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Truskewycz A, Gundry TD, Khudur LS, Kolobaric A, Taha M, Aburto-Medina A, Ball AS, Shahsavari E. Petroleum Hydrocarbon Contamination in Terrestrial Ecosystems-Fate and Microbial Responses. Molecules 2019; 24:molecules24183400. [PMID: 31546774 PMCID: PMC6767264 DOI: 10.3390/molecules24183400] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 09/06/2019] [Accepted: 09/11/2019] [Indexed: 11/18/2022] Open
Abstract
Petroleum hydrocarbons represent the most frequent environmental contaminant. The introduction of petroleum hydrocarbons into a pristine environment immediately changes the nature of that environment, resulting in reduced ecosystem functionality. Natural attenuation represents the single, most important biological process which removes petroleum hydrocarbons from the environment. It is a process where microorganisms present at the site degrade the organic contaminants without the input of external bioremediation enhancers (i.e., electron donors, electron acceptors, other microorganisms or nutrients). So successful is this natural attenuation process that in environmental biotechnology, bioremediation has developed steadily over the past 50 years based on this natural biodegradation process. Bioremediation is recognized as the most environmentally friendly remediation approach for the removal of petroleum hydrocarbons from an environment as it does not require intensive chemical, mechanical, and costly interventions. However, it is under-utilized as a commercial remediation strategy due to incomplete hydrocarbon catabolism and lengthy remediation times when compared with rival technologies. This review aims to describe the fate of petroleum hydrocarbons in the environment and discuss their interactions with abiotic and biotic components of the environment under both aerobic and anaerobic conditions. Furthermore, the mechanisms for dealing with petroleum hydrocarbon contamination in the environment will be examined. When petroleum hydrocarbons contaminate land, they start to interact with its surrounding, including physical (dispersion), physiochemical (evaporation, dissolution, sorption), chemical (photo-oxidation, auto-oxidation), and biological (plant and microbial catabolism of hydrocarbons) interactions. As microorganism (including bacteria and fungi) play an important role in the degradation of petroleum hydrocarbons, investigations into the microbial communities within contaminated soils is essential for any bioremediation project. This review highlights the fate of petroleum hydrocarbons in tertial environments, as well as the contributions of different microbial consortia for optimum petroleum hydrocarbon bioremediation potential. The impact of high-throughput metagenomic sequencing in determining the underlying degradation mechanisms is also discussed. This knowledge will aid the development of more efficient, cost-effective commercial bioremediation technologies.
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Affiliation(s)
- Adam Truskewycz
- Centre for Environmental Sustainability and Remediation, School of Science, RMIT University, Bundoora, VIC 3083, Australia.
| | - Taylor D Gundry
- Centre for Environmental Sustainability and Remediation, School of Science, RMIT University, Bundoora, VIC 3083, Australia.
| | - Leadin S Khudur
- Centre for Environmental Sustainability and Remediation, School of Science, RMIT University, Bundoora, VIC 3083, Australia.
| | - Adam Kolobaric
- Centre for Environmental Sustainability and Remediation, School of Science, RMIT University, Bundoora, VIC 3083, Australia.
| | - Mohamed Taha
- Centre for Environmental Sustainability and Remediation, School of Science, RMIT University, Bundoora, VIC 3083, Australia.
- Department of Biochemistry, Faculty of Agriculture, Benha University, Moshtohor, Toukh, Qaliuobia 13736, Egypt.
| | - Arturo Aburto-Medina
- Centre for Environmental Sustainability and Remediation, School of Science, RMIT University, Bundoora, VIC 3083, Australia.
| | - Andrew S Ball
- Centre for Environmental Sustainability and Remediation, School of Science, RMIT University, Bundoora, VIC 3083, Australia.
| | - Esmaeil Shahsavari
- Centre for Environmental Sustainability and Remediation, School of Science, RMIT University, Bundoora, VIC 3083, Australia.
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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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103
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A Reverse Ecology Approach Based on a Biological Definition of Microbial Populations. Cell 2019; 178:820-834.e14. [DOI: 10.1016/j.cell.2019.06.033] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 05/28/2019] [Accepted: 06/24/2019] [Indexed: 01/30/2023]
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104
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Kondakova T, Kumar S, Cronan JE. A novel synthesis of trans-unsaturated fatty acids by the Gram-positive commensal bacterium Enterococcus faecalis FA2-2. Chem Phys Lipids 2019; 222:23-35. [PMID: 31054954 PMCID: PMC7392533 DOI: 10.1016/j.chemphyslip.2019.04.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 04/15/2019] [Accepted: 04/29/2019] [Indexed: 11/30/2022]
Abstract
A key mechanism of Pseudomonas spp. adaptation to environmental stressors is their ability to convert the cis-unsaturated fatty acids of the membrane lipids to their trans-isomers to rigidify the membrane and thereby resist stresses. Although this Cti-catalyzed enzymatic isomerization has been well investigated in the P. putida paradigm, several bacterial species have been found to produce trans-unsaturated fatty acids. Although cti orthologs have only been reported in Gram-negative bacteria, we report that E. faecalis FA2-2 cultures synthesize trans-unsaturated fatty acids during growth by a mechanism similar of P. putida. Although the role of trans-unsaturated fatty acids (trans-UFAs) in E. faecalis remains obscure, our results indicate that organic solvents, as well as the membrane altering antibiotic, daptomycin, had no effect on trans-UFA formation in E. faecalis FA2-2. Moreover trans-UFA production in E. faecalis FA2-2 membranes was constant in oxidative stress conditions or when metal chelator EDTA was added, raising the question about the role of heme domain in cis-trans isomerization in E. faecalis FA2-2. Although growth temperature and growth phase had significant effects on cis-trans isomerization, the bulk physical properties of the membranes seems unlikely to be altered by the low levels of trans-UFA. Hence, any effects seems likely to be on membrane proteins and membrane enzyme activities. We also report investigations of cti gene distribution in bacteria was and suggest the distribution to be triggered by habitat population associations. Three major Cti clusters were defined, corresponding to Pseudomonas, Pseudoalteromonas and Vibrio Cti proteins.
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Affiliation(s)
- Tatiana Kondakova
- Department of Microbiology, University of Illinois, Urbana, IL, 61801, USA
| | - Sneha Kumar
- Department of Microbiology, University of Illinois, Urbana, IL, 61801, USA
| | - John E Cronan
- Department of Microbiology, University of Illinois, Urbana, IL, 61801, USA; Department of Biochemistry, University of Illinois, Urbana, IL, 61801, USA.
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105
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Greenlon A, Chang PL, Damtew ZM, Muleta A, Carrasquilla-Garcia N, Kim D, Nguyen HP, Suryawanshi V, Krieg CP, Yadav SK, Patel JS, Mukherjee A, Udupa S, Benjelloun I, Thami-Alami I, Yasin M, Patil B, Singh S, Sarma BK, von Wettberg EJB, Kahraman A, Bukun B, Assefa F, Tesfaye K, Fikre A, Cook DR. Global-level population genomics reveals differential effects of geography and phylogeny on horizontal gene transfer in soil bacteria. Proc Natl Acad Sci U S A 2019; 116:15200-15209. [PMID: 31285337 PMCID: PMC6660780 DOI: 10.1073/pnas.1900056116] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Although microorganisms are known to dominate Earth's biospheres and drive biogeochemical cycling, little is known about the geographic distributions of microbial populations or the environmental factors that pattern those distributions. We used a global-level hierarchical sampling scheme to comprehensively characterize the evolutionary relationships and distributional limitations of the nitrogen-fixing bacterial symbionts of the crop chickpea, generating 1,027 draft whole-genome sequences at the level of bacterial populations, including 14 high-quality PacBio genomes from a phylogenetically representative subset. We find that diverse Mesorhizobium taxa perform symbiosis with chickpea and have largely overlapping global distributions. However, sampled locations cluster based on the phylogenetic diversity of Mesorhizobium populations, and diversity clusters correspond to edaphic and environmental factors, primarily soil type and latitude. Despite long-standing evolutionary divergence and geographic isolation, the diverse taxa observed to nodulate chickpea share a set of integrative conjugative elements (ICEs) that encode the major functions of the symbiosis. This symbiosis ICE takes 2 forms in the bacterial chromosome-tripartite and monopartite-with tripartite ICEs confined to a broadly distributed superspecies clade. The pairwise evolutionary relatedness of these elements is controlled as much by geographic distance as by the evolutionary relatedness of the background genome. In contrast, diversity in the broader gene content of Mesorhizobium genomes follows a tight linear relationship with core genome phylogenetic distance, with little detectable effect of geography. These results illustrate how geography and demography can operate differentially on the evolution of bacterial genomes and offer useful insights for the development of improved technologies for sustainable agriculture.
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Affiliation(s)
- Alex Greenlon
- Department of Plant Pathology, University of California, Davis, CA 95616
| | - Peter L Chang
- Department of Plant Pathology, University of California, Davis, CA 95616
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089
| | - Zehara Mohammed Damtew
- College of Natural Sciences, Addis Ababa University, Addis Ababa, 32853 Ethiopia
- Debre Zeit Agricultural Research Center, Ethiopian Institute for Agricultural Research, Bishoftu, Ethiopia
| | - Atsede Muleta
- College of Natural Sciences, Addis Ababa University, Addis Ababa, 32853 Ethiopia
| | | | - Donghyun Kim
- International Crop Research Institute for the Semi-Arid Tropics, Hyderabad 502324, India
| | - Hien P Nguyen
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 183-8509 Tokyo, Japan
| | - Vasantika Suryawanshi
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089
| | - Christopher P Krieg
- Department of Biological Sciences, Florida International University, Miami, FL 33199
| | - Sudheer Kumar Yadav
- Department of Mycology and Plant Pathology, Banaras Hindu University, Varanasi 221005, India
| | - Jai Singh Patel
- Department of Mycology and Plant Pathology, Banaras Hindu University, Varanasi 221005, India
| | - Arpan Mukherjee
- Department of Mycology and Plant Pathology, Banaras Hindu University, Varanasi 221005, India
| | - Sripada Udupa
- Biodiversity and Integrated Gene Management Program, International Center for Agricultural Research in the Dry Areas, 10112 Rabat, Morocco
| | - Imane Benjelloun
- Institute National de la Recherche Agronomique, 10100 Rabat, Morocco
| | - Imane Thami-Alami
- Institute National de la Recherche Agronomique, 10100 Rabat, Morocco
| | | | - Bhuvaneshwara Patil
- Department of Genetics and Plant Breeding, University of Agricultural Sciences, Dharwad 580001, India
| | - Sarvjeet Singh
- Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana 141027, India
| | - Birinchi Kumar Sarma
- Department of Mycology and Plant Pathology, Banaras Hindu University, Varanasi 221005, India
| | - Eric J B von Wettberg
- Department of Biological Sciences, Florida International University, Miami, FL 33199
- Department of Plant and Soil Science, University of Vermont, Burlington, VT 05405
| | - Abdullah Kahraman
- Department of Field Crops, Faculty of Agriculture, Harran University, 63100 Sanliurfa, Turkey
| | - Bekir Bukun
- Department of Plant Protection, Dicle University, 21280 Diyarbakir, Turkey
| | - Fassil Assefa
- College of Natural Sciences, Addis Ababa University, Addis Ababa, 32853 Ethiopia
| | - Kassahun Tesfaye
- College of Natural Sciences, Addis Ababa University, Addis Ababa, 32853 Ethiopia
| | - Asnake Fikre
- Debre Zeit Agricultural Research Center, Ethiopian Institute for Agricultural Research, Bishoftu, Ethiopia
| | - Douglas R Cook
- Department of Plant Pathology, University of California, Davis, CA 95616;
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106
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Antibiotic resistance in Pseudomonas aeruginosa - Mechanisms, epidemiology and evolution. Drug Resist Updat 2019; 44:100640. [PMID: 31492517 DOI: 10.1016/j.drup.2019.07.002] [Citation(s) in RCA: 252] [Impact Index Per Article: 50.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 07/11/2019] [Accepted: 07/12/2019] [Indexed: 12/13/2022]
Abstract
Antibiotics are powerful drugs used in the treatment of bacterial infections. The inappropriate use of these medicines has driven the dissemination of antibiotic resistance (AR) in most bacteria. Pseudomonas aeruginosa is an opportunistic pathogen commonly involved in environmental- and difficult-to-treat hospital-acquired infections. This species is frequently resistant to several antibiotics, being in the "critical" category of the WHO's priority pathogens list for research and development of new antibiotics. In addition to a remarkable intrinsic resistance to several antibiotics, P. aeruginosa can acquire resistance through chromosomal mutations and acquisition of AR genes. P. aeruginosa has one of the largest bacterial genomes and possesses a significant assortment of genes acquired by horizontal gene transfer (HGT), which are frequently localized within integrons and mobile genetic elements (MGEs), such as transposons, insertion sequences, genomic islands, phages, plasmids and integrative and conjugative elements (ICEs). This genomic diversity results in a non-clonal population structure, punctuated by specific clones that are associated with significant morbidity and mortality worldwide, the so-called high-risk clones. Acquisition of MGEs produces a fitness cost in the host, that can be eased over time by compensatory mutations during MGE-host coevolution. Even though plasmids and ICEs are important drivers of AR, the underlying evolutionary traits that promote this dissemination are poorly understood. In this review, we provide a comprehensive description of the main strategies involved in AR in P. aeruginosa and the leading drivers of HGT in this species. The most recently developed genomic tools that allowed a better understanding of the features contributing for the success of P. aeruginosa are discussed.
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107
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Gao S, Gold SE, Wisecaver JH, Zhang Y, Guo L, Ma LJ, Rokas A, Glenn AE. Genome-wide analysis of Fusarium verticillioides reveals inter-kingdom contribution of horizontal gene transfer to the expansion of metabolism. Fungal Genet Biol 2019; 128:60-73. [DOI: 10.1016/j.fgb.2019.04.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 03/02/2019] [Accepted: 04/01/2019] [Indexed: 11/30/2022]
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108
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Botelho J, Grosso F, Peixe L. WITHDRAWN: Antibiotic resistance in Pseudomonas aeruginosa – mechanisms, epidemiology and evolution. Drug Resist Updat 2019. [DOI: 10.1016/j.drup.2019.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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109
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Rangel LT, Marden J, Colston S, Setubal JC, Graf J, Gogarten JP. Identification and characterization of putative Aeromonas spp. T3SS effectors. PLoS One 2019; 14:e0214035. [PMID: 31163020 PMCID: PMC6548356 DOI: 10.1371/journal.pone.0214035] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Accepted: 05/21/2019] [Indexed: 11/23/2022] Open
Abstract
The genetic determinants of bacterial pathogenicity are highly variable between species and strains. However, a factor that is commonly associated with virulent Gram-negative bacteria, including many Aeromonas spp., is the type 3 secretion system (T3SS), which is used to inject effector proteins into target eukaryotic cells. In this study, we developed a bioinformatics pipeline to identify T3SS effector proteins, applied this approach to the genomes of 105 Aeromonas strains isolated from environmental, mutualistic, or pathogenic contexts and evaluated the cytotoxicity of the identified effectors through their heterologous expression in yeast. The developed pipeline uses a two-step approach, where candidate Aeromonas gene families are initially selected using Hidden Markov Model (HMM) profile searches against the Virulence Factors DataBase (VFDB), followed by strict comparisons against positive and negative control datasets, greatly reducing the number of false positives. This approach identified 21 Aeromonas T3SS likely effector families, of which 8 represent known or characterized effectors, while the remaining 13 have not previously been described in Aeromonas. We experimentally validated our in silico findings by assessing the cytotoxicity of representative effectors in Saccharomyces cerevisiae BY4741, with 15 out of 21 assayed proteins eliciting a cytotoxic effect in yeast. The results of this study demonstrate the utility of our approach, combining a novel in silico search method with in vivo experimental validation, and will be useful in future research aimed at identifying and authenticating bacterial effector proteins from other genera.
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Affiliation(s)
- Luiz Thiberio Rangel
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, United States of America
- Interunidades em Bioinformática, Universidade de São Paulo, São Paulo, Brasil
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brasil
| | - Jeremiah Marden
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, United States of America
| | - Sophie Colston
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, United States of America
| | - João Carlos Setubal
- Interunidades em Bioinformática, Universidade de São Paulo, São Paulo, Brasil
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brasil
| | - Joerg Graf
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, United States of America
- Institute for Systems Genomics, University of Connecticut, Storrs, Connecticut, United States of America
| | - Johann Peter Gogarten
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, United States of America
- Institute for Systems Genomics, University of Connecticut, Storrs, Connecticut, United States of America
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110
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Liu Q, Liu HC, Zhou YG, Xin YH. Microevolution and Adaptive Strategy of Psychrophilic Species Flavobacterium bomense sp. nov. Isolated From Glaciers. Front Microbiol 2019; 10:1069. [PMID: 31178833 PMCID: PMC6538692 DOI: 10.3389/fmicb.2019.01069] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 04/29/2019] [Indexed: 12/17/2022] Open
Abstract
Numerous mountain glaciers located on the Tibetan Plateau are inhabited by abundant microorganisms. The microorganisms on the glacier surface are exposed to the cold, barren, and high-ultraviolet radiation environments. Although the microbial community composition on glaciers has been revealed by high-throughput sequencing, little is known about the microevolution and adaptive strategy of certain bacterial populations. In this study, we used a polyphasic approach to determine the taxonomic status of 11 psychrophilic Flavobacterium strains isolated from glaciers on the Tibetan Plateau and performed a comparative genomic analysis. The phylogenetic tree based on the concatenated single-copy gene sequences showed the 11 strains clustered together, forming a distinct and novel clade in the genus Flavobacterium. The average nucleotide identity (ANI) values among these strains were higher than 96%. However, the values much lower than 90% between them and related species indicated that they represent a novel species and the name Flavobacterium bomense sp. nov. is proposed. The core and accessory genomes of strains in this new Flavobacterium species showed diverse distinct patterns of gene content and metabolism pathway. In order to infer the driving evolutionary forces of the core genomes, homologous recombination was found to contribute twice as much to nucleotide substitutions as mutations. A series of genes encoding proteins with known or predicted roles in cold adaptation were found in their genomes, for example, cold-shock protein, proteorhodopsin, osmoprotection, and membrane-related proteins. A comparative analysis of the group with optimal growth temperature (OGT) ≤ 20°C and the group with OGT > 20°C of the 32 Flavobacterium type strains and 11 new strains revealed multiple amino acid substitutions, including the decrease of the proline and glutamine content and the increase of the methionine and isoleucine content in the group with OGT ≤ 20°C, which may contribute to increased protein flexibility at low temperatures. Thus, this study discovered a novel Flavobacterium species in glaciers, which has high intraspecific diversity and multiple adaptation mechanisms that enable them to cope and thrive in extreme habitats.
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Affiliation(s)
- Qing Liu
- China General Microbiological Culture Collection Center (CGMCC), Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Hong-Can Liu
- China General Microbiological Culture Collection Center (CGMCC), Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Yu-Guang Zhou
- China General Microbiological Culture Collection Center (CGMCC), Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Yu-Hua Xin
- China General Microbiological Culture Collection Center (CGMCC), Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
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111
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Klimenko AI, Matushkin YG, Kolchanov NA, Lashin SA. Spatial heterogeneity promotes antagonistic evolutionary scenarios in microbial community explained by ecological stratification: a simulation study. Ecol Modell 2019. [DOI: 10.1016/j.ecolmodel.2019.02.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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112
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Raymond F, Boissinot M, Ouameur AA, Déraspe M, Plante PL, Kpanou SR, Bérubé È, Huletsky A, Roy PH, Ouellette M, Bergeron MG, Corbeil J. Culture-enriched human gut microbiomes reveal core and accessory resistance genes. MICROBIOME 2019; 7:56. [PMID: 30953542 PMCID: PMC6451232 DOI: 10.1186/s40168-019-0669-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 03/20/2019] [Indexed: 05/10/2023]
Abstract
BACKGROUND Low-abundance microorganisms of the gut microbiome are often referred to as a reservoir for antibiotic resistance genes. Unfortunately, these less-abundant bacteria can be overlooked by deep shotgun sequencing. In addition, it is a challenge to associate the presence of resistance genes with their risk of acquisition by pathogens. In this study, we used liquid culture enrichment of stools to assemble the genome of lower-abundance bacteria from fecal samples. We then investigated the gene content recovered from these culture-enriched and culture-independent metagenomes in relation with their taxonomic origin, specifically antibiotic resistance genes. We finally used a pangenome approach to associate resistance genes with the core or accessory genome of Enterobacteriaceae and inferred their propensity to horizontal gene transfer. RESULTS Using culture-enrichment approaches with stools allowed assembly of 187 bacterial species with an assembly size greater than 1 million nucleotides. Of these, 67 were found only in culture-enriched conditions, and 22 only in culture-independent microbiomes. These assembled metagenomes allowed the evaluation of the gene content of specific subcommunities of the gut microbiome. We observed that differentially distributed metabolic enzymes were associated with specific culture conditions and, for the most part, with specific taxa. Gene content differences between microbiomes, for example, antibiotic resistance, were for the most part not associated with metabolic enzymes, but with other functions. We used a pangenome approach to determine if the resistance genes found in Enterobacteriaceae, specifically E. cloacae or E. coli, were part of the core genome or of the accessory genome of this species. In our healthy volunteer cohort, we found that E. cloacae contigs harbored resistance genes that were part of the core genome of the species, while E. coli had a large accessory resistome proximal to mobile elements. CONCLUSION Liquid culture of stools contributed to an improved functional and comparative genomics study of less-abundant gut bacteria, specifically those associated with antibiotic resistance. Defining whether a gene is part of the core genome of a species helped in interpreting the genomes recovered from culture-independent or culture-enriched microbiomes.
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Affiliation(s)
- Frédéric Raymond
- École de nutrition, Faculté des sciences de l'agriculture et de l'alimentation, Université Laval, Québec City, Canada.
- Institut sur la nutrition et les aliments fonctionnels, Québec, Canada.
| | - Maurice Boissinot
- Centre de Recherche en Infectiologie de l'Université Laval, Axe Maladies Infectieuses et Immunitaires, Centre de Recherche du CHU de Québec-Université Laval, Québec City, Canada
| | - Amin Ahmed Ouameur
- Centre de Recherche en Infectiologie de l'Université Laval, Axe Maladies Infectieuses et Immunitaires, Centre de Recherche du CHU de Québec-Université Laval, Québec City, Canada
| | - Maxime Déraspe
- Centre de Recherche en Infectiologie de l'Université Laval, Axe Maladies Infectieuses et Immunitaires, Centre de Recherche du CHU de Québec-Université Laval, Québec City, Canada
- Centre de recherche en données massives, Université Laval, Québec City, Canada
| | - Pier-Luc Plante
- Centre de Recherche en Infectiologie de l'Université Laval, Axe Maladies Infectieuses et Immunitaires, Centre de Recherche du CHU de Québec-Université Laval, Québec City, Canada
- Centre de recherche en données massives, Université Laval, Québec City, Canada
| | - Sewagnouin Rogia Kpanou
- Centre de Recherche en Infectiologie de l'Université Laval, Axe Maladies Infectieuses et Immunitaires, Centre de Recherche du CHU de Québec-Université Laval, Québec City, Canada
- Centre de recherche en données massives, Université Laval, Québec City, Canada
| | - Ève Bérubé
- Centre de Recherche en Infectiologie de l'Université Laval, Axe Maladies Infectieuses et Immunitaires, Centre de Recherche du CHU de Québec-Université Laval, Québec City, Canada
| | - Ann Huletsky
- Centre de Recherche en Infectiologie de l'Université Laval, Axe Maladies Infectieuses et Immunitaires, Centre de Recherche du CHU de Québec-Université Laval, Québec City, Canada
| | - Paul H Roy
- Centre de Recherche en Infectiologie de l'Université Laval, Axe Maladies Infectieuses et Immunitaires, Centre de Recherche du CHU de Québec-Université Laval, Québec City, Canada
- Département de biochimie, de microbiologie et de bio-informatique, Faculté des Sciences et de Génie, Université Laval, Québec City, Canada
| | - Marc Ouellette
- Centre de Recherche en Infectiologie de l'Université Laval, Axe Maladies Infectieuses et Immunitaires, Centre de Recherche du CHU de Québec-Université Laval, Québec City, Canada
- Département de Microbiologie, Infectiologie et d'Immunologie, Faculté de Médecine, Université Laval, Québec City, Canada
| | - Michel G Bergeron
- Centre de Recherche en Infectiologie de l'Université Laval, Axe Maladies Infectieuses et Immunitaires, Centre de Recherche du CHU de Québec-Université Laval, Québec City, Canada
- Département de Microbiologie, Infectiologie et d'Immunologie, Faculté de Médecine, Université Laval, Québec City, Canada
| | - Jacques Corbeil
- Centre de Recherche en Infectiologie de l'Université Laval, Axe Maladies Infectieuses et Immunitaires, Centre de Recherche du CHU de Québec-Université Laval, Québec City, Canada
- Centre de recherche en données massives, Université Laval, Québec City, Canada
- Département de médecine moléculaire, Faculté de Médecine, Université Laval, Québec City, Canada
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113
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Sevigny JL, Rothenheber D, Diaz KS, Zhang Y, Agustsson K, Bergeron RD, Thomas WK. Marker genes as predictors of shared genomic function. BMC Genomics 2019; 20:268. [PMID: 30947688 PMCID: PMC6449922 DOI: 10.1186/s12864-019-5641-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 03/24/2019] [Indexed: 12/15/2022] Open
Abstract
Background Although high-throughput marker gene studies provide valuable insight into the diversity and relative abundance of taxa in microbial communities, they do not provide direct measures of their functional capacity. Recently, scientists have shown a general desire to predict functional profiles of microbial communities based on phylogenetic identification inferred from marker genes, and recent tools have been developed to link the two. However, to date, no large-scale examination has quantified the correlation between the marker gene based taxonomic identity and protein coding gene conservation. Here we utilize 4872 representative prokaryotic genomes from NCBI to investigate the relationship between marker gene identity and shared protein coding gene content. Results Even at 99–100% marker gene identity, genomes share on average less than 75% of their protein coding gene content. This occurs regardless of the marker gene(s) used: V4 region of the 16S rRNA, complete 16S rRNA, or single copy orthologs through a multi-locus sequence analysis. An important aspect related to this observation is the intra-organism variation of 16S copies from a single genome. Although the majority of 16S copies were found to have high sequence similarity (> 99%), several genomes contained copies that were highly diverged (< 97% identity). Conclusions This is the largest comparison between marker gene similarity and shared protein coding gene content to date. The study highlights the limitations of inferring a microbial community’s functions based on marker gene phylogeny. The data presented expands upon the results of previous studies that examined one or few bacterial species and supports the hypothesis that 16S rRNA and other marker genes cannot be directly used to fully predict the functional potential of a bacterial community. Electronic supplementary material The online version of this article (10.1186/s12864-019-5641-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Joseph L Sevigny
- Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, 46 College Rd, Rudman Hall, Durham, NH, 03824, USA. .,Hubbard Center for Genome Studies, University of New Hampshire, 35 Colovos Rd, Gregg Hall, Durham, NH, 03824, USA.
| | - Derek Rothenheber
- Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, 46 College Rd, Rudman Hall, Durham, NH, 03824, USA
| | - Krystalle Sharlyn Diaz
- Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, 46 College Rd, Rudman Hall, Durham, NH, 03824, USA.,Hubbard Center for Genome Studies, University of New Hampshire, 35 Colovos Rd, Gregg Hall, Durham, NH, 03824, USA
| | - Ying Zhang
- Department of Computer Science, University of New Hampshire, 33 Academic Way, Kingsbury Hall, Durham, NH, 0324, USA
| | - Kristin Agustsson
- Department of Computer Science, University of New Hampshire, 33 Academic Way, Kingsbury Hall, Durham, NH, 0324, USA
| | - R Daniel Bergeron
- Department of Computer Science, University of New Hampshire, 33 Academic Way, Kingsbury Hall, Durham, NH, 0324, USA
| | - W Kelley Thomas
- Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, 46 College Rd, Rudman Hall, Durham, NH, 03824, USA.,Hubbard Center for Genome Studies, University of New Hampshire, 35 Colovos Rd, Gregg Hall, Durham, NH, 03824, USA
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114
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Schmutzer M, Barraclough TG. The role of recombination, niche-specific gene pools and flexible genomes in the ecological speciation of bacteria. Ecol Evol 2019; 9:4544-4556. [PMID: 31031926 PMCID: PMC6476844 DOI: 10.1002/ece3.5052] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 02/16/2019] [Accepted: 02/18/2019] [Indexed: 12/21/2022] Open
Abstract
Bacteria diversify into genetic clusters analogous to those observed in sexual eukaryotes, but the definition of bacterial species is an ongoing problem. Recent work has focused on adaptation to distinct ecological niches as the main driver of clustering, but there remains debate about the role of recombination in that process. One view is that homologous recombination occurs too rarely for gene flow to constrain divergent selection. Another view is that homologous recombination is frequent enough in many bacterial populations that barriers to gene flow are needed to permit divergence. Niche-specific gene pools have been proposed as a general mechanism to limit gene flow. We use theoretical models to evaluate additional hypotheses that evolving genetic architecture, specifically the effect sizes of genes and gene gain and loss, can limit gene flow between diverging populations. Our model predicts that (a) in the presence of gene flow and recombination, ecological divergence is concentrated in few loci of large effect and (b) high rates of gene flow plus recombination promote gene loss and favor the evolution of niche-specific genes. The results show that changing genetic architecture and gene loss can facilitate ecological divergence, even without niche-specific gene pools. We discuss these results in the context of recent studies of sympatric divergence in microbes.
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115
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Population Genomics Insights into Adaptive Evolution and Ecological Differentiation in Streptomycetes. Appl Environ Microbiol 2019; 85:AEM.02555-18. [PMID: 30658977 DOI: 10.1128/aem.02555-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 01/14/2019] [Indexed: 12/20/2022] Open
Abstract
Deciphering the genomic variation that represents microevolutionary processes toward species divergence is key to understanding microbial speciation, which has long been under debate. Streptomycetes are filamentous bacteria that are ubiquitous in nature and the richest source of antibiotics; however, their speciation processes remain unknown. To tackle this issue, we performed a comprehensive population genomics analysis on Streptomyces albidoflavus residing in different habitats and with a worldwide distribution and identified and characterized the foundational changes within the species. We detected three well-defined phylogenomic clades, of which clades I and III mainly contained free-living (soil/marine) and insect-associated strains, respectively, and clade II had a mixed origin. By performing genome-wide association studies (GWAS), we identified a number of genetic variants associated with free-living or entomic (denoting or relating to insects) habitats in both the accessory and core genomes. These variants contributed collectively to the population structure and had annotated or confirmed functions that likely facilitate differential adaptation of the species. In addition, we detected higher levels of homologous recombination within each clade and in the free-living group than within the whole species and in the entomic group. A subset of the insect-associated strains (clade III) showed a relatively independent evolutionary trajectory with more symbiosis-favorable genes but little genetic interchange with the other lineages. Our results demonstrate that ecological adaptation promotes genetic differentiation in S. albidoflavus, suggesting a model of ecological speciation with gene flow in streptomycetes.IMPORTANCE Species are the fundamental units of ecology and evolution, and speciation leads to the astounding diversity of life on Earth. Studying speciation is thus of great significance to understand, protect, and exploit biodiversity, but it is a challenge in the microbial world. In this study, using population genomics, we placed Streptomyces albidoflavus strains in a spectrum of speciation and showed that the genetic differences between phylogenomic clusters evolved mainly by environmental selection and gene-specific sweeps. These findings highlight the role of ecology in structuring recombining bacterial species, making a step toward a deeper understanding of microbial speciation. Our results also raise concerns of an underrated microbial diversity at the intraspecies level, which can be utilized for mining of ecologically relevant natural products.
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116
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Varble A, Meaden S, Barrangou R, Westra ER, Marraffini LA. Recombination between phages and CRISPR-cas loci facilitates horizontal gene transfer in staphylococci. Nat Microbiol 2019; 4:956-963. [PMID: 30886355 PMCID: PMC6533911 DOI: 10.1038/s41564-019-0400-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 01/31/2019] [Indexed: 11/09/2022]
Abstract
CRISPR (clustered regularly interspaced short palindromic repeats) loci and their associated (cas) genes encode an adaptive immune system that protects prokaryotes from viral1 and plasmid2 invaders. Following viral (phage) infection, a small fraction of the prokaryotic cells are able to integrate a small sequence of the invader's genome into the CRISPR array1. These sequences, known as spacers, are transcribed and processed into small CRISPR RNA guides3-5 that associate with Cas nucleases to specify a viral target for destruction6-9. Although CRISPR-cas loci are widely distributed throughout microbial genomes and often display hallmarks of horizontal gene transfer10-12, the drivers of CRISPR dissemination remain unclear. Here, we show that spacers can recombine with phage target sequences to mediate a form of specialized transduction of CRISPR elements. Phage targets in phage 85, ΦNM1, ΦNM4 and Φ12 can recombine with spacers in either chromosomal or plasmid-borne CRISPR loci in Staphylococcus, leading to either the transfer of CRISPR-adjacent genes or the propagation of acquired immunity to other bacteria in the population, respectively. Our data demonstrate that spacer sequences not only specify the targets of Cas nucleases but also can promote horizontal gene transfer.
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Affiliation(s)
- Andrew Varble
- Laboratory of Bacteriology, The Rockefeller University, New York, NY, USA
| | - Sean Meaden
- Environment and Sustainability Institute, Centre for Ecology and Conservation, University of Exeter, Biosciences, Penryn, Cornwall, UK
| | - Rodolphe Barrangou
- Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, NC, USA
| | - Edze R Westra
- Environment and Sustainability Institute, Centre for Ecology and Conservation, University of Exeter, Biosciences, Penryn, Cornwall, UK
| | - Luciano A Marraffini
- Laboratory of Bacteriology, The Rockefeller University, New York, NY, USA. .,Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA.
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117
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Tsoi R, Dai Z, You L. Emerging strategies for engineering microbial communities. Biotechnol Adv 2019; 37:107372. [PMID: 30880142 DOI: 10.1016/j.biotechadv.2019.03.011] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 03/13/2019] [Accepted: 03/13/2019] [Indexed: 12/11/2022]
Abstract
From biosynthesis to bioremediation, microbes have been engineered to address a variety of biotechnological applications. A promising direction in these endeavors is harnessing the power of designer microbial consortia that consist of multiple populations with well-defined interactions. Consortia can accomplish tasks that are difficult or potentially impossible to achieve using monocultures. Despite their potential, the rules underlying microbial community maintenance and function (i.e. the task the consortium is engineered to carry out) are not well defined, though rapid progress is being made. This limited understanding is in part due to the greater challenges associated with increased complexity when dealing with multi-population interactions. Here, we review key features and design strategies that emerge from the analysis of both natural and engineered microbial communities. These strategies can provide new insights into natural consortia and expand the toolbox available to engineers working to develop novel synthetic consortia.
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Affiliation(s)
- Ryan Tsoi
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| | - Zhuojun Dai
- Institute for Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China
| | - Lingchong You
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA; Center for Genomic and Computational Biology, Duke University, Durham, NC 27708, USA; Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27708, USA.
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118
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Palmer M, Venter SN, Coetzee MP, Steenkamp ET. Prokaryotic species are sui generis evolutionary units. Syst Appl Microbiol 2019; 42:145-158. [DOI: 10.1016/j.syapm.2018.10.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 10/02/2018] [Accepted: 10/03/2018] [Indexed: 12/25/2022]
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Abstract
Microbial populations exchange genetic material through a process called homologous recombination. Although this process has been studied in particular organisms, we lack an understanding of its differential impact over the genome and across microbes with different life-styles. We used a common analytical framework to assess this process in a representative set of microorganisms. Our results uncovered important trends. First, microbes with different lifestyles are differentially impacted, with endosymbionts and obligate pathogens being those less prone to undergo this process. Second, certain genetic elements such as restriction-modification systems seem to be associated with higher rates of recombination. Most importantly, recombined genomes show the footprints of natural selection in which recombined regions preferentially contain genes that can be related to specific ecological adaptations. Taken together, our results clarify the relative contributions of factors modulating homologous recombination and show evidence for a clear a role of this process in shaping microbial genomes and driving ecological adaptations. Homologous recombination (HR) enables the exchange of genetic material between and within species. Recent studies suggest that this process plays a major role in the microevolution of microbial genomes, contributing to core genome homogenization and to the maintenance of cohesive population structures. However, we still have a very poor understanding of the possible adaptive roles of intraspecific HR and of the factors that determine its differential impact across clades and lifestyles. Here we used a unified methodological framework to assess HR in 338 complete genomes from 54 phylogenetically diverse and representative prokaryotic species, encompassing different lifestyles and a broad phylogenetic distribution. Our results indicate that lifestyle and presence of restriction-modification (RM) machineries are among the main factors shaping HR patterns, with symbionts and intracellular pathogens having the lowest HR levels. Similarly, the size of exchanged genomic fragments correlated with the presence of RM and competence machineries. Finally, genes exchanged by HR showed functional enrichments which could be related to adaptations to different environments and ecological strategies. Taken together, our results clarify the factors underlying HR impact and suggest important adaptive roles of genes exchanged through this mechanism. Our results also revealed that the extent of genetic exchange correlated with lifestyle and some genomic features. Moreover, the genes in exchanged regions were enriched for functions that reflected specific adaptations, supporting identification of HR as one of the main evolutionary mechanisms shaping prokaryotic core genomes.
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120
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Comparative Genomic Analysis Reveals the Distribution, Organization, and Evolution of Metal Resistance Genes in the Genus Acidithiobacillus. Appl Environ Microbiol 2019; 85:AEM.02153-18. [PMID: 30389769 DOI: 10.1128/aem.02153-18] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 10/19/2018] [Indexed: 12/28/2022] Open
Abstract
Members of the genus Acidithiobacillus, which can adapt to extremely high concentrations of heavy metals, are universally found at acid mine drainage (AMD) sites. Here, we performed a comparative genomic analysis of 37 strains within the genus Acidithiobacillus to answer the untouched questions as to the mechanisms and the evolutionary history of metal resistance genes in Acidithiobacillus spp. The results showed that the evolutionary history of metal resistance genes in Acidithiobacillus spp. involved a combination of gene gains and losses, horizontal gene transfer (HGT), and gene duplication. Phylogenetic analyses revealed that metal resistance genes in Acidithiobacillus spp. were acquired by early HGT events from species that shared habitats with Acidithiobacillus spp., such as Acidihalobacter, Thiobacillus, Acidiferrobacter, and Thiomonas species. Multicopper oxidase genes involved in copper detoxification were lost in iron-oxidizing Acidithiobacillus ferridurans, Acidithiobacillus ferrivorans, and Acidithiobacillus ferrooxidans and were replaced by rusticyanin genes during evolution. In addition, widespread purifying selection and the predicted high expression levels emphasized the indispensable roles of metal resistance genes in the ability of Acidithiobacillus spp. to adapt to harsh environments. Altogether, the results suggested that Acidithiobacillus spp. recruited and consolidated additional novel functionalities during the adaption to challenging environments via HGT, gene duplication, and purifying selection. This study sheds light on the distribution, organization, functionality, and complex evolutionary history of metal resistance genes in Acidithiobacillus spp.IMPORTANCE Horizontal gene transfer (HGT), natural selection, and gene duplication are three main engines that drive the adaptive evolution of microbial genomes. Previous studies indicated that HGT was a main adaptive mechanism in acidophiles to cope with heavy-metal-rich environments. However, evidences of HGT in Acidithiobacillus species in response to challenging metal-rich environments and the mechanisms addressing how metal resistance genes originated and evolved in Acidithiobacillus are still lacking. The findings of this study revealed a fascinating phenomenon of putative cross-phylum HGT, suggesting that Acidithiobacillus spp. recruited and consolidated additional novel functionalities during the adaption to challenging environments via HGT, gene duplication, and purifying selection. Altogether, the insights gained in this study have improved our understanding of the metal resistance strategies of Acidithiobacillus spp.
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121
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Recombination of ecologically and evolutionarily significant loci maintains genetic cohesion in the Pseudomonas syringae species complex. Genome Biol 2019; 20:3. [PMID: 30606234 PMCID: PMC6317194 DOI: 10.1186/s13059-018-1606-y] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 12/06/2018] [Indexed: 01/25/2023] Open
Abstract
Background Pseudomonas syringae is a highly diverse bacterial species complex capable of causing a wide range of serious diseases on numerous agronomically important crops. We examine the evolutionary relationships of 391 agricultural and environmental strains using whole-genome sequencing and evolutionary genomic analyses. Results We describe the phylogenetic distribution of all 77,728 orthologous gene families in the pan-genome, reconstruct the core genome phylogeny using the 2410 core genes, hierarchically cluster the accessory genome, identify the diversity and distribution of type III secretion systems and their effectors, predict ecologically and evolutionary relevant loci, and establish the molecular evolutionary processes operating on gene families. Phylogenetic and recombination analyses reveals that the species complex is subdivided into primary and secondary phylogroups, with the former primarily comprised of agricultural isolates, including all of the well-studied P. syringae strains. In contrast, the secondary phylogroups include numerous environmental isolates. These phylogroups also have levels of genetic diversity typically found among distinct species. An analysis of rates of recombination within and between phylogroups revealed a higher rate of recombination within primary phylogroups than between primary and secondary phylogroups. We also find that “ecologically significant” virulence-associated loci and “evolutionarily significant” loci under positive selection are over-represented among loci that undergo inter-phylogroup genetic exchange. Conclusions While inter-phylogroup recombination occurs relatively rarely, it is an important force maintaining the genetic cohesion of the species complex, particularly among primary phylogroup strains. This level of genetic cohesion, and the shared plant-associated niche, argues for considering the primary phylogroups as a single biological species. Electronic supplementary material The online version of this article (10.1186/s13059-018-1606-y) contains supplementary material, which is available to authorized users.
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Alahmad A, Decocq G, Spicher F, Kheirbeik L, Kobaissi A, Tetu T, Dubois F, Duclercq J. Cover crops in arable lands increase functional complementarity and redundancy of bacterial communities. J Appl Ecol 2018. [DOI: 10.1111/1365-2664.13307] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Abdelrahman Alahmad
- Unité ‘Ecologie et Dynamique des Systèmes Anthropisés’ (EDYSAN UMR CNRS 7058 CNRS)Université du Picardie Jules Verne, UFR des Sciences Amiens France
| | - Guillaume Decocq
- Unité ‘Ecologie et Dynamique des Systèmes Anthropisés’ (EDYSAN UMR CNRS 7058 CNRS)Université du Picardie Jules Verne, UFR des Sciences Amiens France
| | - Fabien Spicher
- Unité ‘Ecologie et Dynamique des Systèmes Anthropisés’ (EDYSAN UMR CNRS 7058 CNRS)Université du Picardie Jules Verne, UFR des Sciences Amiens France
| | - Louay Kheirbeik
- Unité ‘Ecologie et Dynamique des Systèmes Anthropisés’ (EDYSAN UMR CNRS 7058 CNRS)Université du Picardie Jules Verne, UFR des Sciences Amiens France
| | - Ahmad Kobaissi
- Applied Plant Biotechnology LaboratoryFaculty of Sciences ILebanese University Beirut Lebanon
| | - Thierry Tetu
- Unité ‘Ecologie et Dynamique des Systèmes Anthropisés’ (EDYSAN UMR CNRS 7058 CNRS)Université du Picardie Jules Verne, UFR des Sciences Amiens France
| | - Frédéric Dubois
- Unité ‘Ecologie et Dynamique des Systèmes Anthropisés’ (EDYSAN UMR CNRS 7058 CNRS)Université du Picardie Jules Verne, UFR des Sciences Amiens France
| | - Jérôme Duclercq
- Unité ‘Ecologie et Dynamique des Systèmes Anthropisés’ (EDYSAN UMR CNRS 7058 CNRS)Université du Picardie Jules Verne, UFR des Sciences Amiens France
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Sharpton SR, Yong GJM, Terrault NA, Lynch SV. Gut Microbial Metabolism and Nonalcoholic Fatty Liver Disease. Hepatol Commun 2018; 3:29-43. [PMID: 30619992 PMCID: PMC6312661 DOI: 10.1002/hep4.1284] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Accepted: 10/23/2018] [Indexed: 12/18/2022] Open
Abstract
The gut microbiome, the multispecies community of microbes that exists in the gastrointestinal tract, encodes several orders of magnitude more functional genes than the human genome. It also plays a pivotal role in human health, in part due to metabolism of environmental, dietary, and host‐derived substrates, which produce bioactive metabolites. Perturbations to the composition and associated metabolic output of the gut microbiome have been associated with a number of chronic liver diseases, including nonalcoholic fatty liver disease (NAFLD). Here, we review the rapidly evolving suite of next‐generation techniques used for studying gut microbiome composition, functional gene content, and bioactive products and discuss relationships with the pathogenesis of NAFLD.
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Affiliation(s)
- Suzanne R Sharpton
- Department of Medicine, Division of Gastroenterology University of California San Francisco San Francisco CA
| | - Germaine J M Yong
- Department of Medicine, Division of Gastroenterology University of California San Francisco San Francisco CA
| | - Norah A Terrault
- Department of Medicine, Division of Gastroenterology University of California San Francisco San Francisco CA
| | - Susan V Lynch
- Department of Medicine, Division of Gastroenterology University of California San Francisco San Francisco CA
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Rosen MJ, Davison M, Fisher DS, Bhaya D. Probing the ecological and evolutionary history of a thermophilic cyanobacterial population via statistical properties of its microdiversity. PLoS One 2018; 13:e0205396. [PMID: 30427861 PMCID: PMC6235289 DOI: 10.1371/journal.pone.0205396] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 09/25/2018] [Indexed: 12/11/2022] Open
Abstract
Despite extensive DNA sequencing data derived from natural microbial communities, it remains a major challenge to identify the key evolutionary and ecological forces that shape microbial populations. We have focused on the extensive microdiversity of the cyanobacterium Synechococcus sp., which is a dominant member of the dense phototrophic biofilms in the hot springs of Yellowstone National Park. From deep amplicon sequencing of many loci and statistical analyses of these data, we showed previously that the population has undergone an unexpectedly high degree of homologous recombination, unlinking synonymous SNP-pair correlations even on intragenic length scales. Here, we analyze the genic amino acid diversity, which provides new evidence of selection and insights into the evolutionary history of the population. Surprisingly, some features of the data, including the spectrum of distances between genic-alleles, appear consistent with primarily asexual neutral drift. Yet the non-synonymous site frequency spectrum has too large an excess of low-frequency polymorphisms to result from negative selection on deleterious mutations given the distribution of coalescent times that we infer. And our previous analyses showed that the population is not asexual. Taken together, these apparently contradictory data suggest that selection, epistasis, and hitchhiking all play essential roles in generating and stabilizing the diversity. We discuss these as well as potential roles of ecological niches at genomic and genic levels. From quantitative properties of the diversity and comparative genomic data, we infer aspects of the history and inter-spring dispersal of the meta-population since it was established in the Yellowstone Caldera. Our investigations illustrate the need for combining multiple types of sequencing data and quantitative statistical analyses to develop an understanding of microdiversity in natural microbial populations.
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Affiliation(s)
- Michael J. Rosen
- Applied Physics Department, Stanford University, Stanford, CA, United States of America
| | - Michelle Davison
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, United States of America
| | - Daniel S. Fisher
- Applied Physics Department, Stanford University, Stanford, CA, United States of America
| | - Devaki Bhaya
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, United States of America
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Azarian T, Mitchell PK, Georgieva M, Thompson CM, Ghouila A, Pollard AJ, von Gottberg A, du Plessis M, Antonio M, Kwambana-Adams BA, Clarke SC, Everett D, Cornick J, Sadowy E, Hryniewicz W, Skoczynska A, Moïsi JC, McGee L, Beall B, Metcalf BJ, Breiman RF, Ho PL, Reid R, O’Brien KL, Gladstone RA, Bentley SD, Hanage WP. Global emergence and population dynamics of divergent serotype 3 CC180 pneumococci. PLoS Pathog 2018; 14:e1007438. [PMID: 30475919 PMCID: PMC6283594 DOI: 10.1371/journal.ppat.1007438] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 12/06/2018] [Accepted: 10/25/2018] [Indexed: 12/23/2022] Open
Abstract
Streptococcus pneumoniae serotype 3 remains a significant cause of morbidity and mortality worldwide, despite inclusion in the 13-valent pneumococcal conjugate vaccine (PCV13). Serotype 3 increased in carriage since the implementation of PCV13 in the USA, while invasive disease rates remain unchanged. We investigated the persistence of serotype 3 in carriage and disease, through genomic analyses of a global sample of 301 serotype 3 isolates of the Netherlands3-31 (PMEN31) clone CC180, combined with associated patient data and PCV utilization among countries of isolate collection. We assessed phenotypic variation between dominant clades in capsule charge (zeta potential), capsular polysaccharide shedding, and susceptibility to opsonophagocytic killing, which have previously been associated with carriage duration, invasiveness, and vaccine escape. We identified a recent shift in the CC180 population attributed to a lineage termed Clade II, which was estimated by Bayesian coalescent analysis to have first appeared in 1968 [95% HPD: 1939-1989] and increased in prevalence and effective population size thereafter. Clade II isolates are divergent from the pre-PCV13 serotype 3 population in non-capsular antigenic composition, competence, and antibiotic susceptibility, the last of which resulting from the acquisition of a Tn916-like conjugative transposon. Differences in recombination rates among clades correlated with variations in the ATP-binding subunit of Clp protease, as well as amino acid substitutions in the comCDE operon. Opsonophagocytic killing assays elucidated the low observed efficacy of PCV13 against serotype 3. Variation in PCV13 use among sampled countries was not independently correlated with the CC180 population shift; therefore, genotypic and phenotypic differences in protein antigens and, in particular, antibiotic resistance may have contributed to the increase of Clade II. Our analysis emphasizes the need for routine, representative sampling of isolates from disperse geographic regions, including historically under-sampled areas. We also highlight the value of genomics in resolving antigenic and epidemiological variations within a serotype, which may have implications for future vaccine development.
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Affiliation(s)
- Taj Azarian
- Center for Communicable Disease Dynamics, Department of Epidemiology, T.H. Chan School of Public Health, Harvard University, Boston, Massachusetts, United States of America
| | - Patrick K. Mitchell
- Center for Communicable Disease Dynamics, Department of Epidemiology, T.H. Chan School of Public Health, Harvard University, Boston, Massachusetts, United States of America
| | - Maria Georgieva
- Center for Communicable Disease Dynamics, Department of Epidemiology, T.H. Chan School of Public Health, Harvard University, Boston, Massachusetts, United States of America
| | - Claudette M. Thompson
- Center for Communicable Disease Dynamics, Department of Epidemiology, T.H. Chan School of Public Health, Harvard University, Boston, Massachusetts, United States of America
| | - Amel Ghouila
- Institut Pasteur de Tunis, LR11IPT02, Laboratory of Transmission, Control and Immunobiology of Infections (LTCII), Tunis-Belvédère, Tunisia
| | - Andrew J. Pollard
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford; NIHR Oxford Biomedical Research Centre, Centre for Clinical Vaccinology and Tropical Medicine (CCVTM), Churchill Hospital, Oxford, United Kingdom
| | - Anne von Gottberg
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa
| | - Mignon du Plessis
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa
| | - Martin Antonio
- Medical Research Council Unit The Gambia, Fajara, The Gambia
| | | | - Stuart C. Clarke
- Faculty of Medicine and Institute for Life Sciences and Global Health Research Institute, University of Southampton, Southampton, United Kingdom
- NIHR Southampton Biomedical Research Centre, Southampton General Hospital, Southampton, United Kingdom
| | - Dean Everett
- Queens Research Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Jennifer Cornick
- Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
| | - Ewa Sadowy
- National Medicines Institute, Warsaw, Poland
| | | | | | - Jennifer C. Moïsi
- Pfizer Vaccines, Medical Development, Scientific and Clinical Affairs, Paris, France
| | - Lesley McGee
- Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Bernard Beall
- Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Benjamin J. Metcalf
- Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Robert F. Breiman
- Global Health Institute, Emory University, Atlanta, Georgia, United States of America
| | - PL Ho
- Department of Microbiology, Queen Mary Hospital University of Hong Kong, Hong Kong, People’s Republic of China
| | - Raymond Reid
- Center for American Indian Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Katherine L. O’Brien
- Center for American Indian Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Rebecca A. Gladstone
- Wellcome Trust, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Stephen D. Bentley
- Wellcome Trust, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - William P. Hanage
- Center for Communicable Disease Dynamics, Department of Epidemiology, T.H. Chan School of Public Health, Harvard University, Boston, Massachusetts, United States of America
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A tale of three kingdoms: members of the Phylum Nematoda independently acquired the detoxifying enzyme cyanase through horizontal gene transfer from plants and bacteria. Parasitology 2018; 146:445-452. [PMID: 30301483 DOI: 10.1017/s0031182018001701] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Horizontal gene transfer (HGT) has played an important role in the evolution of nematodes. Among candidate genes, cyanase, which is typically found only in plants, bacteria and fungi, is present in more than 35 members of the Phylum Nematoda, but absent from free-living and clade V organisms. Phylogenetic analyses showed that the cyanases of clade I organisms Trichinella spp., Trichuris spp. and Soboliphyme baturini (Subclass: Dorylaimia) represent a well-supported monophyletic clade with plant cyanases. In contrast, all cyanases found within the Subclass Chromadoria which encompasses filarioids, ascaridoids and strongyloids are homologous to those of bacteria. Western blots exhibited typical multimeric forms of the native molecule in protein extracts of Trichinella spiralis muscle larvae, where immunohistochemical staining localized the protein to the worm hypodermis and underlying muscle. Recombinant Trichinella cyanase was bioactive where gene transcription profiles support functional activity in vivo. Results suggest that: (1) independent HGT in parasitic nematodes originated from different Kingdoms; (2) cyanase acquired an active role in the biology of extant Trichinella; (3) acquisition occurred more than 400 million years ago (MYA), prior to the divergence of the Trichinellida and Dioctophymatida, and (4) early, free-living ancestors of the genus Trichinella had an association with terrestrial plants.
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127
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Fan Y, Xiao Y, Momeni B, Liu YY. Horizontal gene transfer can help maintain the equilibrium of microbial communities. J Theor Biol 2018; 454:53-59. [DOI: 10.1016/j.jtbi.2018.05.036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 05/23/2018] [Accepted: 05/29/2018] [Indexed: 01/15/2023]
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128
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Genome guided investigation of antibiotics producing actinomycetales strain isolated from a Macau mangrove ecosystem. Sci Rep 2018; 8:14271. [PMID: 30250135 PMCID: PMC6155160 DOI: 10.1038/s41598-018-32076-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 08/31/2018] [Indexed: 01/15/2023] Open
Abstract
Actinomycetes are a heterogeneous group of gram positive filamentous bacteria that have been found to produce a wide range of valuable bioactive secondary metabolites, particularly antibiotics. Moreover, actinomycetes isolated from unexplored environments show an unprecedented potential to generate novel active compounds. Hence, in order to search for novel antibiotics, we isolated and characterized actinomycetes strains from plant samples collected from a mangrove in Macau. Within the class of actinobacteria, fourteen actinomycetes isolates have been isolated and identified belonging to the genus of Streptomyces, Micromonospora, Mycobacterium, Brevibacterium, Curtobacterium and Kineococcus based on their 16S rRNA sequences. Further whole genome sequencing analysis of one of the isolated Streptomyces sp., which presented 99.13% sequence similarity with Streptomyces parvulus strain 2297, showed that it consisted of 118 scaffolds, 8,348,559 base pairs and had a 72.28% G + C content. In addition, genome-mining revealed that the isolated Streptomyces sp. contains 109 gene clusters responsible for the biosynthesis of known and/or novel secondary metabolites, including different types of terpene, T1pks, T2pks, T3pks, Nrps, indole, siderophore, bacteriocin, thiopeptide, phosphonate, lanthipeptide, ectoine, butyrolactone, T3pks-Nrps, and T1pks-Nrps. Meanwhile, the small molecules present in ethyl acetate extract of the fermentation broth of this strain were analyzed by LC-MS. Predicted secondary metabolites of melanin and desferrioxamine B were identified and both of them were firstly found to be produced by the Streptomyces parvulus strain. Our study highlights that combining genome mining is an efficient method to detect potentially promising natural products from mangrove-derived actinomycetes.
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129
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Marcelletti S, Scortichini M. Some strains that have converged to infect Prunus spp. trees are members of distinct Pseudomonas syringae genomospecies and ecotypes as revealed by in silico genomic comparison. Arch Microbiol 2018; 201:67-80. [PMID: 30229267 DOI: 10.1007/s00203-018-1573-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Revised: 09/06/2018] [Accepted: 09/13/2018] [Indexed: 11/29/2022]
Abstract
A complementary taxonomic and population genetic study was performed to delineate genetically and ecologically distinct species within the Pseudomonas syringae complex by assessing 16 strains including pathovar strains that have converged to infect Prunus spp. trees, and two outgroups. Both average nucleotide identity and genome-to-genome distance comparison methods revealed the occurrence of distinct genomospecies, namely 1, 2, 3 and 8 (sensu Gardan et al.), with the latter two being closely related. Strains classified as P. s. pv. morsprunorum clustered into two distinct genomospecies, namely 2 and 8. Both the AdaptML and hierarchical Bayesian analysis of population structure methods highlighted the presence of three ecotypes, and the taxonomically related genomospecies 3 and 8 strains were members of the same ecotype. The distribution of pathogenic and virulence-associated genetic traits among Pseudomonas strains did not reveal any distinct type III secretion system effector or phytotoxin distribution pattern that characterized single genomospecies and strains that infect Prunus spp. The complete WHOP (Woody HOst and Pseudomonas spp.) genomic region and the entire β-ketoadipate gene cluster, including the catBCA operon, were found only in the members of genomospecies 2 and in the two P. s. pv. morsprunorum strains of genomospecies 8. A reduced gene flow between the three ecotypes suggested that point mutations played a larger role during the evolution of the strains than recombination. Our data support the idea that Prunus trees can be infected by different strains of distinct Pseudomonas genomospecies/ecotypes through diverse mechanisms of host colonization and infection. Such strains may represent particular lineages that emerged from environments other than that of the infected plant upon acquiring genetic traits that gave them the ability to cause plant diseases. The complementary assessment of bacterial strains using both taxonomic approaches and methods that reveal ecologically homogeneous populations has proven useful in confirming the cohesion of bacterial clusters.
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Affiliation(s)
- Simone Marcelletti
- Council for Agricultural Research and Analysis of Agricultural Economics (CREA), Research Centre for Olive, Fruit Trees and Citrus, Via di Fioranello, 52, 00134, Rome, Italy
| | - Marco Scortichini
- Council for Agricultural Research and Analysis of Agricultural Economics (CREA), Research Centre for Olive, Fruit Trees and Citrus, Via di Fioranello, 52, 00134, Rome, Italy.
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130
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Roy R, Samanta S, Patra S, Mahato NK, Saha RP. In silico identification and characterization of sensory motifs in the transcriptional regulators of the ArsR-SmtB family. Metallomics 2018; 10:1476-1500. [PMID: 30191942 DOI: 10.1039/c8mt00082d] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The ArsR-SmtB family of proteins displays the greatest diversity among the bacterial metal-binding transcriptional regulators with regard to the variety of metal ions that they can sense. In the presence of increased levels of toxic heavy metals, these proteins dissociate from their cognate DNA upon the direct binding of metal ions to the appropriate sites, designated motifs on the proteins, either at the interface of the dimers or at the intra-subunit locations. In addition to the metal-mediated regulation, some proteins were also found to control transcription via redox reactions. In the present work, we have identified several new sequence motifs and expanded the knowledge base of metal binding sites in the ArsR-SmtB family of transcriptional repressors, and characterized them in terms of the ligands to the metal, distribution among different phyla of bacteria and archaea, amino acid propensities, protein length distributions and evolutionary interrelationships. We built structural models of the motifs to show the importance of specific residues in an individual motif. The wide abundance of these motifs in sequences of bacteria and archaea indicates the importance of these regulators in combating metal-toxicity within and outside of the hosts. We also show that by using residue composition, one can distinguish the ArsR-SmtB proteins from other metalloregulatory families. In addition, we show the importance of horizontal gene transfer in microorganisms, residing in similar habitats, on the evolution of the structural motifs in the family. Knowledge of the diverse metalloregulatory systems in microorganisms could enable us to manipulate specific genes that may result in a toxic metal-free environment.
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Affiliation(s)
- Rima Roy
- Department of Biotechnology, School of Biotechnology, Adamas University, Kolkata 700 126, India.
| | - Saikat Samanta
- Department of Biotechnology, School of Biotechnology, Adamas University, Kolkata 700 126, India.
| | - Surajit Patra
- Department of Biotechnology, School of Biotechnology, Adamas University, Kolkata 700 126, India.
| | - Nav Kumar Mahato
- Department of Mathematics, School of Science, Adamas University, Kolkata 700 126, India
| | - Rudra P Saha
- Department of Biotechnology, School of Biotechnology, Adamas University, Kolkata 700 126, India.
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131
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Flórez LV, Scherlach K, Miller IJ, Rodrigues A, Kwan JC, Hertweck C, Kaltenpoth M. An antifungal polyketide associated with horizontally acquired genes supports symbiont-mediated defense in Lagria villosa beetles. Nat Commun 2018; 9:2478. [PMID: 29946103 PMCID: PMC6018673 DOI: 10.1038/s41467-018-04955-6] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 06/05/2018] [Indexed: 12/13/2022] Open
Abstract
Microbial symbionts are often a source of chemical novelty and can contribute to host defense against antagonists. However, the ecological relevance of chemical mediators remains unclear for most systems. Lagria beetles live in symbiosis with multiple strains of Burkholderia bacteria that protect their offspring against pathogens. Here, we describe the antifungal polyketide lagriamide, and provide evidence supporting that it is produced by an uncultured symbiont, Burkholderia gladioli Lv-StB, which is dominant in field-collected Lagria villosa. Interestingly, lagriamide is structurally similar to bistramides, defensive compounds found in marine tunicates. We identify a gene cluster that is probably involved in lagriamide biosynthesis, provide evidence for horizontal acquisition of these genes, and show that the naturally occurring symbiont strains on the egg are protective in the soil environment. Our findings highlight the potential of microbial symbionts and horizontal gene transfer as influential sources of ecological innovation.
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Affiliation(s)
- Laura V Flórez
- Department for Evolutionary Ecology, Institute of Organismic and Molecular Evolution, Johannes Gutenberg University, Johann-Joachim-Becher-Weg 13, 55128, Mainz, Germany.
| | - Kirstin Scherlach
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Products Research and Infection Biology, HKI, Beutenbergstr. 11a, 07745, Jena, Germany.
| | - Ian J Miller
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin, 777 Highland Ave, Madison, WI, 53705-2222, USA
| | - Andre Rodrigues
- Department of Biochemistry and Microbiology, UNESP-São Paulo State University, Av. 24A, n. 1515-Bela Vista, Rio Claro, SP, 13506-900, Brazil
| | - Jason C Kwan
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin, 777 Highland Ave, Madison, WI, 53705-2222, USA
| | - Christian Hertweck
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Products Research and Infection Biology, HKI, Beutenbergstr. 11a, 07745, Jena, Germany
- Natural Product Chemistry, Friedrich Schiller University, 07743, Jena, Germany
| | - Martin Kaltenpoth
- Department for Evolutionary Ecology, Institute of Organismic and Molecular Evolution, Johannes Gutenberg University, Johann-Joachim-Becher-Weg 13, 55128, Mainz, Germany
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132
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Bakermans C. Adaptations to marine versus terrestrial low temperature environments as revealed by comparative genomic analyses of the genus Psychrobacter. FEMS Microbiol Ecol 2018; 94:5032373. [DOI: 10.1093/femsec/fiy102] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 05/27/2018] [Indexed: 12/13/2022] Open
Affiliation(s)
- Corien Bakermans
- Division of Mathematics and Natural Sciences, Penn State Altoona, United States
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133
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Daniel R, Simon M, Wemheuer B. Editorial: Molecular Ecology and Genetic Diversity of the Roseobacter Clade. Front Microbiol 2018; 9:1185. [PMID: 29910792 PMCID: PMC5992283 DOI: 10.3389/fmicb.2018.01185] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 05/16/2018] [Indexed: 12/26/2022] Open
Affiliation(s)
- Rolf Daniel
- Genomic and Applied Microbiology and Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, University of Göttingen, Göttingen, Germany
| | - Meinhard Simon
- Biology of Geological Processes, Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, Germany
| | - Bernd Wemheuer
- Genomic and Applied Microbiology and Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, University of Göttingen, Göttingen, Germany.,Centre for Marine Bio-Innovation, The University of New South Wales, Sydney, NSW, Australia.,School of Biological Earth and Environmental Sciences, The University of New South Wales, Sydney, NSW, Australia
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134
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Hendrickson HL, Barbeau D, Ceschin R, Lawrence JG. Chromosome architecture constrains horizontal gene transfer in bacteria. PLoS Genet 2018; 14:e1007421. [PMID: 29813058 PMCID: PMC5993296 DOI: 10.1371/journal.pgen.1007421] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Revised: 06/08/2018] [Accepted: 05/16/2018] [Indexed: 11/19/2022] Open
Abstract
Despite significant frequencies of lateral gene transfer between species, higher taxonomic groups of bacteria show ecological and phenotypic cohesion. This suggests that barriers prevent panmictic dissemination of genes via lateral gene transfer. We have proposed that most bacterial genomes have a functional architecture imposed by Architecture IMparting Sequences (AIMS). AIMS are defined as 8 base pair sequences preferentially abundant on leading strands, whose abundance and strand-bias are positively correlated with proximity to the replication terminus. We determined that inversions whose endpoints lie within a single chromosome arm, which would reverse the polarity of AIMS in the inverted region, are both shorter and less frequent near the replication terminus. This distribution is consistent with the increased selection on AIMS function in this region, thus constraining DNA rearrangement. To test the hypothesis that AIMS also constrain DNA transfer between genomes, AIMS were identified in genomes while ignoring atypical, potentially laterally-transferred genes. The strand-bias of AIMS within recently acquired genes was negatively correlated with the distance of those genes from their genome’s replication terminus. This suggests that selection for AIMS function prevents the acquisition of genes whose AIMS are not found predominantly in the permissive orientation. This constraint has led to the loss of at least 18% of genes acquired by transfer in the terminus-proximal region. We used completely sequenced genomes to produce a predictive road map of paths of expected horizontal gene transfer between species based on AIMS compatibility between donor and recipient genomes. These results support a model whereby organisms retain introgressed genes only if the benefits conferred by their encoded functions outweigh the detriments incurred by the presence of foreign DNA lacking genome-wide architectural information. The potential success of horizontal gene transfer events is historically equated to the benefits conferred by encoded products. Here we show that gene transfer events are observed less frequently if the introduced genes disrupt important patterns of genomic information, suggesting that this disruption would confer an unacceptable cost. As a result, gene transfer events are less likely to be successful if the potential donor genomes have incompatible genome architecture. Because more distantly-related genes are less compatible, chromosome architecture serves as a mechanism to bias gene transfer events to those involving closer relatives, thereby providing a mechanism for the genotypic and phenotypic cohesion of higher taxonomic groups.
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Affiliation(s)
- Heather L. Hendrickson
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Institute of Natural and Mathematical Sciences, Massey University, Auckland, New Zealand
| | - Dominique Barbeau
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Robin Ceschin
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Jeffrey G. Lawrence
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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135
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Hall JPJ, Brockhurst MA, Harrison E. Sampling the mobile gene pool: innovation via horizontal gene transfer in bacteria. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0424. [PMID: 29061896 DOI: 10.1098/rstb.2016.0424] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2017] [Indexed: 12/26/2022] Open
Abstract
In biological systems, evolutionary innovations can spread not only from parent to offspring (i.e. vertical transmission), but also 'horizontally' between individuals, who may or may not be related. Nowhere is this more apparent than in bacteria, where novel ecological traits can spread rapidly within and between species through horizontal gene transfer (HGT). This important evolutionary process is predominantly a by-product of the infectious spread of mobile genetic elements (MGEs). We will discuss the ecological conditions that favour the spread of traits by HGT, the evolutionary and social consequences of sharing traits, and how HGT is shaped by inherent conflicts between bacteria and MGEs.This article is part of the themed issue 'Process and pattern in innovations from cells to societies'.
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Affiliation(s)
- James P J Hall
- Department of Animal and Plant Sciences, Alfred Denny Building, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Michael A Brockhurst
- Department of Animal and Plant Sciences, Alfred Denny Building, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Ellie Harrison
- P3 Institute, Department of Animal and Plant Sciences, Arthur Willis Environment Centre, University of Sheffield, 1 Maxfield Avenue, Sheffield S10 1AE, UK
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136
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Kim H, Kwak W, Yoon SH, Kang DK, Kim H. Horizontal gene transfer of Chlamydia: Novel insights from tree reconciliation. PLoS One 2018; 13:e0195139. [PMID: 29621277 PMCID: PMC5886423 DOI: 10.1371/journal.pone.0195139] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 03/16/2018] [Indexed: 01/07/2023] Open
Abstract
Recent comparative genomics studies have suggested that horizontal gene transfer (HGT) is one of the major processes in bacterial evolution. In this study, HGT events of 64 Chlamydia strains were investigated based on the pipeline employed in HGTree database constructed in our recent study. Tree reconciliation method was applied in order to calculate feasible HGT events. Following initial detection and an evaluation procedure, evidence of the HGT was identified in 548 gene families including 42 gene families transferred from outside of Chlamydiae phylum with high reliability. The donor species of inter-phylum HGT consists of 12 different bacterial and archaeal phyla, suggesting that Chlamydia might have even more various host range than in previous reports. In addition, each species of Chlamydia showed varying preference towards HGT, and genes engaged in HGT within Chlamydia and between other species showed different functional distribution. Also, examination of individual gene flows of niche-specific genes suggested that many of such genes are transferred mainly within Chlamydia genus. Our results uncovered novel features of HGT acting on Chlamydia genome evolution, and it would be also strong evidence that HGT is an ongoing process for intracellular pathogens. We expect that the results provide more insight into lineage- and niche-specific adaptations regarding their infectivity and pathogenicity.
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Affiliation(s)
- Hyaekang Kim
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea
| | - Woori Kwak
- C&K genomics, Seoul National University Research Park, Seoul, Republic of Korea
| | - Sook Hee Yoon
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea
| | - Dae-Kyung Kang
- Department of Animal Resources Science, Dankook University, Cheonan, Republic of Korea
| | - Heebal Kim
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea
- C&K genomics, Seoul National University Research Park, Seoul, Republic of Korea
- * E-mail:
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137
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Azarian T, Grant LR, Arnold BJ, Hammitt LL, Reid R, Santosham M, Weatherholtz R, Goklish N, Thompson CM, Bentley SD, O’Brien KL, Hanage WP, Lipsitch M. The impact of serotype-specific vaccination on phylodynamic parameters of Streptococcus pneumoniae and the pneumococcal pan-genome. PLoS Pathog 2018; 14:e1006966. [PMID: 29617440 PMCID: PMC5902063 DOI: 10.1371/journal.ppat.1006966] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 04/16/2018] [Accepted: 03/09/2018] [Indexed: 11/18/2022] Open
Abstract
In the United States, the introduction of the heptavalent pneumococcal conjugate vaccine (PCV) largely eliminated vaccine serotypes (VT); non-vaccine serotypes (NVT) subsequently increased in carriage and disease. Vaccination also disrupts the composition of the pneumococcal pangenome, which includes mobile genetic elements and polymorphic non-capsular antigens important for virulence, transmission, and pneumococcal ecology. Antigenic proteins are of interest for future vaccines; yet, little is known about how the they are affected by PCV use. To investigate the evolutionary impact of vaccination, we assessed recombination, evolution, and pathogen demographic history of 937 pneumococci collected from 1998-2012 among Navajo and White Mountain Apache Native American communities. We analyzed changes in the pneumococcal pangenome, focusing on metabolic loci and 19 polymorphic protein antigens. We found the impact of PCV on the pneumococcal population could be observed in reduced diversity, a smaller pangenome, and changing frequencies of accessory clusters of orthologous groups (COGs). Post-PCV7, diversity rebounded through clonal expansion of NVT lineages and inferred in-migration of two previously unobserved lineages. Accessory COGs frequencies trended toward pre-PCV7 values with increasing time since vaccine introduction. Contemporary frequencies of protein antigen variants are better predicted by pre-PCV7 values (1998-2000) than the preceding period (2006-2008), suggesting balancing selection may have acted in maintaining variant frequencies in this population. Overall, we present the largest genomic analysis of pneumococcal carriage in the United States to date, which includes a snapshot of a true vaccine-naïve community prior to the introduction of PCV7. These data improve our understanding of pneumococcal evolution and emphasize the need to consider pangenome composition when inferring the impact of vaccination and developing future protein-based pneumococcal vaccines.
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Affiliation(s)
- Taj Azarian
- Center for Communicable Disease Dynamics, Department of Epidemiology, T.H. Chan School of Public Health, Harvard University; Cambridge, Massachusetts, United States of America
- * E-mail:
| | - Lindsay R. Grant
- Center for American Indian Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; United States of America
| | - Brian J. Arnold
- Center for Communicable Disease Dynamics, Department of Epidemiology, T.H. Chan School of Public Health, Harvard University; Cambridge, Massachusetts, United States of America
| | - Laura L. Hammitt
- Center for American Indian Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; United States of America
| | - Raymond Reid
- Center for American Indian Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; United States of America
| | - Mathuram Santosham
- Center for American Indian Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; United States of America
| | - Robert Weatherholtz
- Center for American Indian Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; United States of America
| | - Novalene Goklish
- Center for American Indian Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; United States of America
| | - Claudette M. Thompson
- Center for Communicable Disease Dynamics, Department of Epidemiology, T.H. Chan School of Public Health, Harvard University; Cambridge, Massachusetts, United States of America
| | | | - Katherine L. O’Brien
- Center for American Indian Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; United States of America
| | - William P. Hanage
- Center for Communicable Disease Dynamics, Department of Epidemiology, T.H. Chan School of Public Health, Harvard University; Cambridge, Massachusetts, United States of America
| | - Marc Lipsitch
- Center for Communicable Disease Dynamics, Department of Epidemiology, T.H. Chan School of Public Health, Harvard University; Cambridge, Massachusetts, United States of America
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138
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Straub C, Colombi E, Li L, Huang H, Templeton MD, McCann HC, Rainey PB. The ecological genetics ofPseudomonas syringaefrom kiwifruit leaves. Environ Microbiol 2018. [DOI: 10.1111/1462-2920.14092] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Christina Straub
- New Zealand Institute for Advanced Study, Massey UniversityAuckland New Zealand
| | - Elena Colombi
- New Zealand Institute for Advanced Study, Massey UniversityAuckland New Zealand
| | - Li Li
- Key Laboratory of Plant Germplasm Enhancement and Specialty AgricultureWuhan Botanical Garden, Chinese Academy of SciencesWuhan People's Republic of China
| | - Hongwen Huang
- Key Laboratory of Plant Germplasm Enhancement and Specialty AgricultureWuhan Botanical Garden, Chinese Academy of SciencesWuhan People's Republic of China
- Key Laboratory of Plant Resources Conservation and Sustainable UtilizationSouth China Botanical Garden, Chinese Academy of SciencesGuangzhou People's Republic of China
| | | | - Honour C. McCann
- New Zealand Institute for Advanced Study, Massey UniversityAuckland New Zealand
| | - Paul B. Rainey
- New Zealand Institute for Advanced Study, Massey UniversityAuckland New Zealand
- Max Planck Institute for Evolutionary Biology, Department of Microbial Population BiologyPlön Germany
- École Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris Tech), Laboratoire de Génétique de l'EvolutionParis France
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139
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Meng JW, He DC, Zhu W, Yang LN, Wu EJ, Xie JH, Shang LP, Zhan J. Human-Mediated Gene Flow Contributes to Metapopulation Genetic Structure of the Pathogenic Fungus Alternaria alternata from Potato. FRONTIERS IN PLANT SCIENCE 2018; 9:198. [PMID: 29497439 PMCID: PMC5818430 DOI: 10.3389/fpls.2018.00198] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 02/01/2018] [Indexed: 06/01/2023]
Abstract
Metapopulation structure generated by recurrent extinctions and recolonizations plays an important role in the evolution of species but is rarely considered in agricultural systems. In this study, generation and mechanism of metapopulation structure were investigated by microsatellite assaying 725 isolates of Alternaria alternata sampled from potato hosts at 16 locations across China. We found a single major cluster, no isolate-geography associations and no bottlenecks in the A. alternata isolates, suggesting a metapopulation genetic structure of the pathogen. We also found weak isolation-by-distance, lower among than within cropping region population differentiation, concordant moving directions of potato products and net gene flow and the highest gene diversity in the region with the most potato imports. These results indicate that in addition to natural dispersal, human-mediated gene flow also contributes to the generation and dynamics of the metapopulation genetic structure of A. alternata in China. Metapopulation structure increases the adaptive capacity of the plant pathogen as a result of enhanced genetic variation and reduced population fragmentation. Consequently, rigid quarantine regulations may be required to reduce population connectivity and the evolutionary potential of A. alternata and other pathogens with a similar population dynamics for a sustainable plant disease management.
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Affiliation(s)
- Jing-Wen Meng
- Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Dun-Chun He
- Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Wen Zhu
- Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Li-Na Yang
- Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - E-Jiao Wu
- Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Jia-Hui Xie
- Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Li-Ping Shang
- Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Jiasui Zhan
- Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China
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140
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Hauck S, Maiden MCJ. Clonally Evolving Pathogenic Bacteria. MOLECULAR MECHANISMS OF MICROBIAL EVOLUTION 2018. [DOI: 10.1007/978-3-319-69078-0_12] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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141
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Chase AB, Martiny JBH. The importance of resolving biogeographic patterns of microbial microdiversity. MICROBIOLOGY AUSTRALIA 2018. [DOI: 10.1071/ma18003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
For centuries, ecologists have used biogeographic patterns to test the processes governing the assembly and maintenance of plant and animal communities. Similarly, evolutionary biologists have used historical biogeography (e.g. phylogeography) to understand the importance of geological events as barriers to dispersal that shape species distributions. As the field of microbial biogeography initially developed, the utilisation of highly conserved marker genes, such as the 16S ribosomal RNA gene, stimulated investigations into the biogeographic patterns of the microbial community as a whole. Here, we propose that we should now consider the biogeographic patterns of microdiversity, the fine-scale genetic diversity observed within a traditional ribosomal-based operational taxonomic unit.
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142
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A Reverse Ecology Framework for Bacteria and Archaea. POPULATION GENOMICS: MICROORGANISMS 2018. [DOI: 10.1007/13836_2018_46] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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143
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Abstract
The small molecules produced by environmental bacteria have been mainstays of both chemical and biological research for decades, and some have led to important therapeutic interventions. These small molecules have been shaped by natural selection as they evolved to fulfill changing functional roles in their native environments. This minireview describes some recent systematic studies providing illustrative examples that involve the acquisition and alteration of genetic information for molecular innovation by bacteria in well-defined environments. Two different bacterial genera are featured, Pseudonocardia and Salinispora, and, although the small-molecule repertoires of both have benefited from horizontal gene transfer, Pseudonocardia spp. have relied on plasmid-based tactics while Salinispora spp. have relied on chromosomally integrated genomic islands.
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Affiliation(s)
- Antonio C Ruzzini
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Jon Clardy
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
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144
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Porter SS, Faber-Hammond JJ, Friesen ML. Co-invading symbiotic mutualists of Medicago polymorpha retain high ancestral diversity and contain diverse accessory genomes. FEMS Microbiol Ecol 2017; 94:4705886. [DOI: 10.1093/femsec/fix168] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 11/29/2017] [Indexed: 02/06/2023] Open
Affiliation(s)
- Stephanie S Porter
- School of Biological Sciences, Washington State University, 14204 NE Salmon Creek Ave, Vancouver, WA 98686, USA
| | - Joshua J Faber-Hammond
- School of Biological Sciences, Washington State University, 14204 NE Salmon Creek Ave, Vancouver, WA 98686, USA
| | - Maren L Friesen
- Department of Plant Biology, Michigan State University, 612 Wilson Road, East Lansing, MI, 48824, USA
- Department of Plant Pathology, Washington State University, P.O. Box 646430 Pullman, WA 99164, USA
- Department of Crop and Soil Sciences, Washington State University, P.O. Box 646420 Pullman, WA 99164, USA
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145
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Cardona G, Pons JC. Reconstruction of LGT networks from tri-LGT-nets. J Math Biol 2017; 75:1669-1692. [PMID: 28451760 DOI: 10.1007/s00285-017-1131-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 02/16/2017] [Indexed: 01/06/2023]
Abstract
Phylogenetic networks have gained attention from the scientific community due to the evidence of the existence of evolutionary events that cannot be represented using trees. A variant of phylogenetic networks, called LGT networks, models specifically lateral gene transfer events, which cannot be properly represented with generic phylogenetic networks. In this paper we treat the problem of the reconstruction of LGT networks from substructures induced by three leaves, which we call tri-LGT-nets. We first restrict ourselves to a class of LGT networks that are both mathematically treatable and biologically significant, called BAN-LGT networks. Then, we study the decomposition of such networks in subnetworks with three leaves and ask whether or not this decomposition determines the network. The answer to this question is negative, but if we further impose time-consistency (species involved in a later gene transfer must coexist) the answer is affirmative, up to some redundancy that can never be recovered but is fully characterized.
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Affiliation(s)
- Gabriel Cardona
- Department of Mathematics and Computer Science, University of the Balearic Islands, 07122, Palma, Spain.
| | - Joan Carles Pons
- Department of Mathematics and Computer Science, University of the Balearic Islands, 07122, Palma, Spain
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146
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Roughgarden J, Gilbert SF, Rosenberg E, Zilber-Rosenberg I, Lloyd EA. Holobionts as Units of Selection and a Model of Their Population Dynamics and Evolution. ACTA ACUST UNITED AC 2017. [DOI: 10.1007/s13752-017-0287-1] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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147
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Thavamani P, Samkumar RA, Satheesh V, Subashchandrabose SR, Ramadass K, Naidu R, Venkateswarlu K, Megharaj M. Microbes from mined sites: Harnessing their potential for reclamation of derelict mine sites. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 230:495-505. [PMID: 28688926 DOI: 10.1016/j.envpol.2017.06.056] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 05/12/2017] [Accepted: 06/17/2017] [Indexed: 05/11/2023]
Abstract
Derelict mines pose potential risks to environmental health. Several factors such as soil structure, organic matter, and nutrient content are the greatly affected qualities in mined soils. Soil microbial communities are an important element for successful reclamation because of their major role in nutrient cycling, plant establishment, geochemical transformations, and soil formation. Yet, microorganisms generally remain an undervalued asset in mined sites. The microbial diversity in derelict mine sites consists of diverse species belonging to four key phyla: Proteobacteria, Acidobacteria, Firmicutes, and Bacteroidetes. The activity of plant symbiotic microorganisms including root-colonizing rhizobacteria and ectomycorrhizal fungi of existing vegetation in the mined sites is very high since most of these microbes are extremophiles. This review outlines the importance of microorganisms to soil health and the rehabilitation of derelict mines and how microbial activity and diversity can be exploited to better plan the soil rehabilitation. Besides highlighting the major breakthroughs in the application of microorganisms for mined site reclamation, we provide a critical view on plant-microbiome interactions to improve revegetation at the mined sites. Also, the need has been emphasized for deciphering the molecular mechanisms of adaptation and resistance of rhizosphere and non-rhizosphere microbes in abandoned mine sites, understanding their role in remediation, and subsequent harnessing of their potential to pave the way in future rehabilitation strategies for mined sites.
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Affiliation(s)
- Palanisami Thavamani
- Global Centre for Environmental Remediation, University of Newcastle, Australia.
| | - R Amos Samkumar
- ICAR- National Research Centre on Plant Biotechnology, Pusa, New Delhi 110012, India
| | - Viswanathan Satheesh
- ICAR- National Research Centre on Plant Biotechnology, Pusa, New Delhi 110012, India
| | | | - Kavitha Ramadass
- Future Industries Institute, University of South Australia, Australia
| | - Ravi Naidu
- Global Centre for Environmental Remediation, University of Newcastle, Australia
| | - Kadiyala Venkateswarlu
- Formerly Department of Microbiology, Sri Krishnadevaraya University, Anantapur 515055, India
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148
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Cury J, Touchon M, Rocha EPC. Integrative and conjugative elements and their hosts: composition, distribution and organization. Nucleic Acids Res 2017; 45:8943-8956. [PMID: 28911112 PMCID: PMC5587801 DOI: 10.1093/nar/gkx607] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 07/04/2017] [Indexed: 12/22/2022] Open
Abstract
Conjugation of single-stranded DNA drives horizontal gene transfer between bacteria and was widely studied in conjugative plasmids. The organization and function of integrative and conjugative elements (ICE), even if they are more abundant, was only studied in a few model systems. Comparative genomics of ICE has been precluded by the difficulty in finding and delimiting these elements. Here, we present the results of a method that circumvents these problems by requiring only the identification of the conjugation genes and the species’ pan-genome. We delimited 200 ICEs and this allowed the first large-scale characterization of these elements. We quantified the presence in ICEs of a wide set of functions associated with the biology of mobile genetic elements, including some that are typically associated with plasmids, such as partition and replication. Protein sequence similarity networks and phylogenetic analyses revealed that ICEs are structured in functional modules. Integrases and conjugation systems have different evolutionary histories, even if the gene repertoires of ICEs can be grouped in function of conjugation types. Our characterization of the composition and organization of ICEs paves the way for future functional and evolutionary analyses of their cargo genes, composed of a majority of unknown function genes.
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Affiliation(s)
- Jean Cury
- Microbial Evolutionary Genomics, Institut Pasteur, 28, rue du Dr Roux, Paris 75015, France.,CNRS, UMR3525, 28, rue Dr Roux, Paris 75015, France
| | - Marie Touchon
- Microbial Evolutionary Genomics, Institut Pasteur, 28, rue du Dr Roux, Paris 75015, France.,CNRS, UMR3525, 28, rue Dr Roux, Paris 75015, France
| | - Eduardo P C Rocha
- Microbial Evolutionary Genomics, Institut Pasteur, 28, rue du Dr Roux, Paris 75015, France.,CNRS, UMR3525, 28, rue Dr Roux, Paris 75015, France
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149
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Meyer KA, Davis TW, Watson SB, Denef VJ, Berry MA, Dick GJ. Genome sequences of lower Great Lakes Microcystis sp. reveal strain-specific genes that are present and expressed in western Lake Erie blooms. PLoS One 2017; 12:e0183859. [PMID: 29020009 PMCID: PMC5647855 DOI: 10.1371/journal.pone.0183859] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 08/11/2017] [Indexed: 12/15/2022] Open
Abstract
Blooms of the potentially toxic cyanobacterium Microcystis are increasing worldwide. In the Laurentian Great Lakes they pose major socioeconomic, ecological, and human health threats, particularly in western Lake Erie. However, the interpretation of "omics" data is constrained by the highly variable genome of Microcystis and the small number of reference genome sequences from strains isolated from the Great Lakes. To address this, we sequenced two Microcystis isolates from Lake Erie (Microcystis aeruginosa LE3 and M. wesenbergii LE013-01) and one from upstream Lake St. Clair (M. cf aeruginosa LSC13-02), and compared these data to the genomes of seventeen Microcystis spp. from across the globe as well as one metagenome and seven metatranscriptomes from a 2014 Lake Erie Microcystis bloom. For the publically available strains analyzed, the core genome is ~1900 genes, representing ~11% of total genes in the pan-genome and ~45% of each strain's genome. The flexible genome content was related to Microcystis subclades defined by phylogenetic analysis of both housekeeping genes and total core genes. To our knowledge this is the first evidence that the flexible genome is linked to the core genome of the Microcystis species complex. The majority of strain-specific genes were present and expressed in bloom communities in Lake Erie. Roughly 8% of these genes from the lower Great Lakes are involved in genome plasticity (rapid gain, loss, or rearrangement of genes) and resistance to foreign genetic elements (such as CRISPR-Cas systems). Intriguingly, strain-specific genes from Microcystis cultured from around the world were also present and expressed in the Lake Erie blooms, suggesting that the Microcystis pangenome is truly global. The presence and expression of flexible genes, including strain-specific genes, suggests that strain-level genomic diversity may be important in maintaining Microcystis abundance during bloom events.
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Affiliation(s)
- Kevin Anthony Meyer
- Cooperative Institute for Great Lakes Research (CIGLR), University of
Michigan, Ann Arbor, MI, United States of America
- Department of Earth and Environmental Sciences, University of Michigan,
Ann Arbor, MI, United States of America
| | - Timothy W. Davis
- NOAA Great Lakes Environmental Research Laboratory, Ann Arbor, MI, United
States of America
| | - Susan B. Watson
- Environment and Climate Change Canada, Burlington, ON,
Canada
| | - Vincent J. Denef
- Department of Ecology and Evolutionary Biology, University of Michigan,
Ann Arbor, MI, United States of America
| | - Michelle A. Berry
- Department of Ecology and Evolutionary Biology, University of Michigan,
Ann Arbor, MI, United States of America
| | - Gregory J. Dick
- Department of Earth and Environmental Sciences, University of Michigan,
Ann Arbor, MI, United States of America
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150
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Lagos F, Cartes C, Vera T, Haussmann D, Figueroa J. Identification of genomic islands in Chilean Piscirickettsia salmonis strains and analysis of gene expression involved in virulence. JOURNAL OF FISH DISEASES 2017; 40:1321-1331. [PMID: 28150307 DOI: 10.1111/jfd.12604] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 11/23/2016] [Accepted: 11/27/2016] [Indexed: 06/06/2023]
Abstract
Piscirickettsia salmonis, an agent of Piscirickettsiosis, is the cause of major losses in the Chilean salmon industry. We identified, characterized and bioinformatically analysed genomic islands in field strains of P. Salmonis, using the bioinformatic software PIPS, that uses the characteristics of the islands of pathogenicity to identify them. We analysed nine partially sequenced genomes in different new field strains, and compared them with the LF-89 (Type strain) genome, selecting a genomic island present in all of them. We then evaluated the relative expression of three genes present in that island. From the obtained results, we conclude that the expression of the tcf gene is directly proportional to the cytopathogenicity in vitro of the bacteria; the product of the dnsa gene could contribute to its pathogenicity, but would be potentiated by one or more factors. The product of the gene liso is necessary for the virulence process and could have functions in early stages of infection. Regarding the strains, the IBM-040 strain showed a significant increase in the expression of all the genes in the study. Contrarily, LF-89 only presented a significant increase in expression of the gene liso, which correlates with the cytopathogenicity in vitro observed in the SHK-1 cells.
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Affiliation(s)
- F Lagos
- Centro FONDAP: Interdisciplinary Center for Aquaculture Research (INCAR), Concepción, Chile
| | - C Cartes
- Facultad de Ciencias, Instituto de Bioquímica y Microbiología, Universidad Austral de Chile, Valdivia, Chile
| | - T Vera
- Facultad de Ciencias, Instituto de Bioquímica y Microbiología, Universidad Austral de Chile, Valdivia, Chile
| | - D Haussmann
- Centro FONDAP: Interdisciplinary Center for Aquaculture Research (INCAR), Concepción, Chile
- Facultad de Ciencias, Instituto de Bioquímica y Microbiología, Universidad Austral de Chile, Valdivia, Chile
- Departmento de Ciencias Básicas, Facultad de Ciencias, Universidad Santo Tomás, Valdivia, Chile
| | - J Figueroa
- Centro FONDAP: Interdisciplinary Center for Aquaculture Research (INCAR), Concepción, Chile
- Facultad de Ciencias, Instituto de Bioquímica y Microbiología, Universidad Austral de Chile, Valdivia, Chile
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