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Engin AB, Engin ED, Engin A. Effects of co-selection of antibiotic-resistance and metal-resistance genes on antibiotic-resistance potency of environmental bacteria and related ecological risk factors. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2023; 98:104081. [PMID: 36805463 DOI: 10.1016/j.etap.2023.104081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 01/23/2023] [Accepted: 02/12/2023] [Indexed: 06/18/2023]
Abstract
The inadequate elimination of micropollutants in wastewater treatment plants (WWTP), cause to increase in the incidence of antibiotic resistant bacterial strains. Growth of microbial pathogens in WWTP is one of the serious public health problems. The widespread and simultaneous emergence of antibiotic resistance genes (ARGs) and heavy metal resistance genes (HMRGs) in the environment with heavy metals create persistent and selective pressure for co-selection of both genes on environmental microorganisms. Co-localization of ARGs and HMRGs on the same horizontal mobile genetic elements (MGEs) allows the spreading of numerous antibiotic-resistant strains of bacteria in aquatic and terrestrial environment. The biofilm formation and colonization potential of environmental bacteria leads to the co-selection of multi-antibiotic resistance and multi-metal tolerance. Horizontal gene transfer (HGT), co-localization of both ARGs and HMRGs on the same MGEs, and the shared resistomes are important bacteria-associated ecological risks factors, which reduce the effectiveness of antibiotics against bacterial infections.
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Affiliation(s)
- Ayse Basak Engin
- Gazi University, Faculty of Pharmacy, Department of Toxicology, Ankara, Turkey.
| | - Evren Doruk Engin
- Ankara University, Biotechnology Institute, Gumusdere Campus, Kecioren, Ankara, Turkey
| | - Atilla Engin
- Gazi University, Faculty of Medicine, Department of General Surgery, Ankara, Turkey
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2
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Malmstrom CM, Martin MD, Gagnevin L. Exploring the Emergence and Evolution of Plant Pathogenic Microbes Using Historical and Paleontological Sources. ANNUAL REVIEW OF PHYTOPATHOLOGY 2022; 60:187-209. [PMID: 35483672 DOI: 10.1146/annurev-phyto-021021-041830] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Biotechnological advances now permit broad exploration of past microbial communities preserved in diverse substrates. Despite biomolecular degradation, high-throughput sequencing of preserved materials can yield invaluable genomic and metagenomic data from the past. This line of research has expanded from its initial human- and animal-centric foci to include plant-associated microbes (viruses, archaea, bacteria, fungi, and oomycetes), for which historical, archaeological, and paleontological data illuminate past epidemics and evolutionary history. Genetic mechanisms underlying the acquisition of microbial pathogenicity, including hybridization, polyploidization, and horizontal gene transfer, can now be reconstructed, as can gene-for-gene coevolution with plant hosts. Epidemiological parameters, such as geographic origin and range expansion, can also be assessed. Building on published case studies with individual phytomicrobial taxa, the stage is now set for broader, community-wide studies of preserved plant microbiomes to strengthen mechanistic understanding of microbial interactions and plant disease emergence.
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Affiliation(s)
- Carolyn M Malmstrom
- Department of Plant Biology and Program in Ecology, Evolution, and Behavior, Michigan State University, East Lansing, Michigan, USA
| | - Michael D Martin
- Department of Natural History, University Museum, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Lionel Gagnevin
- Plant Health Institute of Montpellier, CIRAD, Montpellier, France;
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3
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Jangir PK, Yang Q, Shaw LP, Caballero JD, Ogunlana L, Wheatley R, Walsh T, MacLean RC. Pre-existing chromosomal polymorphisms in pathogenic E. coli potentiate the evolution of resistance to a last-resort antibiotic. eLife 2022; 11:78834. [PMID: 35943060 PMCID: PMC9363117 DOI: 10.7554/elife.78834] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 07/22/2022] [Indexed: 12/17/2022] Open
Abstract
Bacterial pathogens show high levels of chromosomal genetic diversity, but the influence of this diversity on the evolution of antibiotic resistance by plasmid acquisition remains unclear. Here, we address this problem in the context of colistin, a 'last line of defence' antibiotic. Using experimental evolution, we show that a plasmid carrying the MCR-1 colistin resistance gene dramatically increases the ability of Escherichia coli to evolve high-level colistin resistance by acquiring mutations in lpxC, an essential chromosomal gene involved in lipopolysaccharide biosynthesis. Crucially, lpxC mutations increase colistin resistance in the presence of the MCR-1 gene, but decrease the resistance of wild-type cells, revealing positive sign epistasis for antibiotic resistance between the chromosomal mutations and a mobile resistance gene. Analysis of public genomic datasets shows that lpxC polymorphisms are common in pathogenic E. coli, including those carrying MCR-1, highlighting the clinical relevance of this interaction. Importantly, lpxC diversity is high in pathogenic E. coli from regions with no history of MCR-1 acquisition, suggesting that pre-existing lpxC polymorphisms potentiated the evolution of high-level colistin resistance by MCR-1 acquisition. More broadly, these findings highlight the importance of standing genetic variation and plasmid/chromosomal interactions in the evolutionary dynamics of antibiotic resistance.
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Affiliation(s)
- Pramod K Jangir
- Department of Zoology, University of OxfordOxfordUnited Kingdom
| | - Qiue Yang
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry UniversityFuzhouChina
| | - Liam P Shaw
- Department of Zoology, University of OxfordOxfordUnited Kingdom
| | | | - Lois Ogunlana
- Department of Zoology, University of OxfordOxfordUnited Kingdom
| | - Rachel Wheatley
- Department of Zoology, University of OxfordOxfordUnited Kingdom
| | - Timothy Walsh
- Department of Zoology, University of OxfordOxfordUnited Kingdom
| | - R Craig MacLean
- Department of Zoology, University of OxfordOxfordUnited Kingdom
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Abstract
Horizontal gene transfer (HGT) is arguably the most conspicuous feature of bacterial evolution. Evidence for HGT is found in most bacterial genomes. Although HGT can considerably alter bacterial genomes, not all transfer events may be biologically significant and may instead represent the outcome of an incessant evolutionary process that only occasionally has a beneficial purpose. When adaptive transfers occur, HGT and positive selection may result in specific, detectable signatures in genomes, such as gene-specific sweeps or increased transfer rates for genes that are ecologically relevant. In this Review, we first discuss the various mechanisms whereby HGT occurs, how the genetic signatures shape patterns of genomic variation and the distinct bioinformatic algorithms developed to detect these patterns. We then discuss the evolutionary theory behind HGT and positive selection in bacteria, and discuss the approaches developed over the past decade to detect transferred DNA that may be involved in adaptation to new environments.
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Baquero F, Martínez JL, F. Lanza V, Rodríguez-Beltrán J, Galán JC, San Millán A, Cantón R, Coque TM. Evolutionary Pathways and Trajectories in Antibiotic Resistance. Clin Microbiol Rev 2021; 34:e0005019. [PMID: 34190572 PMCID: PMC8404696 DOI: 10.1128/cmr.00050-19] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Evolution is the hallmark of life. Descriptions of the evolution of microorganisms have provided a wealth of information, but knowledge regarding "what happened" has precluded a deeper understanding of "how" evolution has proceeded, as in the case of antimicrobial resistance. The difficulty in answering the "how" question lies in the multihierarchical dimensions of evolutionary processes, nested in complex networks, encompassing all units of selection, from genes to communities and ecosystems. At the simplest ontological level (as resistance genes), evolution proceeds by random (mutation and drift) and directional (natural selection) processes; however, sequential pathways of adaptive variation can occasionally be observed, and under fixed circumstances (particular fitness landscapes), evolution is predictable. At the highest level (such as that of plasmids, clones, species, microbiotas), the systems' degrees of freedom increase dramatically, related to the variable dispersal, fragmentation, relatedness, or coalescence of bacterial populations, depending on heterogeneous and changing niches and selective gradients in complex environments. Evolutionary trajectories of antibiotic resistance find their way in these changing landscapes subjected to random variations, becoming highly entropic and therefore unpredictable. However, experimental, phylogenetic, and ecogenetic analyses reveal preferential frequented paths (highways) where antibiotic resistance flows and propagates, allowing some understanding of evolutionary dynamics, modeling and designing interventions. Studies on antibiotic resistance have an applied aspect in improving individual health, One Health, and Global Health, as well as an academic value for understanding evolution. Most importantly, they have a heuristic significance as a model to reduce the negative influence of anthropogenic effects on the environment.
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Affiliation(s)
- F. Baquero
- Department of Microbiology, Ramón y Cajal University Hospital, Ramón y Cajal Institute for Health Research (IRYCIS), Network Center for Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - J. L. Martínez
- National Center for Biotechnology (CNB-CSIC), Madrid, Spain
| | - V. F. Lanza
- Department of Microbiology, Ramón y Cajal University Hospital, Ramón y Cajal Institute for Health Research (IRYCIS), Network Center for Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
- Central Bioinformatics Unit, Ramón y Cajal Institute for Health Research (IRYCIS), Madrid, Spain
| | - J. Rodríguez-Beltrán
- Department of Microbiology, Ramón y Cajal University Hospital, Ramón y Cajal Institute for Health Research (IRYCIS), Network Center for Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - J. C. Galán
- Department of Microbiology, Ramón y Cajal University Hospital, Ramón y Cajal Institute for Health Research (IRYCIS), Network Center for Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - A. San Millán
- National Center for Biotechnology (CNB-CSIC), Madrid, Spain
| | - R. Cantón
- Department of Microbiology, Ramón y Cajal University Hospital, Ramón y Cajal Institute for Health Research (IRYCIS), Network Center for Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - T. M. Coque
- Department of Microbiology, Ramón y Cajal University Hospital, Ramón y Cajal Institute for Health Research (IRYCIS), Network Center for Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
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Antibacterial Agents Adsorbed on Active Carbon: A New Approach for S. aureus and E. coli Pathogen Elimination. Pathogens 2021; 10:pathogens10081066. [PMID: 34451530 PMCID: PMC8401764 DOI: 10.3390/pathogens10081066] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 08/13/2021] [Accepted: 08/20/2021] [Indexed: 01/21/2023] Open
Abstract
Antibiotic overuse and mass production have led to a global problem with the treatment of antibacterial infections. Thus, any possibility to limit the number of antibacterial drugs used will contribute to a decrease in the development of pathogenic bacterial resistance. In this study, the enhanced bacterial growth reduction of pharmaceutical activated carbon (PAC) material with adsorbed antimicrobial agents compared to the activity of pure antibacterial drugs was investigated. Sulfamethoxazole (SMZ) at a concentration of 1.1 mg/mL retained the growth of S. aureus and E. coli at 20.5% and 26.5%, respectively, whereas SMZ adsorbed on PAC increased the reduction of the tested bacteria in the range of 47-72%. The use of PAC with adsorbed gentamycin (G) over 24 h improved the effectiveness of E. coli growth reduction by 50% compared to the application of pure antibiotic (3.6 µg/mL). The increased reduction of S. aureus growth by 6% using G with PAC for a 24-h incubation time compared to the use of pure antibiotics at a concentration of 3.6 µg/mL was observed. The results provide proof-of-principle that the new approach of activated carbon with adsorbed antimicrobial agents could yield an attractive background with potential as a new starting material for S. aureus and E. coli pathogen elimination, e.g., in wound-healing treatment in the future.
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He M, Lei T, Jiang F, Zhang J, Zeng H, Wang J, Chen M, Xue L, Wu S, Ye Q, Pang R, Ding Y, Wu Q. Genetic Diversity and Population Structure of Vibrio parahaemolyticus Isolated From Clinical and Food Sources. Front Microbiol 2021; 12:708795. [PMID: 34385993 PMCID: PMC8353399 DOI: 10.3389/fmicb.2021.708795] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 07/02/2021] [Indexed: 01/22/2023] Open
Abstract
Vibrio parahaemolyticus is a common foodborne pathogen that causes gastroenteritis worldwide. Determining its prevalence and genetic diversity will minimize the risk of infection and the associated economic burden. Multilocus sequence typing (MLST) is an important tool for molecular epidemiology and population genetic studies of bacteria. Here, we analyzed the genetic and evolutionary relationships of 162 V. parahaemolyticus strains isolated in the Guangdong Province, China, using MLST. In the study, 120 strains were isolated from food samples, and 42 strains were isolated from clinical samples. All strains were categorized into 100 sequence types (STs), of which 58 were novel (48 from the food isolates and 10 from the clinical isolates). ST415 was the most prevalent ST among the food isolates, while ST3 was the most prevalent ST among the clinical isolates. Further, 12 clonal complexes, 14 doublets, and 73 singletons were identified in all ST clusters, indicating high genetic diversity of the analyzed strains. At the concatenated sequence level, non-synonymous sites in both, food and clinical isolates, were associated with purifying selection. Of note, the dN/dS ration was greater than 1 for some housekeeping genes in all isolates. This is the first time that some loci under positive selection were identified. These observations confirm frequent recombination events in V. parahaemolyticus. Recombination was much more important than mutation for genetic heterogeneity of the food isolates, but the probabilities of recombination and mutations were almost equal for the clinical isolates. Based on the phylogenetic analysis, the clinical isolates were concentrated in the maximum-likelihood tree, while the food isolates were heterogeneously distributed. In conclusion, the food and clinical isolates of V. parahaemolyticus from the Guangdong Province are similar, but show different evolutionary trends. This may help prevent large-scale spread of highly virulent strains and provides a genetic basis for the discovery of microevolutionary relationships in V. parahaemolyticus populations.
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Affiliation(s)
- Min He
- School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China.,Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Tao Lei
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Fufeng Jiang
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China.,School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, China
| | - Jumei Zhang
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Haiyan Zeng
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Juan Wang
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Moutong Chen
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Liang Xue
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Shi Wu
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Qinghua Ye
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Rui Pang
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Yu Ding
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Qingping Wu
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
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8
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Nationwide genomic atlas of soil-dwelling Listeria reveals effects of selection and population ecology on pangenome evolution. Nat Microbiol 2021; 6:1021-1030. [PMID: 34267358 DOI: 10.1038/s41564-021-00935-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 06/15/2021] [Indexed: 12/15/2022]
Abstract
Natural bacterial populations can display enormous genomic diversity, primarily in the form of gene content variation caused by the frequent exchange of DNA with the local environment. However, the ecological drivers of genomic variability and the role of selection remain controversial. Here, we address this gap by developing a nationwide atlas of 1,854 Listeria isolates, collected systematically from soils across the contiguous United States. We found that Listeria was present across a wide range of environmental parameters, being mainly controlled by soil moisture, molybdenum and salinity concentrations. Whole-genome data from 594 representative strains allowed us to decompose Listeria diversity into 12 phylogroups, each with large differences in habitat breadth and endemism. 'Cosmopolitan' phylogroups, prevalent across many different habitats, had more open pangenomes and displayed weaker linkage disequilibrium, reflecting higher rates of gene gain and loss, and allele exchange than phylogroups with narrow habitat ranges. Cosmopolitan phylogroups also had a large fraction of genes affected by positive selection. The effect of positive selection was more pronounced in the phylogroup-specific core genome, suggesting that lineage-specific core genes are important drivers of adaptation. These results indicate that genome flexibility and recombination are the consequence of selection to survive in variable environments.
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9
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Harrow GL, Lees JA, Hanage WP, Lipsitch M, Corander J, Colijn C, Croucher NJ. Negative frequency-dependent selection and asymmetrical transformation stabilise multi-strain bacterial population structures. THE ISME JOURNAL 2021; 15:1523-1538. [PMID: 33408365 PMCID: PMC8115253 DOI: 10.1038/s41396-020-00867-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 12/01/2020] [Accepted: 12/03/2020] [Indexed: 02/06/2023]
Abstract
Streptococcus pneumoniae can be divided into many strains, each a distinct set of isolates sharing similar core and accessory genomes, which co-circulate within the same hosts. Previous analyses suggested the short-term vaccine-associated dynamics of S. pneumoniae strains may be mediated through multi-locus negative frequency-dependent selection (NFDS), which maintains accessory loci at equilibrium frequencies. Long-term simulations demonstrated NFDS stabilised clonally-evolving multi-strain populations through preventing the loss of variation through drift, based on polymorphism frequencies, pairwise genetic distances and phylogenies. However, allowing symmetrical recombination between isolates evolving under multi-locus NFDS generated unstructured populations of diverse genotypes. Replication of the observed data improved when multi-locus NFDS was combined with recombination that was instead asymmetrical, favouring deletion of accessory loci over insertion. This combination separated populations into strains through outbreeding depression, resulting from recombinants with reduced accessory genomes having lower fitness than their parental genotypes. Although simplistic modelling of recombination likely limited these simulations' ability to maintain some properties of genomic data as accurately as those lacking recombination, the combination of asymmetrical recombination and multi-locus NFDS could restore multi-strain population structures from randomised initial populations. As many bacteria inhibit insertions into their chromosomes, this combination may commonly underlie the co-existence of strains within a niche.
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Affiliation(s)
- Gabrielle L Harrow
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, Norfolk Place, London, W2 1PG, UK
| | - John A Lees
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, Norfolk Place, London, W2 1PG, UK
| | - William P Hanage
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T.H. Chan School of Public Health, 677 Huntington Avenue, Boston, MA, 02115, USA
| | - Marc Lipsitch
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T.H. Chan School of Public Health, 677 Huntington Avenue, Boston, MA, 02115, USA
| | - Jukka Corander
- Department of Biostatistics, University of Oslo, Oslo, Norway
- Helsinki Institute of Information Technology, Department of Mathematics and Statistics, University of Helsinki, Helsinki, Finland
- Parasites & Microbes Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Caroline Colijn
- Parasites & Microbes Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
- Department of Mathematics, Simon Fraser University, Burnaby, BC, Canada
| | - Nicholas J Croucher
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, Norfolk Place, London, W2 1PG, UK.
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Cherak Z, Loucif L, Moussi A, Rolain JM. Carbapenemase-producing Gram-negative bacteria in aquatic environments: a review. J Glob Antimicrob Resist 2021; 25:287-309. [PMID: 33895415 DOI: 10.1016/j.jgar.2021.03.024] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 03/04/2021] [Accepted: 03/20/2021] [Indexed: 01/05/2023] Open
Abstract
Antibiotic resistance is one of the greatest public-health challenges worldwide, especially with regard to Gram-negative bacteria (GNB). Carbapenems are the β-lactam antibiotics of choice with the broadest spectrum of activity and, in many cases, are the last-resort treatment for several bacterial infections. Carbapenemase-encoding genes, mainly carried by mobile genetic elements, are the main mechanism of resistance against carbapenems in GNB. These enzymes exhibit a versatile hydrolytic capacity and confer resistance to most β-lactam antibiotics. After being considered a clinical issue, increasing attention is being giving to the dissemination of such resistance mechanisms in the environment and especially through water. Aquatic environments are among the most significant microbial habitats on our planet, known as a favourable medium for antibiotic gene transfer, and they play a crucial role in the huge spread of drug resistance in the environment and the community. In this review, we present current knowledge regarding the spread of carbapenemase-producing isolates in different aquatic environments, which may help the implementation of control and prevention strategies against the spread of such dangerous resistant agents in the environment.
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Affiliation(s)
- Zineb Cherak
- Laboratoire de Génétique, Biotechnologie et Valorisation des Bio-ressources (GBVB), Faculté des Sciences Exactes et des Sciences de la Nature et de la Vie, Université Mohamed Khider, Biskra, Algeria
| | - Lotfi Loucif
- Laboratoire de Biotechnologie des Molécules Bioactives et de la Physiopathologie Cellulaire (LBMBPC), Département de Microbiologie et de Biochimie, Faculté des Sciences de la Nature et de la Vie, Université de Batna 2, Batna, Algeria.
| | - Abdelhamid Moussi
- Laboratoire de Génétique, Biotechnologie et Valorisation des Bio-ressources (GBVB), Faculté des Sciences Exactes et des Sciences de la Nature et de la Vie, Université Mohamed Khider, Biskra, Algeria
| | - Jean-Marc Rolain
- Aix-Marseille Université, IRD, MEPHI, Faculté de Médecine et de Pharmacie, Marseille, France; IHU Méditerranée Infection, Marseille, France; and Assistance Publique des Hôpitaux de Marseille, Marseille, France
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11
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Overview on the role of heavy metals tolerance on developing antibiotic resistance in both Gram-negative and Gram-positive bacteria. Arch Microbiol 2021; 203:2761-2770. [PMID: 33811263 DOI: 10.1007/s00203-021-02275-w] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 02/11/2021] [Accepted: 03/10/2021] [Indexed: 12/26/2022]
Abstract
Environmental health is a critical concern, continuously contaminated by physical and biological components (viz., anthropogenic activity), which adversely affect on biodiversity, ecosystems and human health. Nonetheless, environmental pollution has great impact on microbial communities, especially bacteria, which try to evolve in changing environment. For instance, during the course of adaptation, bacteria easily become resistance to antibiotics and heavy metals. Antibiotic resistance genes are now one of the most vital pollutants, provided as a source of frequent horizontal gene transfer. In this review, the environmental cause of multidrug resistance (MDR) that was supposed to be driven by either heavy metals or combination of environmental factors was essentially reviewed, especially focussed on the correlation between accumulation of heavy metals and development of MDR by bacteria. This kind of correlation was seemed to be non-significant, i.e. paradoxical. Gram-positive bacteria accumulating much of toxic heavy metal (i.e. highly stress tolerance) were unlikely to become MDR, whereas Gram-negative bacteria that often avoid accumulation of toxic heavy metal by efflux pump systems were come out to be more prone to MDR. So far, other than antibiotic contaminant, no such available data strongly support the direct influence of heavy metals in bacterial evolution of MDR; combinations of factors may drive the evolution of antibiotic resistance. Therefore, Gram-positive bacteria are most likely to be an efficient member in treatment of industrial waste water, especially in the removal of heavy metals, perhaps inducing the less chance of antibiotic resistance pollution in the environment.
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12
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Taylor AR, Echeverry DF, Anderson TJC, Neafsey DE, Buckee CO. Identity-by-descent with uncertainty characterises connectivity of Plasmodium falciparum populations on the Colombian-Pacific coast. PLoS Genet 2020; 16:e1009101. [PMID: 33196661 PMCID: PMC7704048 DOI: 10.1371/journal.pgen.1009101] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 11/30/2020] [Accepted: 09/08/2020] [Indexed: 01/09/2023] Open
Abstract
Characterising connectivity between geographically separated biological populations is a common goal in many fields. Recent approaches to understanding connectivity between malaria parasite populations, with implications for disease control efforts, have used estimates of relatedness based on identity-by-descent (IBD). However, uncertainty around estimated relatedness has not been accounted for. IBD-based relatedness estimates with uncertainty were computed for pairs of monoclonal Plasmodium falciparum samples collected from five cities on the Colombian-Pacific coast where long-term clonal propagation of P. falciparum is frequent. The cities include two official ports, Buenaventura and Tumaco, that are separated geographically but connected by frequent marine traffic. Fractions of highly-related sample pairs (whose classification using a threshold accounts for uncertainty) were greater within cities versus between. However, based on both highly-related fractions and on a threshold-free approach (Wasserstein distances between parasite populations) connectivity between Buenaventura and Tumaco was disproportionally high. Buenaventura-Tumaco connectivity was consistent with transmission events involving parasites from five clonal components (groups of statistically indistinguishable parasites identified under a graph theoretic framework). To conclude, P. falciparum population connectivity on the Colombian-Pacific coast abides by accessibility not isolation-by-distance, potentially implicating marine traffic in malaria transmission with opportunities for targeted intervention. Further investigations are required to test this hypothesis. For the first time in malaria epidemiology (and to our knowledge in ecological and epidemiological studies more generally), we account for uncertainty around estimated relatedness (an important consideration for studies that plan to use genotype versus whole genome sequence data to estimate IBD-based relatedness); we also use threshold-free methods to compare parasite populations and identify clonal components. Threshold-free methods are especially important in analyses of malaria parasites and other recombining organisms with mixed mating systems where thresholds do not have clear interpretation (e.g. due to clonal propagation) and thus undermine the cross-comparison of studies.
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Affiliation(s)
- Aimee R. Taylor
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, USA
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Diego F. Echeverry
- Centro Internacional de Entrenamiento e Investigaciones Médicas (CIDEIM), Cali, Colombia
- Universidad Icesi, Calle 18 No. 122-135, Cali, Colombia
- Departamento de Microbiologia, Facultad de Salud, Universidad del Valle, Cali, Colombia
| | - Timothy J. C. Anderson
- Disease Intervention and Prevention Program, Texas Biomedical Research Institute, San Antonio, Texas, USA
| | - Daniel E. Neafsey
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Caroline O. Buckee
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, USA
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Vaz C, Nascimento M, Carriço JA, Rocher T, Francisco AP. Distance-based phylogenetic inference from typing data: a unifying view. Brief Bioinform 2020; 22:5879060. [PMID: 32734294 DOI: 10.1093/bib/bbaa147] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 05/22/2020] [Accepted: 06/09/2020] [Indexed: 11/14/2022] Open
Abstract
Typing methods are widely used in the surveillance of infectious diseases, outbreaks investigation and studies of the natural history of an infection. Moreover, their use is becoming standard, in particular with the introduction of high-throughput sequencing. On the other hand, the data being generated are massive and many algorithms have been proposed for a phylogenetic analysis of typing data, addressing both correctness and scalability issues. Most of the distance-based algorithms for inferring phylogenetic trees follow the closest pair joining scheme. This is one of the approaches used in hierarchical clustering. Moreover, although phylogenetic inference algorithms may seem rather different, the main difference among them resides on how one defines cluster proximity and on which optimization criterion is used. Both cluster proximity and optimization criteria rely often on a model of evolution. In this work, we review, and we provide a unified view of these algorithms. This is an important step not only to better understand such algorithms but also to identify possible computational bottlenecks and improvements, important to deal with large data sets.
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Affiliation(s)
- Cátia Vaz
- Instituto Superior de Engenharia de Lisboa, Instituto Politécnico de Lisboa, and a researcher at INESC-ID
| | - Marta Nascimento
- Instituto Superior Técnico, Universidade de Lisboa and a researcher at INESC-ID
| | - João A Carriço
- Faculdade de Medicina, Instituto de Microbiologia and Instituto de Medicina Molecular, Universidade de Lisboa
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Sunsandee N, Ramakul P, Phatanasri S, Pancharoen U. Biosorption of dicloxacillin from pharmaceutical waste water using tannin from Indian almond leaf: Kinetic and equilibrium studies. ACTA ACUST UNITED AC 2020; 27:e00488. [PMID: 32577411 PMCID: PMC7305391 DOI: 10.1016/j.btre.2020.e00488] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 05/19/2020] [Accepted: 06/08/2020] [Indexed: 01/16/2023]
Abstract
The maximum adsorption capacity was 86.93 %. Experimental data were in agreement with pseudo-second-order kinetics. Experimental data were followed Langmuir isotherm model. Biosorption of dicloxacilin onto T. catappa L. biomass is possible, spontaneous and exothermic process.
This study focused on the use of Indian almond leaf biomass, a local plant widely found in Thailand, on removal of dicloxacillin from pharmaceutical waste water by biosorption. The biosorption characteristics of dicloxacillin were investigated in terms of equilibrium, kinetics and thermodynamics. Optimum biosorption conditions were determined from pH, initial dicloxacillin concentration, biomass dosage, contact time, and temperature. The maximum adsorption capacity was 86.93 % (pH 6.0, 0.1 g/L biomass, dicloxacillin concentration 20 mg/L, contact time 24 h, temperature 283.15 K). The thermodynamic parameters (298.15 K), free energy change, enthalpy change and entropy change were -3475.79 J/mol, −25.36 kJ/mol, and −73.40 J/mol/K, respectively. The best interpretation for the experimental data was given by the Langmuir isotherm with correlation coefficient of 0.965. The results were found to tie in well with pseudo-second-order kinetics. Considering the cost-effectiveness, Indian almond leaf biomass is considered to be suitable to remove dicloxacillin from pharmaceutical waste water.
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Affiliation(s)
- Niti Sunsandee
- Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand
| | - Prakorn Ramakul
- Department of Chemical Engineering, Faculty of Engineering and Industrial Technology, Silpakorn University, Nakhon Pathom 73000, Thailand
| | - Suphot Phatanasri
- Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand
| | - Ura Pancharoen
- Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand
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Meparambu Prabhakaran D, Ramamurthy T, Thomas S. Genetic and virulence characterisation of Vibrio parahaemolyticus isolated from Indian coast. BMC Microbiol 2020; 20:62. [PMID: 32293257 PMCID: PMC7092547 DOI: 10.1186/s12866-020-01746-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 03/05/2020] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND V. parahaemolyticus is autochthonous to the marine environment and causes seafood-borne gastroenteritis in humans. Generally, V. parahaemolyticus recovered from the environment and/or seafood is thought to be non-pathogenic and the relationship between environmental isolates and acute diarrhoeal disease is poorly understood. In this study, we explored the virulence potential of environmental V. parahaemolyticus isolated from water, plankton and assorted seafood samples collected from the Indian coast. RESULTS Twenty-two V. parahaemolyticus isolates from seafood harboured virulence associated genes encoding the thermostable-direct haemolysin (TDH), TDH-related haemolysin (TRH), and Type 3 secretion systems (T3SS) and 95.5% of the toxigenic isolates had pandemic strain attributes (toxRS/new+). Nine serovars, with pandemic strain traits were newly identified and an O4:K36 tdh-trh+V. parahaemolyticus bearing pandemic marker gene was recognised for the first time. Results obtained by reverse transcription PCR showed trh, T3SS1 and T3SS2β to be functional in the seafood isolates. Moreover, the environmental strains were cytotoxic and could invade Caco-2 cells upon infection as well as induce changes to the tight junction protein, ZO-1 and the actin cytoskeleton. CONCLUSION Our study provides evidence that environmental isolates of V. parahaemolyticus are potentially invasive and capable of eliciting pathogenic characteristics typical of clinical strains and present a potential health risk. We also demonstrate that virulence of this pathogen is highly complex and hence draws attention for the need to investigate more reliable virulence markers in order to distinguish the environmental and clinical isolates, which will be crucial for the pathogenomics and control of this pathogen.
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Affiliation(s)
- Divya Meparambu Prabhakaran
- Cholera and Biofilm Research Lab, Department of Pathogen Biology, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, 695 014, India
| | - Thandavarayan Ramamurthy
- Centre for Human Microbial Ecology, Translational Health Science and Technology Institute, Faridabad, India
| | - Sabu Thomas
- Cholera and Biofilm Research Lab, Department of Pathogen Biology, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, 695 014, India.
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Gati NS, Middendorf-Bauchart B, Bletz S, Dobrindt U, Mellmann A. Origin and Evolution of Hybrid Shiga Toxin-Producing and Uropathogenic Escherichia coli Strains of Sequence Type 141. J Clin Microbiol 2019; 58:e01309-19. [PMID: 31619530 PMCID: PMC6935910 DOI: 10.1128/jcm.01309-19] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 10/14/2019] [Indexed: 12/16/2022] Open
Abstract
Hybrid Shiga toxin-producing Escherichia coli (STEC) and uropathogenic E. coli (UPEC) strains of multilocus sequence type 141 (ST141) cause both urinary tract infections and diarrhea in humans and are phylogenetically positioned between STEC and UPEC strains. We used comparative genomic analysis of 85 temporally and spatially diverse ST141 E. coli strains, including 14 STEC/UPEC hybrids, collected in Germany (n = 13) and the United States (n = 1) to reconstruct their molecular evolution. Whole-genome sequencing data showed that 89% of the ST141 E. coli strains either were STEC/UPEC hybrids or contained a mixture of virulence genes from other pathotypes. Core genome analysis and ancestral reconstruction revealed that the ST141 E. coli strains clustered into two lineages that evolved from a common ancestor in the mid-19th century. The STEC/UPEC hybrid emerged ∼100 years ago by acquiring an stx prophage, which integrated into previously unknown insertion site between rcsB and rcsD, followed by the insertion of a pathogenicity island (PAI) similar to PAI II of UPEC strain 536 (PAI II536-like). The two variants of PAI II536-like were associated with tRNA genes leuX and pheU, respectively. Finally, microevolution within PAI II536-like and acquisition of the enterohemorrhagic E. coli plasmid were observed. Our data suggest that intestinal pathogenic E. coli (IPEC)/extraintestinal pathogenic E. coli (ExPEC) hybrids are widespread and that selection pressure within the ST141 E. coli population led to the emergence of the STEC/UPEC hybrid as a clinically important subgroup. We hypothesize that ST141 E. coli strains serve as a melting pot for pathogroup conversion between IPEC and ExPEC, contrasting the classical theory of pathogen emergence from nonpathogens and corroborating our recent phenomenon of heteropathogenicity among pathogenic E. coli strains.
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Affiliation(s)
- Noble Selasi Gati
- University Hospital Münster, Institute of Hygiene, National Consulting Laboratory for Hemolytic Uremic Syndrome (HUS), Münster, Germany
| | - Barbara Middendorf-Bauchart
- University Hospital Münster, Institute of Hygiene, National Consulting Laboratory for Hemolytic Uremic Syndrome (HUS), Münster, Germany
| | - Stefan Bletz
- University Hospital Münster, Institute of Hygiene, National Consulting Laboratory for Hemolytic Uremic Syndrome (HUS), Münster, Germany
| | - Ulrich Dobrindt
- University Hospital Münster, Institute of Hygiene, Microbial Genome-Plasticity, Münster, Germany
| | - Alexander Mellmann
- University Hospital Münster, Institute of Hygiene, National Consulting Laboratory for Hemolytic Uremic Syndrome (HUS), Münster, Germany
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Bamba M, Aoki S, Kajita T, Setoguchi H, Watano Y, Sato S, Tsuchimatsu T. Exploring Genetic Diversity and Signatures of Horizontal Gene Transfer in Nodule Bacteria Associated with Lotus japonicus in Natural Environments. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2019; 32:1110-1120. [PMID: 30880586 DOI: 10.1094/mpmi-02-19-0039-r] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
To investigate the genetic diversity and understand the process of horizontal gene transfer (HGT) in nodule bacteria associated with Lotus japonicus, we analyzed sequences of three housekeeping and five symbiotic genes using samples from a geographically wide range in Japan. A phylogenetic analysis of the housekeeping genes indicated that L. japonicus in natural environments was associated with diverse lineages of Mesorhizobium spp., whereas the sequences of symbiotic genes were highly similar between strains, resulting in remarkably low nucleotide diversity at both synonymous and nonsynonymous sites. Guanine-cytosine content values were lower in symbiotic genes, and relative frequencies of recombination between symbiotic genes were also lower than those between housekeeping genes. An analysis of molecular variance showed significant genetic differentiation among populations in both symbiotic and housekeeping genes. These results confirm that the Mesorhizobium genes required for symbiosis with L. japonicus behave as a genomic island (i.e., a symbiosis island) and suggest that this island has spread into diverse genomic backgrounds of Mesorhizobium via HGT events in natural environments. Furthermore, our data compilation revealed that the genetic diversity of symbiotic genes in L. japonicus-associated symbionts was among the lowest compared with reports of other species, which may be related to the recent population expansion proposed in Japanese populations of L. japonicus.
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Affiliation(s)
- Masaru Bamba
- Department of Biology (Frontier Science Program), Graduate School of Science and Engineering, Chiba University, 1-33 Yayoi, Inage, Chiba 263-8522, Japan
| | - Seishiro Aoki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Tadashi Kajita
- Iriomote Station, Tropical Biosphere Research Center, the University of Ryukyus, 870 Uehara, Taketomi-cho, Yaeyama-gun, Okinawa 907-1541, Japan
| | - Hiroaki Setoguchi
- Graduate School of Human and Environmental Studies, Kyoto University, Yoshidanihonmatsu-cho, Sakyo-ku, Kyoto 606-8501 Japan
| | - Yasuyuki Watano
- Department of Biology, Graduate School of Science, Chiba University
| | - Shusei Sato
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba, Sendai 980-8577, Japan
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Kraemer SA, Ramachandran A, Perron GG. Antibiotic Pollution in the Environment: From Microbial Ecology to Public Policy. Microorganisms 2019; 7:E180. [PMID: 31234491 PMCID: PMC6616856 DOI: 10.3390/microorganisms7060180] [Citation(s) in RCA: 356] [Impact Index Per Article: 71.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 06/06/2019] [Accepted: 06/10/2019] [Indexed: 01/06/2023] Open
Abstract
The ability to fight bacterial infections with antibiotics has been a longstanding cornerstone of modern medicine. However, wide-spread overuse and misuse of antibiotics has led to unintended consequences, which in turn require large-scale changes of policy for mitigation. In this review, we address two broad classes of corollaries of antibiotics overuse and misuse. Firstly, we discuss the spread of antibiotic resistance from hotspots of resistance evolution to the environment, with special concerns given to potential vectors of resistance transmission. Secondly, we outline the effects of antibiotic pollution independent of resistance evolution on natural microbial populations, as well as invertebrates and vertebrates. We close with an overview of current regional policies tasked with curbing the effects of antibiotics pollution and outline areas in which such policies are still under development.
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Affiliation(s)
- Susanne A Kraemer
- Department of Biology, Concordia University, 7141 Sherbrooke Street W, Montreal, QC H4B1R6, Canada.
| | - Arthi Ramachandran
- Department of Biology, Concordia University, 7141 Sherbrooke Street W, Montreal, QC H4B1R6, Canada.
| | - Gabriel G Perron
- Department of Biology, Reem-Kayden Center for Sciences and Computation, Bard College, 31 Campus Road, Annandale-On-Hudson, NY 12504, USA.
- Center for the Study of Land, Water, and Air, Bard College, Annandale-On-Hudson, NY 12504, USA.
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19
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Leal I, Bergeron MJ, Feau N, Tsui CKM, Foord B, Pellow K, Hamelin RC, Sturrock RN. Cryptic Speciation in Western North America and Eastern Eurasia of the Pathogens Responsible for Laminated Root Rot. PHYTOPATHOLOGY 2019; 109:456-468. [PMID: 30145938 DOI: 10.1094/phyto-12-17-0399-r] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Coniferiporia sulphurascens is a facultative fungal pathogen that causes laminated root rot (LRR) in commercially important coniferous species worldwide. This fungus spreads primarily by way of vegetative mycelium transferring at points of contact between infected and healthy roots. Successful intervention to control LRR requires a better understanding of the population structure and genetic variability of C. sulphurascens. In this study, we investigated the population genetic structure and origin of C. sulphurascens populations in western North America and eastern Eurasia collected from multiple coniferous hosts. By analyzing the small and large mitochondrial ribosomal RNA subunit genes combined with six nuclear loci (internal transcribed spacer region, actin, RNA polymerase II largest subunit, RNA polymerase II second-largest subunit, laccase-like multicopper oxidase, and translation elongation factor 1-α), we observed that none of the alleles among the loci were shared between North American (NA) and Eurasian C. sulphurascens populations. In total, 55 multilocus genotypes (MLGs) were retrieved in C. sulphurascens isolates occurring in these two continental regions. Of these, 41 MLGs were observed among 58 isolates collected from widespread locations in British Columbia (Canada) and the northwestern United States, while 14 MLGs were observed among 16 isolates sampled in Siberia and Japan. Our data showed that the levels of genetic differentiation between the NA and Eurasian populations are much greater than the populations from within each continental region; the two continental populations formed clearly divergent phylogenetic clades or lineages since they were separated approximately 7.5 million years ago. Moreover, the Eurasian population could be the source of the NA population. Our study indicates the existence of cryptic diversity in this pathogen species, and strongly suggests that the NA and Eurasian populations represent two lineages, which have progressively diverged from each other in allopatry.
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Affiliation(s)
- I Leal
- First, fifth, sixth, and eighth authors: Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, 506 West Burnside Road, Victoria, BC V8Z 1M5 Canada; second author: Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 rue du P.E.P.S., Québec, QC G1V 4C7 Canada; third and seventh authors: Department of Forest and Conservation Sciences, University of British Columbia, 3041-2424 Main Mall, Vancouver, BC V6T 1Z4 Canada; fourth author: Department of Pathology, Sidra Medicine, PO Box 26999, Doha, Qatar, and Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, Doha, Qatar; and seventh author: Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval/Pavillon Charles-Eugène Marchand, 1030 avenue de la Médecine, Québec, QC G1V 0A6 Canada
| | - M-J Bergeron
- First, fifth, sixth, and eighth authors: Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, 506 West Burnside Road, Victoria, BC V8Z 1M5 Canada; second author: Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 rue du P.E.P.S., Québec, QC G1V 4C7 Canada; third and seventh authors: Department of Forest and Conservation Sciences, University of British Columbia, 3041-2424 Main Mall, Vancouver, BC V6T 1Z4 Canada; fourth author: Department of Pathology, Sidra Medicine, PO Box 26999, Doha, Qatar, and Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, Doha, Qatar; and seventh author: Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval/Pavillon Charles-Eugène Marchand, 1030 avenue de la Médecine, Québec, QC G1V 0A6 Canada
| | - N Feau
- First, fifth, sixth, and eighth authors: Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, 506 West Burnside Road, Victoria, BC V8Z 1M5 Canada; second author: Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 rue du P.E.P.S., Québec, QC G1V 4C7 Canada; third and seventh authors: Department of Forest and Conservation Sciences, University of British Columbia, 3041-2424 Main Mall, Vancouver, BC V6T 1Z4 Canada; fourth author: Department of Pathology, Sidra Medicine, PO Box 26999, Doha, Qatar, and Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, Doha, Qatar; and seventh author: Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval/Pavillon Charles-Eugène Marchand, 1030 avenue de la Médecine, Québec, QC G1V 0A6 Canada
| | - C K M Tsui
- First, fifth, sixth, and eighth authors: Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, 506 West Burnside Road, Victoria, BC V8Z 1M5 Canada; second author: Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 rue du P.E.P.S., Québec, QC G1V 4C7 Canada; third and seventh authors: Department of Forest and Conservation Sciences, University of British Columbia, 3041-2424 Main Mall, Vancouver, BC V6T 1Z4 Canada; fourth author: Department of Pathology, Sidra Medicine, PO Box 26999, Doha, Qatar, and Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, Doha, Qatar; and seventh author: Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval/Pavillon Charles-Eugène Marchand, 1030 avenue de la Médecine, Québec, QC G1V 0A6 Canada
| | - B Foord
- First, fifth, sixth, and eighth authors: Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, 506 West Burnside Road, Victoria, BC V8Z 1M5 Canada; second author: Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 rue du P.E.P.S., Québec, QC G1V 4C7 Canada; third and seventh authors: Department of Forest and Conservation Sciences, University of British Columbia, 3041-2424 Main Mall, Vancouver, BC V6T 1Z4 Canada; fourth author: Department of Pathology, Sidra Medicine, PO Box 26999, Doha, Qatar, and Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, Doha, Qatar; and seventh author: Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval/Pavillon Charles-Eugène Marchand, 1030 avenue de la Médecine, Québec, QC G1V 0A6 Canada
| | - K Pellow
- First, fifth, sixth, and eighth authors: Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, 506 West Burnside Road, Victoria, BC V8Z 1M5 Canada; second author: Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 rue du P.E.P.S., Québec, QC G1V 4C7 Canada; third and seventh authors: Department of Forest and Conservation Sciences, University of British Columbia, 3041-2424 Main Mall, Vancouver, BC V6T 1Z4 Canada; fourth author: Department of Pathology, Sidra Medicine, PO Box 26999, Doha, Qatar, and Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, Doha, Qatar; and seventh author: Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval/Pavillon Charles-Eugène Marchand, 1030 avenue de la Médecine, Québec, QC G1V 0A6 Canada
| | - R C Hamelin
- First, fifth, sixth, and eighth authors: Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, 506 West Burnside Road, Victoria, BC V8Z 1M5 Canada; second author: Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 rue du P.E.P.S., Québec, QC G1V 4C7 Canada; third and seventh authors: Department of Forest and Conservation Sciences, University of British Columbia, 3041-2424 Main Mall, Vancouver, BC V6T 1Z4 Canada; fourth author: Department of Pathology, Sidra Medicine, PO Box 26999, Doha, Qatar, and Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, Doha, Qatar; and seventh author: Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval/Pavillon Charles-Eugène Marchand, 1030 avenue de la Médecine, Québec, QC G1V 0A6 Canada
| | - R N Sturrock
- First, fifth, sixth, and eighth authors: Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, 506 West Burnside Road, Victoria, BC V8Z 1M5 Canada; second author: Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 rue du P.E.P.S., Québec, QC G1V 4C7 Canada; third and seventh authors: Department of Forest and Conservation Sciences, University of British Columbia, 3041-2424 Main Mall, Vancouver, BC V6T 1Z4 Canada; fourth author: Department of Pathology, Sidra Medicine, PO Box 26999, Doha, Qatar, and Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, Doha, Qatar; and seventh author: Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval/Pavillon Charles-Eugène Marchand, 1030 avenue de la Médecine, Québec, QC G1V 0A6 Canada
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Castañeda-Montes F, Avitia M, Sepúlveda-Robles O, Cruz-Sánchez V, Kameyama L, Guarneros G, Escalante A. Population structure of Pseudomonas aeruginosa through a MLST approach and antibiotic resistance profiling of a Mexican clinical collection. INFECTION GENETICS AND EVOLUTION 2018; 65:43-54. [DOI: 10.1016/j.meegid.2018.06.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 06/05/2018] [Accepted: 06/06/2018] [Indexed: 01/14/2023]
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21
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Muñoz M, Camargo M, Ramírez JD. Estimating the Intra-taxa Diversity, Population Genetic Structure, and Evolutionary Pathways of Cryptococcus neoformans and Cryptococcus gattii. Front Genet 2018; 9:148. [PMID: 29740480 PMCID: PMC5928140 DOI: 10.3389/fgene.2018.00148] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 04/09/2018] [Indexed: 12/20/2022] Open
Abstract
Members of the Cryptococcus complex, includes Cryptococcus neoformans (most common fungal infection of the brain) and Cryptococcus gattii (high-impact emerging pathogen worldwide). Currently, the fungal multilocus sequence typing database (Fungal MLST Database) constitutes a valuable data repository of the genes used for molecular typing of these pathogens. We analyzed the data available in the Fungal MLST Database for seven housekeeping genes, with the aim to evaluate its contribution in the description of intra-taxa diversity, population genetic structure, and evolutionary patterns. Although the Fungal MLST Database has a greater number of reports for C. neoformans (n = 487) than for C. gattii (n = 344), similar results were obtained for both species in terms of allelic diversity. Phylogenetic reconstructions revealed grouping by molecular type in both species and allowed us to propose differences in evolutionary patterns (gradualism in the case of C. neoformans and punctuated evolution in the case of C. gattii). In addition, C. neoformans showed a population genetic structure consisting of 37 clonal complexes (CCs; CC1 being predominant), high crosslinking [without sequence type (ST) grouping by molecular type], marked divergence events in phylogenetic analysis, and few introgression events (mainly between VNI and VNIV). By contrast, C. gattii showed 50 CCs (with greater homogeneity in ST number by CC) and clustering by molecular type with marked crosslinking events in phylogenetic networks being less evident. Understanding relationships at the molecular level for species of the Cryptococcus complex, based on the sequences of the housekeeping genes, provides information for describing the evolutionary history of these emerging pathogens.
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Affiliation(s)
- Marina Muñoz
- Grupo de Investigaciones Microbiológicas-UR (GIMUR), Programa de Biología, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia
- Centro de Tecnología en Salud (CETESA), Upqua SAS, Bogotá, Colombia
- Posgrado Interfacultades Doctorado en Biotecnología, Facultad de Ciencias, Universidad Nacional de Colombia, Bogotá, Colombia
| | - Milena Camargo
- Centro de Tecnología en Salud (CETESA), Upqua SAS, Bogotá, Colombia
- Departamento de Biología Molecular e Inmunología, Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia
- Doctorado en Ciencias Biomédicas y Biológicas, Universidad del Rosario, Bogotá, Colombia
| | - Juan D. Ramírez
- Grupo de Investigaciones Microbiológicas-UR (GIMUR), Programa de Biología, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia
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22
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Kaczmarek M, Mullett MS, McDonald JE, Denman S. Multilocus sequence typing provides insights into the population structure and evolutionary potential of Brenneria goodwinii, associated with acute oak decline. PLoS One 2017; 12:e0178390. [PMID: 28570630 PMCID: PMC5453491 DOI: 10.1371/journal.pone.0178390] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 05/14/2017] [Indexed: 11/18/2022] Open
Abstract
Brenneria goodwinii is one of the most frequently isolated Gram-negative bacteria from native oak species, Quercus robur and Q. petraea, affected by acute oak decline (AOD) in the UK. We investigated the population biology of this bacterial species using a multilocus sequence analysis to determine the population structure and evolutionary potential. Seven partial housekeeping genes were used in the analyses. Amongst 44 bacterial strains from seven different locations, we identified 22 unique sequence types [STs]; only one ST was found at two separate locations. Phylogenetic and cluster-based analyses suggested that B. goodwinii STs form two main distinct groups; however, no geographical pattern of their distribution could be observed. Clonality and recombination tests demonstrated that the studied population is primarily clonal, however both mutation and recombination processes play a role in shaping the genetic structure and evolution of the population. Our study suggests that the B. goodwinii population on oak in the UK has an endemic form, with background recombination appearing to generate new alleles more frequently than mutation, despite the introduction of nucleotide substitutions being approximately twice less likely than mutation. The newly emerged STs subsequently undergo clonal expansion to become dominant genotypes within their specific geographical locations and even within the individual host oak trees.
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Affiliation(s)
- Maciej Kaczmarek
- Bangor University, School of Biological Sciences, Bangor, Gwynedd, United Kingdom
- Forest Research, Centre for Ecosystems, Society and Biosecurity, Alice Holt Lodge, Farnham, Surrey, United Kingdom
- * E-mail: (SD); (MK)
| | - Martin S. Mullett
- Forest Research, Centre for Ecosystems, Society and Biosecurity, Alice Holt Lodge, Farnham, Surrey, United Kingdom
| | - James E. McDonald
- Bangor University, School of Biological Sciences, Bangor, Gwynedd, United Kingdom
| | - Sandra Denman
- Forest Research, Centre for Ecosystems, Society and Biosecurity, Alice Holt Lodge, Farnham, Surrey, United Kingdom
- * E-mail: (SD); (MK)
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Abstract
Bacteria can exchange and acquire new genetic material from other organisms directly and via the environment. This process, known as bacterial recombination, has a strong impact on the evolution of bacteria, for example, leading to the spread of antibiotic resistance across clades and species, and to the avoidance of clonal interference. Recombination hinders phylogenetic and transmission inference because it creates patterns of substitutions (homoplasies) inconsistent with the hypothesis of a single evolutionary tree. Bacterial recombination is typically modeled as statistically akin to gene conversion in eukaryotes, i.e., using the coalescent with gene conversion (CGC). However, this model can be very computationally demanding as it needs to account for the correlations of evolutionary histories of even distant loci. So, with the increasing popularity of whole genome sequencing, the need has emerged for a faster approach to model and simulate bacterial genome evolution. We present a new model that approximates the coalescent with gene conversion: the bacterial sequential Markov coalescent (BSMC). Our approach is based on a similar idea to the sequential Markov coalescent (SMC)-an approximation of the coalescent with crossover recombination. However, bacterial recombination poses hurdles to a sequential Markov approximation, as it leads to strong correlations and linkage disequilibrium across very distant sites in the genome. Our BSMC overcomes these difficulties, and shows a considerable reduction in computational demand compared to the exact CGC, and very similar patterns in simulated data. We implemented our BSMC model within new simulation software FastSimBac. In addition to the decreased computational demand compared to previous bacterial genome evolution simulators, FastSimBac provides more general options for evolutionary scenarios, allowing population structure with migration, speciation, population size changes, and recombination hotspots. FastSimBac is available from https://bitbucket.org/nicofmay/fastsimbac, and is distributed as open source under the terms of the GNU General Public License. Lastly, we use the BSMC within an Approximate Bayesian Computation (ABC) inference scheme, and suggest that parameters simulated under the exact CGC can correctly be recovered, further showcasing the accuracy of the BSMC. With this ABC we infer recombination rate, mutation rate, and recombination tract length of Bacillus cereus from a whole genome alignment.
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Affiliation(s)
- Nicola De Maio
- Institute for Emerging Infections, Oxford Martin School, University of Oxford, Oxford, OX1 3PA, United Kingdom
- Nuffield Department of Medicine, University of Oxford, Oxford, OX1 3PA, United Kingdom
| | - Daniel J Wilson
- Institute for Emerging Infections, Oxford Martin School, University of Oxford, Oxford, OX1 3PA, United Kingdom
- Nuffield Department of Medicine, University of Oxford, Oxford, OX1 3PA, United Kingdom
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, OX1 3PA, United Kingdom
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Kreis RA, Dillard HR, Smart CD. Population Diversity and Sensitivity to Azoxystrobin of Alternaria brassicicola in New York State. PLANT DISEASE 2016; 100:2422-2426. [PMID: 30686174 DOI: 10.1094/pdis-03-16-0414-re] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Alternaria brassicicola is the causal agent of Alternaria leaf spot, a common disease of brassica crops in New York State. New York isolates of A. brassicicola were collected from a variety of brassica crops and locations to evaluate the population diversity and screen for fungicide sensitivity. Isolates were genotyped for 10 microsatellite loci and assayed for sensitivity to azoxystrobin, a quinone outside inhibitor fungicide. The New York State population of A. brassicicola was found to have high levels of genotypic diversity and the population was found to be in linkage disequilibrium. Based on in vitro assays, the effective concentrations of azoxystrobin reducing spore germination by 50% ranged from 0.22 to 14.12 μg/ml. In order to confirm the sensitivity of 47 isolates to azoxystrobin, the cytb gene was characterized and sequenced to determine whether any of the mutations known to confer resistance to azoxystrobin were present. The mutations F129L, G137R, and G143A were not detected in the isolates studied.
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Affiliation(s)
- Rachel A Kreis
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Geneva, NY 14456
| | - Helene R Dillard
- College of Agricultural and Environmental Sciences, University of California, Davis, CA 95616
| | - Christine D Smart
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Geneva, NY 14456
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25
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Pires Dos Santos T, Damborg P, Moodley A, Guardabassi L. Systematic Review on Global Epidemiology of Methicillin-Resistant Staphylococcus pseudintermedius: Inference of Population Structure from Multilocus Sequence Typing Data. Front Microbiol 2016; 7:1599. [PMID: 27803691 PMCID: PMC5067483 DOI: 10.3389/fmicb.2016.01599] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 09/26/2016] [Indexed: 12/14/2022] Open
Abstract
Background and rationale: Methicillin-resistant Staphylococcus pseudintermedius (MRSP) is a major cause of infections in dogs, also posing a zoonotic risk to humans. This systematic review aimed to determine the global epidemiology of MRSP and provide new insights into the population structure of this important veterinary pathogen. Methodology: Web of Science was searched systematically for articles reporting data on multilocus sequence typing (MLST) of S. pseudintermedius isolates from dogs or other animal or human patients and carriers. Data from the eligible studies were then integrated with data from the MLST database for this species. Analysis of MLST data was performed with eBURST and ClonalFrame, and the proportion of MRSP isolates resistant to selected antimicrobial drugs was determined for the most predominant clonal complexes. Results: Fifty-eight studies published over the last 10 years were included in the review. MRSP represented 76% of the 1428 isolates characterized by the current MLST scheme. The population of S. pseudintermedius was highly diverse and included five major MRSP clonal complexes (CCs). CC71, previously described as the epidemic European clone, is now widespread worldwide. In Europe, CC258, which is more frequently susceptible to enrofloxacin and aminoglycosides, and more frequently resistant to sulphonamides/trimethoprim than CC71, is increasingly reported in various countries. CC68, previously described as the epidemic North American clone, is frequently reported in this region but also in Europe, while CC45 (associated with chloramphenicol resistance) and CC112 are prevalent in Asia. It was estimated that clonal diversification in this species is primarily driven by homologous recombination (r/m = 7.52). Conclusion: This study provides evidence that S. pseudintermedius has an epidemic population structure, in which five successful MRSP lineages with specific traits regarding antimicrobial resistance, genetic diversity and geographical distribution have emerged upon a weakly clonal background through acquisition of SCCmec and other mobile genetic elements.
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Affiliation(s)
- Teresa Pires Dos Santos
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen Frederiksberg, Denmark
| | - Peter Damborg
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen Frederiksberg, Denmark
| | - Arshnee Moodley
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen Frederiksberg, Denmark
| | - Luca Guardabassi
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of CopenhagenFrederiksberg, Denmark; Department of Biomedical Sciences, Ross University School of Veterinary MedicineSt Kitts, West Indies
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26
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Hui BB, Whiley DM, Donovan B, Law MG, Regan DG. Identifying factors that lead to the persistence of imported gonorrhoeae strains: a modelling study. Sex Transm Infect 2016; 93:221-225. [PMID: 28432206 DOI: 10.1136/sextrans-2016-052738] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 09/15/2016] [Accepted: 09/29/2016] [Indexed: 11/03/2022] Open
Abstract
OBJECTIVE The importation of Neisseria gonorrhoeae (NG) strains from overseas is believed to be the main source of antimicrobial resistance in Australia. With recent sporadic cases of ceftriaxone-resistant gonorrhoea reported in Australia and elsewhere, we sought to model the potential for imported NG strains to persist in the men who have sex with men (MSM) population in Australia. METHODS We developed an individual-based model to simulate the transmission of NG in a population of urban MSM, and used this model to investigate factors contributing to the probability that an imported NG strain will persist. RESULTS The probability of the imported NG strain persisting as the result of a single importation event is less than 1%, but the probability increases to 1% if the imported NG strain is resistant to treatment, and further increases to 3.1% if the imported NG strain can also form mixed infections with the local NG strain. The probability of the imported NG strain persisting increases to 4.4% if there are at least three importation events per month within a 1-year period. CONCLUSION The imported NG strain is unlikely to persist as a result of a single importation event. However, the probability of persistence increases if the imported NG strain is resistant to treatment, can form mixed infections with the local NG strain or there are frequent importation events. Identification of the factors that determine the likelihood of persistence of an imported NG strain could contribute to our capacity to respond appropriately and in a timely fashion.
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Affiliation(s)
- Ben B Hui
- The Kirby Institute, UNSW Australia, Sydney, New South Wales, Australia
| | - David M Whiley
- University of Queensland Centre for Clinical Research, University of Queensland, Brisbane, Queensland, Australia
| | - Basil Donovan
- The Kirby Institute, UNSW Australia, Sydney, New South Wales, Australia.,Sydney Sexual Health Centre, Sydney Hospital, Sydney, New South Wales, Australia
| | - Matthew G Law
- The Kirby Institute, UNSW Australia, Sydney, New South Wales, Australia
| | - David G Regan
- The Kirby Institute, UNSW Australia, Sydney, New South Wales, Australia
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27
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Hanage WP. Not So Simple After All: Bacteria, Their Population Genetics, and Recombination. Cold Spring Harb Perspect Biol 2016; 8:cshperspect.a018069. [PMID: 27091940 DOI: 10.1101/cshperspect.a018069] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The pervasive nature of bacterial recombination has become clear. Despite this, the population genetics of bacteria persist in being viewed as simple. Here, I argue against that characterization. After summarizing the history of the topic, I survey the evidence for remarkable and unexplained variation in recombination rate among and within bacterial species. I finally argue that despite recent assertions that recombination means bacterial genes are "public goods," in bacteria the level of selection is the gene, and genes can be understood to have niches with dimensions including the other contents of the genome in which they find themselves.
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Affiliation(s)
- William P Hanage
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts 02115
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28
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Vaghefi N, Hay FS, Kikkert JR, Pethybridge SJ. Genotypic Diversity and Resistance to Azoxystrobin of Cercospora beticola on Processing Table Beet in New York. PLANT DISEASE 2016; 100:1466-1473. [PMID: 30686198 DOI: 10.1094/pdis-09-15-1014-re] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Cercospora leaf spot (CLS), caused by Cercospora beticola, is one of the major diseases affecting productivity and profitability of beet production worldwide. Fungicides are critical for the control of this disease and one of the most commonly used products is the quinone outside inhibitor (QOI) azoxystrobin. In total, 150 C. beticola isolates were collected from two commercial processing table beet fields in Batavia, NY in 2014. The mating types of the entire population were determined, and genetic diversity of a subset of samples (n = 48) was assessed using five microsatellite loci. Sensitivity to azoxystrobin was tested using a spore germination assay. The cytochrome b gene was sequenced to check for the presence of point mutations known to confer QOI resistance in fungi. High allelic diversity (He = 0.50) and genotypic diversity (D* = 0.96), gametic equilibrium of the microsatellite loci, and equal ratios of mating types were suggestive of a mixed mode of reproduction for C. beticola. Resistance to azoxystrobin was prevalent because 41% of the isolates had values for effective concentrations reducing spore germination by 50% (EC50) > 0.2 μg/ml. The G143A mutation, known to cause QOI resistance in C. beticola, was found in isolates with EC50 values between 0.207 and 19.397 μg/ml. A single isolate with an EC50 of 0.272 μg/ml carried the F129L mutation, known to be associated with low levels of QOI resistance in fungi. This is the first report of the F129L mutation in C. beticola. The implications of these findings for the epidemiology and control of CLS in table beet fields in New York are discussed.
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Affiliation(s)
- Niloofar Vaghefi
- School of Integrative Plant Sciences, Plant Pathology & Plant-Microbe Biology Section, Cornell University, Geneva, NY 14456
| | - Frank S Hay
- School of Integrative Plant Sciences, Plant Pathology & Plant-Microbe Biology Section, Cornell University, Geneva, NY 14456
| | | | - Sarah J Pethybridge
- School of Integrative Plant Sciences, Plant Pathology & Plant-Microbe Biology Section, Cornell University, Geneva, NY 14456
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29
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Whole-Genome Sequencing for Routine Pathogen Surveillance in Public Health: a Population Snapshot of Invasive Staphylococcus aureus in Europe. mBio 2016; 7:mBio.00444-16. [PMID: 27150362 PMCID: PMC4959656 DOI: 10.1128/mbio.00444-16] [Citation(s) in RCA: 141] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The implementation of routine whole-genome sequencing (WGS) promises to transform our ability to monitor the emergence and spread of bacterial pathogens. Here we combined WGS data from 308 invasive Staphylococcus aureus isolates corresponding to a pan-European population snapshot, with epidemiological and resistance data. Geospatial visualization of the data is made possible by a generic software tool designed for public health purposes that is available at the project URL (http://www.microreact.org/project/EkUvg9uY?tt=rc). Our analysis demonstrates that high-risk clones can be identified on the basis of population level properties such as clonal relatedness, abundance, and spatial structuring and by inferring virulence and resistance properties on the basis of gene content. We also show that in silico predictions of antibiotic resistance profiles are at least as reliable as phenotypic testing. We argue that this work provides a comprehensive road map illustrating the three vital components for future molecular epidemiological surveillance: (i) large-scale structured surveys, (ii) WGS, and (iii) community-oriented database infrastructure and analysis tools. The spread of antibiotic-resistant bacteria is a public health emergency of global concern, threatening medical intervention at every level of health care delivery. Several recent studies have demonstrated the promise of routine whole-genome sequencing (WGS) of bacterial pathogens for epidemiological surveillance, outbreak detection, and infection control. However, as this technology becomes more widely adopted, the key challenges of generating representative national and international data sets and the development of bioinformatic tools to manage and interpret the data become increasingly pertinent. This study provides a road map for the integration of WGS data into routine pathogen surveillance. We emphasize the importance of large-scale routine surveys to provide the population context for more targeted or localized investigation and the development of open-access bioinformatic tools to provide the means to combine and compare independently generated data with publicly available data sets.
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30
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The impact of host metapopulation structure on the population genetics of colonizing bacteria. J Theor Biol 2016; 396:53-62. [DOI: 10.1016/j.jtbi.2016.02.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 01/15/2016] [Accepted: 02/13/2016] [Indexed: 11/17/2022]
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Hollowell AC, Regus JU, Turissini D, Gano-Cohen KA, Bantay R, Bernardo A, Moore D, Pham J, Sachs JL. Metapopulation dominance and genomic-island acquisition of Bradyrhizobium with superior catabolic capabilities. Proc Biol Sci 2016; 283:20160496. [PMID: 27122562 PMCID: PMC4855393 DOI: 10.1098/rspb.2016.0496] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 04/04/2016] [Indexed: 01/05/2023] Open
Abstract
Root nodule-forming rhizobia exhibit a bipartite lifestyle, replicating in soil and also within plant cells where they fix nitrogen for legume hosts. Host control models posit that legume hosts act as a predominant selective force on rhizobia, but few studies have examined rhizobial fitness in natural populations. Here, we genotyped and phenotyped Bradyrhizobium isolates across more than 800 km of the native Acmispon strigosus host range. We sequenced chromosomal genes expressed under free-living conditions and accessory symbiosis loci expressed in planta and encoded on an integrated 'symbiosis island' (SI). We uncovered a massive clonal expansion restricted to the Bradyrhizobium chromosome, with a single chromosomal haplotype dominating populations, ranging more than 700 km, and acquiring 42 divergent SI haplotypes, none of which were spatially widespread. For focal genotypes, we quantified utilization of 190 sole-carbon sources relevant to soil fitness. Chromosomal haplotypes that were both widespread and dominant exhibited superior growth on diverse carbon sources, whereas these patterns were not mirrored among SI haplotypes. Abundance, spatial range and catabolic superiority of chromosomal, but not symbiosis genotypes suggests that fitness in the soil environment, rather than symbiosis with hosts, might be the key driver of Bradyrhizobium dominance.
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Affiliation(s)
- Amanda C Hollowell
- Department of Biology, University of California, Riverside, CA 92521, USA
| | - John U Regus
- Department of Biology, University of California, Riverside, CA 92521, USA
| | - David Turissini
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | | | - Roxanne Bantay
- Department of Biology, University of California, Riverside, CA 92521, USA
| | - Andrew Bernardo
- Department of Biology, University of California, Riverside, CA 92521, USA
| | - Devora Moore
- Department of Biology, University of California, Riverside, CA 92521, USA
| | - Jonathan Pham
- Department of Biology, University of California, Riverside, CA 92521, USA
| | - Joel L Sachs
- Department of Biology, University of California, Riverside, CA 92521, USA Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA
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Ashrafi R, Pulkkinen K, Sundberg LR, Pekkala N, Ketola T. A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates. BMC Microbiol 2015; 15:243. [PMID: 26518592 PMCID: PMC4628280 DOI: 10.1186/s12866-015-0576-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 10/16/2015] [Indexed: 12/02/2022] Open
Abstract
Background Columnaris disease caused by Flavobacterium columnare is a serious problem in aquaculture, annually causing large economic losses around the world. Despite considerable research, the molecular epidemiology of F. columnare remains poorly understood. Methods We investigated the population structure and spatiotemporal changes in the genetic diversity of F. columnare population in Finland by using a multilocus sequence typing (MLST) and analysis (MLSA) based on DNA sequence variation within six housekeeping genes. A total of 83 strains of F. columnare were collected from eight different areas located across the country between 2003 and 2012. Results Partial sequencing of six housekeeping genes (trpB, tuf, atpA, rpoD, gyrB and dnaK) revealed eight sequence types and a moderate level of genetic diversity (H = 0.460). Phylogenetic analysis of the concatenated protein-encoding gene sequence data (ca. 3,509 nucleotides) formed two lineages, which could be further divided into five clusters. All analysed F. columnare strains appeared to have a genetic origin distinct from that of another important fish pathogen form the genus Flavobacterium, F. psychrophilum. Although the value of the index of association between alleles, 0.292 (P < 0.001), supports some degree of clonality for this species in Finland, recombination has introduced molecular diversity to the population almost three times more than mutation. Conclusion The results suggest that Finnish F. columnare strains have an epidemic population structure followed by clonal expansion of successful genotypes. Our study with reproducible methodology and comparable results establishes a robust framework for the discrimination and phylogenetic analysis of F. columnare isolates, which will help to improve our understanding about geographic distribution and epidemiology of columnaris disease. Electronic supplementary material The online version of this article (doi:10.1186/s12866-015-0576-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Roghaieh Ashrafi
- Centre of Excellence in Biological Interactions, Department of Biological and Environmental Science, University of Jyvaskyla, P.O. Box 35, Jyväskylän yliopisto, FI-40014, Finland.
| | - Katja Pulkkinen
- Department of Biological and Environmental Science, University of Jyvaskyla, P.O. Box 35, Jyväskylän yliopisto, FI-40014, Finland.
| | - Lotta-Riina Sundberg
- Centre of Excellence in Biological Interactions, Department of Biological and Environmental Science, University of Jyvaskyla, P.O. Box 35, Jyväskylän yliopisto, FI-40014, Finland.
| | - Nina Pekkala
- Department of Biological and Environmental Science, University of Jyvaskyla, P.O. Box 35, Jyväskylän yliopisto, FI-40014, Finland.
| | - Tarmo Ketola
- Centre of Excellence in Biological Interactions, Department of Biological and Environmental Science, University of Jyvaskyla, P.O. Box 35, Jyväskylän yliopisto, FI-40014, Finland.
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The evolution and epidemiology of Listeria monocytogenes in Europe and the United States. INFECTION GENETICS AND EVOLUTION 2015; 35:172-83. [DOI: 10.1016/j.meegid.2015.08.008] [Citation(s) in RCA: 145] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 08/03/2015] [Accepted: 08/04/2015] [Indexed: 11/20/2022]
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Hawksworth J, Levy M, Smale C, Cheung D, Whittle A, Longhurst D, Muir P, Gibson W. Population structure and genetic diversity of the parasite Trichomonas vaginalis in Bristol, UK. INFECTION GENETICS AND EVOLUTION 2015; 34:36-43. [DOI: 10.1016/j.meegid.2015.06.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 06/03/2015] [Accepted: 06/04/2015] [Indexed: 10/23/2022]
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35
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Fischer-Le Saux M, Bonneau S, Essakhi S, Manceau C, Jacques MA. Aggressive Emerging Pathovars of Xanthomonas arboricola Represent Widespread Epidemic Clones Distinct from Poorly Pathogenic Strains, as Revealed by Multilocus Sequence Typing. Appl Environ Microbiol 2015; 81:4651-68. [PMID: 25934623 PMCID: PMC4551192 DOI: 10.1128/aem.00050-15] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 04/25/2015] [Indexed: 12/11/2022] Open
Abstract
Deep and comprehensive knowledge of the genetic structure of pathogenic species is the cornerstone on which the design of precise molecular diagnostic tools is built. Xanthomonas arboricola is divided into pathovars, some of which are classified as quarantine organisms in many countries and are responsible for diseases on nut and stone fruit trees that have emerged worldwide. Recent taxonomic studies of the genus Xanthomonas showed that strains isolated from other hosts should be classified in X. arboricola, extending the host range of the species. To investigate the genetic structure of X. arboricola and the genetic relationships between highly pathogenic strains and strains apparently not relevant to plant health, we conducted multilocus sequence analyses on a collection of strains representative of the known diversity of the species. Most of the pathovars were clustered in separate monophyletic groups. The pathovars pruni, corylina, and juglandis, responsible for pandemics in specific hosts, were highly phylogenetically related and clustered in three distinct clonal complexes. In contrast, strains with no or uncertain pathogenicity were represented by numerous unrelated singletons scattered in the phylogenic tree. Depending on the pathovar, intra- and interspecies recombination played contrasting roles in generating nucleotide polymorphism. This work provides a population genetics framework for molecular epidemiological surveys of emerging plant pathogens within X. arboricola. Based on our results, we propose to reclassify three former pathovars of Xanthomonas campestris as X. arboricola pv. arracaciae comb. nov., X. arboricola pv. guizotiae comb. nov., and X. arboricola pv. zantedeschiae comb. nov. An emended description of X. arboricola Vauterin et al. 1995 is provided.
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Affiliation(s)
- Marion Fischer-Le Saux
- INRA, UMR1345 IRHS Institut de Recherche en Horticulture et Semences, Beaucouzé, France Université d'Angers, UMR1345 IRHS Institut de Recherche en Horticulture et Semences, Beaucouzé, France Agrocampus Ouest, UMR1345 IRHS Institut de Recherche en Horticulture et Semences, Beaucouzé, France
| | - Sophie Bonneau
- INRA, UMR1345 IRHS Institut de Recherche en Horticulture et Semences, Beaucouzé, France Université d'Angers, UMR1345 IRHS Institut de Recherche en Horticulture et Semences, Beaucouzé, France Agrocampus Ouest, UMR1345 IRHS Institut de Recherche en Horticulture et Semences, Beaucouzé, France
| | - Salwa Essakhi
- INRA, UMR1345 IRHS Institut de Recherche en Horticulture et Semences, Beaucouzé, France Université d'Angers, UMR1345 IRHS Institut de Recherche en Horticulture et Semences, Beaucouzé, France Agrocampus Ouest, UMR1345 IRHS Institut de Recherche en Horticulture et Semences, Beaucouzé, France
| | - Charles Manceau
- INRA, UMR1345 IRHS Institut de Recherche en Horticulture et Semences, Beaucouzé, France Université d'Angers, UMR1345 IRHS Institut de Recherche en Horticulture et Semences, Beaucouzé, France Agrocampus Ouest, UMR1345 IRHS Institut de Recherche en Horticulture et Semences, Beaucouzé, France
| | - Marie-Agnès Jacques
- INRA, UMR1345 IRHS Institut de Recherche en Horticulture et Semences, Beaucouzé, France Université d'Angers, UMR1345 IRHS Institut de Recherche en Horticulture et Semences, Beaucouzé, France Agrocampus Ouest, UMR1345 IRHS Institut de Recherche en Horticulture et Semences, Beaucouzé, France
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Papke RT, Corral P, Ram-Mohan N, de la Haba RR, Sánchez-Porro C, Makkay A, Ventosa A. Horizontal gene transfer, dispersal and haloarchaeal speciation. Life (Basel) 2015; 5:1405-26. [PMID: 25997110 PMCID: PMC4500145 DOI: 10.3390/life5021405] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 05/08/2015] [Accepted: 05/11/2015] [Indexed: 11/28/2022] Open
Abstract
The Halobacteria are a well-studied archaeal class and numerous investigations are showing how their diversity is distributed amongst genomes and geographic locations. Evidence indicates that recombination between species continuously facilitates the arrival of new genes, and within species, it is frequent enough to spread acquired genes amongst all individuals in the population. To create permanent independent diversity and generate new species, barriers to recombination are probably required. The data support an interpretation that rates of evolution (e.g., horizontal gene transfer and mutation) are faster at creating geographically localized variation than dispersal and invasion are at homogenizing genetic differences between locations. Therefore, we suggest that recurrent episodes of dispersal followed by variable periods of endemism break the homogenizing forces of intrapopulation recombination and that this process might be the principal stimulus leading to divergence and speciation in Halobacteria.
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Affiliation(s)
- R. Thane Papke
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA; E-Mails: (N.R.-M.); (A.M.)
- Author to whom correspondence should be addressed; E-Mail:
| | - Paulina Corral
- Department of Microbiology and Parasitology, University of Seville, 41004 Seville, Spain; E-Mails: (P.C.); (R.R.H.); (C.S.-P.); (A.V.)
| | - Nikhil Ram-Mohan
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA; E-Mails: (N.R.-M.); (A.M.)
| | - Rafael R. de la Haba
- Department of Microbiology and Parasitology, University of Seville, 41004 Seville, Spain; E-Mails: (P.C.); (R.R.H.); (C.S.-P.); (A.V.)
| | - Cristina Sánchez-Porro
- Department of Microbiology and Parasitology, University of Seville, 41004 Seville, Spain; E-Mails: (P.C.); (R.R.H.); (C.S.-P.); (A.V.)
| | - Andrea Makkay
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA; E-Mails: (N.R.-M.); (A.M.)
| | - Antonio Ventosa
- Department of Microbiology and Parasitology, University of Seville, 41004 Seville, Spain; E-Mails: (P.C.); (R.R.H.); (C.S.-P.); (A.V.)
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Teixeira AS, Monteiro PT, Carriço JA, Ramirez M, Francisco AP. Not seeing the forest for the trees: size of the minimum spanning trees (MSTs) forest and branch significance in MST-based phylogenetic analysis. PLoS One 2015; 10:e0119315. [PMID: 25799056 PMCID: PMC4370493 DOI: 10.1371/journal.pone.0119315] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 12/18/2014] [Indexed: 11/23/2022] Open
Abstract
Trees, including minimum spanning trees (MSTs), are commonly used in phylogenetic studies. But, for the research community, it may be unclear that the presented tree is just a hypothesis, chosen from among many possible alternatives. In this scenario, it is important to quantify our confidence in both the trees and the branches/edges included in such trees. In this paper, we address this problem for MSTs by introducing a new edge betweenness metric for undirected and weighted graphs. This spanning edge betweenness metric is defined as the fraction of equivalent MSTs where a given edge is present. The metric provides a per edge statistic that is similar to that of the bootstrap approach frequently used in phylogenetics to support the grouping of taxa. We provide methods for the exact computation of this metric based on the well known Kirchhoff’s matrix tree theorem. Moreover, we implement and make available a module for the PHYLOViZ software and evaluate the proposed metric concerning both effectiveness and computational performance. Analysis of trees generated using multilocus sequence typing data (MLST) and the goeBURST algorithm revealed that the space of possible MSTs in real data sets is extremely large. Selection of the edge to be represented using bootstrap could lead to unreliable results since alternative edges are present in the same fraction of equivalent MSTs. The choice of the MST to be presented, results from criteria implemented in the algorithm that must be based in biologically plausible models.
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Affiliation(s)
- Andreia Sofia Teixeira
- INESC-ID Lisboa, Lisbon, Portugal
- Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- Instituto de Microbiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Pedro T. Monteiro
- INESC-ID Lisboa, Lisbon, Portugal
- Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - João A Carriço
- INESC-ID Lisboa, Lisbon, Portugal
- Instituto de Microbiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Mário Ramirez
- Instituto de Microbiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Alexandre P. Francisco
- INESC-ID Lisboa, Lisbon, Portugal
- Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- * E-mail:
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Evolution and population genomics of the Lyme borreliosis pathogen, Borrelia burgdorferi. Trends Genet 2015; 31:201-7. [PMID: 25765920 DOI: 10.1016/j.tig.2015.02.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 02/12/2015] [Accepted: 02/13/2015] [Indexed: 11/22/2022]
Abstract
Population genomic studies have the potential to address many unresolved questions about microbial pathogens by facilitating the identification of genes underlying ecologically important traits, such as novel virulence factors and adaptations to humans or other host species. Additionally, this framework improves estimations of population demography and evolutionary history to accurately reconstruct recent epidemics and identify the molecular and environmental factors that resulted in the outbreak. The Lyme disease bacterium, Borrelia burgdorferi, exemplifies the power and promise of the application of population genomics to microbial pathogens. We discuss here the future of evolutionary studies in B. burgdorferi, focusing on the primary evolutionary forces of horizontal gene transfer, natural selection, and migration, as investigations transition from analyses of single genes to genomes.
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Perron GG, Inglis RF, Pennings PS, Cobey S. Fighting microbial drug resistance: a primer on the role of evolutionary biology in public health. Evol Appl 2015; 8:211-22. [PMID: 25861380 PMCID: PMC4380916 DOI: 10.1111/eva.12254] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 02/18/2015] [Indexed: 01/03/2023] Open
Abstract
Although microbes have been evolving resistance to antimicrobials for millennia, the spread of resistance in pathogen populations calls for the development of new drugs and treatment strategies. We propose that successful, long-term resistance management requires a better understanding of how resistance evolves in the first place. This is an opportunity for evolutionary biologists to engage in public health, a collaboration that has substantial precedent. Resistance evolution has been an important tool for developing and testing evolutionary theory, especially theory related to the genetic basis of new traits and constraints on adaptation. The present era is no exception. The articles in this issue highlight the breadth of current research on resistance evolution and also its challenges. In this introduction, we review the conceptual advances that have been achieved from studying resistance evolution and describe a path forward.
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Affiliation(s)
- Gabriel G Perron
- Department of Biology, Bard College Annandale-on-Hudson, NY, USA
| | - R Fredrik Inglis
- Department of Biology, Washington University in St. Louis St. Louis, MO, USA
| | - Pleuni S Pennings
- Department of Biology, San Francisco State University San Francisco, CA, USA
| | - Sarah Cobey
- Department of Ecology and Evolution, University of Chicago Chicago, IL, USA
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LaCross NC, Marrs CF, Gilsdorf JR. Otitis media associated polymorphisms in the hemin receptor HemR of nontypeable Haemophilus influenzae. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2014; 26:47-57. [PMID: 24820341 PMCID: PMC4499511 DOI: 10.1016/j.meegid.2014.05.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 04/15/2014] [Accepted: 05/02/2014] [Indexed: 02/01/2023]
Abstract
Nontypeable Haemophilus influenzae (NTHi) colonize the human pharynx asymptomatically, and are also an important cause of otitis media (OM). Previous studies have demonstrated that some genes are more prevalent in OM-causing NTHi strains than in commensal strains, suggesting a role in virulence. These studies, however, are unable to investigate the possible associations between gene polymorphisms and disease. This study examined amino acid polymorphisms and sequence diversity in a potential virulence gene, the hemin receptor hemR, from a previously characterized NTHi strain collection containing both commensal and OM organisms to identify possible associations between the polymorphisms and otitis media. The full open reading frame of hemR was sequenced from a total of 146 NTHi isolates, yielding a total of 47 unique HemR amino acid sequences. The predicted structure of HemR showed substantial similarity to a class of monomeric TonB dependent, ligand-gated channels involved in iron acquisition in other gram negative bacteria. Fifteen amino acid polymorphisms were significantly more prevalent at the 90% confidence level among commensal compared to OM isolates. Upon controlling for the confounding effect of population structure, over half of the polymorphism-otitis media relationships lost statistical significance, emphasizing the importance of assessing the effect of population structure in association studies. The seven polymorphisms that retained significance were dispersed throughout the protein in various functional and structural domains, including the signal peptide, N-terminal plug domain, and intra- and extracellular loops. The alternate amino acid of only one of these seven polymorphisms was more common among OM isolates, demonstrating a strong trend toward the consensus sequence among disease causing NTHi. We hypothesize that variability at these positions in HemR may result in a reduced ability to acquire iron, rendering NTHi with such versions of the gene less fit for survival in the middle ear environment.
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Affiliation(s)
- Nathan C LaCross
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA.
| | - Carl F Marrs
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA
| | - Janet R Gilsdorf
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA; Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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Andronov EE, Onishchuk OP, Kurchak ON, Provorov NA. Population structure of the clover rhizobia Rhizobium leguminosarum bv. trifolii upon transition from soil into the nodular niche. Microbiology (Reading) 2014. [DOI: 10.1134/s0026261714030035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Bletz S, Bielaszewska M, Leopold SR, Köck R, Witten A, Schuldes J, Zhang W, Karch H, Mellmann A. Evolution of enterohemorrhagic escherichia coli O26 based on single-nucleotide polymorphisms. Genome Biol Evol 2014; 5:1807-16. [PMID: 24105689 PMCID: PMC3814194 DOI: 10.1093/gbe/evt136] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) O26:H11/H− is the predominant non-O157 EHEC serotype among patients with diarrhea, bloody diarrhea, and hemolytic uremic syndrome (HUS) worldwide. To elucidate their phylogeny and association between their phylogenetic background and clinical outcome of the infection, we investigated 120 EHEC O26:H11/H− strains isolated between 1965 and 2012 from asymptomatic carriers and patients with diarrhea or HUS. Whole-genome shotgun sequencing (WGS) was applied to ten representative EHEC O26 isolates to determine single nucleotide polymorphism (SNP) localizations within a predefined set of core genes. A multiplex SNP assay, comprising a randomly distributed subset of 48 SNPs, was established to detect SNPs in 110 additional EHEC O26 strains. Within approximately 1 Mb of core genes, WGS resulted in 476 high-quality bi-allelic SNP localizations. Forty-eight of these were subsequently investigated in 110 EHEC O26 and four different SNP clonal complexes (SNP-CC) were identified. SNP-CC2 was significantly associated with the development of HUS. Within the subsequently established evolutionary model of EHEC O26, we dated the emergence of human EHEC O26 to approximately 19,700 years ago and demonstrated a recent evolution within humans into the 4 SNP-CCs over the past 1,650 years. WGS and subsequent SNP typing enabled us to gain new insights into the evolution of EHEC O26 suggesting a common theme in this EHEC group with analogies to EHEC O157. In addition, the SNP-CC analysis may help to assess a risk in infected individuals for the progression to HUS and to implement more specific infection control measures.
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Affiliation(s)
- Stefan Bletz
- Institute of Hygiene, University of Münster, Germany
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Chiyo PI, Grieneisen LE, Wittemyer G, Moss CJ, Lee PC, Douglas-Hamilton I, Archie EA. The influence of social structure, habitat, and host traits on the transmission of Escherichia coli in wild elephants. PLoS One 2014; 9:e93408. [PMID: 24705319 PMCID: PMC3976290 DOI: 10.1371/journal.pone.0093408] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 03/05/2014] [Indexed: 11/18/2022] Open
Abstract
Social structure is proposed to influence the transmission of both directly and environmentally transmitted infectious agents. However in natural populations, many other factors also influence transmission, including variation in individual susceptibility and aspects of the environment that promote or inhibit exposure to infection. We used a population genetic approach to investigate the effects of social structure, environment, and host traits on the transmission of Escherichia coli infecting two populations of wild elephants: one in Amboseli National Park and another in Samburu National Reserve, Kenya. If E. coli transmission is strongly influenced by elephant social structure, E. coli infecting elephants from the same social group should be genetically more similar than E. coli sampled from members of different social groups. However, we found no support for this prediction. Instead, E. coli was panmictic across social groups, and transmission patterns were largely dominated by habitat and host traits. For instance, habitat overlap between elephant social groups predicted E. coli genetic similarity, but only in the relatively drier habitat of Samburu, and not in Amboseli, where the habitat contains large, permanent swamps. In terms of host traits, adult males were infected with more diverse haplotypes, and males were slightly more likely to harbor strains with higher pathogenic potential, as compared to adult females. In addition, elephants from similar birth cohorts were infected with genetically more similar E. coli than elephants more disparate in age. This age-structured transmission may be driven by temporal shifts in genetic structure of E. coli in the environment and the effects of age on bacterial colonization. Together, our results support the idea that, in elephants, social structure often will not exhibit strong effects on the transmission of generalist, fecal-oral transmitted bacteria. We discuss our results in the context of social, environmental, and host-related factors that influence transmission patterns.
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Affiliation(s)
- Patrick I. Chiyo
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Laura E. Grieneisen
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - George Wittemyer
- Department of Fish, Wildlife and Conservation Biology, Colorado State University, Fort Collins, Colorado, United States of America
- Save the Elephants, Nairobi, Kenya
| | | | - Phyllis C. Lee
- Amboseli Trust for Elephants, Langata, Nairobi, Kenya
- Behaviour and Evolution Research Group, Department of Psychology, University of Stirling, Scotland, United Kingdom
| | | | - Elizabeth A. Archie
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, United States of America
- * E-mail:
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Multilocus sequence typing identifies epidemic clones of Flavobacterium psychrophilum in Nordic countries. Appl Environ Microbiol 2014; 80:2728-36. [PMID: 24561585 DOI: 10.1128/aem.04233-13] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Flavobacterium psychrophilum is the causative agent of bacterial cold water disease (BCWD), which affects a variety of freshwater-reared salmonid species. A large-scale study was performed to investigate the genetic diversity of F. psychrophilum in the four Nordic countries: Denmark, Finland, Norway, and Sweden. Multilocus sequence typing of 560 geographically and temporally disparate F. psychrophilum isolates collected from various sources between 1983 and 2012 revealed 81 different sequence types (STs) belonging to 12 clonal complexes (CCs) and 30 singleton STs. The largest CC, CC-ST10, which represented almost exclusively isolates from rainbow trout and included the most predominant genotype, ST2, comprised 65% of all isolates examined. In Norway, with a shorter history (<10 years) of BCWD in rainbow trout, ST2 was the only isolated CC-ST10 genotype, suggesting a recent introduction of an epidemic clone. The study identified five additional CCs shared between countries and five country-specific CCs, some with apparent host specificity. Almost 80% of the singleton STs were isolated from non-rainbow trout species or the environment. The present study reveals a simultaneous presence of genetically distinct CCs in the Nordic countries and points out specific F. psychrophilum STs posing a threat to the salmonid production. The study provides a significant contribution toward mapping the genetic diversity of F. psychrophilum globally and support for the existence of an epidemic population structure where recombination is a significant driver in F. psychrophilum evolution. Evidence indicating dissemination of a putatively virulent clonal complex (CC-ST10) with commercial movement of fish or fish products is strengthened.
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Nielsen KM, Bøhn T, Townsend JP. Detecting rare gene transfer events in bacterial populations. Front Microbiol 2014; 4:415. [PMID: 24432015 PMCID: PMC3882822 DOI: 10.3389/fmicb.2013.00415] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 12/16/2013] [Indexed: 11/23/2022] Open
Abstract
Horizontal gene transfer (HGT) enables bacteria to access, share, and recombine genetic variation, resulting in genetic diversity that cannot be obtained through mutational processes alone. In most cases, the observation of evolutionary successful HGT events relies on the outcome of initially rare events that lead to novel functions in the new host, and that exhibit a positive effect on host fitness. Conversely, the large majority of HGT events occurring in bacterial populations will go undetected due to lack of replication success of transformants. Moreover, other HGT events that would be highly beneficial to new hosts can fail to ensue due to lack of physical proximity to the donor organism, lack of a suitable gene transfer mechanism, genetic compatibility, and stochasticity in tempo-spatial occurrence. Experimental attempts to detect HGT events in bacterial populations have typically focused on the transformed cells or their immediate offspring. However, rare HGT events occurring in large and structured populations are unlikely to reach relative population sizes that will allow their immediate identification; the exception being the unusually strong positive selection conferred by antibiotics. Most HGT events are not expected to alter the likelihood of host survival to such an extreme extent, and will confer only minor changes in host fitness. Due to the large population sizes of bacteria and the time scales involved, the process and outcome of HGT are often not amenable to experimental investigation. Population genetic modeling of the growth dynamics of bacteria with differing HGT rates and resulting fitness changes is therefore necessary to guide sampling design and predict realistic time frames for detection of HGT, as it occurs in laboratory or natural settings. Here we review the key population genetic parameters, consider their complexity and highlight knowledge gaps for further research.
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Affiliation(s)
- Kaare M Nielsen
- Department of Pharmacy, Faculty of Health Sciences, University of Tromsø Tromsø, Norway ; GenØk-Centre for Biosafety, The Science Park Tromsø, Norway
| | - Thomas Bøhn
- Department of Pharmacy, Faculty of Health Sciences, University of Tromsø Tromsø, Norway ; GenØk-Centre for Biosafety, The Science Park Tromsø, Norway
| | - Jeffrey P Townsend
- Department of Biostatistics, Yale University New Haven, CT, USA ; Program in Computational Biology and Bioinformatics, Yale University New Haven, CT, USA ; Program in Microbiology, Yale University New Haven, CT, USA
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O'Malley MA. When integration fails: Prokaryote phylogeny and the tree of life. STUDIES IN HISTORY AND PHILOSOPHY OF BIOLOGICAL AND BIOMEDICAL SCIENCES 2013; 44:551-62. [PMID: 23137776 DOI: 10.1016/j.shpsc.2012.10.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Much is being written these days about integration, its desirability and even its necessity when complex research problems are to be addressed. Seldom, however, do we hear much about the failure of such efforts. Because integration is an ongoing activity rather than a final achievement, and because today's literature about integration consists mostly of manifesto statements rather than precise descriptions, an examination of unsuccessful integration could be illuminating to understand better how it works. This paper will examine the case of prokaryote phylogeny and its apparent failure to achieve integration within broader tree-of-life accounts of evolutionary history (often called 'universal phylogeny'). Despite the fact that integrated databases exist of molecules pertinent to the phylogenetic reconstruction of all lineages of life, and even though the same methods can be used to construct phylogenies wherever the organisms fall on the tree of life, prokaryote phylogeny remains at best only partly integrated within tree-of-life efforts. I will examine why integration does not occur, compare it with integrative practices in animal and other eukaryote phylogeny, and reflect on whether there might be different expectations of what integration should achieve. Finally, I will draw some general conclusions about integration and its function as a 'meta-heuristic' in the normative commitments guiding scientific practice.
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Affiliation(s)
- Maureen A O'Malley
- Department of Philosophy, University of Sydney, Quadrangle A14, NSW 2006, Australia.
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Kim H, Newell AD, Cota-Sieckmeyer RG, Rupe JC, Fakhoury AM, Bluhm BH. Mating-type distribution and genetic diversity of Cercospora sojina populations on soybean from Arkansas: evidence for potential sexual reproduction. PHYTOPATHOLOGY 2013; 103:1045-51. [PMID: 23721180 DOI: 10.1094/phyto-09-12-0229-r] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Cercospora sojina causes frogeye leaf spot of soybean, which can cause serious economic losses in the United States. In this study, 132 C. sojina isolates were collected from six fields (from two counties, Cross and Crawford) in Arkansas. To determine mating type, a multiplex polymerase chain reaction assay was developed with primers specific for C. sojina. Of the 132 isolates, 68 isolates had the MAT1-1-1 idiomorph and 64 isolates had the MAT1-2 idiomorph; no isolates possessed both idiomorphs. Both mating types were present in a variety of spatial scales, including separate lesions on individual leaves. Clone-corrected data from eight microsatellites indicated that mating-type loci were present in approximately equal proportions in all populations analyzed, which suggests that Arkansas populations of C. sojina are undergoing cryptic sexual reproduction. All six populations evaluated had high genotypic diversity of 26 to 79%. In addition, among strains isolated from a single leaf, multiple and distinct haplotypes were associated with both mating types, supporting the hypothesis that sexual reproduction occurs within the populations. Most populations showed significant gametic disequilibrium but levels of disequilibrium were relatively low, particularly in populations from Crawford County. A low differentiation index (GST) was observed for all simple-sequence repeat markers across all populations. Furthermore, the value of G statistics between populations suggests that significant genetic exchange exists among the populations. Taken together, these results demonstrate that C. sojina populations from Arkansas are genetically diverse and most likely undergoing sexual reproduction.
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48
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LaCross NC, Marrs CF, Gilsdorf JR. Population structure in nontypeable Haemophilus influenzae. INFECTION GENETICS AND EVOLUTION 2012; 14:125-36. [PMID: 23266487 DOI: 10.1016/j.meegid.2012.11.023] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Revised: 11/28/2012] [Accepted: 11/30/2012] [Indexed: 01/28/2023]
Abstract
Nontypeable Haemophilus influenzae (NTHi) frequently colonize the human pharynx asymptomatically, and are an important cause of otitis media in children. Past studies have identified typeable H. influenzae as being clonal, but the population structure of NTHi has not been extensively characterized. The research presented here investigated the diversity and population structure in a well-characterized collection of NTHi isolated from the middle ears of children with otitis media or the pharynges of healthy children in three disparate geographic regions. Multilocus sequence typing identified 109 unique sequence types among 170 commensal and otitis media-associated NTHi isolates from Finland, Israel, and the US. The largest clonal complex contained only five sequence types, indicating a high level of genetic diversity. The eBURST v3, ClonalFrame 1.1, and structure 2.3.3 programs were used to further characterize diversity and population structure from the sequence typing data. Little clustering was apparent by either disease state (otitis media or commensalism) or geography in the ClonalFrame phylogeny. Population structure was clearly evident, with support for eight populations when all 170 isolates were analyzed. Interestingly, one population contained only commensal isolates, while two others consisted solely of otitis media isolates, suggesting associations between population structure and disease.
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Affiliation(s)
- Nathan C LaCross
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA.
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Tang J, Bromfield ESP, Rodrigue N, Cloutier S, Tambong JT. Microevolution of symbiotic Bradyrhizobium populations associated with soybeans in east North America. Ecol Evol 2012; 2:2943-61. [PMID: 23301163 PMCID: PMC3538991 DOI: 10.1002/ece3.404] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 09/17/2012] [Indexed: 11/22/2022] Open
Abstract
Microevolution and origins of Bradyrhizobium populations associated with soybeans at two field sites (A and B, 280 km apart in Canada) with contrasting histories of inoculation was investigated using probabilistic analyses of six core (housekeeping) gene sequences. These analyses supported division of 220 isolates in five lineages corresponding either to B. japonicum groups 1 and 1a or to one of three novel lineages within the genus Bradyrhizobium. None of the isolates from site A and about 20% from site B (the only site with a recent inoculation history) were attributed to inoculation sources. The data suggest that most isolates were of indigenous origin based on sequence analysis of 148 isolates of soybean-nodulating bacteria from native legumes (Amphicarpaea bracteata and Desmodium canadense). Isolates from D. canadense clustered with B. japonicum group 1, whereas those from A. bracteata were placed in two novel lineages encountered at soybean field sites. One of these novel lineages predominated at soybean sites and exhibited a significant clonal expansion likely reflecting selection by the plant host. Homologous recombination events detected in the 35 sequence types from soybean sites had an effect on genetic diversification that was approximately equal to mutation. Interlineage transfer of core genes was infrequent and mostly attributable to gyrB that had a history of frequent recombination. Symbiotic gene sequences (nodC and nifH) of isolates from soybean sites and native legumes clustered in two lineages corresponding to B. japonicum and B. elkani with the inheritance of these genes appearing predominantly by vertical transmission. The data suggest that soybean-nodulating bacteria associated with native legumes represent a novel source of ecologically adapted bacteria for soybean inoculation.
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Affiliation(s)
- Jie Tang
- Agriculture and Agri-Food Canada 960 Carling Ave, Ottawa, Ontario, Canada, K1A 0C6
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50
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González-González A, Sánchez-Reyes LL, Delgado Sapien G, Eguiarte LE, Souza V. Hierarchical clustering of genetic diversity associated to different levels of mutation and recombination in Escherichia coli: a study based on Mexican isolates. INFECTION GENETICS AND EVOLUTION 2012; 13:187-97. [PMID: 22995280 DOI: 10.1016/j.meegid.2012.09.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 09/04/2012] [Accepted: 09/05/2012] [Indexed: 02/01/2023]
Abstract
Escherichia coli occur as either free-living microorganisms, or within the colons of mammals and birds as pathogenic or commensal bacteria. Although the Mexican population of intestinal E. coli maintains high levels of genetic diversity, the exact mechanisms by which this occurs remain unknown. We therefore investigated the role of homologous recombination and point mutation in the genetic diversification and population structure of Mexican strains of E. coli. This was explored using a multi locus sequence typing (MLST) approach in a non-outbreak related, host-wide sample of 128 isolates. Overall, genetic diversification in this sample appears to be driven primarily by homologous recombination, and to a lesser extent, by point mutation. Since genetic diversity is hierarchically organized according to the MLST genealogy, we observed that there is not a homogeneous recombination rate, but that different rates emerge at different clustering levels such as phylogenetic group, lineage and clonal complex (CC). Moreover, we detected clear signature of substructure among the A+B1 phylogenetic group, where the majority of isolates were differentiated into four discrete lineages. Substructure pattern is revealed by the presence of several CCs associated to a particular life style and host as well as to different genetic diversification mechanisms. We propose these findings as an alternative explanation for the maintenance of the clear phylogenetic signal of this species despite the prevalence of homologous recombination. Finally, we corroborate using both phylogenetic and genetic population approaches as an effective mean to establish epidemiological surveillance tailored to the ecological specificities of each geographic region.
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Affiliation(s)
- Andrea González-González
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, México D.F., Mexico
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