, Gastrointestinal Bacteria Reference Unit, 61 Colindale Avenue, London NW9 5EQ, United Kingdom.
| | - Martin C J Maiden
- Department of Zoology, University of Oxford, Peter Medawar Building for Pathogen Research, South Parks Road, Oxford OX1 3SY, United Kingdom; National Institute for Health Research, Health Protection Research Unit, Gastrointestinal Infections, University of Oxford, United Kingdom.
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11
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van Tonder AJ, Bray JE, Jolley KA, Jansen van Rensburg M, Quirk SJ, Haraldsson G, Maiden MCJ, Bentley SD, Haraldsson Á, Erlendsdóttir H, Kristinsson KG, Brueggemann AB. Genomic Analyses of >3,100 Nasopharyngeal Pneumococci Revealed Significant Differences Between Pneumococci Recovered in Four Different Geographical Regions. Front Microbiol 2019; 10:317. [PMID: 30858837 PMCID: PMC6398412 DOI: 10.3389/fmicb.2019.00317] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 02/06/2019] [Indexed: 01/11/2023] Open
Abstract
Understanding the structure of a bacterial population is essential in order to understand bacterial evolution. Estimating the core genome (those genes common to all, or nearly all, strains of a species) is a key component of such analyses. The size and composition of the core genome varies by dataset, but we hypothesized that the variation between different collections of the same bacterial species would be minimal. To investigate this, we analyzed the genome sequences of 3,118 pneumococci recovered from healthy individuals in Reykjavik (Iceland), Southampton (United Kingdom), Boston (United States), and Maela (Thailand). The analyses revealed a “supercore” genome (genes shared by all 3,118 pneumococci) of 558 genes, although an additional 354 core genes were shared by pneumococci from Reykjavik, Southampton, and Boston. Overall, the size and composition of the core and pan-genomes among pneumococci recovered in Reykjavik, Southampton, and Boston were similar. Maela pneumococci were distinctly different in that they had a smaller core genome and larger pan-genome. The pan-genome of Maela pneumococci contained several >25 Kb sequence regions (flanked by pneumococcal genes) that were homologous to genomic regions found in other bacterial species. Overall, our work revealed that some subsets of the global pneumococcal population are highly heterogeneous, and our hypothesis was rejected. This is an important finding in terms of understanding genetic variation among pneumococci and is also an essential point of consideration before generalizing the findings from a single dataset to the wider pneumococcal population.
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Affiliation(s)
- Andries J van Tonder
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom.,Parasites and Microbes, Wellcome Sanger Institute, Hinxton, United Kingdom
| | - James E Bray
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Keith A Jolley
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | | | - Sigríður J Quirk
- Clinical Microbiology, University of Iceland and Landspitali University Hospital, Reykjavik, Iceland
| | - Gunnsteinn Haraldsson
- Clinical Microbiology, University of Iceland and Landspitali University Hospital, Reykjavik, Iceland
| | | | - Stephen D Bentley
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, United Kingdom.,Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom.,Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Ásgeir Haraldsson
- Children's Hospital Iceland, Landspitali University Hospital, Reykjavik, Iceland
| | - Helga Erlendsdóttir
- Clinical Microbiology, University of Iceland and Landspitali University Hospital, Reykjavik, Iceland
| | - Karl G Kristinsson
- Clinical Microbiology, University of Iceland and Landspitali University Hospital, Reykjavik, Iceland
| | - Angela B Brueggemann
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom.,Department of Medicine, Imperial College London, London, United Kingdom
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12
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Identification of Streptococcus pneumoniae by a real-time PCR assay targeting SP2020. Sci Rep 2019; 9:3285. [PMID: 30824850 PMCID: PMC6397248 DOI: 10.1038/s41598-019-39791-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 01/21/2019] [Indexed: 11/15/2022] Open
Abstract
Real-time PCR targeting lytA (the major autolysin gene) and piaB (permease gene of the pia ABC transporter) are currently used as the gold-standard culture-independent assays for Streptococcus pneumoniae identification. We evaluated the performance of a new real-time PCR assay – targeting SP2020 (putative transcriptional regulator gene) – and compared its performance with the assays previously described. A collection of 150 pneumococci, 433 non-pneumococci and 240 polymicrobial samples (obtained from nasopharynx, oropharynx, and saliva; 80 from each site) was tested. SP2020 and lytA-CDC assays had the best performance (sensitivity of 100% for each compared to 95.3% for piaB). The specificity for lytA and piaB was 99.5% and for SP2020 was 99.8%. Misidentifications occurred for the three genes: lytA, piaB and SP2020 were found in non-pneumococcal strains; piaB was absent in some pneumococci including a serotype 6B strain. Combining lytA and SP2020 assays resulted in no misidentifications. Most polymicrobial samples (88.8%) yielded concordant results for the three molecular targets. The remaining samples seemed to contain non-typeable pneumococci (0.8%), and non-pneumococci positive for lytA (1.7%) or SP2020 (8.7%). We propose that combined detection of both lytA-CDC and SP2020 is a powerful strategy for the identification of pneumococcus either in pure cultures or in polymicrobial samples.
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13
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Costa SS, Sobkowiak B, Parreira R, Edgeworth JD, Viveiros M, Clark TG, Couto I. Genetic Diversity of norA, Coding for a Main Efflux Pump of Staphylococcus aureus. Front Genet 2019; 9:710. [PMID: 30687388 PMCID: PMC6333699 DOI: 10.3389/fgene.2018.00710] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 12/18/2018] [Indexed: 12/14/2022] Open
Abstract
NorA is the best studied efflux system of Staphylococcus aureus and therefore frequently used as a model for investigating efflux-mediated resistance in this pathogen. NorA activity is associated with resistance to fluoroquinolones, several antiseptics and disinfectants and several reports have pointed out the role of efflux systems, including NorA, as a first-line response to antimicrobials in S. aureus. Genetic diversity studies of the gene norA have described three alleles; norAI, norAII and norAIII. However, the epidemiology of these alleles and their impact on NorA activity remains unclear. Additionally, increasing studies do not account for norA variability when establishing relations between resistance phenotypes and norA presence or reported absence, which actually corresponds, as we now demonstrate, to different norA alleles. In the present study we assessed the variability of the norA gene present in the genome of over 1,000 S. aureus isolates, corresponding to 112 S. aureus strains with whole genome sequences publicly available; 917 MRSA strains sourced from a London-based study and nine MRSA isolates collected in a major Hospital in Lisbon, Portugal. Our analyses show that norA is part of the core genome of S. aureus. It also suggests that occurrence of norA variants reflects the population structure of this major pathogen. Overall, this work highlights the ubiquitous nature of norA in S. aureus which must be taken into account when studying the role played by this important determinant on S. aureus resistance to antimicrobials.
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Affiliation(s)
- Sofia Santos Costa
- Global Health and Tropical Medicine, Instituto de Higiene e Medicina Tropical, Universidade NOVA de Lisboa, Lisbon, Portugal
| | - Benjamin Sobkowiak
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Ricardo Parreira
- Global Health and Tropical Medicine, Instituto de Higiene e Medicina Tropical, Universidade NOVA de Lisboa, Lisbon, Portugal
| | - Jonathan D. Edgeworth
- Department of Infectious Diseases, Centre for Clinical Infection and Diagnostics Research, Guy’s and St Thomas’ NHS Foundation Trust, King’s College London, London, United Kingdom
| | - Miguel Viveiros
- Global Health and Tropical Medicine, Instituto de Higiene e Medicina Tropical, Universidade NOVA de Lisboa, Lisbon, Portugal
| | - Taane G. Clark
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Isabel Couto
- Global Health and Tropical Medicine, Instituto de Higiene e Medicina Tropical, Universidade NOVA de Lisboa, Lisbon, Portugal
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14
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Effect of Vaccination on Pneumococci Isolated from the Nasopharynx of Healthy Children and the Middle Ear of Children with Otitis Media in Iceland. J Clin Microbiol 2018; 56:JCM.01046-18. [PMID: 30257906 PMCID: PMC6258863 DOI: 10.1128/jcm.01046-18] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 09/20/2018] [Indexed: 12/02/2022] Open
Abstract
Vaccination with pneumococcal conjugate vaccines (PCVs) disrupts the pneumococcal population. Our aim was to determine the impact of the 10-valent PCV on the serotypes, genetic lineages, and antimicrobial susceptibility of pneumococci isolated from children in Iceland. Vaccination with pneumococcal conjugate vaccines (PCVs) disrupts the pneumococcal population. Our aim was to determine the impact of the 10-valent PCV on the serotypes, genetic lineages, and antimicrobial susceptibility of pneumococci isolated from children in Iceland. Pneumococci were collected between 2009 and 2017 from the nasopharynges of healthy children attending 15 day care centers and from the middle ears (MEs) of children with acute otitis media from the greater Reykjavik capital area. Isolates were serotyped and tested for antimicrobial susceptibility. Whole-genome sequencing (WGS) was performed on alternate isolates from 2009 to 2014, and serotypes and multilocus sequence types (STs) were extracted from the WGS data. Two study periods were defined: 2009 to 2011 (PreVac) and 2012 to 2017 (PostVac). The overall nasopharyngeal carriage rate was similar between the two periods (67.3% PreVac and 61.5% PostVac, P = 0.090). Vaccine-type (VT) pneumococci decreased and nonvaccine-type (NVT) pneumococci (serotypes 6C, 15A, 15B/C, 21, 22F, 23A, 23B, 35F, and 35B) significantly increased in different age strata post-PCV introduction. The total number of pneumococci recovered from ME samples significantly decreased as did the proportion that were VTs, although NVT pneumococci (6C, 15B/C, 23A, and 23B) increased significantly. Most serotype 6C pneumococci were multidrug resistant (MDR). Serotype 19F was the predominant serotype associated with MEs, and it significantly decreased post-PCV introduction: these isolates were predominantly MDR and of the Taiwan19F-14 PMEN lineage. Overall, the nasopharyngeal carriage rate remained constant and the number of ME-associated pneumococci decreased significantly post-PCV introduction; however, there was a concomitant and statistically significant shift from VTs to NVTs in both collections of pneumococci.
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15
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Rezaei Javan R, van Tonder AJ, King JP, Harrold CL, Brueggemann AB. Genome Sequencing Reveals a Large and Diverse Repertoire of Antimicrobial Peptides. Front Microbiol 2018; 9:2012. [PMID: 30210481 PMCID: PMC6120550 DOI: 10.3389/fmicb.2018.02012] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 08/09/2018] [Indexed: 12/14/2022] Open
Abstract
Competition among bacterial members of the same ecological niche is mediated by bacteriocins: antimicrobial peptides produced by bacterial species to kill other bacteria. Bacteriocins are also promising candidates for novel antimicrobials. Streptococcus pneumoniae (the “pneumococcus”) is a leading cause of morbidity and mortality worldwide and a frequent colonizer of the human nasopharynx. Here, 14 newly discovered bacteriocin gene clusters were identified among >6,200 pneumococcal genomes. The molecular epidemiology of the bacteriocin clusters was investigated using a large global and historical pneumococcal dataset dating from 1916. These analyses revealed extraordinary bacteriocin diversity among pneumococci and the majority of bacteriocin clusters were also found in other streptococcal species. Genomic hotspots for the integration of different bacteriocin gene clusters were discovered. Experimentally, bacteriocin genes were transcriptionally active when the pneumococcus was under stress and when two strains were co-cultured in broth. These findings reveal much more diversity among bacterial defense mechanisms than previously appreciated, which fundamentally broaden our understanding of bacteriocins relative to intraspecies and interspecies nasopharyngeal competition and bacterial population structure.
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Affiliation(s)
- Reza Rezaei Javan
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | | | - James P King
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Caroline L Harrold
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Angela B Brueggemann
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom.,Department of Medicine, Imperial College London, London, United Kingdom
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16
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Bakermans C. Adaptations to marine versus terrestrial low temperature environments as revealed by comparative genomic analyses of the genus Psychrobacter. FEMS Microbiol Ecol 2018; 94:5032373. [DOI: 10.1093/femsec/fiy102] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 05/27/2018] [Indexed: 12/13/2022] Open
Affiliation(s)
- Corien Bakermans
- Division of Mathematics and Natural Sciences, Penn State Altoona, United States
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17
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Defining and Evaluating a Core Genome Multilocus Sequence Typing Scheme for Genome-Wide Typing of Clostridium difficile. J Clin Microbiol 2018; 56:JCM.01987-17. [PMID: 29618503 DOI: 10.1128/jcm.01987-17] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 03/28/2018] [Indexed: 01/18/2023] Open
Abstract
Clostridium difficile, recently renamed Clostridioides difficile, is the most common cause of antibiotic-associated nosocomial gastrointestinal infections worldwide. To differentiate endogenous infections and transmission events, highly discriminatory subtyping is necessary. Today, methods based on whole-genome sequencing data are increasingly used to subtype bacterial pathogens; however, frequently a standardized methodology and typing nomenclature are missing. Here we report a core genome multilocus sequence typing (cgMLST) approach developed for C. difficile Initially, we determined the breadth of the C. difficile population based on all available MLST sequence types with Bayesian inference (BAPS). The resulting BAPS partitions were used in combination with C. difficile clade information to select representative isolates that were subsequently used to define cgMLST target genes. Finally, we evaluated the novel cgMLST scheme with genomes from 3,025 isolates. BAPS grouping (n = 6 groups) together with the clade information led to a total of 11 representative isolates that were included for cgMLST definition and resulted in 2,270 cgMLST genes that were present in all isolates. Overall, 2,184 to 2,268 cgMLST targets were detected in the genome sequences of 70 outbreak-associated and reference strains, and on average 99.3% cgMLST targets (1,116 to 2,270 targets) were present in 2,954 genomes downloaded from the NCBI database, underlining the representativeness of the cgMLST scheme. Moreover, reanalyzing different cluster scenarios with cgMLST were concordant to published single nucleotide variant analyses. In conclusion, the novel cgMLST is representative for the whole C. difficile population, is highly discriminatory in outbreak situations, and provides a unique nomenclature facilitating interlaboratory exchange.
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18
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Pearce ME, Alikhan NF, Dallman TJ, Zhou Z, Grant K, Maiden MCJ. Comparative analysis of core genome MLST and SNP typing within a European Salmonella serovar Enteritidis outbreak. Int J Food Microbiol 2018; 274:1-11. [PMID: 29574242 PMCID: PMC5899760 DOI: 10.1016/j.ijfoodmicro.2018.02.023] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 02/23/2018] [Accepted: 02/27/2018] [Indexed: 01/10/2023]
Abstract
Multi-country outbreaks of foodborne bacterial disease present challenges in their detection, tracking, and notification. As food is increasingly distributed across borders, such outbreaks are becoming more common. This increases the need for high-resolution, accessible, and replicable isolate typing schemes. Here we evaluate a core genome multilocus typing (cgMLST) scheme for the high-resolution reproducible typing of Salmonella enterica (S. enterica) isolates, by its application to a large European outbreak of S. enterica serovar Enteritidis. This outbreak had been extensively characterised using single nucleotide polymorphism (SNP)-based approaches. The cgMLST analysis was congruent with the original SNP-based analysis, the epidemiological data, and whole genome MLST (wgMLST) analysis. Combination of the cgMLST and epidemiological data confirmed that the genetic diversity among the isolates predated the outbreak, and was likely present at the infection source. There was consequently no link between country of isolation and genetic diversity, but the cgMLST clusters were congruent with date of isolation. Furthermore, comparison with publicly available Enteritidis isolate data demonstrated that the cgMLST scheme presented is highly scalable, enabling outbreaks to be contextualised within the Salmonella genus. The cgMLST scheme is therefore shown to be a standardised and scalable typing method, which allows Salmonella outbreaks to be analysed and compared across laboratories and jurisdictions. cgMLST is proposed as a universal typing scheme for Salmonella. cgMLST is congruent with SNP analyses and easier to implement across laboratories. Genomic data are consistent with the epidemiology of the outbreak.
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Affiliation(s)
- Madison E Pearce
- Department of Zoology, University of Oxford, Peter Medawar Building for Pathogen Research, South Parks Road, Oxford OX1 3SY, United Kingdom; National Institute for Health Research, Health Protection Research Unit, Gastrointestinal Infections, University of Oxford, United Kingdom.
| | - Nabil-Fareed Alikhan
- Warwick Medical School, University of Warwick, Coventry CV4 7AL, United Kingdom.
| | - Timothy J Dallman
- Public Health England, Gastrointestinal Bacteria Reference Unit, 61 Colindale Avenue, London NW9 5EQ, United Kingdom.
| | - Zhemin Zhou
- Warwick Medical School, University of Warwick, Coventry CV4 7AL, United Kingdom.
| | - Kathie Grant
- Public Health England, Gastrointestinal Bacteria Reference Unit, 61 Colindale Avenue, London NW9 5EQ, United Kingdom.
| | - Martin C J Maiden
- Department of Zoology, University of Oxford, Peter Medawar Building for Pathogen Research, South Parks Road, Oxford OX1 3SY, United Kingdom; National Institute for Health Research, Health Protection Research Unit, Gastrointestinal Infections, University of Oxford, United Kingdom.
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19
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Cody AJ, Bray JE, Jolley KA, McCarthy ND, Maiden MCJ. Core Genome Multilocus Sequence Typing Scheme for Stable, Comparative Analyses of Campylobacter jejuni and C. coli Human Disease Isolates. J Clin Microbiol 2017; 55:2086-2097. [PMID: 28446571 PMCID: PMC5483910 DOI: 10.1128/jcm.00080-17] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 04/13/2017] [Indexed: 12/11/2022] Open
Abstract
Human campylobacteriosis, caused by Campylobacter jejuni and C. coli, remains a leading cause of bacterial gastroenteritis in many countries, but the epidemiology of campylobacteriosis outbreaks remains poorly defined, largely due to limitations in the resolution and comparability of isolate characterization methods. Whole-genome sequencing (WGS) data enable the improvement of sequence-based typing approaches, such as multilocus sequence typing (MLST), by substantially increasing the number of loci examined. A core genome MLST (cgMLST) scheme defines a comprehensive set of those loci present in most members of a bacterial group, balancing very high resolution with comparability across the diversity of the group. Here we propose a set of 1,343 loci as a human campylobacteriosis cgMLST scheme (v1.0), the allelic profiles of which can be assigned to core genome sequence types. The 1,343 loci chosen were a subset of the 1,643 loci identified in the reannotation of the genome sequence of C. jejuni isolate NCTC 11168, chosen as being present in >95% of draft genomes of 2,472 representative United Kingdom campylobacteriosis isolates, comprising 2,207 (89.3%) C. jejuni isolates and 265 (10.7%) C. coli isolates. Validation of the cgMLST scheme was undertaken with 1,478 further high-quality draft genomes, containing 150 or fewer contiguous sequences, from disease isolate collections: 99.5% of these isolates contained ≥95% of the 1,343 cgMLST loci. In addition to the rapid and effective high-resolution analysis of large numbers of diverse isolates, the cgMLST scheme enabled the efficient identification of very closely related isolates from a well-defined single-source campylobacteriosis outbreak.
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Affiliation(s)
- Alison J Cody
- Department of Zoology, University of Oxford, Oxford, United Kingdom
- NIHR Health Protection Research Unit in Gastrointestinal Infections, University of Oxford, Oxford, United Kingdom
| | - James E Bray
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Keith A Jolley
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Noel D McCarthy
- Department of Zoology, University of Oxford, Oxford, United Kingdom
- NIHR Health Protection Research Unit in Gastrointestinal Infections, University of Oxford, Oxford, United Kingdom
- Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Martin C J Maiden
- Department of Zoology, University of Oxford, Oxford, United Kingdom
- NIHR Health Protection Research Unit in Gastrointestinal Infections, University of Oxford, Oxford, United Kingdom
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20
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Patel S. Pathogenicity-associated protein domains: The fiercely-conserved evolutionary signatures. GENE REPORTS 2017; 7:127-141. [PMID: 32363241 PMCID: PMC7185390 DOI: 10.1016/j.genrep.2017.04.004] [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: 12/18/2016] [Revised: 03/29/2017] [Accepted: 04/07/2017] [Indexed: 12/15/2022]
Abstract
Proteins have highly conserved domains that determine their functionality. Out of the thousands of domains discovered so far across all living forms, some of the predominant clinically-relevant domains include IENR1, HNHc, HELICc, Pro-kuma_activ, Tryp_SPc, Lactamase_B, PbH1, ChtBD3, CBM49, acidPPc, G3P_acyltransf, RPOL8c, KbaA, HAMP, HisKA, Hr1, Dak2, APC2, Citrate_ly_lig, DALR, VKc, YARHG, WR1, PWI, ZnF_BED, TUDOR, MHC_II_beta, Integrin_B_tail, Excalibur, DISIN, Cadherin, ACTIN, PROF, Robl_LC7, MIT, Kelch, GAS2, B41, Cyclin_C, Connexin_CCC, OmpH, Bac_rhodopsin, AAA, Knot1, NH, Galanin, IB, Elicitin, ACTH, Cache_2, CHASE, AgrB, PRP, IGR, and Antimicrobial21. These domains are distributed in nucleases/helicases, proteases, esterases, lipases, glycosylase, GTPases, phosphatases, methyltransferases, acyltransferase, acetyltransferase, polymerase, kinase, ligase, synthetase, oxidoreductase, protease inhibitors, nucleic acid binding proteins, adhesion and immunity-related proteins, cytoskeletal component-manipulating proteins, lipid biosynthesis and metabolism proteins, membrane-associated proteins, hormone-like and signaling proteins, etc. These domains are ubiquitous stretches or folds of the proteins in pathogens and allergens. Pathogenesis alleviation efforts can benefit enormously if the characteristics of these domains are known. Hence, this review catalogs and discusses the role of such pivotal domains, suggesting hypotheses for better understanding of pathogenesis at molecular level. Proteins have highly conserved regions or domains across pathogens and allergens. Knowledge on these critical domains can facilitate our understanding of pathogenesis mechanisms. Such immune manipulation-related domains include IENR1, HNHc, HELICc, ACTIN, PROF, Robl_LC7, OmpH etc. These domains are presnt in enzyme, transcription regulators, adhesion proteins, and hormones. This review discusses and hypothesizes on these domains.
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Key Words
- CARDs, caspase activation and recruitment domains
- CBM, carbohydrate binding module
- CTD, C-terminal domain
- ChtBD, chitin-binding domain
- Diversification
- HNHc, homing endonucleases
- HTH, helix-turn-helix
- IENR1, intron-encoded endonuclease repeat
- Immune manipulation
- PAMPs, pathogen associated molecular patterns
- Pathogenesis
- Phylogenetic conservation
- Protein domains
- SMART, Simple Modular Architecture Research Tool
- Shuffling
- UDG, uracil DNA glycosylase
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Affiliation(s)
- Seema Patel
- Bioinformatics and Medical Informatics Research Center, San Diego State University, San Diego 92182, USA
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21
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Pneumococcal prophages are diverse, but not without structure or history. Sci Rep 2017; 7:42976. [PMID: 28218261 PMCID: PMC5317160 DOI: 10.1038/srep42976] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 01/17/2017] [Indexed: 11/24/2022] Open
Abstract
Bacteriophages (phages) infect many bacterial species, but little is known about the diversity of phages among the pneumococcus, a leading global pathogen. The objectives of this study were to determine the prevalence, diversity and molecular epidemiology of prophages (phage DNA integrated within the bacterial genome) among pneumococci isolated over the past 90 years. Nearly 500 pneumococcal genomes were investigated and RNA sequencing was used to explore prophage gene expression. We revealed that every pneumococcal genome contained prophage DNA. 286 full-length/putatively full-length pneumococcal prophages were identified, of which 163 have not previously been reported. Full-length prophages clustered into four major groups and every group dated from the 1930–40 s onward. There was limited evidence for genes shared between prophage clusters. Prophages typically integrated in one of five different sites within the pneumococcal genome. 72% of prophages possessed the virulence genes pblA and/or pblB. Individual prophages and the host pneumococcal genetic lineage were strongly associated and some prophages persisted for many decades. RNA sequencing provided clear evidence of prophage gene expression. Overall, pneumococcal prophages were highly prevalent, demonstrated a structured population, possessed genes associated with virulence, and were expressed under experimental conditions. Pneumococcal prophages are likely to play a more important role in pneumococcal biology and evolution than previously recognised.
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22
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van Vliet AHM. Use of pan-genome analysis for the identification of lineage-specific genes of Helicobacter pylori. FEMS Microbiol Lett 2016; 364:fnw296. [PMID: 28011701 DOI: 10.1093/femsle/fnw296] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 09/08/2016] [Accepted: 12/22/2016] [Indexed: 12/23/2022] Open
Abstract
The human bacterial pathogen Helicobacter pylori has a highly variable genome, with significant allelic and sequence diversity between isolates and even within well-characterised strains, hampering comparative genomics of H. pylori In this study, pan-genome analysis has been used to identify lineage-specific genes of H. pylori A total of 346 H. pylori genomes spanning the hpAfrica1, hpAfrica2, hpAsia2, hpEurope, hspAmerind and hspEAsia multilocus sequence typing (MLST) lineages were searched for genes specifically overrepresented or underrepresented in MLST lineages or associated with the cag pathogenicity island. The only genes overrepresented in cag-positive genomes were the cag pathogenicity island genes themselves. In contrast, a total of 125 genes were either overrepresented or underrepresented in one or more MLST lineages. Of these 125 genes, alcohol/aldehyde-reducing enzymes linked with acid resistance and production of toxic aldehydes were found to be overrepresented in African lineages. Conversely, the FecA2 ferric citrate receptor was missing from hspAmerind genomes, but present in all other lineages. This work shows the applicability of pan-genome analysis for identification of lineage-specific genes of H. pylori, facilitating further investigation to allow linkage of differential distribution of genes with disease outcome or virulence of H. pylori.
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Affiliation(s)
- Arnoud H M van Vliet
- School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey GU2 7AD, UK
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Fields FR, Lee SW, McConnell MJ. Using bacterial genomes and essential genes for the development of new antibiotics. Biochem Pharmacol 2016; 134:74-86. [PMID: 27940263 DOI: 10.1016/j.bcp.2016.12.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 12/05/2016] [Indexed: 10/20/2022]
Abstract
The shrinking antibiotic development pipeline together with the global increase in antibiotic resistant infections requires that new molecules with antimicrobial activity are developed. Traditional empirical screening approaches of natural and non-natural compounds have identified the majority of antibiotics that are currently available, however this approach has produced relatively few new antibiotics over the last few decades. The vast amount of bacterial genome sequence information that has become available since the sequencing of the first bacterial genome more than 20years ago holds potential for contributing to the discovery of novel antimicrobial compounds. Comparative genomic approaches can identify genes that are highly conserved within and between bacterial species, and thus may represent genes that participate in key bacterial processes. Whole genome mutagenesis studies can also identify genes necessary for bacterial growth and survival under different environmental conditions, making them attractive targets for the development of novel inhibitory compounds. In addition, transcriptomic and proteomic approaches can be used to characterize RNA and protein levels on a cellular scale, providing information on bacterial physiology that can be applied to antibiotic target identification. Finally, bacterial genomes can be mined to identify biosynthetic pathways that produce many intrinsic antimicrobial compounds and peptides. In this review, we provide an overview of past and current efforts aimed at using bacterial genomic data in the discovery and development of novel antibiotics.
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Affiliation(s)
- Francisco R Fields
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, United States
| | - Shaun W Lee
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, United States
| | - Michael J McConnell
- Biomedical Institute of Seville, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain.
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van Tonder AJ, Bray JE, Quirk SJ, Haraldsson G, Jolley KA, Maiden MCJ, Hoffmann S, Bentley SD, Haraldsson Á, Erlendsdóttir H, Kristinsson KG, Brueggemann AB. Putatively novel serotypes and the potential for reduced vaccine effectiveness: capsular locus diversity revealed among 5405 pneumococcal genomes. Microb Genom 2016; 2:000090. [PMID: 28133541 PMCID: PMC5266551 DOI: 10.1099/mgen.0.000090] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 09/20/2016] [Indexed: 01/14/2023] Open
Abstract
The pneumococcus is a leading global pathogen and a key virulence factor possessed by the majority of pneumococci is an antigenic polysaccharide capsule ('serotype'), which is encoded by the capsular (cps) locus. Approximately 100 different serotypes are known, but the extent of sequence diversity within the cps loci of individual serotypes is not well understood. Investigating serotype-specific sequence variation is crucial to the design of sequence-based serotyping methodology, understanding pneumococcal conjugate vaccine (PCV) effectiveness and the design of future PCVs. The availability of large genome datasets makes it possible to assess population-level variation among pneumococcal serotypes and in this study 5405 pneumococcal genomes were used to investigate cps locus diversity among 49 different serotypes. Pneumococci had been recovered between 1916 and 2014 from people of all ages living in 51 countries. Serotypes were deduced bioinformatically, cps locus sequences were extracted and variation was assessed within the cps locus, in the context of pneumococcal genetic lineages. Overall, cps locus sequence diversity varied markedly: low to moderate diversity was revealed among serogroups/types 1, 3, 7, 9, 11 and 22; whereas serogroups/types 6, 19, 23, 14, 15, 18, 33 and 35 displayed high diversity. Putative novel and/or hybrid cps loci were identified among all serogroups/types apart from 1, 3 and 9. This study demonstrated that cps locus sequence diversity varied widely between serogroups/types. Investigation of the biochemical structure of the polysaccharide capsule of major variants, particularly PCV-related serotypes and those that appear to be novel or hybrids, is warranted.
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Affiliation(s)
| | - James E. Bray
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Sigríður J. Quirk
- Clinical Microbiology, University of Iceland and Landspitali University Hospital, Reykjavik, Iceland
| | - Gunnsteinn Haraldsson
- Clinical Microbiology, University of Iceland and Landspitali University Hospital, Reykjavik, Iceland
| | - Keith A. Jolley
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | | | - Steen Hoffmann
- Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark
| | - Stephen D. Bentley
- Pathogen Genomics, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
| | - Ásgeir Haraldsson
- Clinical Microbiology, University of Iceland and Landspitali University Hospital, Reykjavik, Iceland
| | - Helga Erlendsdóttir
- Clinical Microbiology, University of Iceland and Landspitali University Hospital, Reykjavik, Iceland
| | - Karl G. Kristinsson
- Clinical Microbiology, University of Iceland and Landspitali University Hospital, Reykjavik, Iceland
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25
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Cibrián-Jaramillo A, Barona-Gómez F. Increasing Metagenomic Resolution of Microbiome Interactions Through Functional Phylogenomics and Bacterial Sub-Communities. Front Genet 2016; 7:4. [PMID: 26904093 PMCID: PMC4748306 DOI: 10.3389/fgene.2016.00004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 01/17/2016] [Indexed: 11/13/2022] Open
Abstract
The genomic composition of the microbiome and its relationship with the environment is an exciting open question in biology. Metagenomics is a useful tool in the discovery of previously unknown taxa, but its use to understand the functional and ecological capacities of the microbiome is limited until taxonomy and function are understood in the context of the community. We suggest that this can be achieved using a combined functional phylogenomics and co-culture-based experimental strategy that can increase our capacity to measure sub-community interactions. Functional phylogenomics can identify and partition the genome such that hidden gene functions and gene clusters with unique evolutionary signals are revealed. We can test these phylogenomic predictions using an experimental model based on sub-community populations that represent a subset of the diversity directly obtained from environmental samples. These populations increase the detection of mechanisms that drive functional forces in the assembly of the microbiome, in particular the role of metabolites from key taxa in community interactions. Our combined approach leverages the potential of metagenomics to address biological questions from ecological systems.
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Affiliation(s)
- Angélica Cibrián-Jaramillo
- Laboratorio Nacional de Genómica para la Biodiversidad (Langebio), Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (Cinvestav) Irapuato, Mexico
| | - Francisco Barona-Gómez
- Laboratorio Nacional de Genómica para la Biodiversidad (Langebio), Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (Cinvestav) Irapuato, Mexico
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26
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27
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Pulido MR, García-Quintanilla M, Gil-Marqués ML, McConnell MJ. Identifying targets for antibiotic development using omics technologies. Drug Discov Today 2015; 21:465-72. [PMID: 26691873 DOI: 10.1016/j.drudis.2015.11.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 11/05/2015] [Accepted: 11/26/2015] [Indexed: 12/16/2022]
Abstract
The lack of new compounds in the antibiotic development pipeline together with the increasing incidence of infections caused by antibiotic-resistant bacteria on a global scale represents an alarming public health problem. Advances in genomic, transcriptomic and proteomic technologies permit the characterization of bacterial physiology at an unprecedented scale, and thus can facilitate the identification of bacterial factors that could serve as targets for the development of new antibiotics. Recent studies employing these technologies have permitted the elucidation of key components in multiple bacterial processes such as bacterial survival, persistence in the host and infection. The continued use of these approaches and the incorporation of emerging omics technologies hold great potential in elucidating high value targets for antibiotic development.
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Affiliation(s)
- Marina R Pulido
- Biomedical Institute of Seville/University Hospital Virgen del Rocío, Seville, Spain
| | | | - M Luisa Gil-Marqués
- Biomedical Institute of Seville/University Hospital Virgen del Rocío, Seville, Spain
| | - Michael J McConnell
- Biomedical Institute of Seville/University Hospital Virgen del Rocío, Seville, Spain.
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28
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Gardner SN, Frey KG, Redden CL, Thissen JB, Allen JE, Allred AF, Dyer MD, Mokashi VP, Slezak TR. Targeted amplification for enhanced detection of biothreat agents by next-generation sequencing. BMC Res Notes 2015; 8:682. [PMID: 26572552 PMCID: PMC4647626 DOI: 10.1186/s13104-015-1530-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 09/28/2015] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Historically, identification of causal agents of disease has relied heavily on the ability to culture the organism in the laboratory and/or the use of pathogen-specific antibodies or sequence-based probes. However, these methods can be limiting: Even highly sensitive PCR-based assays must be continually updated due to signature degradation as new target strains and near neighbors are sequenced. Thus, there has been a need for assays that do not suffer as greatly from these limitations and/or biases. Recent advances in library preparation technologies for Next-Generation Sequencing (NGS) are focusing on the use of targeted amplification and targeted enrichment/capture to ensure that the most highly discriminating regions of the genomes of known targets (organism-unique regions and/or regions containing functionally important genes or phylogenetically-discriminating SNPs) will be sequenced, regardless of the complex sample background. RESULTS In the present study, we have assessed the feasibility of targeted sequence enhancement via amplification to facilitate detection of a bacterial pathogen present in low copy numbers in a background of human genomic material. Our results indicate that the targeted amplification of signature regions can effectively identify pathogen genomic material present in as little as 10 copies per ml in a complex sample. Importantly, the correct species and strain calls could be made in amplified samples, while this was not possible in unamplified samples. CONCLUSIONS The results presented here demonstrate the efficacy of a targeted amplification approach to biothreat detection, using multiple highly-discriminative amplicons per biothreat organism that provide redundancy in case of variation in some primer regions. Importantly, strain level discrimination was possible at levels of 10 genome equivalents. Similar results could be obtained through use of panels focused on the identification of amplicons targeted for specific genes or SNPs instead of, or in addition to, those targeted for specific organisms (ongoing gene-targeting work to be reported later). Note that without some form of targeted enhancement, the enormous background present in complex clinical and environmental samples makes it highly unlikely that sufficient coverage of key pathogen(s) present in the sample will be achieved with current NGS technology to guarantee that the most highly discriminating regions will be sequenced.
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Affiliation(s)
- Shea N Gardner
- Bioinformatics, Global Security Program, Lawrence Livermore National Laboratory, 7000 East Avenue, L-174, Livermore, CA, 94550, USA.
| | - Kenneth G Frey
- Naval Medical Research Center, NMRC-Frederick, 8400 Research Plaza, Fort Detrick, MD, 21702, USA. .,Henry M. Jackson Foundation, 6720-A Rockledge Drive, Suite 100, Bethesda, MD, 20817, USA.
| | - Cassie L Redden
- Naval Medical Research Center, NMRC-Frederick, 8400 Research Plaza, Fort Detrick, MD, 21702, USA. .,Henry M. Jackson Foundation, 6720-A Rockledge Drive, Suite 100, Bethesda, MD, 20817, USA.
| | - James B Thissen
- Bioinformatics, Global Security Program, Lawrence Livermore National Laboratory, 7000 East Avenue, L-174, Livermore, CA, 94550, USA.
| | - Jonathan E Allen
- Bioinformatics, Global Security Program, Lawrence Livermore National Laboratory, 7000 East Avenue, L-174, Livermore, CA, 94550, USA.
| | - Adam F Allred
- Thermo Fisher Scientific, 180 Oyster Point Boulevard, Building 200, South San Francisco, CA, 94080, USA.
| | - Matthew D Dyer
- Thermo Fisher Scientific, 180 Oyster Point Boulevard, Building 200, South San Francisco, CA, 94080, USA.
| | - Vishwesh P Mokashi
- Naval Medical Research Center, NMRC-Frederick, 8400 Research Plaza, Fort Detrick, MD, 21702, USA.
| | - Tom R Slezak
- Bioinformatics, Global Security Program, Lawrence Livermore National Laboratory, 7000 East Avenue, L-174, Livermore, CA, 94550, USA.
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29
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Population genomic datasets describing the post-vaccine evolutionary epidemiology of Streptococcus pneumoniae. Sci Data 2015; 2:150058. [PMID: 26528397 PMCID: PMC4622223 DOI: 10.1038/sdata.2015.58] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 09/28/2015] [Indexed: 11/08/2022] Open
Abstract
Streptococcus pneumoniae is common nasopharyngeal commensal bacterium and important human pathogen. Vaccines against a subset of pneumococcal antigenic diversity have reduced rates of disease, without changing the frequency of asymptomatic carriage, through altering the bacterial population structure. These changes can be studied in detail through using genome sequencing to characterise systematically-sampled collections of carried S. pneumoniae. This dataset consists of 616 annotated draft genomes of isolates collected from children during routine visits to primary care physicians in Massachusetts between 2001, shortly after the seven valent polysaccharide conjugate vaccine was introduced, and 2007. Also made available are a core genome alignment and phylogeny describing the overall population structure, clusters of orthologous protein sequences, software for inferring serotype from Illumina reads, and whole genome alignments for the analysis of closely-related sets of pneumococci. These data can be used to study both bacterial evolution and the epidemiology of a pathogen population under selection from vaccine-induced immunity.
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30
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Bogaardt C, van Tonder AJ, Brueggemann AB. Genomic analyses of pneumococci reveal a wide diversity of bacteriocins - including pneumocyclicin, a novel circular bacteriocin. BMC Genomics 2015. [PMID: 26215050 PMCID: PMC4517551 DOI: 10.1186/s12864-015-1729-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Background One of the most important global pathogens infecting all age groups is Streptococcus pneumoniae (the ‘pneumococcus’). Pneumococci reside in the paediatric nasopharynx, where they compete for space and resources, and one competition strategy is to produce a bacteriocin (antimicrobial peptide or protein) to attack other bacteria and an immunity protein to protect against self-destruction. We analysed a collection of 336 diverse pneumococcal genomes dating from 1916 onwards, identified bacteriocin cassettes, detailed their genetic composition and sequence diversity, and evaluated the data in the context of the pneumococcal population structure. Results We found that all genomes maintained a blp bacteriocin cassette and we identified several novel blp cassettes and genes. The composition of the ‘bacteriocin/immunity region’ of the blp cassette was highly variable: one cassette possessed six bacteriocin genes and eight putative immunity genes, whereas another cassette had only one of each. Both widely-distributed and highly clonal blp cassettes were identified. Most surprisingly, one-third of pneumococcal genomes also possessed a cassette encoding a novel circular bacteriocin that we called pneumocyclicin, which shared a similar genetic organisation to well-characterised circular bacteriocin cassettes in other bacterial species. Pneumocyclicin cassettes were mainly of one genetic cluster and largely found among seven major pneumococcal clonal complexes. Conclusions These detailed genomic analyses revealed a novel pneumocyclicin cassette and a wide variety of blp bacteriocin cassettes, suggesting that competition in the nasopharynx is a complex biological phenomenon. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1729-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Carlijn Bogaardt
- Nuffield Department of Medicine, Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom.
| | - Andries J van Tonder
- Nuffield Department of Medicine, Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom.
| | - Angela B Brueggemann
- Nuffield Department of Medicine, Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom.
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31
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Use of Alignment-Free Phylogenetics for Rapid Genome Sequence-Based Typing of Helicobacter pylori Virulence Markers and Antibiotic Susceptibility. J Clin Microbiol 2015; 53:2877-88. [PMID: 26135867 PMCID: PMC4540916 DOI: 10.1128/jcm.01357-15] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 06/19/2015] [Indexed: 12/18/2022] Open
Abstract
Whole-genome sequencing is becoming a leading technology in the typing and epidemiology of microbial pathogens, but the increase in genomic information necessitates significant investment in bioinformatic resources and expertise, and currently used methodologies struggle with genetically heterogeneous bacteria such as the human gastric pathogen Helicobacter pylori. Here we demonstrate that the alignment-free analysis method feature frequency profiling (FFP) can be used to rapidly construct phylogenetic trees of draft bacterial genome sequences on a standard desktop computer and that coupling with in silico genotyping methods gives useful information for comparative and clinical genomic and molecular epidemiology applications. FFP-based phylogenetic trees of seven gastric Helicobacter species matched those obtained by analysis of 16S rRNA genes and ribosomal proteins, and FFP- and core genome single nucleotide polymorphism-based analysis of 63 H. pylori genomes again showed comparable phylogenetic clustering, consistent with genomotypes assigned by using multilocus sequence typing (MLST). Analysis of 377 H. pylori genomes highlighted the conservation of genomotypes and linkage with phylogeographic characteristics and predicted the presence of an incomplete or nonfunctional cag pathogenicity island in 18/276 genomes. In silico analysis of antibiotic susceptibility markers suggests that most H. pylori hspAmerind and hspEAsia isolates are predicted to carry the T2812C mutation potentially conferring low-level clarithromycin resistance, while levels of metronidazole resistance were similar in all multilocus sequence types. In conclusion, the use of FFP phylogenetic clustering and in silico genotyping allows determination of genome evolution and phylogeographic clustering and can contribute to clinical microbiology by genomotyping for outbreak management and the prediction of pathogenic potential and antibiotic susceptibility.
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32
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Defining and Evaluating a Core Genome Multilocus Sequence Typing Scheme for Whole-Genome Sequence-Based Typing of Listeria monocytogenes. J Clin Microbiol 2015; 53:2869-76. [PMID: 26135865 PMCID: PMC4540939 DOI: 10.1128/jcm.01193-15] [Citation(s) in RCA: 198] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 06/13/2015] [Indexed: 11/20/2022] Open
Abstract
Whole-genome sequencing (WGS) has emerged today as an ultimate typing tool to characterize Listeria monocytogenes outbreaks. However, data analysis and interlaboratory comparability of WGS data are still challenging for most public health laboratories. Therefore, we have developed and evaluated a new L. monocytogenes typing scheme based on genome-wide gene-by-gene comparisons (core genome multilocus the sequence typing [cgMLST]) to allow for a unique typing nomenclature. Initially, we determined the breadth of the L. monocytogenes population based on MLST data with a Bayesian approach. Based on the genome sequence data of representative isolates for the whole population, cgMLST target genes were defined and reappraised with 67 L. monocytogenes isolates from two outbreaks and serotype reference strains. The Bayesian population analysis generated five L. monocytogenes groups. Using all available NCBI RefSeq genomes (n = 36) and six additionally sequenced strains, all genetic groups were covered. Pairwise comparisons of these 42 genome sequences resulted in 1,701 cgMLST targets present in all 42 genomes with 100% overlap and ≥90% sequence similarity. Overall, ≥99.1% of the cgMLST targets were present in 67 outbreak and serotype reference strains, underlining the representativeness of the cgMLST scheme. Moreover, cgMLST enabled clustering of outbreak isolates with ≤10 alleles difference and unambiguous separation from unrelated outgroup isolates. In conclusion, the novel cgMLST scheme not only improves outbreak investigations but also enables, due to the availability of the automatically curated cgMLST nomenclature, interlaboratory exchange of data that are crucial, especially for rapid responses during transsectorial outbreaks.
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Sheppard SK, Maiden MCJ. The evolution of Campylobacter jejuni and Campylobacter coli. Cold Spring Harb Perspect Biol 2015; 7:a018119. [PMID: 26101080 DOI: 10.1101/cshperspect.a018119] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The global significance of Campylobacter jejuni and Campylobacter coli as gastrointestinal human pathogens has motivated numerous studies to characterize their population biology and evolution. These bacteria are a common component of the intestinal microbiota of numerous bird and mammal species and cause disease in humans, typically via consumption of contaminated meat products, especially poultry meat. Sequence-based molecular typing methods, such as multilocus sequence typing (MLST) and whole genome sequencing (WGS), have been instructive for understanding the epidemiology and evolution of these bacteria and how phenotypic variation relates to the high degree of genetic structuring in C. coli and C. jejuni populations. Here, we describe aspects of the relatively short history of coevolution between humans and pathogenic Campylobacter, by reviewing research investigating how mutation and lateral or horizontal gene transfer (LGT or HGT, respectively) interact to create the observed population structure. These genetic changes occur in a complex fitness landscape with divergent ecologies, including multiple host species, which can lead to rapid adaptation, for example, through frame-shift mutations that alter gene expression or the acquisition of novel genetic elements by HGT. Recombination is a particularly strong evolutionary force in Campylobacter, leading to the emergence of new lineages and even large-scale genome-wide interspecies introgression between C. jejuni and C. coli. The increasing availability of large genome datasets is enhancing understanding of Campylobacter evolution through the application of methods, such as genome-wide association studies, but MLST-derived clonal complex designations remain a useful method for describing population structure.
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Affiliation(s)
- Samuel K Sheppard
- College of Medicine, Institute of Life Science, Swansea University, Singleton Park, Swansea SA2 8PP, United Kingdom
| | - Martin C J Maiden
- Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom
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Downing T. Tackling Drug Resistant Infection Outbreaks of Global Pandemic Escherichia coli ST131 Using Evolutionary and Epidemiological Genomics. Microorganisms 2015; 3:236-67. [PMID: 27682088 PMCID: PMC5023239 DOI: 10.3390/microorganisms3020236] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 04/28/2015] [Accepted: 04/30/2015] [Indexed: 11/16/2022] Open
Abstract
High-throughput molecular screening is required to investigate the origin and diffusion of antimicrobial resistance in pathogen outbreaks. The most frequent cause of human infection is Escherichia coli, which is dominated by sequence type 131 (ST131)-a set of rapidly radiating pandemic clones. The highly infectious clades of ST131 originated firstly by a mutation enhancing conjugation and adhesion. Secondly, single-nucleotide polymorphisms occurred enabling fluoroquinolone-resistance, which is near-fixed in all ST131. Thirdly, broader resistance through beta-lactamases has been gained and lost frequently, symptomatic of conflicting environmental selective effects. This flexible approach to gene exchange is worrying and supports the proposition that ST131 will develop an even wider range of plasmid and chromosomal elements promoting antimicrobial resistance. To stop ST131, deep genome sequencing is required to understand the origin, evolution and spread of antimicrobial resistance genes. Phylogenetic methods that decipher past events can predict future patterns of virulence and transmission based on genetic signatures of adaptation and gene exchange. Both the effect of partial antimicrobial exposure and cell dormancy caused by variation in gene expression may accelerate the development of resistance. High-throughput sequencing can decode measurable evolution of cell populations within patients associated with systems-wide changes in gene expression during treatments. A multi-faceted approach can enhance assessment of antimicrobial resistance in E. coli ST131 by examining transmission dynamics between hosts to achieve a goal of pre-empting resistance before it emerges by optimising antimicrobial treatment protocols.
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Affiliation(s)
- Tim Downing
- School of Biotechnology, Faculty of Science and Health, Dublin City University, Dublin 9, Ireland.
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35
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Genomics Reveals the Worldwide Distribution of Multidrug-Resistant Serotype 6E Pneumococci. J Clin Microbiol 2015; 53:2271-85. [PMID: 25972423 PMCID: PMC4473186 DOI: 10.1128/jcm.00744-15] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 05/06/2015] [Indexed: 02/02/2023] Open
Abstract
The pneumococcus is a leading pathogen infecting children and adults. Safe, effective vaccines exist, and they work by inducing antibodies to the polysaccharide capsule (unique for each serotype) that surrounds the cell; however, current vaccines are limited by the fact that only a few of the nearly 100 antigenically distinct serotypes are included in the formulations. Within the serotypes, serogroup 6 pneumococci are a frequent cause of serious disease and common colonizers of the nasopharynx in children. Serotype 6E was first reported in 2004 but was thought to be rare; however, we and others have detected serotype 6E among recent pneumococcal collections. Therefore, we analyzed a diverse data set of ∼1,000 serogroup 6 genomes, assessed the prevalence and distribution of serotype 6E, analyzed the genetic diversity among serogroup 6 pneumococci, and investigated whether pneumococcal conjugate vaccine-induced serotype 6A and 6B antibodies mediate the killing of serotype 6E pneumococci. We found that 43% of all genomes were of serotype 6E, and they were recovered worldwide from healthy children and patients of all ages with pneumococcal disease. Four genetic lineages, three of which were multidrug resistant, described ∼90% of the serotype 6E pneumococci. Serological assays demonstrated that vaccine-induced serotype 6B antibodies were able to elicit killing of serotype 6E pneumococci. We also revealed three major genetic clusters of serotype 6A capsular sequences, discovered a new hybrid 6C/6E serotype, and identified 44 examples of serotype switching. Therefore, while vaccines appear to offer protection against serotype 6E, genetic variants may reduce vaccine efficacy in the longer term because of the emergence of serotypes that can evade vaccine-induced immunity.
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Vernikos G, Medini D, Riley DR, Tettelin H. Ten years of pan-genome analyses. Curr Opin Microbiol 2014; 23:148-54. [PMID: 25483351 DOI: 10.1016/j.mib.2014.11.016] [Citation(s) in RCA: 298] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 11/19/2014] [Accepted: 11/20/2014] [Indexed: 10/24/2022]
Abstract
Next generation sequencing technologies have engendered a genome sequence data deluge in public databases. Genome analyses have transitioned from single or few genomes to hundreds to thousands of genomes. Pan-genome analyses provide a framework for estimating the genomic diversity of the dataset at hand and predicting the number of additional whole genomes sequences that would be necessary to fully characterize that diversity. We review recent implementations of the pan-genome approach, its impact and limits, and we propose possible extensions, including analyses at the whole genome multiple sequence alignment level.
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Affiliation(s)
- George Vernikos
- Novartis (Hellas) S.A.C.I., 12th Km Athens-Lamia North Road, 14451 Metamorfossi, Athens, Greece
| | - Duccio Medini
- Novartis Vaccines Research, Via Fiorentina 1, 53100 Siena, Italy
| | - David R Riley
- Institute for Genome Sciences, Department of Microbiology and Immunology, University of Maryland School of Medicine, 801 West Baltimore Street, Baltimore, MD 21201, USA
| | - Hervé Tettelin
- Institute for Genome Sciences, Department of Microbiology and Immunology, University of Maryland School of Medicine, 801 West Baltimore Street, Baltimore, MD 21201, USA.
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37
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Ojala T, Kankainen M, Castro J, Cerca N, Edelman S, Westerlund-Wikström B, Paulin L, Holm L, Auvinen P. Comparative genomics of Lactobacillus crispatus suggests novel mechanisms for the competitive exclusion of Gardnerella vaginalis. BMC Genomics 2014; 15:1070. [PMID: 25480015 PMCID: PMC4300991 DOI: 10.1186/1471-2164-15-1070] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 11/24/2014] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Lactobacillus crispatus is a ubiquitous micro-organism encountered in a wide range of host-associated habitats. It can be recovered from the gastrointestinal tract of animals and it is a common constituent of the vaginal microbiota of humans. Moreover, L. crispatus can contribute to the urogenital health of the host through competitive exclusion and the production of antimicrobial agents. In order to investigate the genetic diversity of this important urogenital species, we performed a comparative genomic analysis of L. crispatus. RESULTS Utilizing the completed genome sequence of a strain ST1 and the draft genome sequences of nine other L. crispatus isolates, we defined the scale and scope of the pan- and core genomic potential of L. crispatus. Our comparative analysis identified 1,224 and 2,705 ortholog groups present in all or only some of the ten strains, respectively. Based on mathematical modeling, sequencing of additional L. crispatus isolates would result in the identification of new genes and functions, whereas the conserved core of the ten strains was a good representation of the final L. crispatus core genome, estimated to level at about 1,116 ortholog groups. Importantly, the current core was observed to encode bacterial components potentially promoting urogenital health. Using antibody fragments specific for one of the conserved L. crispatus adhesins, we demonstrated that the L. crispatus core proteins have a potential to reduce the ability of Gardnerella vaginalis to adhere to epithelial cells. These findings thereby suggest that L. crispatus core proteins could protect the vagina from G. vaginalis and bacterial vaginosis. CONCLUSIONS Our pan-genome analysis provides insights into the intraspecific genome variability and the collective molecular mechanisms of the species L. crispatus. Using this approach, we described the differences and similarities between the genomes and identified features likely to be important for urogenital health. Notably, the conserved genetic backbone of L. crispatus accounted for close to 60% of the ortholog groups of an average L. crispatus strain and included factors for the competitive exclusion of G. vaginalis, providing an explanation on how this urogenital species could improve vaginal health.
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Affiliation(s)
- Teija Ojala
- Institute of Biotechnology, University of Helsinki, Viikinkaari 4, PO Box 56, FI-00014 Helsinki, Finland.
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