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Larsen TG, Samaniego Castruita JA, Worning P, Westh H, Bartels MD. Within-host genomic evolution of methicillin-resistant Staphylococcus aureus in long-term carriers. Appl Microbiol Biotechnol 2024; 108:95. [PMID: 38212970 PMCID: PMC10784349 DOI: 10.1007/s00253-023-12932-3] [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: 08/01/2023] [Revised: 11/14/2023] [Accepted: 11/27/2023] [Indexed: 01/13/2024]
Abstract
Assessing the genomic evolution of Staphylococcus aureus can help us understand how the bacteria adapt to its environment. In this study, we aimed to assess the mutation rate within 144 methicillin-resistant Staphylococcus aureus (MRSA) carriers with a carriage time from 4 to 11 years, including some carriers who belonged to the same households. We found that 23 of the 144 individuals had completely different MRSA types over time and were therefore not long-term carriers of the same MRSA. From the remaining 121 individuals, we performed whole-genome sequencing (WGS) on 424 isolates and then compared these pairwise using core genome multilocus sequence typing (cgMLST) and single-nucleotide polymorphism (SNP) analyses. We found a median within-host mutation rate in long-term MRSA carriers of 4.9 (3.4-6.9) SNPs/genome/year and 2.7 (1.8-4.2) allelic differences/genome/year, when excluding presumed recombination. Furthermore, we stratified the cohort into subgroups and found no significant difference between the median mutation rate of members of households, individuals with presumed continued exposure, e.g., from travel and persons without known continued exposure. Finally, we found that SNPs occurred at random within the genes in our cohort. KEY POINTS: • Median mutation rate within long-term MRSA carriers of 4.9 (3.4-6.9) SNPs/genome/year • Similar median mutation rates in subgroups (households, travelers) • No hotspots for SNPs within the genome.
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Affiliation(s)
- Tine Graakjær Larsen
- Department of Clinical Microbiology, Copenhagen University Hospital - Amager and Hvidovre, Copenhagen, Denmark
- Department of Infectious Disease Epidemiology and Prevention, Statens Serum Institut, Copenhagen, Denmark
| | | | - Peder Worning
- Department of Clinical Microbiology, Copenhagen University Hospital - Amager and Hvidovre, Copenhagen, Denmark
| | - Henrik Westh
- Department of Clinical Microbiology, Copenhagen University Hospital - Amager and Hvidovre, Copenhagen, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Mette Damkjær Bartels
- Department of Clinical Microbiology, Copenhagen University Hospital - Amager and Hvidovre, Copenhagen, Denmark.
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark.
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2
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Torrance EL, Diop A, Bobay LM. Homologous Recombination Shapes the Architecture and Evolution of Bacterial Genomes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.31.596828. [PMID: 38895235 PMCID: PMC11185547 DOI: 10.1101/2024.05.31.596828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Homologous recombination is a key evolutionary force that varies considerably across bacterial species. However, how the landscape of homologous recombination varies across genes and within individual genomes has only been studied in a few species. Here, we used Approximate Bayesian Computation to estimate the recombination rate along the genomes of 145 bacterial species. Our results show that homologous recombination varies greatly along bacterial genomes and shapes many aspects of genome architecture and evolution. The genomic landscape of recombination presents several key signatures: rates are highest near the origin of replication in most species, patterns of recombination generally appear symmetrical in both replichores (i.e. replicational halves of circular chromosomes) and most species have genomic hotpots of recombination. Furthermore, many closely related species share conserved landscapes of recombination across orthologs indicating that recombination landscapes are conserved over significant evolutionary distances. We show evidence that recombination drives the evolution of GC-content through increasing the effectiveness of selection and not through biased gene conversion, thereby contributing to an ongoing debate. Finally, we demonstrate that the rate of recombination varies across gene function and that many hotspots of recombination are associated with adaptive and mobile regions often encoding genes involved in pathogenicity.
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Affiliation(s)
- Ellis L Torrance
- Dept. of Biology, University of North Carolina Greensboro, Greensboro, NC 27412
- Systems Biology Dept., Sandia National Laboratories, Livermore, CA 94551
| | - Awa Diop
- Dept. of Biological Sciences, North Carolina State University, Raleigh, NC 27695
| | - Louis-Marie Bobay
- Dept. of Biology, University of North Carolina Greensboro, Greensboro, NC 27412
- Dept. of Biological Sciences, North Carolina State University, Raleigh, NC 27695
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3
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Vo T, Pontarotti P, Rolain JM, Merhej V. Mechanisms of acquisition of the vanA operon among vancomycin-resistant Staphylococcus aureus genomes: The tip of the iceberg? Int J Antimicrob Agents 2024; 63:107154. [PMID: 38599552 DOI: 10.1016/j.ijantimicag.2024.107154] [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] [Received: 11/23/2023] [Revised: 01/26/2024] [Accepted: 03/19/2024] [Indexed: 04/12/2024]
Abstract
BACKGROUND Vancomycin is frequently used as a last line of defence against infections due to multidrug-resistant Staphylococcus aureus (S. aureus). A recent finding described the acquisition of vancomycin-resistant S. aureus strains by the integration of an enterococcal plasmid containing the vanA operon into the S. aureus chromosome via homologous recombination involving a specific integration site called locus L2. METHODS To characterise all mechanisms of acquisition of vanA, this study analysed the 15 706 S. aureus genomes to look for vanA and described its genetic environment. RESULTS A complete vanA operon was found in 25 S. aureus strains isolated from 12 patients, including nine co-isolated with vancomycin-resistant Enterococcus strains. VanA was found within transposon Tn1546-like elements on 17 plasmids and eight chromosomes. VanA might be acquired through conjugation of enterococcal and staphylococcal plasmids, transposition of Tn1546 carrying vanA and plasmid integration into the chromosome. Further, L2 was detected in 2087 genomes (13.3%) of S. aureus strains across different continents. Six potential chromosomal hotspots for integration of the entire vanA-containing enterococcal plasmid were identified by homologous recombination via L2. CONCLUSIONS These findings suggest that the recently described scenario in a New York patient could be reproduced anywhere. Surveillance of this possibility is mandatory, especially in patients with vancomycin-resistant Enterococcus infection or colonisation.
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Affiliation(s)
- Tram Vo
- Aix Marseille University, MEPHI, Marseille, France; Institut Hospitalo-Universitaire (IHU) Méditerranée Infection, Marseille, France
| | - Pierre Pontarotti
- Aix Marseille University, MEPHI, Marseille, France; Institut Hospitalo-Universitaire (IHU) Méditerranée Infection, Marseille, France; Centre National de la Recherche Scientifique (CNRS)-SNC5039, Marseille, France
| | - Jean-Marc Rolain
- Institut Hospitalo-Universitaire (IHU) Méditerranée Infection, Marseille, France; Aix Marseille University, APHM, MEPHI, Marseille, France
| | - Vicky Merhej
- Aix Marseille University, MEPHI, Marseille, France; Institut Hospitalo-Universitaire (IHU) Méditerranée Infection, Marseille, France.
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Turchi B, Campobasso C, Nardinocchi A, Wagemans J, Torracca B, Lood C, Di Giuseppe G, Nieri P, Bertelloni F, Turini L, Ruffo V, Lavigne R, Di Luca M. Isolation and characterization of novel Staphylococcus aureus bacteriophage Hesat from dairy origin. Appl Microbiol Biotechnol 2024; 108:299. [PMID: 38619619 PMCID: PMC11018700 DOI: 10.1007/s00253-024-13129-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 03/05/2024] [Accepted: 03/27/2024] [Indexed: 04/16/2024]
Abstract
A novel temperate phage, named Hesat, was isolated by the incubation of a dairy strain of Staphylococcus aureus belonging to spa-type t127 with either bovine or ovine milk. Hesat represents a new species of temperate phage within the Phietavirus genus of the Azeredovirinae subfamily. Its genome has a length of 43,129 bp and a GC content of 35.11% and contains 75 predicted ORFs, some of which linked to virulence. This includes (i) a pathogenicity island (SaPln2), homologous to the type II toxin-antitoxin system PemK/MazF family toxin; (ii) a DUF3113 protein (gp30) that is putatively involved in the derepression of the global repressor Stl; and (iii) a cluster coding for a PVL. Genomic analysis of the host strain indicates Hesat is a resident prophage. Interestingly, its induction was obtained by exposing the bacterium to milk, while the conventional mitomycin C-based approach failed. The host range of phage Hesat appears to be broad, as it was able to lyse 24 out of 30 tested S. aureus isolates. Furthermore, when tested at high titer (108 PFU/ml), Hesat phage was also able to lyse a Staphylococcus muscae isolate, a coagulase-negative staphylococcal strain. KEY POINTS: • A new phage species was isolated from a Staphylococcus aureus bovine strain. • Pathogenicity island and PVL genes are encoded within phage genome. • The phage is active against most of S. aureus strains from both animal and human origins.
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Affiliation(s)
- Barbara Turchi
- Department of Veterinary Sciences, University of Pisa, Viale Delle Piagge 2, 56124, Pisa, Italy
| | - Claudia Campobasso
- Department of Biology, University of Pisa, Via San Zeno 37, 56127, Pisa, Italy
- Department of Biosystems, KU Leuven, Kasteelpark Arenberg 21, Box 2462, 3001, Louvain, Belgium
| | - Arianna Nardinocchi
- Department of Biology, University of Pisa, Via San Zeno 37, 56127, Pisa, Italy
| | - Jeroen Wagemans
- Department of Biosystems, KU Leuven, Kasteelpark Arenberg 21, Box 2462, 3001, Louvain, Belgium
| | - Beatrice Torracca
- Department of Veterinary Sciences, University of Pisa, Viale Delle Piagge 2, 56124, Pisa, Italy
| | - Cédric Lood
- Department of Biosystems, KU Leuven, Kasteelpark Arenberg 21, Box 2462, 3001, Louvain, Belgium
- Department of Microbial and Molecular Systems, Centre for Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, Box 2460, 3001, Leuven, Belgium
| | | | - Paola Nieri
- Department of Pharmacy, University of Pisa, Via Bonanno Pisano 6, 56126, Pisa, Italy
| | - Fabrizio Bertelloni
- Department of Veterinary Sciences, University of Pisa, Viale Delle Piagge 2, 56124, Pisa, Italy
| | - Luca Turini
- Department of Veterinary Sciences, University of Pisa, Viale Delle Piagge 2, 56124, Pisa, Italy
| | - Valeria Ruffo
- Department of Veterinary Sciences, University of Pisa, Viale Delle Piagge 2, 56124, Pisa, Italy
| | - Rob Lavigne
- Department of Biosystems, KU Leuven, Kasteelpark Arenberg 21, Box 2462, 3001, Louvain, Belgium
| | - Mariagrazia Di Luca
- Department of Biology, University of Pisa, Via San Zeno 37, 56127, Pisa, Italy.
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Boob AG, Zhu Z, Intasian P, Jain M, Petrov V, Lane ST, Tan SI, Xun G, Zhao H. CRISPR-COPIES: an in silico platform for discovery of neutral integration sites for CRISPR/Cas-facilitated gene integration. Nucleic Acids Res 2024; 52:e30. [PMID: 38346683 PMCID: PMC11014336 DOI: 10.1093/nar/gkae062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Revised: 01/09/2024] [Accepted: 01/19/2024] [Indexed: 04/14/2024] Open
Abstract
The CRISPR/Cas system has emerged as a powerful tool for genome editing in metabolic engineering and human gene therapy. However, locating the optimal site on the chromosome to integrate heterologous genes using the CRISPR/Cas system remains an open question. Selecting a suitable site for gene integration involves considering multiple complex criteria, including factors related to CRISPR/Cas-mediated integration, genetic stability, and gene expression. Consequently, identifying such sites on specific or different chromosomal locations typically requires extensive characterization efforts. To address these challenges, we have developed CRISPR-COPIES, a COmputational Pipeline for the Identification of CRISPR/Cas-facilitated intEgration Sites. This tool leverages ScaNN, a state-of-the-art model on the embedding-based nearest neighbor search for fast and accurate off-target search, and can identify genome-wide intergenic sites for most bacterial and fungal genomes within minutes. As a proof of concept, we utilized CRISPR-COPIES to characterize neutral integration sites in three diverse species: Saccharomyces cerevisiae, Cupriavidus necator, and HEK293T cells. In addition, we developed a user-friendly web interface for CRISPR-COPIES (https://biofoundry.web.illinois.edu/copies/). We anticipate that CRISPR-COPIES will serve as a valuable tool for targeted DNA integration and aid in the characterization of synthetic biology toolkits, enable rapid strain construction to produce valuable biochemicals, and support human gene and cell therapy applications.
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Affiliation(s)
- Aashutosh Girish Boob
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Zhixin Zhu
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Pattarawan Intasian
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology, Wangchan Valley, Rayong 21210, Thailand
| | - Manan Jain
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Vassily Andrew Petrov
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Stephan Thomas Lane
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Shih-I Tan
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Guanhua Xun
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Huimin Zhao
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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6
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Arizala D, Arif M. Impact of Homologous Recombination on Core Genome Evolution and Host Adaptation of Pectobacterium parmentieri. Genome Biol Evol 2024; 16:evae032. [PMID: 38385549 PMCID: PMC10946231 DOI: 10.1093/gbe/evae032] [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: 12/15/2023] [Revised: 02/02/2024] [Accepted: 02/11/2024] [Indexed: 02/23/2024] Open
Abstract
Homologous recombination is a major force mechanism driving bacterial evolution, host adaptability, and acquisition of novel virulence traits. Pectobacterium parmentieri is a plant bacterial pathogen distributed worldwide, primarily affecting potatoes, by causing soft rot and blackleg diseases. The goal of this investigation was to understand the impact of homologous recombination on the genomic evolution of P. parmentieri. Analysis of P. parmentieri genomes using Roary revealed a dynamic pan-genome with 3,742 core genes and over 55% accessory genome variability. Bayesian population structure analysis identified 7 lineages, indicating species heterogeneity. ClonalFrameML analysis displayed 5,125 recombination events, with the lineage 4 exhibiting the highest events. fastGEAR analysis identified 486 ancestral and 941 recent recombination events ranging from 43 bp to 119 kb and 36 bp to 13.96 kb, respectively, suggesting ongoing adaptation. Notably, 11% (412 genes) of the core genome underwent recent recombination, with lineage 1 as the main donor. The prevalence of recent recombination (double compared to ancient) events implies continuous adaptation, possibly driven by global potato trade. Recombination events were found in genes involved in vital cellular processes (DNA replication, DNA repair, RNA processing, homeostasis, and metabolism), pathogenicity determinants (type secretion systems, cell-wall degrading enzymes, iron scavengers, lipopolysaccharides (LPS), flagellum, etc.), antimicrobial compounds (phenazine and colicin) and even CRISPR-Cas genes. Overall, these results emphasize the potential role of homologous recombination in P. parmentieri's evolutionary dynamics, influencing host colonization, pathogenicity, adaptive immunity, and ecological fitness.
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Affiliation(s)
- Dario Arizala
- Department of Plant and Environmental Protection Sciences, University of Hawaii at Manoa, Honolulu, HI, USA
| | - Mohammad Arif
- Department of Plant and Environmental Protection Sciences, University of Hawaii at Manoa, Honolulu, HI, USA
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7
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Yuan C, An T, Li X, Zou J, Lin Z, Gu J, Hu R, Fang Z. Genomic analysis of Ralstonia pickettii reveals the genetic features for potential pathogenicity and adaptive evolution in drinking water. Front Microbiol 2024; 14:1272636. [PMID: 38370577 PMCID: PMC10869594 DOI: 10.3389/fmicb.2023.1272636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 12/13/2023] [Indexed: 02/20/2024] Open
Abstract
Ralstonia pickettii, the most critical clinical pathogen of the genus Ralstonia, has been identified as a causative agent of numerous harmful infections. Additionally, Ralstonia pickettii demonstrates adaptability to extreme environmental conditions, such as those found in drinking water. In this study, we conducted a comprehensive genomic analysis to investigate the genomic characteristics related to potential pathogenicity and adaptive evolution in drinking water environments of Ralstonia pickettii. Through phylogenetic analysis and population genetic analysis, we divided Ralstonia pickettii into five Groups, two of which were associated with drinking water environments. The open pan-genome with a large and flexible gene repertoire indicated a high genetic plasticity. Significant differences in functional enrichment were observed between the core- and pan-genome of different groups. Diverse mobile genetic elements (MGEs), extensive genomic rearrangements, and horizontal gene transfer (HGT) events played a crucial role in generating genetic diversity. In drinking water environments, Ralstonia pickettii exhibited strong adaptability, and the acquisition of specific adaptive genes was potentially facilitated by genomic islands (GIs) and HGT. Furthermore, environmental pressures drove the adaptive evolution of Ralstonia pickettii, leading to the accumulation of unique mutations in key genes. These mutations may have a significant impact on various physiological functions, particularly carbon metabolism and energy metabolism. The presence of virulence-related elements associated with macromolecular secretion systems, virulence factors, and antimicrobial resistance indicated the potential pathogenicity of Ralstonia pickettii, making it capable of causing multiple nosocomial infections. This study provides comprehensive insights into the potential pathogenicity and adaptive evolution of Ralstonia pickettii in drinking water environments from a genomic perspective.
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Affiliation(s)
- Chao Yuan
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Environment, Nutrition and Public Health, Tianjin Medical University, Tianjin, China
- Center for International Collaborative Research on Environment, Nutrition and Public Health, School of Public Health, Tianjin Medical University, Tianjin, China
- School of Public Health, Tianjin Medical University, Tianjin, China
| | - Tianfeng An
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Environment, Nutrition and Public Health, Tianjin Medical University, Tianjin, China
- Center for International Collaborative Research on Environment, Nutrition and Public Health, School of Public Health, Tianjin Medical University, Tianjin, China
- School of Public Health, Tianjin Medical University, Tianjin, China
| | - Xinlong Li
- School of Public Health, Tianjin Medical University, Tianjin, China
| | - Jiao Zou
- School of Public Health, Tianjin Medical University, Tianjin, China
| | - Zhan Lin
- School of Public Health, Tianjin Medical University, Tianjin, China
| | - Jiale Gu
- School of Public Health, Tianjin Medical University, Tianjin, China
| | - Ruixia Hu
- Tianjin Key Laboratory of Environment, Nutrition and Public Health, Tianjin Medical University, Tianjin, China
- Center for International Collaborative Research on Environment, Nutrition and Public Health, School of Public Health, Tianjin Medical University, Tianjin, China
- School of Public Health, Tianjin Medical University, Tianjin, China
| | - Zhongze Fang
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Environment, Nutrition and Public Health, Tianjin Medical University, Tianjin, China
- Center for International Collaborative Research on Environment, Nutrition and Public Health, School of Public Health, Tianjin Medical University, Tianjin, China
- School of Public Health, Tianjin Medical University, Tianjin, China
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Sheykhsaran E, Sadeghi J, Memar MY, Ghotaslou R, Baghi HB, Sharifi Y, Sefidan FY, Laghousi D, Abbasi A. Epidemiological characterization of clinical isolates of meticillin resistant Staphylococcus aureus through multilocus sequence typing and staphylococcal cassette chromosome mec typing in Northwest Iran. Mol Biol Rep 2024; 51:58. [PMID: 38165438 DOI: 10.1007/s11033-023-08951-y] [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] [Received: 10/11/2023] [Accepted: 11/07/2023] [Indexed: 01/03/2024]
Abstract
BACKGROUND Methicillin-resistant Staphylococcus aureus (MRSA), is considered a potential and aggressive nosocomial pathogen. It accounts for 50% of S. aureus isolates in tertiary hospitals in Iran, however, there is no sufficient evolutionary and epidemiological investigation about this medically important bacterium. We aimed to study the lineage and evolution of MRSA in Northwest Iran during 2021-2022 based on the obtained phenotypic and genotypic characteristics. MATERIALS AND METHODS Seventy-two non-duplicate MRSA isolates were collected from 3 referral hospitals in Tabriz, Ardebil, and Urmia cities. The antimicrobial susceptibility patterns were determined by disk diffusion test and micro broth dilution methods. Thereafter 4 virulence genes (eta, etb, pvl, tst) and 5 types of staphylococcal cassette chromosome mec (SCCmec) were detected by PCR. In the final step, representative isolates were selected to be studied by Multilocus sequence typing (MLST). RESULTS The highest resistance was observed to erythromycin and clindamycin at a rate of 76.4%, followed by ciprofloxacin (61.1%), gentamicin (54.2%), rifampin (38.9%), and co-trimoxazole (27.8%). All isolates were susceptible to vancomycin. The virulence genes of etb, pvl, tst, and eta were detected in 50%, 29.2%, 21.8%, and 13.9% of isolates, respectively. SCCmec types III and I were the most prevalent types, followed by types IV, II, and V. MLST analysis revealed 6 sequence types: ST6854, ST5282, ST127, ST7804, ST1607, and ST7784. Two MLST-based clonal complexes (CC8, and CC97) were identified as well. CONCLUSION The ST numbers were non-repetitive. CC8 as a pandemic clone and an individual lineage and clinically significant clade was reported as the most prevalent clonal complex. It is essential periodic evaluations of antibiotic susceptibility patterns and study the evolutionary characteristics of medical-challenging microorganisms in particular MRSA to effectively treat and restrict the outbreaks.
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Affiliation(s)
- Elham Sheykhsaran
- Immunology Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran
- Students' Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
- Department of Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, PO Box 5165665931, Tabriz, Iran
| | - Javid Sadeghi
- Immunology Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran.
- Department of Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, PO Box 5165665931, Tabriz, Iran.
| | - Mohammad Yousef Memar
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Reza Ghotaslou
- Department of Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, PO Box 5165665931, Tabriz, Iran
| | - Hossein Bannazadeh Baghi
- Immunology Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
- Department of Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, PO Box 5165665931, Tabriz, Iran
| | - Yaeghob Sharifi
- Department of Clinical Microbiology, School of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Fatemeh Yeganeh Sefidan
- Department of Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, PO Box 5165665931, Tabriz, Iran
| | - Delara Laghousi
- Social Determinants of Health Research Center, Health Management and Safety Promotion Research Institute, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Amin Abbasi
- Student Research Committee, Department of Food Sciences and Technology Research Institute, Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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9
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Kovařovic V, Finstrlová A, Sedláček I, Petráš P, Švec P, Mašlaňová I, Neumann-Schaal M, Šedo O, Botka T, Staňková E, Doškař J, Pantůček R. Staphylococcus brunensis sp. nov. isolated from human clinical specimens with a staphylococcal cassette chromosome-related genomic island outside of the rlmH gene bearing the ccrDE recombinase gene complex. Microbiol Spectr 2023; 11:e0134223. [PMID: 37712674 PMCID: PMC10581047 DOI: 10.1128/spectrum.01342-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 07/03/2023] [Indexed: 09/16/2023] Open
Abstract
Novel species of coagulase-negative staphylococci, which could serve as reservoirs of virulence and antimicrobial resistance factors for opportunistic pathogens from the genus Staphylococcus, are recognized in human and animal specimens due to advances in diagnostic techniques. Here, we used whole-genome sequencing, extensive biotyping, MALDI-TOF mass spectrometry, and chemotaxonomy to characterize five coagulase-negative strains from the Staphylococcus haemolyticus phylogenetic clade obtained from human ear swabs, wounds, and bile. Based on the results of polyphasic taxonomy, we propose the species Staphylococcus brunensis sp. nov. (type strain NRL/St 16/872T = CCM 9024T = LMG 31872T = DSM 111349T). The genomic analysis revealed numerous variable genomic elements, including staphylococcal cassette chromosome (SCC), prophages, plasmids, and a unique 18.8 kb-long genomic island SbCIccrDE integrated into the ribosomal protein L7 serine acetyltransferase gene rimL. SbCIccrDE has a cassette chromosome recombinase (ccr) gene complex with a typical structure found in SCCs. Based on nucleotide and amino acid identity to other known ccr genes and the distinct integration site that differs from the canonical methyltransferase gene rlmH exploited by SCCs, we classified the ccr genes as novel variants, ccrDE. The comparative genomic analysis of SbCIccrDE with related islands shows that they can accumulate virulence and antimicrobial resistance factors creating novel resistance elements, which reflects the evolution of SCC. The spread of these resistance islands into established pathogens such as Staphylococcus aureus would pose a great threat to the healthcare system. IMPORTANCE The coagulase-negative staphylococci are important opportunistic human pathogens, which cause bloodstream and foreign body infections, mainly in immunocompromised patients. The mobile elements, primarily the staphylococcal cassette chromosome mec, which confers resistance to methicillin, are the key to the successful dissemination of staphylococci into healthcare and community settings. Here, we present a novel species of the Staphylococcus genus isolated from human clinical material. The detailed analysis of its genome revealed a previously undescribed genomic island, which is closely related to the staphylococcal cassette chromosome and has the potential to accumulate and spread virulence and resistance determinants. The island harbors a set of conserved genes required for its mobilization, which we recognized as novel cassette chromosome recombinase genes ccrDE. Similar islands were revealed not only in the genomes of coagulase-negative staphylococci but also in S. aureus. The comparative genomic study contributes substantially to the understanding of the evolution and pathogenesis of staphylococci.
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Affiliation(s)
- Vojtěch Kovařovic
- Department of Experimental Biology, Division of Genetics and Molecular Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Adéla Finstrlová
- Department of Experimental Biology, Division of Genetics and Molecular Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Ivo Sedláček
- Department of Experimental Biology, Czech Collection of Microorganisms, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Petr Petráš
- Reference Laboratory for Staphylococci, National Institute of Public Health, Praha, Czech Republic
| | - Pavel Švec
- Department of Experimental Biology, Czech Collection of Microorganisms, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Ivana Mašlaňová
- Department of Experimental Biology, Division of Genetics and Molecular Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Meina Neumann-Schaal
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Ondrej Šedo
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Tibor Botka
- Department of Experimental Biology, Division of Genetics and Molecular Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Eva Staňková
- Department of Experimental Biology, Czech Collection of Microorganisms, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Jiří Doškař
- Department of Experimental Biology, Division of Genetics and Molecular Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Roman Pantůček
- Department of Experimental Biology, Division of Genetics and Molecular Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
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10
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Conte AL, Brunetti F, Marazzato M, Longhi C, Maurizi L, Raponi G, Palamara AT, Grassi S, Conte MP. Atopic dermatitis-derived Staphylococcus aureus strains: what makes them special in the interplay with the host. Front Cell Infect Microbiol 2023; 13:1194254. [PMID: 37389215 PMCID: PMC10303148 DOI: 10.3389/fcimb.2023.1194254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Accepted: 05/22/2023] [Indexed: 07/01/2023] Open
Abstract
Background Atopic dermatitis (AD) is a chronic inflammatory skin condition whose pathogenesis involves genetic predisposition, epidermal barrier dysfunction, alterations in the immune responses and microbial dysbiosis. Clinical studies have shown a link between Staphylococcus aureus and the pathogenesis of AD, although the origins and genetic diversity of S. aureus colonizing patients with AD is poorly understood. The aim of the study was to investigate if specific clones might be associated with the disease. Methods WGS analyses were performed on 38 S. aureus strains, deriving from AD patients and healthy carriers. Genotypes (i.e. MLST, spa-, agr- and SCCmec-typing), genomic content (e.g. virulome and resistome), and the pan-genome structure of strains have been investigated. Phenotypic analyses were performed to determine the antibiotic susceptibility, the biofilm production and the invasiveness within the investigated S. aureus population. Results Strains isolated from AD patients revealed a high degree of genetic heterogeneity and a shared set of virulence factors and antimicrobial resistance genes, suggesting that no genotype and genomic content are uniquely associated with AD. The same strains were characterized by a lower variability in terms of gene content, indicating that the inflammatory conditions could exert a selective pressure leading to the optimization of the gene repertoire. Furthermore, genes related to specific mechanisms, like post-translational modification, protein turnover and chaperones as well as intracellular trafficking, secretion and vesicular transport, were significantly more enriched in AD strains. Phenotypic analysis revealed that all of our AD strains were strong or moderate biofilm producers, while less than half showed invasive capabilities. Conclusions We conclude that in AD skin, the functional role played by S. aureus may depend on differential gene expression patterns and/or on post-translational modification mechanisms rather than being associated with peculiar genetic features.
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Affiliation(s)
- Antonietta Lucia Conte
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
| | - Francesca Brunetti
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
| | - Massimiliano Marazzato
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
| | - Catia Longhi
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
| | - Linda Maurizi
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
| | - Giammarco Raponi
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
| | - Anna Teresa Palamara
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Laboratory Affiliated to Institute Pasteur Italia- Cenci Bolognetti Foundation, Rome, Italy
| | - Sara Grassi
- Dermatology Clinic, Department of Clinical Internal, Anesthesiological and Cardiovascular Sciences, Sapienza University of Rome, Rome, Italy
| | - Maria Pia Conte
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
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11
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Ikhimiukor OO, Souza SSR, Marcovici MM, Nye GJ, Gibson R, Andam CP. Leaky barriers to gene sharing between locally co-existing coagulase-negative Staphylococcus species. Commun Biol 2023; 6:482. [PMID: 37137974 PMCID: PMC10156822 DOI: 10.1038/s42003-023-04877-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 04/26/2023] [Indexed: 05/05/2023] Open
Abstract
Coagulase-negative Staphylococcus (CoNS) are opportunistic pathogens implicated in many human and animal infections. The evolutionary history of CoNS remains obscure because of the historical lack of recognition for their clinical importance and poor taxonomic sampling. Here, we sequenced the genomes of 191 CoNS isolates representing 15 species sampled from diseased animals diagnosed in a veterinary diagnostic laboratory. We found that CoNS are important reservoirs of diverse phages, plasmids and mobilizable genes encoding antimicrobial resistance, heavy metal resistance, and virulence. Frequent exchange of DNA between certain donor-recipient partners suggests that specific lineages act as hubs of gene sharing. We also detected frequent recombination between CoNS regardless of their animal host species, indicating that ecological barriers to horizontal gene transfer can be surmounted in co-circulating lineages. Our findings reveal frequent but structured patterns of transfer that exist within and between CoNS species, which are driven by their overlapping ecology and geographical proximity.
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Affiliation(s)
- Odion O Ikhimiukor
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY, USA.
| | - Stephanie S R Souza
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY, USA
| | - Michael M Marcovici
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY, USA
| | - Griffin J Nye
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH, USA
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, USA
| | - Robert Gibson
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH, USA
- New Hampshire Veterinary Diagnostic Laboratory, Durham, NH, USA
| | - Cheryl P Andam
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY, USA.
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12
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Howden BP, Giulieri SG, Wong Fok Lung T, Baines SL, Sharkey LK, Lee JYH, Hachani A, Monk IR, Stinear TP. Staphylococcus aureus host interactions and adaptation. Nat Rev Microbiol 2023; 21:380-395. [PMID: 36707725 PMCID: PMC9882747 DOI: 10.1038/s41579-023-00852-y] [Citation(s) in RCA: 114] [Impact Index Per Article: 114.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2023] [Indexed: 01/28/2023]
Abstract
Invasive Staphylococcus aureus infections are common, causing high mortality, compounded by the propensity of the bacterium to develop drug resistance. S. aureus is an excellent case study of the potential for a bacterium to be commensal, colonizing, latent or disease-causing; these states defined by the interplay between S. aureus and host. This interplay is multidimensional and evolving, exemplified by the spread of S. aureus between humans and other animal reservoirs and the lack of success in vaccine development. In this Review, we examine recent advances in understanding the S. aureus-host interactions that lead to infections. We revisit the primary role of neutrophils in controlling infection, summarizing the discovery of new immune evasion molecules and the discovery of new functions ascribed to well-known virulence factors. We explore the intriguing intersection of bacterial and host metabolism, where crosstalk in both directions can influence immune responses and infection outcomes. This Review also assesses the surprising genomic plasticity of S. aureus, its dualism as a multi-mammalian species commensal and opportunistic pathogen and our developing understanding of the roles of other bacteria in shaping S. aureus colonization.
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Affiliation(s)
- Benjamin P. Howden
- grid.1008.90000 0001 2179 088XCentre for Pathogen Genomics, The University of Melbourne, Melbourne, Victoria Australia ,grid.1008.90000 0001 2179 088XDepartment of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria Australia ,grid.410678.c0000 0000 9374 3516Department of Infectious Diseases, Austin Health, Heidelberg, Victoria Australia ,grid.416153.40000 0004 0624 1200Microbiology Department, Royal Melbourne Hospital, Melbourne, Victoria Australia
| | - Stefano G. Giulieri
- grid.1008.90000 0001 2179 088XDepartment of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria Australia ,grid.416153.40000 0004 0624 1200Victorian Infectious Diseases Service, Royal Melbourne Hospital, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria Australia
| | - Tania Wong Fok Lung
- grid.21729.3f0000000419368729Department of Paediatrics, Columbia University, New York, NY USA
| | - Sarah L. Baines
- grid.1008.90000 0001 2179 088XDepartment of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria Australia
| | - Liam K. Sharkey
- grid.1008.90000 0001 2179 088XDepartment of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria Australia
| | - Jean Y. H. Lee
- grid.1008.90000 0001 2179 088XDepartment of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria Australia ,grid.419789.a0000 0000 9295 3933Department of Infectious Diseases, Monash Health, Clayton, Victoria Australia
| | - Abderrahman Hachani
- grid.1008.90000 0001 2179 088XDepartment of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria Australia
| | - Ian R. Monk
- grid.1008.90000 0001 2179 088XDepartment of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria Australia
| | - Timothy P. Stinear
- grid.1008.90000 0001 2179 088XCentre for Pathogen Genomics, The University of Melbourne, Melbourne, Victoria Australia ,grid.1008.90000 0001 2179 088XDepartment of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria Australia
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13
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Sanchez-Nieves RL, Zhang C, Whitaker RJ. Integrated conjugative plasmid drives high frequency chromosomal gene transfer in Sulfolobus islandicus. Front Microbiol 2023; 14:1114574. [PMID: 36756353 PMCID: PMC9899855 DOI: 10.3389/fmicb.2023.1114574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 01/09/2023] [Indexed: 01/24/2023] Open
Abstract
Gene transfer in crenarchaea has been observed within natural and experimental populations of Sulfolobus. However, the molecular factors that govern how gene transfer and recombination manifest themselves in these populations is still unknown. In this study, we examine a plasmid-mediated mechanism of gene transfer in S. islandicus that results in localized high frequency recombination within the chromosome. Through chromosomal marker exchange assays with defined donors and recipients, we find that while bidirectional exchange occurs among all cells, those possessing the integrated conjugative plasmid, pM164, mobilize a nearby locus at a significantly higher frequency when compared to a more distal marker. We establish that traG is essential for this phenotype and that high frequency recombination can be replicated in transconjugants after plasmid transfer. Mapping recombinants through genomic analysis, we establish the distribution of recombinant tracts with decreasing frequency at increasing distance from pM164. We suggest the bias in transfer is a result of an Hfr (high frequency recombination)-like conjugation mechanism in this strain. In addition, we find recombinants containing distal non-selected recombination events, potentially mediated by a different host-encoded marker exchange (ME) mechanism.
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Affiliation(s)
- Ruben L. Sanchez-Nieves
- Carl R. Woese Institute for Genomic Biology, University of Illinois Urbana-Champaign, Urbana, IL, United States,Department of Microbiology, University of Illinois Urbana-Champaign, Urbana, IL, United States
| | - Changyi Zhang
- Carl R. Woese Institute for Genomic Biology, University of Illinois Urbana-Champaign, Urbana, IL, United States
| | - Rachel J. Whitaker
- Carl R. Woese Institute for Genomic Biology, University of Illinois Urbana-Champaign, Urbana, IL, United States,Department of Microbiology, University of Illinois Urbana-Champaign, Urbana, IL, United States,*Correspondence: Rachel J. Whitaker,
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14
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Joyce LR, Youngblom MA, Cormaty H, Gartstein E, Barber KE, Akins RL, Pepperell CS, Palmer KL. Comparative Genomics of Streptococcus oralis Identifies Large Scale Homologous Recombination and a Genetic Variant Associated with Infection. mSphere 2022; 7:e0050922. [PMID: 36321824 PMCID: PMC9769543 DOI: 10.1128/msphere.00509-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 10/17/2022] [Indexed: 11/07/2022] Open
Abstract
The viridans group streptococci (VGS) are a large consortium of commensal streptococci that colonize the human body. Many species within this group are opportunistic pathogens causing bacteremia and infective endocarditis (IE), yet little is known about why some strains cause invasive disease. Identification of virulence determinants is complicated by the difficulty of distinguishing between the closely related species of this group. Here, we analyzed genomic data from VGS that were isolated from blood cultures in patients with invasive infections and oral swabs of healthy volunteers and then determined the best-performing methods for species identification. Using whole-genome sequence data, we characterized the population structure of a diverse sample of Streptococcus oralis isolates and found evidence of frequent recombination. We used multiple genome-wide association study tools to identify candidate determinants of invasiveness. These tools gave consistent results, leading to the discovery of a single synonymous single nucleotide polymorphism (SNP) that was significantly associated with invasiveness. This SNP was within a previously undescribed gene that was conserved across the majority of VGS species. Using the growth in the presence of human serum and a simulated infective endocarditis vegetation model, we were unable to identify a phenotype for the enriched allele in laboratory assays, suggesting a phenotype may be specific to natural infection. These data highlighted the power of analyzing natural populations for gaining insight into pathogenicity, particularly for organisms with complex population structures like the VGS. IMPORTANCE The viridians group streptococci (VGS) are a large collection of closely related commensal streptococci, with many being opportunistic pathogens causing invasive diseases, such as bacteremia and infective endocarditis. Little is known about virulence determinants in these species, and there is a distinct lack of genomic information available for the VGS. In this study, we collected VGS isolates from invasive infections and healthy volunteers and performed whole-genome sequencing for a suite of downstream analyses. We focused on a diverse sample of Streptococcus oralis genomes and identified high rates of recombination in the population as well as a single genome variant highly enriched in invasive isolates. The variant lies within a previously uncharacterized gene, nrdM, which shared homology with the anaerobic ribonucleoside triphosphate reductase, nrdD, and was highly conserved among VGS. This work increased our knowledge of VGS genomics and indicated that differences in virulence potential among S. oralis isolates were, at least in part, genetically determined.
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Affiliation(s)
- Luke R. Joyce
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, Texas, USA
| | - Madison A. Youngblom
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Medical Microbiology and Immunology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Harshini Cormaty
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, Texas, USA
| | - Evelyn Gartstein
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, Texas, USA
| | - Katie E. Barber
- Department of Pharmacy Practice, University of Mississippi School of Pharmacy, University of Mississippi, Jackson, Mississippi, USA
| | | | - Caitlin S. Pepperell
- Department of Medical Microbiology and Immunology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Medicine (Infectious Diseases), School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Kelli L. Palmer
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, Texas, USA
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15
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Nayar G, Terrizzano I, Seabolt E, Agarwal A, Boucher C, Ruiz J, Slizovskiy IB, Kaufman JH, Noyes NR. ggMOB: Elucidation of genomic conjugative features and associated cargo genes across bacterial genera using genus-genus mobilization networks. Front Genet 2022; 13:1024577. [PMID: 36568361 PMCID: PMC9779932 DOI: 10.3389/fgene.2022.1024577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Accepted: 10/25/2022] [Indexed: 12/14/2022] Open
Abstract
Horizontal gene transfer mediated by conjugation is considered an important evolutionary mechanism of bacteria. It allows organisms to quickly evolve new phenotypic properties including antimicrobial resistance (AMR) and virulence. The frequency of conjugation-mediated cargo gene exchange has not yet been comprehensively studied within and between bacterial taxa. We developed a frequency-based network of genus-genus conjugation features and candidate cargo genes from whole-genome sequence data of over 180,000 bacterial genomes, representing 1,345 genera. Using our method, which we refer to as ggMOB, we revealed that over half of the bacterial genomes contained one or more known conjugation features that matched exactly to at least one other genome. Moreover, the proportion of genomes containing these conjugation features varied substantially by genus and conjugation feature. These results and the genus-level network structure can be viewed interactively in the ggMOB interface, which allows for user-defined filtering of conjugation features and candidate cargo genes. Using the network data, we observed that the ratio of AMR gene representation in conjugative versus non-conjugative genomes exceeded 5:1, confirming that conjugation is a critical force for AMR spread across genera. Finally, we demonstrated that clustering genomes by conjugation profile sometimes correlated well with classical phylogenetic structuring; but that in some cases the clustering was highly discordant, suggesting that the importance of the accessory genome in driving bacterial evolution may be highly variable across both time and taxonomy. These results can advance scientific understanding of bacterial evolution, and can be used as a starting point for probing genus-genus gene exchange within complex microbial communities that include unculturable bacteria. ggMOB is publicly available under the GNU licence at https://ruiz-hci-lab.github.io/ggMOB/.
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Affiliation(s)
- Gowri Nayar
- Department of Biomedical Informatics, Stanford University, Stanford, CA, United States
| | | | - Ed Seabolt
- IBM Research Almaden, San Jose, CA, United States
| | | | - Christina Boucher
- Department of Computer and Information Science and Engineering, University of Florida, Gainesville, FL, United States
| | - Jaime Ruiz
- Department of Computer and Information Science and Engineering, University of Florida, Gainesville, FL, United States
| | - Ilya B. Slizovskiy
- Department of Veterinary Population Medicine, University of Minnesota, Minneapolis, MN, United States
| | | | - Noelle R. Noyes
- Department of Veterinary Population Medicine, University of Minnesota, Minneapolis, MN, United States,*Correspondence: Noelle R. Noyes,
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16
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Huber C, Wolf SA, Ziebuhr W, Holmes MA, Assmann J, Lübke-Becker A, Thürmer A, Semmler T, Brombach J, Bethe A, Bischoff M, Wieler LH, Epping L, Walther B. How to survive pig farming: Mechanism of SCC mec element deletion and metabolic stress adaptation in livestock-associated MRSA. Front Microbiol 2022; 13:969961. [PMID: 36504815 PMCID: PMC9728531 DOI: 10.3389/fmicb.2022.969961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 10/04/2022] [Indexed: 11/24/2022] Open
Abstract
Previous research on methicillin susceptible Staphylococcus aureus (MSSA) belonging to livestock-associated (LA-) sequence type (ST) 398, isolated from pigs and their local surroundings, indicated that differences between these MSSA and their methicillin resistant predecessors (MRSA) are often limited to the absence of the staphylococcal cassette chromosome mec (SCCmec) and few single nucleotide polymorphisms. So far, our understanding on how LA-MRSA endure the environmental conditions associated with pig-farming as well as the putative impact of this particular environment on the mobilisation of SCCmec elements is limited. Thus, we performed in-depth genomic and transcriptomic analyses using the LA-MRSA ST398 strain IMT38951 and its methicillin susceptible descendant. We identified a mosaic-structured SCCmec region including a putative replicative SCCmecVc which is absent from the MSSA chromosome through homologous recombination. Based on our data, such events occur between short repetitive sequences identified within and adjacent to two distinct alleles of the large cassette recombinase genes C (ccrC). We further evaluated the global transcriptomic response of MRSA ST398 to particular pig-farm associated conditions, i.e., contact with host proteins (porcine serum) and a high ammonia concentration. Differential expression of global regulators involved in stress response control were identified, i.e., ammonia-induced alternative sigma factor B-depending activation of genes for the alkaline shock protein 23, the heat shock response and the accessory gene regulator (agr)-controlled transcription of virulence factors. Exposure to serum transiently induced the transcription of distinct virulence factor encoding genes. Transcription of genes reported for mediating the loss of methicillin resistance, especially ccrC, was not significantly different compared to the unchallenged controls. We concluded that, from an evolutionary perspective, bacteria may save energy by incidentally dismissing a fully replicative SCCmec element in contrast to the induction of ccr genes on a population scale. Since the genomic SCCmec integration site is a hot-spot of recombination, occasional losses of elements of 16 kb size may restore capacities for the uptake of foreign genetic material. Subsequent spread of resistance, on the other hand, might depend on the autonomous replication machinery of the deleted SCCmec elements that probably enhance chances for reintegration of SCCmec into susceptible genomes by mere multiplication.
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Affiliation(s)
- Charlotte Huber
- Advanced Light and Electron Microscopy (ZBS4), Robert Koch Institute, Berlin, Germany
| | - Silver A. Wolf
- Genome Sequencing and Genomic Epidemiology (MF2), Robert Koch Institute, Berlin, Germany
| | - Wilma Ziebuhr
- Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Mark A. Holmes
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Julia Assmann
- Advanced Light and Electron Microscopy (ZBS4), Robert Koch Institute, Berlin, Germany
| | - Antina Lübke-Becker
- Institute of Microbiology and Epizootics, Freie Universität Berlin, Berlin, Germany
| | - Andrea Thürmer
- Genome Sequencing and Genomic Epidemiology (MF2), Robert Koch Institute, Berlin, Germany
| | - Torsten Semmler
- Genome Sequencing and Genomic Epidemiology (MF2), Robert Koch Institute, Berlin, Germany
| | - Julian Brombach
- Institute of Microbiology and Epizootics, Freie Universität Berlin, Berlin, Germany
| | - Astrid Bethe
- Institute of Microbiology and Epizootics, Freie Universität Berlin, Berlin, Germany
| | - Markus Bischoff
- Institute of Medical Microbiology and Hygiene, Saarland University, Homburg, Germany
| | - Lothar H. Wieler
- Methodology and Research Infrastructure, Robert Koch Institute, Berlin, Germany
| | - Lennard Epping
- Genome Sequencing and Genomic Epidemiology (MF2), Robert Koch Institute, Berlin, Germany
| | - Birgit Walther
- Advanced Light and Electron Microscopy (ZBS4), Robert Koch Institute, Berlin, Germany,*Correspondence: Birgit Walther,
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17
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Xu Z, Yuan C. Molecular Epidemiology of Staphylococcus aureus in China Reveals the Key Gene Features Involved in Epidemic Transmission and Adaptive Evolution. Microbiol Spectr 2022; 10:e0156422. [PMID: 36190436 PMCID: PMC9603185 DOI: 10.1128/spectrum.01564-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 09/12/2022] [Indexed: 12/31/2022] Open
Abstract
Staphylococcus aureus is a Gram-positive pathogen that causes various infections in humans and domestic animals. In China, S. aureus is the most common Gram-positive pathogen that causes clinical infections. However, there are few comprehensive genome-based molecular epidemiology studies to investigate the genotypic background of the major S. aureus clones that are epidemic in China. Here, four S. aureus isolates that were recovered from hospital personnel were sequenced. In combination with whole-genome sequencing (WGS) data of 328 S. aureus strains as references, we performed a comprehensive molecular epidemiology study to reveal the molecular epidemic characterization of S. aureus that is epidemic in China. It was found that 332 S. aureus isolates were phylogenetically categorized into 4 major epidemic groups with different epidemiology phenotypes. Each group has exclusive features in virulence genotypic profiles, antimicrobial resistance genotypic profiles, core and pangenome features representing the differences involved in genetic features, evolutionary processes, and potential future evolutionary directions. Moreover, a comparative core genome analysis of 332 S. aureus isolates indicated several key genes that contributed to differences in molecular epidemic characterization and promoted the adaptive evolutionary process of each group. This study provides a comprehensive understanding of molecular epidemiological characteristics and adaptive evolutionary directions of major S. aureus clones that are epidemic in China. IMPORTANCE Staphylococcus aureus is an important Gram-positive pathogen that is epidemic worldwide and causes various infections in humans and domestic animals. However, there has been relatively little research on comprehensive molecular epidemiology in China. In this research, we reconstructed the phylogenetic relationship based on whole-genome data of strains almost all over China, screened for resistance and virulence genes, and took core and pan genome analysis to perform a comprehensive molecular epidemiology study of S. aureus that is epidemic in China. Our results highlight that there are 4 major epidemic groups with different epidemiology phenotypes after phylogenetic categorization with exclusive genetic features in virulence genotypic profiles, antimicrobial-resistance genotypic profiles, and core and pangenome features, and we found key gene features involved in epidemic transmission and adaptive evolution. Our findings are critical in describing molecular characteristic profiles of S. aureus infection, which could update existing preventive measures and take appropriate strategies.
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Affiliation(s)
- Zhen Xu
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Tianjin Medical University, Tianjin, PR China
- Tianjin Key Laboratory of Environment, Nutrition and Public Health, Tianjin Medical University, Tianjin, PR China
- Center for International Collaborative Research on Environment, Nutrition and Public Health, School of Public Health, Tianjin Medical University, Tianjin, PR China
| | - Chao Yuan
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Tianjin Medical University, Tianjin, PR China
- Tianjin Key Laboratory of Environment, Nutrition and Public Health, Tianjin Medical University, Tianjin, PR China
- Center for International Collaborative Research on Environment, Nutrition and Public Health, School of Public Health, Tianjin Medical University, Tianjin, PR China
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18
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Didelot X, Parkhill J. A scalable analytical approach from bacterial genomes to epidemiology. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210246. [PMID: 35989600 PMCID: PMC9393561 DOI: 10.1098/rstb.2021.0246] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 02/17/2022] [Indexed: 12/21/2022] Open
Abstract
Recent years have seen a remarkable increase in the practicality of sequencing whole genomes from large numbers of bacterial isolates. The availability of this data has huge potential to deliver new insights into the evolution and epidemiology of bacterial pathogens, but the scalability of the analytical methodology has been lagging behind that of the sequencing technology. Here we present a step-by-step approach for such large-scale genomic epidemiology analyses, from bacterial genomes to epidemiological interpretations. A central component of this approach is the dated phylogeny, which is a phylogenetic tree with branch lengths measured in units of time. The construction of dated phylogenies from bacterial genomic data needs to account for the disruptive effect of recombination on phylogenetic relationships, and we describe how this can be achieved. Dated phylogenies can then be used to perform fine-scale or large-scale epidemiological analyses, depending on the proportion of cases for which genomes are available. A key feature of this approach is computational scalability and in particular the ability to process hundreds or thousands of genomes within a matter of hours. This is a clear advantage of the step-by-step approach described here. We discuss other advantages and disadvantages of the approach, as well as potential improvements and avenues for future research. This article is part of a discussion meeting issue 'Genomic population structures of microbial pathogens'.
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Affiliation(s)
- Xavier Didelot
- School of Life Sciences and Department of Statistics, University of Warwick, Coventry CV4 7AL, UK
| | - Julian Parkhill
- Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, UK
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19
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Metagenomic methylation patterns resolve bacterial genomes of unusual size and structural complexity. THE ISME JOURNAL 2022; 16:1921-1931. [PMID: 35459792 PMCID: PMC9296519 DOI: 10.1038/s41396-022-01242-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 04/05/2022] [Accepted: 04/08/2022] [Indexed: 01/01/2023]
Abstract
The plasticity of bacterial and archaeal genomes makes examining their ecological and evolutionary dynamics both exciting and challenging. The same mechanisms that enable rapid genomic change and adaptation confound current approaches for recovering complete genomes from metagenomes. Here, we use strain-specific patterns of DNA methylation to resolve complex bacterial genomes from long-read metagenomic data of a marine microbial consortium, the “pink berries” of the Sippewissett Marsh (USA). Unique combinations of restriction-modification (RM) systems encoded by the bacteria produced distinctive methylation profiles that were used to accurately bin and classify metagenomic sequences. Using this approach, we finished the largest and most complex circularized bacterial genome ever recovered from a metagenome (7.9 Mb with >600 transposons), the finished genome of Thiohalocapsa sp. PB-PSB1 the dominant bacteria in the consortia. From genomes binned by methylation patterns, we identified instances of horizontal gene transfer between sulfur-cycling symbionts (Thiohalocapsa sp. PB-PSB1 and Desulfofustis sp. PB-SRB1), phage infection, and strain-level structural variation. We also linked the methylation patterns of each metagenome-assembled genome with encoded DNA methyltransferases and discovered new RM defense systems, including novel associations of RM systems with RNase toxins.
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20
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Preska Steinberg A, Lin M, Kussell E. Core genes can have higher recombination rates than accessory genes within global microbial populations. eLife 2022; 11:78533. [PMID: 35801696 PMCID: PMC9444244 DOI: 10.7554/elife.78533] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 06/30/2022] [Indexed: 11/24/2022] Open
Abstract
Recombination is essential to microbial evolution, and is involved in the spread of antibiotic resistance, antigenic variation, and adaptation to the host niche. However, assessing the impact of homologous recombination on accessory genes which are only present in a subset of strains of a given species remains challenging due to their complex phylogenetic relationships. Quantifying homologous recombination for accessory genes (which are important for niche-specific adaptations) in comparison to core genes (which are present in all strains and have essential functions) is critical to understanding how selection acts on variation to shape species diversity and genome structures of bacteria. Here, we apply a computationally efficient, non-phylogenetic approach to measure homologous recombination rates in the core and accessory genome using >100,000 whole genome sequences from Streptococcus pneumoniae and several additional species. By analyzing diverse sets of sequence clusters, we show that core genes often have higher recombination rates than accessory genes, and for some bacterial species the associated effect sizes for these differences are pronounced. In a subset of species, we find that gene frequency and homologous recombination rate are positively correlated. For S. pneumoniae and several additional species, we find that while the recombination rate is higher for the core genome, the mutational divergence is lower, indicating that divergence-based homologous recombination barriers could contribute to differences in recombination rates between the core and accessory genome. Homologous recombination may therefore play a key role in increasing the efficiency of selection in the most conserved parts of the genome.
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Affiliation(s)
| | - Mingzhi Lin
- Department of Biology, New York University, New York, United States
| | - Edo Kussell
- Department of Biology, New York University, New York, United States
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21
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Tempel S, Bedo J, Talla E. From a large-scale genomic analysis of insertion sequences to insights into their regulatory roles in prokaryotes. BMC Genomics 2022; 23:451. [PMID: 35725380 PMCID: PMC9208149 DOI: 10.1186/s12864-022-08678-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 06/07/2022] [Indexed: 12/03/2022] Open
Abstract
Background Insertion sequences (ISs) are mobile repeat sequences and most of them can copy themselves to new host genome locations, leading to genome plasticity and gene regulation in prokaryotes. In this study, we present functional and evolutionary relationships between IS and neighboring genes in a large-scale comparative genomic analysis. Results IS families were located in all prokaryotic phyla, with preferential occurrence of IS3, IS4, IS481, and IS5 families in Alpha-, Beta-, and Gammaproteobacteria, Actinobacteria and Firmicutes as well as in eukaryote host-associated organisms and autotrophic opportunistic pathogens. We defined the concept of the IS-Gene couple (IG), which allowed to highlight the functional and regulatory impacts of an IS on the closest gene. Genes involved in transcriptional regulation and transport activities were found overrepresented in IG. In particular, major facilitator superfamily (MFS) transporters, ATP-binding proteins and transposases raised as favorite neighboring gene functions of IS hotspots. Then, evolutionary conserved IS-Gene sets across taxonomic lineages enabled the classification of IS-gene couples into phylum, class-to-genus, and species syntenic IS-Gene couples. The IS5, IS21, IS4, IS607, IS91, ISL3 and IS200 families displayed two to four times more ISs in the phylum and/or class-to-genus syntenic IGs compared to other IS families. This indicates that those families were probably inserted earlier than others and then subjected to horizontal transfer, transposition and deletion events over time. In phylum syntenic IG category, Betaproteobacteria, Crenarchaeota, Calditrichae, Planctomycetes, Acidithiobacillia and Cyanobacteria phyla act as IS reservoirs for other phyla, and neighboring gene functions are mostly related to transcriptional regulators. Comparison of IS occurrences with predicted regulatory motifs led to ~ 26.5% of motif-containing ISs with 2 motifs per IS in average. These results, concomitantly with short IS-Gene distances, suggest that those ISs would interfere with the expression of neighboring genes and thus form strong candidates for an adaptive pairing. Conclusions All together, our large-scale study provide new insights into the IS genetic context and strongly suggest their regulatory roles. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-022-08678-3.
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Affiliation(s)
- Sebastien Tempel
- Aix Marseille University, CNRS, LCB, Laboratoire de Chimie Bactérienne, 13009, Marseille, France.
| | - Justin Bedo
- Bioinformatics Division, the Walter and Eliza Hall Institute, 1G Royal Parade, Parkville, VIC, 3052, Australia.,School of Computing and Information Systems, the University of Melbourne, Parkville, VIC, 3010, Australia
| | - Emmanuel Talla
- Aix Marseille University, CNRS, LCB, Laboratoire de Chimie Bactérienne, 13009, Marseille, France.
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22
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Khedkar S, Smyshlyaev G, Letunic I, Maistrenko OM, Coelho LP, Orakov A, Forslund SK, Hildebrand F, Luetge M, Schmidt TSB, Barabas O, Bork P. Landscape of mobile genetic elements and their antibiotic resistance cargo in prokaryotic genomes. Nucleic Acids Res 2022; 50:3155-3168. [PMID: 35323968 PMCID: PMC8989519 DOI: 10.1093/nar/gkac163] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 01/30/2022] [Accepted: 03/11/2022] [Indexed: 12/02/2022] Open
Abstract
Prokaryotic Mobile Genetic Elements (MGEs) such as transposons, integrons, phages and plasmids, play important roles in prokaryotic evolution and in the dispersal of cargo functions like antibiotic resistance. However, each of these MGE types is usually annotated and analysed individually, hampering a global understanding of phylogenetic and environmental patterns of MGE dispersal. We thus developed a computational framework that captures diverse MGE types, their cargos and MGE-mediated horizontal transfer events, using recombinases as ubiquitous MGE marker genes and pangenome information for MGE boundary estimation. Applied to ∼84k genomes with habitat annotation, we mapped 2.8 million MGE-specific recombinases to six operational MGE types, which together contain on average 13% of all the genes in a genome. Transposable elements (TEs) dominated across all taxa (∼1.7 million occurrences), outnumbering phages and phage-like elements (<0.4 million). We recorded numerous MGE-mediated horizontal transfer events across diverse phyla and habitats involving all MGE types, disentangled and quantified the extent of hitchhiking of TEs (17%) and integrons (63%) with other MGE categories, and established TEs as dominant carriers of antibiotic resistance genes. We integrated all these findings into a resource (proMGE.embl.de), which should facilitate future studies on the large mobile part of genomes and its horizontal dispersal.
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Affiliation(s)
- Supriya Khedkar
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, 69117 Heidelberg, Germany
| | - Georgy Smyshlyaev
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, 69117 Heidelberg, Germany.,Department of Molecular Biology, University of Geneva, 1211 Geneva, Switzerland
| | - Ivica Letunic
- Biobyte solutions GmbH, Bothestr 142, 69117 Heidelberg, Germany
| | - Oleksandr M Maistrenko
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, 69117 Heidelberg, Germany
| | - Luis Pedro Coelho
- Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai 200433, China
| | - Askarbek Orakov
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, 69117 Heidelberg, Germany
| | - Sofia K Forslund
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, 69117 Heidelberg, Germany.,Max Delbrück Centre for Molecular Medicine, Berlin, Germany.,Experimental and Clinical Research Center, Charité-Universitätsmedizin and Max-Delbrück Center, Berlin, Germany.,Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Falk Hildebrand
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, 69117 Heidelberg, Germany
| | - Mechthild Luetge
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, 69117 Heidelberg, Germany
| | - Thomas S B Schmidt
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, 69117 Heidelberg, Germany
| | - Orsolya Barabas
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, 69117 Heidelberg, Germany.,Department of Molecular Biology, University of Geneva, 1211 Geneva, Switzerland
| | - Peer Bork
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, 69117 Heidelberg, Germany.,Max Delbrück Centre for Molecular Medicine, Berlin, Germany.,Department of Bioinformatics, Biocenter, University of Würzburg, Würzburg, Germany.,Yonsei Frontier Lab (YFL), Yonsei University, Seoul 03722, South Korea
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23
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Lin X, McNichol J, Chu X, Qian Y, Luo H. Cryptic niche differentiation of novel sediment ecotypes of Rugeria pomeroyi correlates with nitrate respiration. Environ Microbiol 2021; 24:390-403. [PMID: 34964547 DOI: 10.1111/1462-2920.15882] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 12/16/2021] [Accepted: 12/18/2021] [Indexed: 10/19/2022]
Abstract
Marine intertidal sediments fluctuate in redox conditions and nutrient availability, and they are also known as an important sink of nitrogen mainly through denitrification, yet how denitrifying bacteria adapt to this dynamic habitat remains largely untapped. Here, we investigated novel intertidal benthic ecotypes of the model pelagic marine bacterium Ruegeria pomeroyi DSS-3 with a population genomic approach. While differing by only 1.3% at the 16S rRNA gene level, members of the intertidal benthic ecotypes are complete denitrifiers whereas the pelagic ecotype representative (DSS-3) is a partial denitrifier lacking a nitrate reductase. The intertidal benthic ecotypes are further differentiated by using non-homologous nitrate reductases and a different set of genes that allow alleviating oxidative stress and acquiring organic substrates. In the presence of nitrate, the two ecotypes showed contrasting growth patterns under initial oxygen concentrations at 1 vol% versus 7 vol% and supplemented with different carbon sources abundant in intertidal sediments. Collectively, this combination of evidence indicates that there are cryptic niches in coastal intertidal sediments that support divergent evolution of denitrifying bacteria. This knowledge will in turn help understand how these benthic environments operate to effectively remove nitrogen.
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Affiliation(s)
- Xingqin Lin
- Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, 518000, China
| | - Jesse McNichol
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Xiao Chu
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Yang Qian
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Haiwei Luo
- Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, 518000, China.,Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
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24
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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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25
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Calland JK, Pascoe B, Bayliss SC, Mourkas E, Berthenet E, Thorpe HA, Hitchings MD, Feil EJ, Corander J, Blaser MJ, Falush D, Sheppard SK. Quantifying bacterial evolution in the wild: A birthday problem for Campylobacter lineages. PLoS Genet 2021; 17:e1009829. [PMID: 34582435 PMCID: PMC8500405 DOI: 10.1371/journal.pgen.1009829] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 10/08/2021] [Accepted: 09/20/2021] [Indexed: 11/20/2022] Open
Abstract
Measuring molecular evolution in bacteria typically requires estimation of the rate at which nucleotide changes accumulate in strains sampled at different times that share a common ancestor. This approach has been useful for dating ecological and evolutionary events that coincide with the emergence of important lineages, such as outbreak strains and obligate human pathogens. However, in multi-host (niche) transmission scenarios, where the pathogen is essentially an opportunistic environmental organism, sampling is often sporadic and rarely reflects the overall population, particularly when concentrated on clinical isolates. This means that approaches that assume recent common ancestry are not applicable. Here we present a new approach to estimate the molecular clock rate in Campylobacter that draws on the popular probability conundrum known as the 'birthday problem'. Using large genomic datasets and comparative genomic approaches, we use isolate pairs that share recent common ancestry to estimate the rate of nucleotide change for the population. Identifying synonymous and non-synonymous nucleotide changes, both within and outside of recombined regions of the genome, we quantify clock-like diversification to estimate synonymous rates of nucleotide change for the common pathogenic bacteria Campylobacter coli (2.4 x 10-6 s/s/y) and Campylobacter jejuni (3.4 x 10-6 s/s/y). Finally, using estimated total rates of nucleotide change, we infer the number of effective lineages within the sample time frame-analogous to a shared birthday-and assess the rate of turnover of lineages in our sample set over short evolutionary timescales. This provides a generalizable approach to calibrating rates in populations of environmental bacteria and shows that multiple lineages are maintained, implying that large-scale clonal sweeps may take hundreds of years or more in these species.
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Affiliation(s)
- Jessica K. Calland
- The Milner Centre for Evolution, University of Bath, Bath, United Kingdom
| | - Ben Pascoe
- The Milner Centre for Evolution, University of Bath, Bath, United Kingdom
| | - Sion C. Bayliss
- The Milner Centre for Evolution, University of Bath, Bath, United Kingdom
| | - Evangelos Mourkas
- The Milner Centre for Evolution, University of Bath, Bath, United Kingdom
| | - Elvire Berthenet
- French National Reference Center for Campylobacters and Helicobacters, University of Bordeaux, Bordeaux, France
- Institute of Life Sciences, Swansea University Medical School, Swansea University, Singleton Park, Swansea, United Kingdom
| | - Harry A. Thorpe
- The Milner Centre for Evolution, University of Bath, Bath, United Kingdom
- Department of Biostatistics, University of Oslo, Oslo, Norway
| | - Matthew D. Hitchings
- Institute of Life Sciences, Swansea University Medical School, Swansea University, Singleton Park, Swansea, United Kingdom
| | - Edward J. Feil
- The Milner Centre for Evolution, University of Bath, Bath, United Kingdom
| | - Jukka Corander
- Department of Biostatistics, University of Oslo, Oslo, Norway
- Department of Mathematics and Statistics, Helsinki Institute for Information Technology, University of Helsinki, Helsinki, Finland
- Parasites and Microbes, Wellcome Sanger Institute, Cambridge, United Kingdom
| | - Martin J. Blaser
- Center for Advanced Biotechnology and Medicine, Rutgers University, New Brunswick, New Jersey, United States of America
| | - Daniel Falush
- Centre for Microbes, Development and Health, Institute Pasteur of Shanghai, Shanghai, China
- * E-mail: (DF); (SKS)
| | - Samuel K. Sheppard
- The Milner Centre for Evolution, University of Bath, Bath, United Kingdom
- Department of Zoology, University of Oxford, Oxford, United Kingdom
- * E-mail: (DF); (SKS)
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26
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Multilocus sequence analysis reveals genetic diversity in Staphylococcus aureus isolate of goat with mastitis persistent after treatment with enrofloxacin. Sci Rep 2021; 11:17252. [PMID: 34446803 PMCID: PMC8390490 DOI: 10.1038/s41598-021-96764-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 07/28/2021] [Indexed: 02/07/2023] Open
Abstract
Staphylococcus aureus is one of the main bacterial agents responsible for cases of mastitis in ruminants, playing an important role in the persistence and chronicity of diseases treated with antimicrobials. Using the multilocus sequence typing technique, network approaches and study of the population diversity of microorganisms, we performed analyzes of S. aureus (ES-GPM) isolated from goats with persistent mastitis (GPM). The most strains of ES-GPM were categorically different phylogenetically from the others and could be divided into two lineages: one with a majority belonging to ES-GPM and the other to varied strains. These two lineages were separated by 27 nuclear polymorphisms. The 43 strains comprised 22 clonal complexes (CCs), of which the ES-GPM strains were present in CC133, CC5 and a new complex formed by the sequence type 4966. The genetic diversity of some alleles showed be greater diversity and polymorphism than others, such as of the aroE and yqiL genes less than glpF gene. In addition, the sequences ES-GPM to the arc gene and glpF alleles showed the greatest number of mutations for ES-GPM in relation to non-ES-GPM. Therefore, this study identified genetic polymorphisms characteristic of S. aureus isolated from milk of goats diagnosed with persistent mastitis after the failed treatment with the antibiotic enrofloxacin. This study may help in the future to identify and discriminate this agent in cases of mastitis, and with that, the most appropriate antibiotic treatment can be performed in advance of the appearance of persistent mastitis caused by the agent, reducing the chances of premature culling and animal suffering.
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27
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Matteoli FP, Pedrosa-Silva F, Dutra-Silva L, Giachini AJ. The global population structure and beta-lactamase repertoire of the opportunistic pathogen Serratia marcescens. Genomics 2021; 113:3523-3532. [PMID: 34400240 DOI: 10.1016/j.ygeno.2021.08.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 07/15/2021] [Accepted: 08/11/2021] [Indexed: 11/26/2022]
Abstract
Serratia marcescens is a global spread nosocomial pathogen. This rod-shaped bacterium displays a broad host range and worldwide geographical distribution. Here we analyze an international collection of this multidrug-resistant, opportunistic pathogen from 35 countries to infer its population structure. We show that S. marcescens comprises 12 lineages; Sm1, Sm4, and Sm10 harbor 78.3% of the known environmental strains. Sm5, Sm6, and Sm7 comprise only human-associated strains which harbor smallest pangenomes, genomic fluidity and lowest levels of core recombination, indicating niche specialization. Sm7 and Sm9 lineages exhibit the most concerning resistome; blaKPC-2 plasmid is widespread in Sm7, whereas Sm9, also an anthropogenic-exclusive lineage, presents highest plasmid/lineage size ratio and plasmid-diversity encoding metallo-beta-lactamases comprising blaNDM-1. The heterogeneity of resistance patterns of S. marcescens lineages elucidated herein highlights the relevance of surveillance programs, using whole-genome sequencing, to provide insights into the molecular epidemiology of carbapenemase producing strains of this species.
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28
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Characterizing a novel SCC mec with a composite structure from a clinical strain of Staphylococcus hominis, C34847. Antimicrob Agents Chemother 2021; 65:e0077721. [PMID: 34370581 DOI: 10.1128/aac.00777-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Staphylococcal cassette chromosome mec (SCCmec) has predominantly been described in methicillin-resistant Staphylococcus aureus. However, studies have indicated that coagulase-negative staphylococci (CoNS) carry a larger diversity of SCC elements. We characterized a composite SCCmec element carrying an uncharacterized ccr1 and type A mec gene combination, in conjunction with a secondary element bearing ccr4, from a clinical strain of S. hominis. The element's complex structure points to a high degree of recombination occurring in SCCmec in CoNS.
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29
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Rai A, Khairnar K. Overview of the risks of Staphylococcus aureus infections and their control by bacteriophages and bacteriophage-encoded products. Braz J Microbiol 2021; 52:2031-2042. [PMID: 34251609 DOI: 10.1007/s42770-021-00566-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 06/29/2021] [Indexed: 12/17/2022] Open
Abstract
Staphylococcus aureus is the leading cause of secondary infections in hospitals and a challenging pathogen in food industries. Decades after it was first reported, β-lactam-resistant S. aureus remains a subject of intense research owing to the ever-increasing issue of drug resistance. S. aureus bacteriophages (phages) or their encoded products are considered an alternative to antibiotics as they have been shown to be effective in treating some S. aureus-associated infections. In this review, we present a concise collection of the literature on the pathogenic potential of S. aureus and examine the prospects of using S. aureus phages and their encoded products as antimicrobials.
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Affiliation(s)
- Akanksha Rai
- Environmental Virology Cell, Council of Scientific and Industrial Research-National Environmental Engineering Research Institute (CSIR NEERI), Nehru Marg, Nagpur, 440020, Maharashtra, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, Uttar Pradesh, India
| | - Krishna Khairnar
- Environmental Virology Cell, Council of Scientific and Industrial Research-National Environmental Engineering Research Institute (CSIR NEERI), Nehru Marg, Nagpur, 440020, Maharashtra, India. .,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, Uttar Pradesh, India.
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The Phosphoarginine Phosphatase PtpB from Staphylococcus aureus Is Involved in Bacterial Stress Adaptation during Infection. Cells 2021; 10:cells10030645. [PMID: 33799337 PMCID: PMC8001253 DOI: 10.3390/cells10030645] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 03/11/2021] [Accepted: 03/12/2021] [Indexed: 01/18/2023] Open
Abstract
Staphylococcus aureus continues to be a public health threat, especially in hospital settings. Studies aimed at deciphering the molecular and cellular mechanisms that underlie pathogenesis, host adaptation, and virulence are required to develop effective treatment strategies. Numerous host-pathogen interactions were found to be dependent on phosphatases-mediated regulation. This study focused on the analysis of the role of the low-molecular weight phosphatase PtpB, in particular, during infection. Deletion of ptpB in S. aureus strain SA564 significantly reduced the capacity of the mutant to withstand intracellular killing by THP-1 macrophages. When injected into normoglycemic C57BL/6 mice, the SA564 ΔptpB mutant displayed markedly reduced bacterial loads in liver and kidney tissues in a murine S. aureus abscess model when compared to the wild type. We also observed that PtpB phosphatase-activity was sensitive to oxidative stress. Our quantitative transcript analyses revealed that PtpB affects the transcription of various genes involved in oxidative stress adaptation and infectivity. Thus, this study disclosed first insights into the physiological role of PtpB during host interaction allowing us to link phosphatase-dependent regulation to oxidative bacterial stress adaptation during infection.
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Thomas A, Chothe S, Byukusenge M, Mathews T, Pierre T, Kariyawasam S, Luley E, Kuchipudi S, Jayarao B. Prevalence and distribution of multilocus sequence types of Staphylococcus aureus isolated from bulk tank milk and cows with mastitis in Pennsylvania. PLoS One 2021; 16:e0248528. [PMID: 33711052 PMCID: PMC7954355 DOI: 10.1371/journal.pone.0248528] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 02/26/2021] [Indexed: 11/19/2022] Open
Abstract
A total of 163 S. aureus isolates; 113 from mastitic milk (MM) and 50 from bulk tank milk (BTM) (2008, 2013–2015) submitted for bacteriologic analysis at the Penn State Animal Diagnostic Laboratory were examined for their phenotypic and genotypic characteristics. Multi-locus sequence typing (MLST) analysis identified 16 unique sequence types (STs) which belonged to eight clonal complexes (CCs). Majority of the isolates were variants of CC97 (68.7%) and CC151 (25.1%). CC97 comprised of seven STs, of which two were new STs (ST3273, ST3274), while CC151 comprised of three STs of which ST3272 was identified for the first time. Several farms had more than one ST type that were either members of the same clonal complex or unrelated STs. On one farm, six different STs of both categories were seen over the years within the farm. It was observed that ST352 and ST151 were the two main clonal populations in cattle not only in Pennsylvania but also globally. Most isolates were susceptible to all the antibiotics evaluated. 6.7% of isolates showed resistance to vancomycin and penicillin. Two isolates of ST398 showed multidrug resistance (>3 antibiotics) against clindamycin, erythromycin, tetracycline, and penicillin. It was noted that 59 of 163 (36.2%) isolates encoded for enterotoxigenic genes. Enterotoxin genes seg/sei accounted for ~85% of enterotoxin positive isolates. Toxic shock syndrome gene tsst-1 alone was positive in two isolates (ST352, ST 2187). 97.5% of CC151 isolates were enterotoxin seg/sei positive. Most isolates were positive for lukED (95%) and lukAB (96.3%) leukotoxin genes. Bovine specific bi-component leucocidin lukMF’ was present in 54% of isolates. A prominent observation of this study was the explicit association of lukMF’ with lineages ST151 and ST352. In conclusion, the findings of the study, suggest that small number of S. aureus STs types (ST352, ST2187, ST3028, and ST151) are associated with majority of cases of bovine mastitis in Pennsylvania dairy farms. It was observed that one ST of S. aureus predominated in the herd and this ST can coexist with several other ST types of S. aureus strains. When STs were interpreted along with virulence, leucocidin genes and antimicrobial resistance, ST-variants allowed better interpretation of the S. aureus molecular epidemiologic findings specifically for tracing recurrence or persistence of infections in cow over time, among cows in the herd, and between herds in Pennsylvania.
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Affiliation(s)
- Asha Thomas
- Penn State Animal Diagnostic Laboratory, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Shubhada Chothe
- Penn State Animal Diagnostic Laboratory, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Maurice Byukusenge
- Penn State Animal Diagnostic Laboratory, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Tammy Mathews
- Penn State Animal Diagnostic Laboratory, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Traci Pierre
- Penn State Animal Diagnostic Laboratory, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Subhashinie Kariyawasam
- Penn State Animal Diagnostic Laboratory, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Erin Luley
- Penn State Animal Diagnostic Laboratory, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Suresh Kuchipudi
- Penn State Animal Diagnostic Laboratory, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Bhushan Jayarao
- Penn State Animal Diagnostic Laboratory, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- * E-mail:
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Moller AG, Winston K, Ji S, Wang J, Hargita Davis MN, Solís-Lemus CR, Read TD. Genes Influencing Phage Host Range in Staphylococcus aureus on a Species-Wide Scale. mSphere 2021; 6:e01263-20. [PMID: 33441407 PMCID: PMC7845607 DOI: 10.1128/msphere.01263-20] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 12/16/2020] [Indexed: 12/20/2022] Open
Abstract
Staphylococcus aureus is a human pathogen that causes serious diseases, ranging from skin infections to septic shock. Bacteriophages (phages) are both natural killers of S. aureus, offering therapeutic possibilities, and important vectors of horizontal gene transfer (HGT) in the species. Here, we used high-throughput approaches to understand the genetic basis of strain-to-strain variation in sensitivity to phages, which defines the host range. We screened 259 diverse S. aureus strains covering more than 40 sequence types for sensitivity to eight phages, which were representatives of the three phage classes that infect the species. The phages were variable in host range, each infecting between 73 and 257 strains. Using genome-wide association approaches, we identified putative loci that affect host range and validated their function using USA300 transposon knockouts. In addition to rediscovering known host range determinants, we found several previously unreported genes affecting bacterial growth during phage infection, including trpA, phoR, isdB, sodM, fmtC, and relA We used the data from our host range matrix to develop predictive models that achieved between 40% and 95% accuracy. This work illustrates the complexity of the genetic basis for phage susceptibility in S. aureus but also shows that with more data, we may be able to understand much of the variation. With a knowledge of host range determination, we can rationally design phage therapy cocktails that target the broadest host range of S. aureus strains and address basic questions regarding phage-host interactions, such as the impact of phage on S. aureus evolution.IMPORTANCEStaphylococcus aureus is a widespread, hospital- and community-acquired pathogen, many strains of which are antibiotic resistant. It causes diverse diseases, ranging from local to systemic infection, and affects both the skin and many internal organs, including the heart, lungs, bones, and brain. Its ubiquity, antibiotic resistance, and disease burden make new therapies urgent. One alternative therapy to antibiotics is phage therapy, in which viruses specific to infecting bacteria clear infection. In this work, we identified and validated S. aureus genes that influence phage host range-the number of strains a phage can infect and kill-by testing strains representative of the diversity of the S. aureus species for phage host range and associating the genome sequences of strains with host range. These findings together improved our understanding of how phage therapy works in the bacterium and improve prediction of phage therapy efficacy based on the predicted host range of the infecting strain.
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Affiliation(s)
- Abraham G Moller
- Microbiology and Molecular Genetics (MMG) Program, Graduate Division of Biological and Biomedical Sciences (GDBBS), Emory University, Atlanta, Georgia, USA
- Division of Infectious Diseases, Department of Medicine, Emory University, Atlanta, Georgia, USA
| | - Kyle Winston
- Department of Epidemiology, Rollins School of Public Health (RSPH), Emory University, Atlanta, Georgia, USA
| | - Shiyu Ji
- Eugene Gangarosa Laboratory Research Fellowship, Emory College Online & Summer Programs, Emory College of Arts and Sciences, Atlanta, Georgia, USA
| | - Junting Wang
- Department of Statistics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Michelle N Hargita Davis
- Division of Infectious Diseases, Department of Medicine, Emory University, Atlanta, Georgia, USA
| | - Claudia R Solís-Lemus
- Wisconsin Institute for Discovery, Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Timothy D Read
- Division of Infectious Diseases, Department of Medicine, Emory University, Atlanta, Georgia, USA
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Global Epidemiology and Evolutionary History of Staphylococcus aureus ST45. J Clin Microbiol 2020; 59:JCM.02198-20. [PMID: 33087430 DOI: 10.1128/jcm.02198-20] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 10/14/2020] [Indexed: 12/19/2022] Open
Abstract
Staphylococcus aureus ST45 is a major global MRSA lineage with huge strain diversity and a high clinical impact. It is one of the most prevalent carrier lineages but also frequently causes severe invasive disease, such as bacteremia. Little is known about its evolutionary history. In this study, we used whole-genome sequencing to analyze a large collection of 451 diverse ST45 isolates from 6 continents and 26 countries. De novo-assembled genomes were used to understand genomic plasticity and to perform coalescent analyses. The ST45 population contained two distinct sublineages, which correlated with the isolates' geographical origins. One sublineage primarily consisted of European/North American isolates, while the second sublineage primarily consisted of African and Australian isolates. Bayesian analysis predicted ST45 originated in northwestern Europe about 500 years ago. Isolation time, host, and clinical symptoms did not correlate with phylogenetic groups. Our phylogenetic analyses suggest multiple acquisitions of the SCCmec element and key virulence factors throughout the evolution of the ST45 lineage.
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Stott CM, Bobay LM. Impact of homologous recombination on core genome phylogenies. BMC Genomics 2020; 21:829. [PMID: 33238876 PMCID: PMC7691112 DOI: 10.1186/s12864-020-07262-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 11/19/2020] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Core genome phylogenies are widely used to build the evolutionary history of individual prokaryote species. By using hundreds or thousands of shared genes, these approaches are the gold standard to reconstruct the relationships of large sets of strains. However, there is growing evidence that bacterial strains exchange DNA through homologous recombination at rates that vary widely across prokaryote species, indicating that core genome phylogenies might not be able to reconstruct true phylogenies when recombination rate is high. Few attempts have been made to evaluate the robustness of core genome phylogenies to recombination, but some analyses suggest that reconstructed trees are not always accurate. RESULTS In this study, we tested the robustness of core genome phylogenies to various levels of recombination rates. By analyzing simulated and empirical data, we observed that core genome phylogenies are relatively robust to recombination rates; nevertheless, our results suggest that many reconstructed trees are not completely accurate even when bootstrap supports are high. We found that some core genome phylogenies are highly robust to recombination whereas others are strongly impacted by it, and we identified that the robustness of core genome phylogenies to recombination is highly linked to the levels of selective pressures acting on a species. Stronger selective pressures lead to less accurate tree reconstructions, presumably because selective pressures more strongly bias the routes of DNA transfers, thereby causing phylogenetic artifacts. CONCLUSIONS Overall, these results have important implications for the application of core genome phylogenies in prokaryotes.
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Affiliation(s)
- Caroline M Stott
- Department of Biology, University of North Carolina Greensboro, 321 McIver Street, PO Box 26170, Greensboro, NC, 27402, USA
| | - Louis-Marie Bobay
- Department of Biology, University of North Carolina Greensboro, 321 McIver Street, PO Box 26170, Greensboro, NC, 27402, USA.
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Staphylococcal Protein A ( spa) Locus Is a Hot Spot for Recombination and Horizontal Gene Transfer in Staphylococcus pseudintermedius. mSphere 2020; 5:5/5/e00666-20. [PMID: 33115833 PMCID: PMC7593597 DOI: 10.1128/msphere.00666-20] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus pseudintermedius is a major canine pathogen but can also occasionally infect humans. Identification of genetic factors contributing to the virulence and clonal success of multidrug-resistant S. pseudintermedius clones is critical for the development of therapeutics against this pathogen. Here, we characterized the genome sequences of a global collection of 622 S. pseudintermedius isolates. We show that all major clones, besides carrying core virulence genes, which are present in all strains, carry one or more lineage-specific genes. Many of these genes have been acquired from other bacterial species through a horizontal gene transfer mechanism. Importantly, we have discovered that the staphylococcal protein A gene (spa), a widely used marker for molecular typing of S. pseudintermedius strains and a potential vaccine candidate antigen, is deleted in 62% of strains. Furthermore, the spa locus in S. pseudintermedius acts as a reservoir to accumulate lineage-associated genes with adaptive functions. Staphylococcus pseudintermedius is a major canine pathogen but also occasionally colonizes and infects humans. Multidrug-resistant methicillin-resistant S. pseudintermedius (MDR MRSP) strains have emerged globally, making treatment and control of this pathogen challenging. Sequence type 71 (ST71), ST68, and ST45 are the most widespread and successful MDR MRSP clones. The potential genetic factors underlying the clonal success of these and other predominant clones remain unknown. Characterization of the pangenome, lineage-associated accessory genes, and genes acquired through horizontal gene transfer from other bacteria is important for identifying such factors. Here, we analyzed genome sequence data from 622 S. pseudintermedius isolates to investigate the evolution of pathogenicity across lineages. We show that the predominant clones carry one or more lineage-associated virulence genes. The gene encoding staphylococcal protein A (SpA), a key virulence factor involved in immune evasion and a potential vaccine antigen, is deleted in 62% of isolates. Most importantly, we have discovered that the spa locus is a hot spot for recombination and horizontal gene transfer in S. pseudintermedius, where genes related to restriction modification, prophage immunity, mercury resistance, and nucleotide and carbohydrate metabolism have been acquired in different lineages. Our study also establishes that ST45 is composed of two distinct sublineages that differ in their accessory gene content and virulence potential. Collectively, this study reports several previously undetected lineage-associated genetic factors that may have a role in the clonal success of the major MDR MRSP clones. These data provide a framework for future experimental studies on S. pseudintermedius pathogenesis and for developing novel therapeutics against this pathogen. IMPORTANCEStaphylococcus pseudintermedius is a major canine pathogen but can also occasionally infect humans. Identification of genetic factors contributing to the virulence and clonal success of multidrug-resistant S. pseudintermedius clones is critical for the development of therapeutics against this pathogen. Here, we characterized the genome sequences of a global collection of 622 S. pseudintermedius isolates. We show that all major clones, besides carrying core virulence genes, which are present in all strains, carry one or more lineage-specific genes. Many of these genes have been acquired from other bacterial species through a horizontal gene transfer mechanism. Importantly, we have discovered that the staphylococcal protein A gene (spa), a widely used marker for molecular typing of S. pseudintermedius strains and a potential vaccine candidate antigen, is deleted in 62% of strains. Furthermore, the spa locus in S. pseudintermedius acts as a reservoir to accumulate lineage-associated genes with adaptive functions.
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Gawlik D, Ruppelt-Lorz A, Müller E, Reißig A, Hotzel H, Braun SD, Söderquist B, Ziegler-Cordts A, Stein C, Pletz MW, Ehricht R, Monecke S. Molecular investigations on a chimeric strain of Staphylococcus aureus sequence type 80. PLoS One 2020; 15:e0232071. [PMID: 33052925 PMCID: PMC7556507 DOI: 10.1371/journal.pone.0232071] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 09/21/2020] [Indexed: 11/18/2022] Open
Abstract
A PVL-positive, methicillin-susceptible Staphylococcus aureus was cultured from pus from cervical lymphadenitis of a patient of East-African origin. Microarray hybridisation assigned the isolate to clonal complex (CC) 80 but revealed unusual features, including the presence of the ORF-CM14 enterotoxin homologue and of an ACME-III element as well as the absence of etD and edinB. The isolate was subjected to both, Illumina and Nanopore sequencing allowing characterisation of deviating regions within the strain´s genome. Atypical features of this strain were attributable to the presence of two genomic regions that originated from other S. aureus lineages and that comprised, respectively, 3% and 1.4% of the genome. One deviating region extended from walJ to sirB. It comprised ORF-CM14 and the ACME-III element. A homologous but larger fragment was also found in an atypical S. aureus CC1/ST567 strain whose lineage might have served as donor of this genomic region. This region itself is a chimera comprising fragments from CC1 as well as fragments of unknown origin. The other deviating region comprised the region from htsB to ecfA2, i.e., another 3% of the genome. It was very similar to CC1 sequences. Either this suggests an incorporation of CC1 DNA into the study strain, or alternatively a recombination event affecting “canonical” CC80. Thus, the study strain bears witness of several recombination events affecting supposedly core genomic genes. Although the exact mechanism is not yet clear, such chimerism seems to be an additional pathway in the evolution of S. aureus. This could facilitate also a transmission of virulence and resistance factors and therefore offer an additional evolutionary advantage.
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Affiliation(s)
- Darius Gawlik
- Institute of Infectious Diseases and Infection Control, University Hospital, Jena, Germany
- PTC—Phage Technology Center GmbH, Bönen, Germany
| | - Antje Ruppelt-Lorz
- Institute for Medical Microbiology and Hygiene, Technical University of Dresden, Dresden, Germany
| | - Elke Müller
- Leibniz Institute of Photonic Technology (IPHT), Jena, Germany
- InfectoGnostics Research Campus, Jena, Germany
| | - Annett Reißig
- Leibniz Institute of Photonic Technology (IPHT), Jena, Germany
- InfectoGnostics Research Campus, Jena, Germany
| | - Helmut Hotzel
- Friedrich-Loeffler-Institut, Institute of Bacterial Infections and Zoonoses, Jena, Germany
| | - Sascha D. Braun
- Leibniz Institute of Photonic Technology (IPHT), Jena, Germany
- InfectoGnostics Research Campus, Jena, Germany
| | - Bo Söderquist
- School of Medical Sciences, Department of Laboratory Medicine, Clinical Microbiology, Faculty of Medicine and Health, Örebro University, Örebro, Sweden
| | | | - Claudia Stein
- Institute of Infectious Diseases and Infection Control, University Hospital, Jena, Germany
| | - Mathias W. Pletz
- Institute of Infectious Diseases and Infection Control, University Hospital, Jena, Germany
| | - Ralf Ehricht
- Leibniz Institute of Photonic Technology (IPHT), Jena, Germany
- InfectoGnostics Research Campus, Jena, Germany
- Institute of Physical Chemistry, Jena University, Jena, Germany
| | - Stefan Monecke
- Institute for Medical Microbiology and Hygiene, Technical University of Dresden, Dresden, Germany
- Leibniz Institute of Photonic Technology (IPHT), Jena, Germany
- InfectoGnostics Research Campus, Jena, Germany
- * E-mail:
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Mobile genetic elements responsible for discordant Staphylococcus aureus phenotypes and genotypes in the same blood culture bottle. Diagn Microbiol Infect Dis 2020; 98:115175. [PMID: 32947112 DOI: 10.1016/j.diagmicrobio.2020.115175] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 08/07/2020] [Accepted: 08/08/2020] [Indexed: 11/22/2022]
Abstract
Approximately 15-20% of the S. aureus genome contains mobile genetic elements that can cause discrepancies between phenotypic and genotypic identification methods. Three blood culture bottles (each from a different patient) that showed discordant results, were shown to contain 2 S. aureus isolates after additional subcultures. One bottle had MRSA and MSSA that by DNA sequence analysis differed only by 31 kb; however, the deletions encompassed parts of SCCmec including mecA and SCCM1. The second bottle contained MRSA and MSSA that differed by 124 kb; the MSSA was missing the entire SCCmec and spa regions. The last bottle contained 2 MRSA, one with ACME II disrupting SCCmec and a 24 bp spa deletion. The deletions in SCCmec and the other elements gave rise to the discrepancies between molecular and the original culture results. Such discrepancies should prompt a search for additional strains in the blood culture bottle.
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Papkou A, Hedge J, Kapel N, Young B, MacLean RC. Efflux pump activity potentiates the evolution of antibiotic resistance across S. aureus isolates. Nat Commun 2020; 11:3970. [PMID: 32769975 PMCID: PMC7414891 DOI: 10.1038/s41467-020-17735-y] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 07/14/2020] [Indexed: 11/23/2022] Open
Abstract
The rise of antibiotic resistance in many bacterial pathogens has been driven by the spread of a few successful strains, suggesting that some bacteria are genetically pre-disposed to evolving resistance. Here, we test this hypothesis by challenging a diverse set of 222 isolates of Staphylococcus aureus with the antibiotic ciprofloxacin in a large-scale evolution experiment. We find that a single efflux pump, norA, causes widespread variation in evolvability across isolates. Elevated norA expression potentiates evolution by increasing the fitness benefit provided by DNA topoisomerase mutations under ciprofloxacin treatment. Amplification of norA provides a further mechanism of rapid evolution in isolates from the CC398 lineage. Crucially, chemical inhibition of NorA effectively prevents the evolution of resistance in all isolates. Our study shows that pre-existing genetic diversity plays a key role in shaping resistance evolution, and it may be possible to predict which strains are likely to evolve resistance and to optimize inhibitor use to prevent this outcome.
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Affiliation(s)
- Andrei Papkou
- Department of Zoology, University of Oxford, 11a Mansfield Road, Oxford, OX1 3PS, UK.
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, Zurich, CH-8057, Switzerland.
| | - Jessica Hedge
- Department of Zoology, University of Oxford, 11a Mansfield Road, Oxford, OX1 3PS, UK
| | - Natalia Kapel
- Department of Zoology, University of Oxford, 11a Mansfield Road, Oxford, OX1 3PS, UK
| | - Bernadette Young
- Nuffield Department of Clinical Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DU, UK
| | - R Craig MacLean
- Department of Zoology, University of Oxford, 11a Mansfield Road, Oxford, OX1 3PS, UK.
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Burghard-Schrod M, Altenburger S, Graumann PL. The Bacillus subtilis dCMP deaminase ComEB acts as a dynamic polar localization factor for ComGA within the competence machinery. Mol Microbiol 2020; 113:906-922. [PMID: 31954084 DOI: 10.1111/mmi.14457] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 01/08/2020] [Accepted: 01/10/2020] [Indexed: 01/15/2023]
Abstract
Bacillus subtilis can import DNA from the environment by an uptake machinery that localizes to a single cell pole. We investigated the roles of ComEB and of the ATPase ComGA during the state of competence. We show that ComEB plays an important role during competence, possibly because it is necessary for the recruitment of GomGA to the cell pole. ComEB localizes to the cell poles even upon expression during exponential phase, indicating that it can serve as polar marker. ComEB is also a deoxycytidylate monophosphate (dCMP) deaminase, for the function of which a conserved cysteine residue is important. However, cysteine-mutant ComEB is still capable of natural transformation, while a comEB deletion strain is highly impaired in competence, indicating that ComEB confers two independent functions. Single-molecule tracking (SMT) reveals that both proteins exchange at the cell poles between bound and unbound in a time scale of a few milliseconds, but turnover of ComGA increases during DNA uptake, whereas the mobility of ComEB is not affected. Our data reveal a highly dynamic role of ComGA during DNA uptake and an unusual role for ComEB as a mediator of polar localization, localizing by diffusion-capture on an extremely rapid time scale and functioning as a moonlighting enzyme.
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Affiliation(s)
- Marie Burghard-Schrod
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Marburg, Germany.,Department of Chemistry, Philipps Universität Marburg, Marburg, Germany
| | - Stephan Altenburger
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Marburg, Germany.,Department of Chemistry, Philipps Universität Marburg, Marburg, Germany
| | - Peter L Graumann
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Marburg, Germany.,Department of Chemistry, Philipps Universität Marburg, Marburg, Germany
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Everitt RG, Culliford R, Medina-Aguayo F, Wilson DJ. Sequential Monte Carlo with transformations. STATISTICS AND COMPUTING 2019; 30:663-676. [PMID: 32116416 PMCID: PMC7026014 DOI: 10.1007/s11222-019-09903-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 09/03/2019] [Indexed: 06/10/2023]
Abstract
This paper examines methodology for performing Bayesian inference sequentially on a sequence of posteriors on spaces of different dimensions. For this, we use sequential Monte Carlo samplers, introducing the innovation of using deterministic transformations to move particles effectively between target distributions with different dimensions. This approach, combined with adaptive methods, yields an extremely flexible and general algorithm for Bayesian model comparison that is suitable for use in applications where the acceptance rate in reversible jump Markov chain Monte Carlo is low. We use this approach on model comparison for mixture models, and for inferring coalescent trees sequentially, as data arrives.
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Affiliation(s)
| | - Richard Culliford
- Department of Mathematics and Statistics, University of Reading, Reading, UK
| | | | - Daniel J. Wilson
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
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Comprehensive Analysis Reveals the Evolution and Pathogenicity of Aeromonas, Viewed from Both Single Isolated Species and Microbial Communities. mSystems 2019; 4:4/5/e00252-19. [PMID: 31641046 PMCID: PMC6811364 DOI: 10.1128/msystems.00252-19] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The genus Aeromonas is a common gastrointestinal pathogen associated with human and animal infections. Due to the high level of cross-species similarity, their evolutionary dynamics and genetic diversity are still fragmented. Hereby, we investigated the pan-genomes of 29 Aeromonas species, as well as Aeromonas species in microbial communities, to clarify their evolutionary dynamics and genetic diversity, with special focus on virulence factors and horizontal gene transfer events. Our study revealed an open pan-genome of Aeromonas containing 10,144 gene families. These Aeromonas species exhibited different functional constraints, with the single-copy core genes and most accessory genes experiencing purifying selection. The significant congruence between core genome and pan-genome trees revealed that core genes mainly affected evolutionary divergences of Aeromonas species. Gene gains and losses revealed a high level of genome plasticity, exhibited by hundreds of gene expansions and contractions, horizontally transferred genes, and mobile genetic elements. The selective constraints shaped virulence gene pools of these Aeromonas strains, where genes encoding hemolysin were ubiquitous. Of these strains, Aeromonas aquatica MX16A seemed to be more resistant, as it harbored most resistance genes. Finally, the virulence factors of Aeromonas in microbial communities were quite dynamic in response to environment changes. For example, the virulence diversity of Aeromonas in microbial communities could reach levels that match some of the most virulent Aeromonas species (such as A. hydrophila) in penetrated-air and modified-air packaging. Our work shed some light onto genetic diversity, evolutionary history, and functional features of Aeromonas, which could facilitate the detection and prevention of infections.IMPORTANCE Aeromonas has long been known as a gastrointestinal pathogen, yet it has many species whose evolutionary dynamics and genetic diversity had been unclear until now. We have conducted pan-genome analysis for 29 Aeromonas species and revealed a high level of genome plasticity exhibited by hundreds of gene expansions and contractions, horizontally transferred genes, and mobile genetic elements. These species also contained many virulence factors both identified from single isolated species and microbial community. This pan-genome study could elevate the level for detection and prevention of Aeromonas infections.
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Yano H, Suzuki H, Maruyama F, Iwamoto T. The recombination-cold region as an epidemiological marker of recombinogenic opportunistic pathogen Mycobacterium avium. BMC Genomics 2019; 20:752. [PMID: 31623552 PMCID: PMC6798384 DOI: 10.1186/s12864-019-6078-2] [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: 12/09/2018] [Accepted: 09/04/2019] [Indexed: 11/10/2022] Open
Abstract
Background The rapid identification of lineage remains a challenge in the genotyping of clinical isolates of recombinogenic pathogens. The chromosome of Mycobacterium avium subsp. hominissuis (MAH), an agent of Mycobacterium avium complex (MAC) lung disease, is often mosaic and is composed of chromosomal segments originating from different lineages. This makes it difficult to infer the MAH lineage in a simple experimental set-up. To overcome this difficulty, we sought to identify chromosomal marker genes containing lineage-specific alleles by genome data mining. Results We conducted genetic population structure analysis, phylogenetic analysis, and a survey of historical recombination using data from 125 global MAH isolates. Six MAH lineages (EA1, EA2, SC1, SC2, SC3, and SC4) were identified in the current dataset. One P-450 gene (locus_tag MAH_0788/MAV_0940) in the recombination-cold region was found to have multiple alleles that could discriminate five lineages. By combining the information about allele type from one additional gene, the six MAH lineages as well as other M. avium subspecies were distinguishable. A recombination-cold region of 116 kb contains an insertion hotspot and is flanked by a mammalian cell-entry protein operon where allelic variants have previously been reported to occur. Hence, we speculate that the acquisition of lineage- or strain-specific insertions has introduced homology breaks in the chromosome, thereby reducing the chance of interlineage recombination. Conclusions The allele types of the newly identified marker genes can be used to predict major lineages of M. avium. The single nucleotide polymorphism typing approach targeting multiallelic loci in recombination-cold regions will facilitate the epidemiological study of MAC, and may also be useful for equivalent studies of other nontuberculous mycobacteria potentially carrying mosaic genomes.
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Affiliation(s)
- Hirokazu Yano
- Graduate School of Life Sciences, Tohoku University, Katahira, Aoba-ku, Sendai, Japan.
| | - Haruo Suzuki
- Faculty of Environment and Information Studies, Keio University, Fujisawa, Japan
| | - Fumito Maruyama
- Office of Industry-Academia-Government and Community Collaboration, Hiroshima University, Hiroshima, Japan
| | - Tomotada Iwamoto
- Department of Infectious Diseases, Kobe Institute of Health, Kobe, Japan.
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Ding W, Baumdicker F, Neher RA. panX: pan-genome analysis and exploration. Nucleic Acids Res 2019; 46:e5. [PMID: 29077859 PMCID: PMC5758898 DOI: 10.1093/nar/gkx977] [Citation(s) in RCA: 143] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 10/10/2017] [Indexed: 11/24/2022] Open
Abstract
Horizontal transfer, gene loss, and duplication result in dynamic bacterial genomes shaped by a complex mixture of different modes of evolution. Closely related strains can differ in the presence or absence of many genes, and the total number of distinct genes found in a set of related isolates—the pan-genome—is often many times larger than the genome of individual isolates. We have developed a pipeline that efficiently identifies orthologous gene clusters in the pan-genome. This pipeline is coupled to a powerful yet easy-to-use web-based visualization for interactive exploration of the pan-genome. The visualization consists of connected components that allow rapid filtering and searching of genes and inspection of their evolutionary history. For each gene cluster, panX displays an alignment, a phylogenetic tree, maps mutations within that cluster to the branches of the tree and infers gain and loss of genes on the core-genome phylogeny. PanX is available at pangenome.de. Custom pan-genomes can be visualized either using a web server or by serving panX locally as a browser-based application.
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Affiliation(s)
- Wei Ding
- Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
| | - Franz Baumdicker
- Mathematisches Institut, Albert-Ludwigs University of Freiburg, 79104 Freiburg, Germany
| | - Richard A Neher
- Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany.,Biozentrum and SIB Swiss Institute of Bioinformatics, University of Basel, 4056 Basel, Switzerland
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44
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Azarian T, Ridgway JP, Yin Z, David MZ. Long-Term Intrahost Evolution of Methicillin Resistant Staphylococcus aureus Among Cystic Fibrosis Patients With Respiratory Carriage. Front Genet 2019; 10:546. [PMID: 31244886 PMCID: PMC6581716 DOI: 10.3389/fgene.2019.00546] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 05/22/2019] [Indexed: 12/29/2022] Open
Abstract
Staphylococcus aureus is the most commonly identified airway colonizer of cystic fibrosis (CF) patients, and infections with methicillin-resistant S. aureus (MRSA) are associated with poor outcomes. Yet, little is known about the intrahost evolution of S. aureus among CF patients. We investigated convergent evolution and adaptation of MRSA among four CF patients with long-term respiratory carriage. For each patient, we performed whole-genome sequencing on an average of 21 isolates (range: 19–23) carried for a mean of 1,403 days (range: 903–1,679), including 25 pairs of isolates collected on the same day. We assessed intrahost diversity, population structure, evolutionary history, evidence of switched intergenic regions (IGRs), and signatures of adaptation in the context of patient age, antibiotic treatment, and co-colonizing microbes. Phylogenetic analysis delineated distinct multilocus sequence type ST5 (n = 3) and ST72 (n = 1) clonal populations in addition to sporadic, non-clonal isolates, and uncovered a putative transmission event. Variation in antibiotic resistance was observed within clonal populations, even among isolates collected on the same day. Rates of molecular evolution ranged from 2.21 to 8.64 nucleotide polymorphisms per year, and lineage ages were consistent with acquisition of colonization in early childhood followed by subsequent persistence of multiple sub-populations. Selection analysis of 1,622 core genes present in all four clonal populations (n = 79) found 11 genes variable in three subjects – most notably, ATP-dependent protease clpX, 2-oxoglutarate dehydrogenase odhA, fmtC, and transcription-repair coupling factor mfd. Only one gene, staphylococcal protein A (spa), was found to have evidence of gene-wide diversifying selection. We identified three instances of intrahost IGR switching events, two of which flanked genes related to quorum sensing. The complex microbial ecology of the CF airway poses challenges for management. We illustrate appreciable intrahost diversity as well as persistence of a dominant lineage. We also show that intrahost adaptation is a continual process, despite purifying selective pressure, and provide targets that should be investigated further for their function in CF adaptation.
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Affiliation(s)
- Taj Azarian
- College of Medicine, University of Central Florida, Orlando, FL, United States
| | - Jessica P Ridgway
- Department of Medicine, University of Chicago, Chicago, IL, United States
| | - Zachary Yin
- Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia
| | - Michael Z David
- Department of Medicine, University of Pennsylvania, Philadelphia, PA, United States
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45
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Chen J, Quiles-Puchalt N, Chiang YN, Bacigalupe R, Fillol-Salom A, Chee MSJ, Fitzgerald JR, Penadés JR. Genome hypermobility by lateral transduction. Science 2018; 362:207-212. [PMID: 30309949 DOI: 10.1126/science.aat5867] [Citation(s) in RCA: 133] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 08/14/2018] [Indexed: 02/01/2023]
Abstract
Genetic transduction is a major evolutionary force that underlies bacterial adaptation. Here we report that the temperate bacteriophages of Staphylococcus aureus engage in a distinct form of transduction we term lateral transduction. Staphylococcal prophages do not follow the previously described excision-replication-packaging pathway but instead excise late in their lytic program. Here, DNA packaging initiates in situ from integrated prophages, and large metameric spans including several hundred kilobases of the S. aureus genome are packaged in phage heads at very high frequency. In situ replication before DNA packaging creates multiple prophage genomes so that lateral-transducing particles form during normal phage maturation, transforming parts of the S. aureus chromosome into hypermobile regions of gene transfer.
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Affiliation(s)
- John Chen
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 5 Science Drive 2, Singapore.
| | - Nuria Quiles-Puchalt
- Institute of Infection, Immunity, and Inflammation, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK
| | - Yin Ning Chiang
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 5 Science Drive 2, Singapore
| | - Rodrigo Bacigalupe
- The Roslin Institute, University of Edinburgh, Easter Bush Campus, Edinburgh EH25 9RG, UK
| | - Alfred Fillol-Salom
- Institute of Infection, Immunity, and Inflammation, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK
| | - Melissa Su Juan Chee
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 5 Science Drive 2, Singapore
| | - J Ross Fitzgerald
- The Roslin Institute, University of Edinburgh, Easter Bush Campus, Edinburgh EH25 9RG, UK
| | - José R Penadés
- Institute of Infection, Immunity, and Inflammation, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK. .,Departamento de Ciencias Biomédicas, Universidad CEU Cardenal Herrera, 46113 Moncada, Spain.,MRC-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, UK
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46
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Elshina E, Allen ER, Flaxman A, van Diemen PM, Milicic A, Rollier CS, Yamaguchi Y, Wyllie DH. Vaccination with the Staphylococcus aureus secreted proteins EapH1 and EapH2 impacts both S. aureus carriage and invasive disease. Vaccine 2018; 37:502-509. [PMID: 30502067 DOI: 10.1016/j.vaccine.2018.11.036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 11/02/2018] [Accepted: 11/13/2018] [Indexed: 12/15/2022]
Abstract
INTRODUCTION There is a need for an efficacious vaccine reducing infections due to Staphylococcus aureus, a common cause of community and hospital infection. Infecting organisms originate from S. aureus populations colonising the nares and bowel. Antimicrobials are widely used to transiently reduce S. aureus colonisation prior to surgery, a practice which is selecting for resistant S. aureus isolates. S. aureus secretes multiple proteins, including the protease inhibitors extracellular adhesion protein homologue 1 and 2 (EapH1 and EapH2). METHODS Mice were vaccinated intramuscularly or intranasally with Adenovirus serotype 5 and Modified Vaccinia Ankara viral vectors expressing EapH1 and EapH2 proteins, or with control viruses. Using murine S. aureus colonisation models, we monitored S. aureus colonisation by sequential stool sampling. Monitoring of S. aureus invasive disease after intravenous challenge was performed using bacterial load and abscess numbers in the kidney. RESULTS Intramuscular vaccination with Adenovirus serotype 5 and Modified Vaccinia Ankara viral vectors expressing EapH1 and EapH2 proteins significantly reduces bacterial recovery in the murine renal abscess model of infection, but the magnitude of the effect is small. A single intranasal vaccination with an adenoviral vaccine expressing these proteins reduced S. aureus gastrointestinal (GI) tract colonisation. CONCLUSION Vaccination against EapH1 / EapH2 proteins may offer an antibiotic independent way to reduce S. aureus colonisation, as well as contributing to protection against S. aureus invasive disease.
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Affiliation(s)
- Elizaveta Elshina
- Jenner Institute, Centre for Cellular and Molecular Physiology, University of Oxford, United Kingdom
| | - Elizabeth R Allen
- Jenner Institute, Centre for Cellular and Molecular Physiology, University of Oxford, United Kingdom
| | - Amy Flaxman
- Jenner Institute, Centre for Cellular and Molecular Physiology, University of Oxford, United Kingdom
| | - Pauline M van Diemen
- Jenner Institute, Centre for Cellular and Molecular Physiology, University of Oxford, United Kingdom
| | - Anita Milicic
- Jenner Institute, Centre for Cellular and Molecular Physiology, University of Oxford, United Kingdom
| | - Christine S Rollier
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and NIHR Oxford Biomedical Research Centre, Centre for Clinical Vaccinology and Tropical Medicine, University of Oxford, United Kingdom
| | - Yuko Yamaguchi
- Jenner Institute, Centre for Cellular and Molecular Physiology, University of Oxford, United Kingdom
| | - David H Wyllie
- Jenner Institute, Centre for Cellular and Molecular Physiology, University of Oxford, United Kingdom.
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47
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Lai YP, Ioerger TR. A statistical method to identify recombination in bacterial genomes based on SNP incompatibility. BMC Bioinformatics 2018; 19:450. [PMID: 30466385 PMCID: PMC6251179 DOI: 10.1186/s12859-018-2456-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 10/31/2018] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Phylogeny estimation for bacteria is likely to reflect their true evolutionary histories only if they are highly clonal. However, recombination events could occur during evolution for some species. The reconstruction of phylogenetic trees from an alignment without considering recombination could be misleading, since the relationships among strains in some parts of the genome might be different than in others. Using a single, global tree can create the appearance of homoplasy in recombined regions. Hence, the identification of recombination breakpoints is essential to better understand the evolutionary relationships of isolates among a bacterial population. RESULTS Previously, we have developed a method (called ACR) to detect potential breakpoints in an alignment by evaluating compatibility of polymorphic sites in a sliding window. To assess the statistical significance of candidate breakpoints, we propose an extension of the algorithm (ptACR) that applies a permutation test to generate a null distribution for comparing the average local compatibility. The performance of ptACR is evaluated on both simulated and empirical datasets. ptACR is shown to have similar sensitivity (true positive rate) but a lower false positive rate and higher F1 score compared to basic ACR. When used to analyze a collection of clinical isolates of Staphylococcus aureus, ptACR finds clear evidence of recombination events in this bacterial pathogen, and is able to identify statistically significant boundaries of chromosomal regions with distinct phylogenies. CONCLUSIONS ptACR is an accurate and efficient method for identifying genomic regions affected by recombination in bacterial genomes.
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Affiliation(s)
- Yi-Pin Lai
- Department of Computer Science & Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Thomas R Ioerger
- Department of Computer Science & Engineering, Texas A&M University, College Station, TX 77843, USA.
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48
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Danzmann RG, Norman JD, Rondeau EB, Messmer AM, Kent MP, Lien S, Igboeli O, Fast MD, Koop BF. A genetic linkage map for the salmon louse (Lepeophtheirus salmonis): evidence for high male:female and inter-familial recombination rate differences. Mol Genet Genomics 2018; 294:343-363. [PMID: 30460550 DOI: 10.1007/s00438-018-1513-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 10/15/2018] [Indexed: 01/28/2023]
Abstract
A salmon louse (Lepeophtheirus salmonis salmonis) genetic linkage map was constructed to serve as a genomic resource for future investigations into the biology of this important marine parasitic copepod species, and to provide insights into the inheritance patterns of genetic markers in this species. SNP genotyping of 8 families confirmed the presence of 15 linkage groups based upon the assignment of 93,773 markers. Progeny sample size weight adjusted map sizes in males (with the exception of SL12 and SL15) ranged in size from 96.50 cM (SL11) to 134.61 cM (SL06), and total combined map steps or bins ranged from 143 (SL09) to 203 (SL13). The SL12 male map was the smallest linkage group with a weight-averaged size of 3.05 cM with 6 recombination bins. Male:female specific recombination rate differences are 10.49:1 and represent one of the largest reported sex-specific differences for any animal species. Recombination ratio differences (M:F) ranged from 1.0 (SL12) to 29:1 (SL15). The number of markers exhibiting normal Mendelian segregation within the sex linkage group SL15 was extremely low (N = 80) in comparison to other linkage groups genotyped [range: 1459 (SL12)-10206 markers (SL05)]. Re-evaluation of Mendelian inheritance patterns of markers unassigned to any mapping parent according to hemizygous segregation patterns (models presented) identified matches for many of these markers to hemizygous patterns. The greatest proportion of these markers assigned to SL15 (N increased to 574). Inclusion of the hemizygous markers revised SL15 sex-specific recombination rate differences to 28:1. Recombination hot- and coldspots were identified across all linkage groups with all linkage groups possessing multiple peaks. Nine of 13 linkage groups evaluated possessed adjacent domains with hot-coldspot transitional zones. The most common pattern was for one end of the linkage to show elevated recombination in addition to internal regions. For SL01 and SL06, however, a terminal region with high recombination was not evident while a central domain possessing extremely high-recombination levels was present. High levels of recombination were weakly coupled to higher levels of SNP variation within domains, but this association was very strong for the central domains of SL01 and SL06. From the pooled paternal half-sib lots (several virgin females placed with 1 male), only 1 or two surviving family lots were obtained. Surviving families possessed parents where both the male and female possessed either inherently low or high recombination rates. This study provides insight into the organization of the sea louse genome, and describes large differences in recombination rate that exist among individuals of the same sex, and between the sexes. These differences in recombination rate may be coupled to the capabilities of this species to adapt to environmental and pharmaceutical treatments, given that family survivorship appears to be enhanced when parents have similar recombination levels.
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Affiliation(s)
- Roy G Danzmann
- Department of Integrative Biology, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada.
| | - Joseph D Norman
- Department of Integrative Biology, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada.,The Hospital for Sick Children, 686 Bay St., Toronto, ON, M5G 0A4, Canada
| | - Eric B Rondeau
- Department of Biology, Centre for Biomedical Research, University of Victoria, 3800 Finnerty Road, Victoria, BC, V8W 3N5, Canada
| | - Amber M Messmer
- Department of Biology, Centre for Biomedical Research, University of Victoria, 3800 Finnerty Road, Victoria, BC, V8W 3N5, Canada
| | - Matthew P Kent
- Department of Animal and Aquacultural Sciences, Centre for Integrative Genetics (CIGENE), Norwegian University of Life Sciences, 1432, As, Norway
| | - Sigbjørn Lien
- Department of Animal and Aquacultural Sciences, Centre for Integrative Genetics (CIGENE), Norwegian University of Life Sciences, 1432, As, Norway
| | - Okechukwu Igboeli
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave., Charlottetown, PEI, C1A 4P3, Canada
| | - Mark D Fast
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave., Charlottetown, PEI, C1A 4P3, Canada
| | - Ben F Koop
- Department of Biology, Centre for Biomedical Research, University of Victoria, 3800 Finnerty Road, Victoria, BC, V8W 3N5, Canada
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Abstract
Enterococcus faecium has a highly variable genome prone to recombination and horizontal gene transfer. Here, we have identified a novel genetic island with an insertion locus and mobilization genes similar to those of staphylococcus cassette chromosome elements SCCmec This novel element termed the enterococcus cassette chromosome (ECC) element was located in the 3' region of rlmH and encoded large serine recombinases ccrAB similar to SCCmec Horizontal transfer of an ECC element termed ECC::cat containing a knock-in cat chloramphenicol resistance determinant occurred in the presence of a conjugative rep pLG1 plasmid. We determined the ECC::cat insertion site in the 3' region of rlmH in the E. faecium recipient by long-read sequencing. ECC::cat also mobilized by homologous recombination through sequence identity between flanking insertion sequence (IS) elements in ECC::cat and the conjugative plasmid. The ccrABEnt genes were found in 69 of 516 E. faecium genomes in GenBank. Full-length ECC elements were retrieved from 32 of these genomes. ECCs were flanked by attR and attL sites of approximately 50 bp. The attECC sequences were found by PCR and sequencing of circularized ECCs in three strains. The genes in ECCs contained an amalgam of common and rare E. faecium genes. Taken together, our data imply that ECC elements act as hot spots for genetic exchange and contribute to the large variation of accessory genes found in E. faecium IMPORTANCE Enterococcus faecium is a bacterium found in a great variety of environments, ranging from the clinic as a nosocomial pathogen to natural habitats such as mammalian intestines, water, and soil. They are known to exchange genetic material through horizontal gene transfer and recombination, leading to great variability of accessory genes and aiding environmental adaptation. Identifying mobile genetic elements causing sequence variation is important to understand how genetic content variation occurs. Here, a novel genetic island, the enterococcus cassette chromosome, is shown to contain a wealth of genes, which may aid E. faecium in adapting to new environments. The transmission mechanism involves the only two conserved genes within ECC, ccrAB Ent, large serine recombinases that insert ECC into the host genome similarly to SCC elements found in staphylococci.
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50
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Walther B, Klein KS, Barton AK, Semmler T, Huber C, Merle R, Tedin K, Mitrach F, Lübke-Becker A, Gehlen H. Equine Methicillin-Resistant Sequence Type 398 Staphylococcus aureus (MRSA) Harbor Mobile Genetic Elements Promoting Host Adaptation. Front Microbiol 2018; 9:2516. [PMID: 30405574 PMCID: PMC6207647 DOI: 10.3389/fmicb.2018.02516] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 10/02/2018] [Indexed: 12/31/2022] Open
Abstract
Continuing introduction of multi-drug resistant, zoonotic pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) in horse clinics challenges the biosafety of employees and animal patients. This study was aimed to determine the occurrence of mobile genetic elements facilitating survival in the early stages of invasive infection in different host species, including humans and horses, in MRSA carried by equine patients admitted to a large horse clinic. A total of 341 equine patients were investigated for carriage of MRSA by hygiene screening directly at hospital admission. MRSA were further investigated by antimicrobial susceptibility testing, whole-genome sequencing and genomic composition, including virulence factors involved in immune evasion and host adaption. From a total of 340 validated specimens from equine nostrils, 3.5% yielded positive results for MRSA. All MRSA were found to be closely related belonging to sequence type (ST) 398_t011 with up to four additional antimicrobial resistances. All MRSA harbored a specific Staphylococcal Pathogenicity Island (SaPIbov5) involved in facilitating survival in ruminant and equine plasma. Moreover, a β-hemolysin (hlb) converting ΦSa3 phage encoding the human-specific Immune Evasion Cluster (IEC) was present in 72% of the isolates. An equid-specific leukotoxin encoded by a further temperate phage (Saeq1) was only rarely detected (22%). Despite the absence of β-hemolysin production for all IEC-positive ST398, a prominent hemolysis zone was demonstrable on sheep blood agar. Thus, IEC might remain undetected among the ST398 lineage, since the presence of IEC is commonly associated with reduction of hemolysis in S. aureus belonging to other genetic backgrounds. Here we describe MRSA-ST398 harboring different mobile genetic elements encoding variants of immune evasion factors and toxins previously shown to contribute to S. aureus invasive diseases in specific host species or ecologic niches. We suggest these combinations contribute to the adaptation of MRSA belonging to ST398 with respect to epidemic spread across different habitats and hosts, and may therefore confer a host “generalist” phenotype.
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Affiliation(s)
- Birgit Walther
- Centre for Infection Medicine, Institute of Microbiology and Epizootics, Freie Universität Berlin, Berlin, Germany.,Advanced Light and Electron Microscopy (ZBS4), Robert Koch Institute, Berlin, Germany
| | - Katja-Sophia Klein
- Equine Clinic, Surgery and Radiology, Freie Universität Berlin, Berlin, Germany
| | - Ann-Kristin Barton
- Equine Clinic, Surgery and Radiology, Freie Universität Berlin, Berlin, Germany
| | - Torsten Semmler
- Microbial Genomics (NG1), Robert Koch Institute, Berlin, Germany
| | - Charlotte Huber
- Microbial Genomics (NG1), Robert Koch Institute, Berlin, Germany
| | - Roswitha Merle
- Institute for Veterinary Epidemiology and Biostatistics, Freie Universität Berlin, Berlin, Germany
| | - Karsten Tedin
- Centre for Infection Medicine, Institute of Microbiology and Epizootics, Freie Universität Berlin, Berlin, Germany
| | - Franziska Mitrach
- Faculty of Environment and Natural Sciences, Institute of Biotechnology, Brandenburg University of Technology Cottbus-Senftenberg, Cottbus, Germany
| | - Antina Lübke-Becker
- Centre for Infection Medicine, Institute of Microbiology and Epizootics, Freie Universität Berlin, Berlin, Germany
| | - Heidrun Gehlen
- Equine Clinic, Surgery and Radiology, Freie Universität Berlin, Berlin, Germany
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