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van Lill M, Venter SN, Muema EK, Palmer M, Chan WY, Beukes CW, Steenkamp ET. SeqCode facilitates naming of South African rhizobia left in limbo. Syst Appl Microbiol 2024; 47:126504. [PMID: 38593622 DOI: 10.1016/j.syapm.2024.126504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 03/13/2024] [Accepted: 03/18/2024] [Indexed: 04/11/2024]
Abstract
South Africa is well-known for the diversity of its legumes and their nitrogen-fixing bacterial symbionts. However, in contrast to their plant partners, remarkably few of these microbes (collectively referred to as rhizobia) from South Africa have been characterised and formally described. This is because the rules of the International Code of Nomenclature of Prokaryotes (ICNP) are at odds with South Africa's National Environmental Management: Biodiversity Act and its associated regulations. The ICNP requires that a culture of the proposed type strain for a novel bacterial species be deposited in two international culture collections and be made available upon request without restrictions, which is not possible under South Africa's current national regulations. Here, we describe seven new Mesorhizobium species obtained from root nodules of Vachellia karroo, an iconic tree legume distributed across various biomes in southern Africa. For this purpose, 18 rhizobial isolates were delineated into putative species using genealogical concordance, after which their plausibility was explored with phenotypic characters and average genome relatedness. For naming these new species, we employed the rules of the recently published Code of Nomenclature of Prokaryotes described from Sequence Data (SeqCode), which utilizes genome sequences as nomenclatural types. The work presented in this study thus provides an illustrative example of how the SeqCode allows for a standardised approach for naming cultivated organisms for which the deposition of a type strain in international culture collections is currently problematic.
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Affiliation(s)
- Melandré van Lill
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa.
| | - Stephanus N Venter
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Esther K Muema
- Department of Soil Science, Faculty of AgriSciences, Stellenbosch University, South Africa
| | - Marike Palmer
- Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada
| | - Wai Y Chan
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | | | - Emma T Steenkamp
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa.
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2
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Lee SD, Yang HL, Kim IS. Four new Microbacterium species isolated from seaweeds and reclassification of five Microbacterium species with a proposal of Paramicrobacterium gen. nov. under a genome-based framework of the genus Microbacterium. Front Microbiol 2023; 14:1299950. [PMID: 38164402 PMCID: PMC10757982 DOI: 10.3389/fmicb.2023.1299950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Accepted: 11/15/2023] [Indexed: 01/03/2024] Open
Abstract
The taxonomic relationships of 10 strains isolated from seaweeds collected from two beaches in Republic of Korea were studied by sequencing and analyses of 16S rRNA genes and whole genomes. For the construction of a more reliable and robust 16S rRNA gene phylogeny, the authentic and nearly complete 16S rRNA gene sequences of all the Microbacterium type strains were selected through pairwise comparison of the sequences contained in several public databases including the List of Prokaryotic names with Standing in Nomenclature (LPSN). The clustering of the ten study strains into five distinct groups was apparent in this single gene-based phylogenetic tree. In addition, the 16S rRNA gene sequences of a few type strains were shown to be incorrectly listed in LPSN. An overall phylogenomic clustering of the genus Microbacterium was performed with a total of 113 genomes by core genome analysis. As a result, nine major (≥ three type strains) and eight minor (two type strains) clusters were defined mostly at gene support index of 92 and mean intra-cluster OrthoANIu of >80.00%. All of the study strains were assigned to a Microbacterium liquefaciens clade and distributed further into four subclusters in the core genome-based phylogenetic tree. In vitro phenotypic assays for physiological, biochemical, and chemotaxonomic characteristics were also carried out with the ten study strains and seven closely related type strains. Comparison of the overall genomic relatedness indices (OGRI) including OrthoANIu and digital DNA-DNA hybridization supported that the study strains constituted four new species of the genus Microbacterium. In addition, some Microbacterium type strains were reclassified as members of preexisting species. Moreover, some of them were embedded in a new genus of the family Microbacteriaceae based on their distinct separation in the core genome-based phylogenetic tree and amino acid identity matrices. Based on the results here, four new species, namely, Microbacterium aurugineum sp. nov., Microbacterium croceum sp. nov., Microbacterium galbinum sp. nov., and Microbacterium sufflavum sp. nov., are described, along with the proposal of Paramicrobacterium gen. nov. containing five reclassified Microbacterium species from the "Microbacterium agarici clade", with Paramicrobacterium agarici gen. nov., comb. nov. as the type species.
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Affiliation(s)
- Soon Dong Lee
- Institute of Jeju Microbial Resources, BioPS Co., Ltd., Jeju, Republic of Korea
| | - Hong Lim Yang
- Institute of Jeju Microbial Resources, BioPS Co., Ltd., Jeju, Republic of Korea
| | - In Seop Kim
- Department of Biological Sciences and Biotechnology, Hannam University, Daejon, Republic of Korea
- BioPS Co., Ltd., Daejeon, Republic of Korea
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3
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Claassens R, Venter SN, Beukes CW, Stępkowski T, Chan WY, Steenkamp ET. Bradyrhizobium xenonodulans sp. nov. isolated from nodules of Australian Acacia species invasive to South Africa. Syst Appl Microbiol 2023; 46:126452. [PMID: 37634485 DOI: 10.1016/j.syapm.2023.126452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 08/08/2023] [Accepted: 08/10/2023] [Indexed: 08/29/2023]
Abstract
A genealogical concordance approach was used to delineate strains isolated from Acacia dealbata and Acacia mearnsii root nodules in South Africa. These isolates form part of Bradyrhizobium based on 16S rRNA sequence similarity. Phylogenetic analysis of six housekeeping genes (atpD, dnaK, glnII, gyrB, recA and rpoB) confirmed that these isolates represent a novel species, while pairwise average nucleotide identity (ANIb) calculations with the closest type strains (B. cosmicum 58S1T, B. betae PL7HG1T, B. ganzhouense CCBAU 51670 T, B. cytisi CTAW11T and B. rifense CTAW71T) resulted in values well below 95-96%. We further performed phenotypic tests which revealed that there are high levels of intraspecies variation, while an additional analysis of the nodA and nifD loci indicated that the symbiotic loci of the strains are closely related to those of Bradyrhizobium isolates with an Australian origin. Strain 14ABT (=LMG 31415 T = SARCC-753 T) is designated as the type strain of the novel species for which we propose the name Bradyrhizobium xenonodulans sp. nov.
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Affiliation(s)
- Ricu Claassens
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, Gauteng, South Africa
| | - Stephanus N Venter
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, Gauteng, South Africa
| | | | - Tomasz Stępkowski
- Department of Biochemistry and Microbiology, Institute of Biology, Warsaw University of Life Sciences (SGGW), Poland
| | - Wai Y Chan
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, Gauteng, South Africa; Right to Care, Centurion, Gauteng, South Africa
| | - Emma T Steenkamp
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, Gauteng, South Africa.
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4
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Dedysh SN. Describing difficult-to-culture bacteria: Taking a shortcut or investing time to discover something new? Syst Appl Microbiol 2023; 46:126439. [PMID: 37413783 DOI: 10.1016/j.syapm.2023.126439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 06/17/2023] [Accepted: 06/29/2023] [Indexed: 07/08/2023]
Abstract
Despite the growing interest in isolating representatives of poorly studied and as-yet-uncultivated bacterial phylogenetic groups, these microorganisms remain difficult objects for taxonomic studies. The time required for describing one of these fastidious bacteria is commonly measured in several years. What is even more problematic, many routine laboratory tests, which were originally developed for fast-growing and fast-responding microorganisms, are not fully suitable for many environmentally relevant, slow-growing bacteria. Standard techniques used in chemotaxonomic analyses do not identify unique lipids produced by these bacteria. A common practice of preparing taxonomic descriptions that report a minimal set of features to name a newly isolated organism deepens a gap between microbial ecologists and taxonomists. By contrast, investing time in detailed analysis of cell biology and experimental verification of genome-encoded capabilities of newly isolated microorganisms opens a window for novel, unexpected findings, which may shape our ideas about the functional role of these microbes in the environment.
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Affiliation(s)
- Svetlana N Dedysh
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow 119071, Russia.
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5
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Vandamme P, Sutcliffe I. Out with the old and in with the new: time to rethink twentieth century chemotaxonomic practices in bacterial taxonomy. Int J Syst Evol Microbiol 2021; 71. [PMID: 34846285 PMCID: PMC8742553 DOI: 10.1099/ijsem.0.005127] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Chemotaxonomic methods played an important role in the development of the polyphasic approach to classification of Archaea and Bacteria. However, we here argue that routine application of these methods is unnecessary in an era when genomic data are available and sufficient for species delineation. Thus, authors who choose not to utilize such methods should not be forced to do so during the peer review and editorial handling of manuscripts describing novel species. Instead, we argue that chemotaxonomy will thrive if improved analytical methods are introduced and deployed, primarily by specialist laboratories, in studies at taxonomic levels above the characterisation of novel species.
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Affiliation(s)
- Peter Vandamme
- Laboratory of Microbiology, Department of Biochemistry and Microbiology, Ghent University, Ghent, Belgium
| | - Iain Sutcliffe
- Northumbria University, Faculty of Health & Life Sciences, Newcastle Upon Tyne, Tyne & Wear, U.K
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6
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Abstract
The remarkable success of taxonomic discovery, powered by culturomics, genomics and metagenomics, creates a pressing need for new bacterial names while holding a mirror up to the slow pace of change in bacterial nomenclature. Here, I take a fresh look at bacterial nomenclature, exploring how we might create a system fit for the age of genomics, playing to the strengths of current practice while minimizing difficulties. Adoption of linguistic pragmatism-obeying the rules while treating recommendations as merely optional-will make it easier to create names derived from descriptions, from people or places or even arbitrarily. Simpler protologues and a relaxed approach to recommendations will also remove much of the need for expert linguistic quality control. Automated computer-based approaches will allow names to be created en masse before they are needed while also relieving microbiologists of the need for competence in Latin. The result will be a system that is accessible, inclusive and digital, while also fully capable of naming the unnamed millions of bacteria.
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Affiliation(s)
- M.J. Pallen
- Quadram Institute Bioscience, Norwich Research Park, Norwich, UK
- Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, UK
- School of Veterinary Medicine, University of Surrey, Guildford, Surrey, UK
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7
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Avontuur JR, Palmer M, Beukes CW, Chan WY, Tasiya T, van Zyl E, Coetzee MPA, Stepkowski T, Venter SN, Steenkamp ET. Bradyrhizobium altum sp. nov., Bradyrhizobium oropedii sp. nov. and Bradyrhizobium acaciae sp. nov. from South Africa show locally restricted and pantropical nodA phylogeographic patterns. Mol Phylogenet Evol 2021; 167:107338. [PMID: 34757168 DOI: 10.1016/j.ympev.2021.107338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 09/22/2021] [Accepted: 10/27/2021] [Indexed: 10/20/2022]
Abstract
Africa is known for its rich legume diversity with a significant number of endemic species originating in South Africa. Many of these legumes associate with rhizobial symbionts of the genus Bradyrhizobium, of which most represent new species. Yet, none of the Bradyrhizobium species from South Africa have been described. In this study, phylogenetic analysis of 16S rRNA gene sequences of fourteen strains isolated in southern Africa from root nodules of diverse legumes (i.e., from the tribes Crotalarieae, Acacieae, Genisteae, Phaseoleae and Cassieae) revealed that they belong to the Bradyrhizobium elkanii supergroup. The taxonomic position and possible novelty of these strains were further interrogated using genealogical concordance of five housekeeping genes (atpD, dnaK, glnII, gyrB and rpoB). These phylogenies consistently recovered four monophyletic groups and one singleton within Bradyrhizobium. Of these groups, two were conspecific with Bradyrhizobium brasilense UFLA 03-321T and Bradyrhizobium ivorense CI-1BT, while the remaining three represented novel taxa. Their existence was further supported with genome data, as well as metabolic and physiological traits. Analysis of nodA gene sequences further showed that the evolution of these bacteria likely involved adapting to local legume hosts and environmental conditions through the acquisition, via horizontal gene transfer, of optimal symbiotic loci. We accordingly propose the following names Bradyrhizobium acaciae sp. nov. 10BBT (SARCC 730T = LMG 31409T), Bradyrhizobium oropedii sp. nov. Pear76T (SARCC 731T = LMG 31408T), and Bradyrhizobium altum sp. nov. Pear77T (SARCC 754T = LMG 31407T) to accommodate three novel species, all of which are symbionts of legumes in South Africa.
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Affiliation(s)
- Juanita R Avontuur
- Department of Biochemistry, Genetics and Microbiology (BGM), Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Marike Palmer
- School of Life Sciences, University of Nevada, Las Vegas, Nevada, United States
| | - Chrizelle W Beukes
- Department of Biochemistry, Genetics and Microbiology (BGM), Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Wai Y Chan
- Department of Biochemistry, Genetics and Microbiology (BGM), Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa; National Institute for Communicable Disease, National Health Laboratory Service, Johannesburg, South Africa
| | - Taponeswa Tasiya
- Department of Biochemistry, Genetics and Microbiology (BGM), Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Elritha van Zyl
- Department of Biochemistry, Genetics and Microbiology (BGM), Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Martin P A Coetzee
- Department of Biochemistry, Genetics and Microbiology (BGM), Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Tomasz Stepkowski
- Department of Biochemistry and Microbiology, Institute of Biology, Warsaw University of Life Sciences (SGGW), Poland
| | - Stephanus N Venter
- Department of Biochemistry, Genetics and Microbiology (BGM), Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa.
| | - Emma T Steenkamp
- Department of Biochemistry, Genetics and Microbiology (BGM), Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
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Abstract
The status Candidatus was introduced to bacterial taxonomy in the 1990s to accommodate uncultured taxa defined by analyses of DNA sequences. Here I review the strengths, weaknesses, opportunities and threats (SWOT) associated with the status Candidatus in the light of a quarter century of use, twinned with recent developments in bacterial taxonomy and sequence-based taxonomic discovery. Despite ambiguities as to its scope, philosophical objections to its use and practical problems in implementation, the status Candidatus has now been applied to over 1000 taxa and has been widely adopted by journals and databases. Although lacking priority under the International Code for Nomenclature of Prokaryotes, many Candidatus names have already achieved de facto standing in the academic literature and in databases via description of a taxon in a peer-reviewed publication, alongside deposition of a genome sequence and there is a clear path to valid publication of such names on culture. Continued and increased use of Candidatus names provides an alternative to the potential upheaval that might accompany creation of a new additional code of nomenclature and provides a ready solution to the urgent challenge of naming many thousands of newly discovered but uncultured species.
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Affiliation(s)
- Mark J Pallen
- University of East Anglia, Norwich Research Park, Norwich, UK.,Quadram Institute Bioscience, Norwich Research Park, Norwich, UK.,School of Veterinary Medicine, University of Surrey, Guildford, Surrey, UK
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Sutcliffe I, Rosselló-Móra R, Trujillo M. Addressing the sublime scale of the microbial world: reconciling an appreciation of microbial diversity with the need to describe species. New Microbes New Infect 2021; 43:100931. [PMID: 34484799 PMCID: PMC8408622 DOI: 10.1016/j.nmni.2021.100931] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 07/07/2021] [Accepted: 08/03/2021] [Indexed: 12/22/2022] Open
Abstract
There are fewer than 20,000 prokaryotic species with validly published names, meaning >99% of a reasonable estimate of microbial diversity remains formally unnamed. Here we explore the damaging consequences of the current practice in which each new species is described in a standardized publication, most typically a 'single strain species description'. This approach is both an impediment to scaling up progress in naming the microbial world and also a significant factor in the poor reputation of the discipline of microbial taxonomy. We conclude that significant changes in author habits are needed and make constructive suggestions as to how author practice should adapt.
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Affiliation(s)
- I.C. Sutcliffe
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, NE1 8ST, UK
| | - R. Rosselló-Móra
- Grup de Microbiologia Marina, IMEDEA (CSIC-UIB), C/Miquel Marques 21, 07190, Esporles, Illes Balears, Spain
| | - M.E. Trujillo
- Dpto. Microbiología y Genética, University of Salamanca, 37007, Salamanca, Spain
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Gago JF, Viver T, Urdiain M, Pastor S, Kämpfer P, Ferreira E, Rossello-Mora R. Description of three new Alteromonas species Alteromonas antoniana sp. nov., Alteromonas lipotrueae sp. nov. and Alteromonas lipotrueiana sp. nov. isolated from marine environments, and proposal for reclassification of the genus Salinimonas as Alteromonas. Syst Appl Microbiol 2021; 44:126226. [PMID: 34171620 DOI: 10.1016/j.syapm.2021.126226] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 06/02/2021] [Accepted: 06/07/2021] [Indexed: 11/26/2022]
Abstract
In the course of a bioprospective study of marine prokaryotes for cosmetic purposes, four strains, MD_567T, MD_652T, MD_674 and PS_109T, were isolated that 16S rRNA gene affiliation indicated could represent three new species within the family Alteromonadaceae. A thorough phylogenetic, genomic and phenotypic taxonomic study confirmed that the isolates could be classified as three new taxa for which we propose the names Alteromonas antoniana sp. nov., Alteromonas lipotrueae sp. nov. and Alteromonas lipotrueiana sp. nov. In addition, the consistent monophyletic nature of the members of the genera Alteromonas and Salinimonas showed that both taxa should be unified, and therefore we also propose the reclassification of the genus Salinimonas within Alteromonas, as well as new combinations for the species of the former. As the specific epithets profundi and sediminis are already used for Alteromonas species, we created the nomina nova "Alteromonas alteriprofundi" nom. nov. and Alteromonas alterisediminis nom. nov. to accommodate the new names for "Salinimonas profundi" and Salinimonas sediminis. Whole genome comparisons also allowed us to detect the unexpected codification of aromatic hydrocarbon biodegradative compounds, such as benzoate and catechol, whose activity was then demonstrated phenotypically. Finally, the high genomic identity between the type strains of Alteromonas stellipolaris and Alteromonas addita indicated that the latter is a junior heterotypic synonym of Alteromonas stellipolaris.
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Affiliation(s)
- Juan F Gago
- Marine Microbiology Group, Department of Animal and Microbial Biodiversity, Mediterranean Institute for Advanced Studies (IMEDEA, CSIC-UIB), Esporles, Spain; Lipotrue S.L., Barcelona, Spain.
| | - Tomeu Viver
- Marine Microbiology Group, Department of Animal and Microbial Biodiversity, Mediterranean Institute for Advanced Studies (IMEDEA, CSIC-UIB), Esporles, Spain
| | - Mercedes Urdiain
- Marine Microbiology Group, Department of Animal and Microbial Biodiversity, Mediterranean Institute for Advanced Studies (IMEDEA, CSIC-UIB), Esporles, Spain
| | | | - Peter Kämpfer
- Institute of Applied Microbiology (IFZ), Justus Liebig Universität Giessen, Giessen, Germany
| | | | - Ramon Rossello-Mora
- Marine Microbiology Group, Department of Animal and Microbial Biodiversity, Mediterranean Institute for Advanced Studies (IMEDEA, CSIC-UIB), Esporles, Spain
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Reliable and Sensitive Nested PCR for the Detection of Chlamydia in Sputum. Microorganisms 2021; 9:microorganisms9050935. [PMID: 33925646 PMCID: PMC8145989 DOI: 10.3390/microorganisms9050935] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 04/25/2021] [Accepted: 04/25/2021] [Indexed: 11/16/2022] Open
Abstract
Chlamydia are Gram-negative, intracellular pathogens colonizing epithelial mucosa. They cause primarily atypical pneumonia and have recently been associated with chronic diseases. Diagnostics relies almost exclusively on serological methods; PCR tests are used rarely because in patients with positive ELISA, it is nearly impossible to identify chlamydial DNA. This paradox is associated with DNA degradation in sputum samples, low abundance, and low sensitivity of PCR systems. In a newly designed and validated “nested” PCR (NPCR) assay, it was possible to amplify DNA of Chlamydia known to infect humans in 31% samples. The reliability of the assay was confirmed by DNA sequencing, and all PCR products belonged exclusively to the Chlamydiales, mainly recognized as Chlamydia pneumoniae. Three samples were related to Ca. Rhabdochlamydia porcellionis and Ca. Renichlamydia lutjani, which infect arthropods. In one case, samples were taken from sick individual, indicating the potential as a human pathogen.
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Šeligová B, Lukáč Ľ, Bábelová M, Vávrová S, Sulo P. Diagnostic reliability of nested PCR depends on the primer design and threshold abundance of Helicobacter pylori in biopsy, stool, and saliva samples. Helicobacter 2020; 25:e12680. [PMID: 32057175 DOI: 10.1111/hel.12680] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 12/23/2019] [Accepted: 01/25/2020] [Indexed: 12/19/2022]
Abstract
BACKGROUND The aim of this work was to find a reliable nested PCR for the detection of Helicobacter pylori in biopsy, stool, and saliva specimens. MATERIALS AND METHODS Novel nested PCR was elaborated and validated on 81 clinical biopsy, stool, and saliva samples from the same individual and compared to available H pylori assays: histology, rapid urease test (RUT), stool antigen test (SAT), 13 C-urea breath test (UBT). RESULTS The efficiency and selectivity of 17 published nested polymerase chain reactions (PCR) available for Helicobacter pylori detection were re-evaluated. Most of them had serious limitations and mistakes in primer design. Hence, we elaborated a nested PCR for the unambiguous identification of H pylori in biopsy, stool, and saliva, using primers targeted to variable regions of the 16S ribosomal RNA (rRNA) gene. Moreover, we determined the detection limit by adding a known number of cells. This number was as low as 0.5 cells in a PCR vial, but due to the DNA isolation procedures, it required 1-5 × 103 cells/g or ml of specimen. The sensitivity for nested PCR from stomach biopsies was on the same scale as 13 C-UBT (93.8%), but it was much lower in amplifications from stool (31.3%). Sequencing of all obtained PCR products exclusively confirmed H pylori-specific DNA sequences. CONCLUSIONS Elaborated nested PCR assay can serve as an auxiliary method for controversial samples (patients with bleeding or taking proton-pump inhibitor) in laboratories with basic equipment. The sensitivity and specificity for the amplification from gastric biopsies was almost like 13 C-UBT. Despite the good sensitivity, the threshold occurrence and the ability to survive in the oral cavity aside from and independent of the stomach is the reason why H pylori DNA cannot be reliably detected in saliva, stool, and some biopsy samples.
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Affiliation(s)
- Barbora Šeligová
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia
| | - Ľudovít Lukáč
- First Department of Internal Medicine, Faculty of Medicine, Comenius University, Bratislava, Slovakia
| | - Michaela Bábelová
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia
| | - Silvia Vávrová
- Department of Molecular Biology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia
| | - Pavol Sulo
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia
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13
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Rossello-Mora R, Konstantinidis KT, Sutcliffe I, Whitman W. Opinion: Response to concerns about the use of DNA sequences as types in the nomenclature of prokaryotes. Syst Appl Microbiol 2020; 43:126070. [PMID: 32081606 DOI: 10.1016/j.syapm.2020.126070] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 02/04/2020] [Accepted: 02/04/2020] [Indexed: 12/16/2022]
Abstract
In the current Opinion we respond to the major concerns by Bisgaard et al. (2019) and Overmann et al. (2019) and conclude that the adoption of sequences as types for the names of prokaryotes will allow for improvements of the taxonomic framework, increased stability of names derived from robust phylogenomic methods, and enable a full circumscription of the microbial world rather than just the cultivated minority.
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Affiliation(s)
- Ramon Rossello-Mora
- Marine Microbiology Group, Department of Animal and Bacterial Diversity, IMEDEA (CSIC-UIB), 07190 Esporles, Balearic Islands, Spain.
| | - Konstantinos T Konstantinidis
- School of Civil & Environmental Engineering and School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Iain Sutcliffe
- Department of Applied Sciences, Northumbria University, Newcastle upon Tyne, UK
| | - William Whitman
- Department of Microbiology, University of Georgia, Athens, GA, USA
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14
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Distinction between Borrelia and Borreliella is more robustly supported by molecular and phenotypic characteristics than all other neighbouring prokaryotic genera: Response to Margos' et al. "The genus Borrelia reloaded" (PLoS ONE 13(12): e0208432). PLoS One 2019; 14:e0221397. [PMID: 31454394 PMCID: PMC6711536 DOI: 10.1371/journal.pone.0221397] [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: 01/09/2019] [Accepted: 07/25/2019] [Indexed: 01/10/2023] Open
Abstract
In a recent publication in PLOS ONE, Gabriele Margos and colleagues have questioned the division of the genus Borrelia into two genera on the basis that the differences in percentage of conserved proteins (POCP) between these two groups is >50%, which an earlier study has suggested as the threshold for differentiating prokaryotic genera. However, the POCP threshold is a poorly characterized and rarely used criterion for establishing distinction among prokaryotic genera. Detailed evaluation of the intergeneric POCP values for 37 genera from 3 different families (viz. Enterobacteriaceae- 24 genera, Morganellaceae-8 genera and Cystobacteraceae-5 genera) presented here shows that the POCP values for all genera within each of these families exceeded >58%. Thus, the suggested POCP threshold is not a useful criterion for delimitation of genus boundary and the objection by Margos et al. on this ground is invalid. Additionally, Margos et al. have questioned the specificities of ~15–20% of the conserved signature indels (CSIs) described in our work. However, as shown here, this concern is due to misunderstanding of the results and the CSIs in question are still highly-specific characteristics of the members of these genera and they provide important information regarding the evolutionary relationships of two new reptiles-echidna-related species viz. Borrelia turcica and Candidatus Borrelia tachyglossi to other Borrelia species. Results presented here show that both these species are deeper-branching members of the genus Borrelia and their placement within this genus is strongly supported by phylogenetic analyses and multiple uniquely shared CSIs with the other Borrelia species. Based on the large body of evidence derived from phylogenetic, genomic, molecular, phenotypic and clinical features, it is contended that the characteristics clearly distinguishing the Borrelia and Borreliella genera are far more numerous and of different kinds than those discerning most (all) other neighbouring genera of prokaryotes. Thus, the placement of these two groups of microorganisms into distinct genera, Borrelia and Borreliella, which clearly recognizes the differences among them, is highly appropriate and it should lead to a better understanding of the clinical, molecular and biological differences between these two important groups of microbes.
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Sutcliffe IC. Valediction: descriptions of novel prokaryotic taxa published in Antonie van Leeuwenhoek—change in editorial policy and a signpost to the future? Antonie van Leeuwenhoek 2019; 112:1281-1282. [DOI: 10.1007/s10482-019-01311-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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16
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de Lajudie PM, Andrews M, Ardley J, Eardly B, Jumas-Bilak E, Kuzmanović N, Lassalle F, Lindström K, Mhamdi R, Martínez-Romero E, Moulin L, Mousavi SA, Nesme X, Peix A, Puławska J, Steenkamp E, Stępkowski T, Tian CF, Vinuesa P, Wei G, Willems A, Zilli J, Young P. Minimal standards for the description of new genera and species of rhizobia and agrobacteria. Int J Syst Evol Microbiol 2019; 69:1852-1863. [PMID: 31140963 DOI: 10.1099/ijsem.0.003426] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Herein the members of the Subcommittee on Taxonomy of Rhizobia and Agrobacteria of the International Committee on Systematics of Prokaryotes review recent developments in rhizobial and agrobacterial taxonomy and propose updated minimal standards for the description of new species (and genera) in these groups. The essential requirements (minimal standards) for description of a new species are (1) a genome sequence of at least the proposed type strain and (2) evidence for differentiation from other species based on genome sequence comparisons. It is also recommended that (3) genetic variation within the species is documented with sequence data from several clearly different strains and (4) phenotypic features are described, and their variation documented with data from a relevant set of representative strains. Furthermore, it is encouraged that information is provided on (5) nodulation or pathogenicity phenotypes, as appropriate, with relevant gene sequences. These guidelines supplement the current rules of general bacterial taxonomy, which require (6) a name that conforms to the International Code of Nomenclature of Prokaryotes, (7) validation of the name by publication either directly in the International Journal of Systematic and Evolutionary Microbiology or in a validation list when published elsewhere, and (8) deposition of the type strain in two international culture collections in separate countries.
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Affiliation(s)
| | - Mitchell Andrews
- 2Faculty of Agriculture and Life Sciences, Lincoln University, Lincoln 7647, New Zealand
| | - Julie Ardley
- 3School of Veterinary and Life Sciences, Murdoch University, Murdoch, Australia
| | | | - Estelle Jumas-Bilak
- 5UMR 5569, Department of Microbiology, Faculty of Pharmacy, University of Montpellier, France
| | - Nemanja Kuzmanović
- 6Julius Kühn-Institut, Federal Research Centre for Cultivated Plants, Institute for Epidemiology and Pathogen Diagnostics, Messeweg 11/12, 38104 Braunschweig, Germany
| | - Florent Lassalle
- 7Department of Infectious Disease Epidemiology - MRC Centre for Outbreak Analysis and Modelling, St Mary's Hospital, Praed Street, London W2 1NY, UK
| | - Kristina Lindström
- 8Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki FI-00014, Finland
| | - Ridha Mhamdi
- 9Centre of Biotechnology of Borj-Cedria, BP 901 Hammam-lif 2050, Tunisia
| | - Esperanza Martínez-Romero
- 10Centro de Ciencias Genómicas, Universidad Nacional Autónoma de Mexico, Cuernavaca, Morelos, Mexico
| | - Lionel Moulin
- 11IRD, CIRAD, University of Montpellier, IPME, Montpellier, France
| | - Seyed Abdollah Mousavi
- 8Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki FI-00014, Finland
| | - Xavier Nesme
- 12LEM, UCBL, CNRS, INRA, Univ Lyon, Villeurbanne, France
| | - Alvaro Peix
- 13Instituto de Recursos Naturales y Agrobiología, IRNASA-CSIC, c/Cordel de Merinas 40-52, 37008 Salamanca, Spain
| | - Joanna Puławska
- 14Department of Phytopathology, Research Institute of Horticulture, ul. Konstytucji 3 Maja 1/3, 96-100 Skierniewice, Poland
| | - Emma Steenkamp
- 15Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria 0002, South Africa
| | - Tomasz Stępkowski
- 16Autonomous Department of Microbial Biology, Faculty of Agriculture and Biology, Warsaw University of Life Sciences (SGGW), Nowoursynowska 159, 02-776 Warsaw, Poland
| | - Chang-Fu Tian
- 17State Key Laboratory of Agrobiotechnology, MOA Key Laboratory of Soil Microbiology, Rhizobium Research Center, College of Biological Sciences, China Agricultural University, 100193, Beijing, PR China
| | - Pablo Vinuesa
- 10Centro de Ciencias Genómicas, Universidad Nacional Autónoma de Mexico, Cuernavaca, Morelos, Mexico
| | - Gehong Wei
- 18Northwest A&F University, Yangling, Shaanxi, PR China
| | - Anne Willems
- 19Department Biochemistry and Microbiology, Lab. Microbiology, Ghent University, Belgium
| | - Jerri Zilli
- 20Embrapa Agrobiologia, BR 465 km 07, Seropédica, Rio de Janeiro, Brazil, 23891-000, Brazil
| | - Peter Young
- 21Department of Biology, University of York, York YO10 5DD, UK
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17
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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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18
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Rosselló-Móra R, Sutcliffe IC. Reflections on the introduction of the Digital Protologue Database - a partial success? Antonie van Leeuwenhoek 2019; 112:141-143. [PMID: 30627980 DOI: 10.1007/s10482-018-01221-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ramon Rosselló-Móra
- Marine Microbiology Group, Department of Animal and Microbial Biodiversity, Institut Mediterrani d'Estudis Avançats (CSIC-UIB), Balearic Islands, Spain.
| | - Iain C Sutcliffe
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK.
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19
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Dialogue on the nomenclature and classification of prokaryotes. Syst Appl Microbiol 2019; 42:5-14. [DOI: 10.1016/j.syapm.2018.07.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 06/08/2018] [Accepted: 07/03/2018] [Indexed: 12/16/2022]
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20
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Rossello-Mora R, Sutcliffe IC. Reflections on the introduction of the Digital Protologue Database - A partial success? Syst Appl Microbiol 2018; 42:1-2. [PMID: 30554810 DOI: 10.1016/j.syapm.2018.12.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Ramon Rossello-Mora
- Marine Microbiology Group, Department of Animal and Microbial Biodiversity, Institut Mediterrani d'Estudis Avançats (CSIC-UIB), Balearic Islands, Spain.
| | - Iain C Sutcliffe
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK.
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21
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Sangal V, Goodfellow M, Blom J, Tan GYA, Klenk HP, Sutcliffe IC. Revisiting the Taxonomic Status of the Biomedically and Industrially Important Genus Amycolatopsis, Using a Phylogenomic Approach. Front Microbiol 2018; 9:2281. [PMID: 30319584 PMCID: PMC6171478 DOI: 10.3389/fmicb.2018.02281] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 09/06/2018] [Indexed: 12/21/2022] Open
Abstract
Strains belonging to the genus Amycolatopsis are well known for the production of a number of important antimicrobials and other bioactive molecules. In this study, we have sequenced the genomes of five Amycolatopsis strains including Amycolatopsis circi DSM 45561T, Amycolatopsis palatopharyngis DSM 44832T and Amycolatopsis thermalba NRRL B-24845T. The genome sequences were analyzed with 52 other publically available Amycolatopsis genomes, representing 34 species, and 12 representatives from related genera including Saccharomonospora, Saccharopolyspora, Saccharothrix, Pseudonocardia and Thermobispora. Based on the core genome phylogeny, Amycolatopsis strains were subdivided into four major clades and several singletons. The genus Amycolatopsis is homogeneous with only three strains noted to group with other genera. Amycolatopsis halophila YIM93223T is quite distinct from other Amycolatopsis strains, both phylogenetically and taxonomically, and belongs to a distinct genus. In addition, Amycolatopsis palatopharyngis DSM 44832T and Amycolatopsis marina CGMCC4 3568T grouped in a clade with Saccharomonospora strains and showed similar taxogenomic differences to this genus as well as other Amycolatopsis strains. The study found a number of strains, particularly those identified as Amycolatopsis orientalis, whose incorrect identification could be resolved by taxogenomic analyses. Similarly, some unclassified strains could be assigned with species designations. The genome sequences of some strains that were independently sequenced by different laboratories were almost identical (99-100% average nucleotide and amino acid identities) consistent with them being the same strain, and confirming the reproducibility and robustness of genomic data. These analyses further demonstrate that whole genome sequencing can reliably resolve intra- and, inter-generic structures and should be incorporated into prokaryotic systematics.
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Affiliation(s)
- Vartul Sangal
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom
| | - Michael Goodfellow
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Jochen Blom
- Bioinformatics and Systems Biology, Justus-Liebig-Universität, Gießen, Germany
| | - Geok Yuan Annie Tan
- Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
| | - Hans-Peter Klenk
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Iain C Sutcliffe
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom
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22
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Overmann J, Huang S, Nübel U, Hahnke RL, Tindall BJ. Relevance of phenotypic information for the taxonomy of not-yet-cultured microorganisms. Syst Appl Microbiol 2018; 42:22-29. [PMID: 30197212 DOI: 10.1016/j.syapm.2018.08.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 08/15/2018] [Accepted: 08/19/2018] [Indexed: 12/12/2022]
Abstract
To date, far less than 1% of the estimated global species of Bacteria and Archaea have been described and their names validly published. Aside from these quantitative limitations, our understanding of phenotypic and functional diversity of prokaryotes is also highly biased as not a single species has been described for 85 of the 118 phyla that are currently recognized. Due to recent advances in sequencing technology and capacity, metagenomic datasets accumulate at an increasing speed and new bacterial and archaeal genome sequences become available at a faster rate than newly described species. The growing gap between the diversity of Bacteria and Archaea held in pure culture and that detected by molecular methods has led to the proposal to establish a formal nomenclature for not-yet-cultured taxa primarily based on sequence information. According to this proposal, the concept of Candidatus species would be extended to groups of closely related genome sequences and their names validly published following established rules of bacterial nomenclature. The corresponding sequences would be deposited in public databases as the type. The suggested alterations of the International Code of Nomenclature of Prokaryotes raise concerns regarding (1) the reliability and stability of nomenclature, (2) the technological and conceptual limitations as well as availability of reference genomes, (3) the information content of in silico functional predictions, and (4) the recognition of evolutionary units of microbial diversity. These challenges need to be overcome to arrive at a meaningful taxonomy of not-yet-cultured prokaryotes with so far poorly understood phenotypes.
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Affiliation(s)
- Jörg Overmann
- Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen, Inhoffenstraße 7B, 38124 Braunschweig, Germany; Deutsches Zentrum für Infektionsforschung (DZIF), Standort Braunschweig-Hannover, Braunschweig, Germany; German Center for Integrative Biodiversity Research (iDiv) Jena Halle Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany.
| | - Sixing Huang
- Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen, Inhoffenstraße 7B, 38124 Braunschweig, Germany
| | - Ulrich Nübel
- Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen, Inhoffenstraße 7B, 38124 Braunschweig, Germany; Deutsches Zentrum für Infektionsforschung (DZIF), Standort Braunschweig-Hannover, Braunschweig, Germany
| | - Richard L Hahnke
- Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen, Inhoffenstraße 7B, 38124 Braunschweig, Germany
| | - Brian J Tindall
- Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen, Inhoffenstraße 7B, 38124 Braunschweig, Germany
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Nouioui I, Carro L, García-López M, Meier-Kolthoff JP, Woyke T, Kyrpides NC, Pukall R, Klenk HP, Goodfellow M, Göker M. Genome-Based Taxonomic Classification of the Phylum Actinobacteria. Front Microbiol 2018; 9:2007. [PMID: 30186281 PMCID: PMC6113628 DOI: 10.3389/fmicb.2018.02007] [Citation(s) in RCA: 405] [Impact Index Per Article: 67.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 08/09/2018] [Indexed: 11/29/2022] Open
Abstract
The application of phylogenetic taxonomic procedures led to improvements in the classification of bacteria assigned to the phylum Actinobacteria but even so there remains a need to further clarify relationships within a taxon that encompasses organisms of agricultural, biotechnological, clinical, and ecological importance. Classification of the morphologically diverse bacteria belonging to this large phylum based on a limited number of features has proved to be difficult, not least when taxonomic decisions rested heavily on interpretation of poorly resolved 16S rRNA gene trees. Here, draft genome sequences of a large collection of actinobacterial type strains were used to infer phylogenetic trees from genome-scale data using principles drawn from phylogenetic systematics. The majority of taxa were found to be monophyletic but several orders, families, and genera, as well as many species and a few subspecies were shown to be in need of revision leading to proposals for the recognition of 2 orders, 10 families, and 17 genera, as well as the transfer of over 100 species to other genera. In addition, emended descriptions are given for many species mainly involving the addition of data on genome size and DNA G+C content, the former can be considered to be a valuable taxonomic marker in actinobacterial systematics. Many of the incongruities detected when the results of the present study were compared with existing classifications had been recognized from 16S rRNA gene trees though whole-genome phylogenies proved to be much better resolved. The few significant incongruities found between 16S/23S rRNA and whole genome trees underline the pitfalls inherent in phylogenies based upon single gene sequences. Similarly good congruence was found between the discontinuous distribution of phenotypic properties and taxa delineated in the phylogenetic trees though diverse non-monophyletic taxa appeared to be based on the use of plesiomorphic character states as diagnostic features.
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Affiliation(s)
- Imen Nouioui
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Lorena Carro
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Marina García-López
- Department of Microorganisms, Leibniz Institute DSMZ – German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Jan P. Meier-Kolthoff
- Department of Microorganisms, Leibniz Institute DSMZ – German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Tanja Woyke
- Department of Energy, Joint Genome Institute, Walnut Creek, CA, United States
| | - Nikos C. Kyrpides
- Department of Energy, Joint Genome Institute, Walnut Creek, CA, United States
| | - Rüdiger Pukall
- Department of Microorganisms, Leibniz Institute DSMZ – German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Hans-Peter Klenk
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Michael Goodfellow
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Markus Göker
- Department of Microorganisms, Leibniz Institute DSMZ – German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
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Pérez-Cataluña A, Collado L, Salgado O, Lefiñanco V, Figueras MJ. A Polyphasic and Taxogenomic Evaluation Uncovers Arcobacter cryaerophilus as a Species Complex That Embraces Four Genomovars. Front Microbiol 2018; 9:805. [PMID: 29755434 PMCID: PMC5934430 DOI: 10.3389/fmicb.2018.00805] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Accepted: 04/10/2018] [Indexed: 12/01/2022] Open
Abstract
The species Arcobacter cryaerophilus is found in many food products of animal origin and is the dominating species in wastewater. In addition, it is associated with cases of farm animal and human infectious diseases,. The species embraces two subgroups i.e., 1A (LMG 24291T = LMG 9904T) and 1B (LMG 10829) that can be differentiated by their 16S rRNA-RFLP pattern. However, some authors, on the basis of the shared intermediate levels of DNA-DNA hybridization, have suggested abandoning the subgroup classification. This contradiction indicates that the taxonomy of this species is not yet resolved. The objective of the present study was to perform a taxonomic evaluation of the diversity of A. cryaerophilus. Genomic information was used along with a Multilocus Phylogenetic Analysis (MLPA) and phenotypic characterization on a group of 52 temporally and geographically dispersed strains, coming from different types of samples and hosts from nine countries. The MLPA analysis showed that those strains formed four clusters (I–IV). Values of Average Nucleotide Identity (ANI) and in silico DNA-DNA Hybridization (isDDH) obtained between 13 genomes representing strains of the four clusters were below the proposed cut-offs of 96 and 70%, respectively, confirming that each of the clusters represented a different genomic species. However, none of the evaluated phenotypic tests enabled their unequivocal differentiation into species. Therefore, the genomic delimited clusters should be considered genomovars of the species A. cryaerophilus. These genomovars could have different clinical importance, since only the cluster I included strains isolated from human specimens. The discovery of at least one stable distinctive phenotypic character would be needed to define each cluster or genomovar as a different species. Until then, we propose naming them “A. cryaerophilus gv. pseudocryaerophilus” (Cluster I = LMG 10229T), “A. cryaerophilus gv. crypticus” (Cluster II = LMG 9065T), “A. cryaerophilus gv. cryaerophilus” (Cluster III = LMG 24291T) and “A. cryaerophilus gv. occultus” (Cluster IV = LMG 29976T).
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Affiliation(s)
- Alba Pérez-Cataluña
- Unit of Microbiology, Department of Basic Health Sciences, Faculty of Medicine and Health Sciences, IISPV, University Rovira i Virgili, Reus, Spain
| | - Luis Collado
- Faculty of Sciences, Institute of Biochemistry and Microbiology, Universidad Austral de Chile, Valdivia, Chile
| | - Oscar Salgado
- Faculty of Sciences, Institute of Biochemistry and Microbiology, Universidad Austral de Chile, Valdivia, Chile.,Laboratory of Microbial Ecology of Extreme Systems, Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Violeta Lefiñanco
- Faculty of Sciences, Institute of Biochemistry and Microbiology, Universidad Austral de Chile, Valdivia, Chile
| | - María J Figueras
- Unit of Microbiology, Department of Basic Health Sciences, Faculty of Medicine and Health Sciences, IISPV, University Rovira i Virgili, Reus, Spain
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Bernatchez S, Anoop V, Saikali Z, Breton M. A microbial identification framework for risk assessment. Food Chem Toxicol 2018; 116:60-65. [PMID: 29458165 DOI: 10.1016/j.fct.2018.02.040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 02/13/2018] [Accepted: 02/15/2018] [Indexed: 11/17/2022]
Abstract
Micro-organisms are increasingly used in a variety of products for commercial uses, including cleaning products. Such microbial-based cleaning products (MBCP) are represented as a more environmentally-friendly alternative to chemically based cleaning products. The identity of the micro-organisms formulated into these products is often considered confidential business information and is not revealed or it is only partly revealed (i.e., identification to the genus, not to the species). That paucity of information complicates the evaluation of the risk associated with their use. The accurate taxonomic identification of those micro-organisms is important so that a suitable risk assessment of the products can be conducted. To alleviate difficulties associated with adequate identification of micro-organisms in MBCP and other products containing micro-organisms, a microbial identification framework for risk assessment (MIFRA) has been elaborated. It serves to provide guidance on a polyphasic tiered approach, combining the data obtained from the use of various methods (i.e., polyphasic approach) combined with the sequential selection of the methods (i.e., tiered) to achieve a satisfactory identity of the micro-organism to an acceptable taxonomic level. The MIFRA is suitable in various risk assessment contexts for micro-organisms used in any commercial product.
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Affiliation(s)
- Stéphane Bernatchez
- Biotechnology Section, New Substances Control and Assessment Bureau, Health Canada, Ottawa, Ontario, K1A 0K9, Canada
| | - Valar Anoop
- Biotechnology Section, New Substances Control and Assessment Bureau, Health Canada, Ottawa, Ontario, K1A 0K9, Canada
| | - Zeina Saikali
- Regulatory Science and Policy, Biotechnology Section, Emerging Priorities Division, Environment Canada, Gatineau, Québec K1A 0H3, Canada
| | - Marie Breton
- Biotechnology Section, New Substances Control and Assessment Bureau, Health Canada, Ottawa, Ontario, K1A 0K9, Canada.
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26
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Palmer M, Steenkamp ET, Coetzee MPA, Blom J, Venter SN. Genome-Based Characterization of Biological Processes That Differentiate Closely Related Bacteria. Front Microbiol 2018; 9:113. [PMID: 29467735 PMCID: PMC5808187 DOI: 10.3389/fmicb.2018.00113] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 01/17/2018] [Indexed: 12/21/2022] Open
Abstract
Bacteriologists have strived toward attaining a natural classification system based on evolutionary relationships for nearly 100 years. In the early twentieth century it was accepted that a phylogeny-based system would be the most appropriate, but in the absence of molecular data, this approach proved exceedingly difficult. Subsequent technical advances and the increasing availability of genome sequencing have allowed for the generation of robust phylogenies at all taxonomic levels. In this study, we explored the possibility of linking biological characters to higher-level taxonomic groups in bacteria by making use of whole genome sequence information. For this purpose, we specifically targeted the genus Pantoea and its four main lineages. The shared gene sets were determined for Pantoea, the four lineages within the genus, as well as its sister-genus Tatumella. This was followed by functional characterization of the gene sets using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. In comparison to Tatumella, various traits involved in nutrient cycling were identified within Pantoea, providing evidence for increased efficacy in recycling of metabolites within the genus. Additionally, a number of traits associated with pathogenicity were identified within species often associated with opportunistic infections, with some support for adaptation toward overcoming host defenses. Some traits were also only conserved within specific lineages, potentially acquired in an ancestor to the lineage and subsequently maintained. It was also observed that the species isolated from the most diverse sources were generally the most versatile in their carbon metabolism. By investigating evolution, based on the more variable genomic regions, it may be possible to detect biologically relevant differences associated with the course of evolution and speciation.
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Affiliation(s)
- Marike Palmer
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa
| | - Emma T Steenkamp
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa
| | - Martin P A Coetzee
- Department of Genetic, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa
| | - Jochen Blom
- Bioinformatics and Systems Biology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Stephanus N Venter
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa
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Montero-Calasanz MDC, Meier-Kolthoff JP, Zhang DF, Yaramis A, Rohde M, Woyke T, Kyrpides NC, Schumann P, Li WJ, Göker M. Genome-Scale Data Call for a Taxonomic Rearrangement of Geodermatophilaceae. Front Microbiol 2017; 8:2501. [PMID: 29312207 PMCID: PMC5742155 DOI: 10.3389/fmicb.2017.02501] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 12/01/2017] [Indexed: 11/13/2022] Open
Abstract
Geodermatophilaceae (order Geodermatophilales, class Actinobacteria) form a comparatively isolated family within the phylum Actinobacteria and harbor many strains adapted to extreme ecological niches and tolerant against reactive oxygen species. Clarifying the evolutionary history of Geodermatophilaceae was so far mainly hampered by the insufficient resolution of the main phylogenetic marker in use, the 16S rRNA gene. In conjunction with the taxonomic characterisation of a motile and aerobic strain, designated YIM M13156T and phylogenetically located within the family, we here carried out a phylogenetic analysis of the genome sequences now available for the type strains of Geodermatophilaceae and re-analyzed the previously assembled phenotypic data. The results indicated that the largest genus, Geodermatophilus, is not monophyletic, hence the arrangement of the genera of Geodermatophilaceae must be reconsidered. Taxonomic markers such as polar lipids and fatty-acids profile, cellular features and temperature ranges are indeed heterogeneous within Geodermatophilus. In contrast to previous studies, we also address which of these features can be interpreted as apomorphies of which taxon, according to the principles of phylogenetic systematics. We thus propose a novel genus, Klenkia, with the type species Klenkia marina sp. nov. and harboring four species formerly assigned to Geodermatophilus, G. brasiliensis, G. soli, G. taihuensis, and G. terrae. Emended descriptions of all species of Geodermatophilaceae are provided for which type-strain genome sequences are publicly available. Our study again demonstrates that the principles of phylogenetic systematics can and should guide the interpretation of both genomic and phenotypic data.
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Affiliation(s)
- Maria del Carmen Montero-Calasanz
- School of Biology, Newcastle University, Newcastle upon Tyne, United Kingdom
- Leibniz Institute, German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Jan P. Meier-Kolthoff
- Leibniz Institute, German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Dao-Feng Zhang
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Adnan Yaramis
- School of Biology, Newcastle University, Newcastle upon Tyne, United Kingdom
- Department of Biotechnology, Middle East Technical University, Ankara, Turkey
| | - Manfred Rohde
- Central Facility for Microscopy, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Tanja Woyke
- Department of Energy, Joint Genome Institute, Walnut Creek, CA, United States
| | - Nikos C. Kyrpides
- Department of Energy, Joint Genome Institute, Walnut Creek, CA, United States
| | - Peter Schumann
- Leibniz Institute, German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Wen-Jun Li
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Markus Göker
- Leibniz Institute, German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
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Nicholson AC, Gulvik CA, Whitney AM, Humrighouse BW, Graziano J, Emery B, Bell M, Loparev V, Juieng P, Gartin J, Bizet C, Clermont D, Criscuolo A, Brisse S, McQuiston JR. Revisiting the taxonomy of the genus Elizabethkingia using whole-genome sequencing, optical mapping, and MALDI-TOF, along with proposal of three novel Elizabethkingia species: Elizabethkingia bruuniana sp. nov., Elizabethkingia ursingii sp. nov., and Elizabethkingia occulta sp. nov. Antonie van Leeuwenhoek 2017; 111:55-72. [PMID: 28856455 DOI: 10.1007/s10482-017-0926-3] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 08/07/2017] [Indexed: 10/19/2022]
Abstract
The genus Elizabethkingia is genetically heterogeneous, and the phenotypic similarities between recognized species pose challenges in correct identification of clinically derived isolates. In addition to the type species Elizabethkingia meningoseptica, and more recently proposed Elizabethkingia miricola, Elizabethkingia anophelis and Elizabethkingia endophytica, four genomospecies have long been recognized. By comparing historic DNA-DNA hybridization results with whole genome sequences, optical maps, and MALDI-TOF mass spectra on a large and diverse set of strains, we propose a comprehensive taxonomic revision of this genus. Genomospecies 1 and 2 contain the type strains E. anophelis and E. miricola, respectively. Genomospecies 3 and 4 are herein proposed as novel species named as Elizabethkingia bruuniana sp. nov. (type strain, G0146T = DSM 2975T = CCUG 69503T = CIP 111191T) and Elizabethkingia ursingii sp. nov. (type strain, G4122T = DSM 2974T = CCUG 69496T = CIP 111192T), respectively. Finally, the new species Elizabethkingia occulta sp. nov. (type strain G4070T = DSM 2976T = CCUG 69505T = CIP 111193T), is proposed.
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Affiliation(s)
- Ainsley C Nicholson
- Special Bacteriology Reference Laboratory, Bacterial Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA, 30333, USA.
| | - Christopher A Gulvik
- Special Bacteriology Reference Laboratory, Bacterial Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA, 30333, USA
| | - Anne M Whitney
- Special Bacteriology Reference Laboratory, Bacterial Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA, 30333, USA
| | - Ben W Humrighouse
- Special Bacteriology Reference Laboratory, Bacterial Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA, 30333, USA
| | - James Graziano
- Special Bacteriology Reference Laboratory, Bacterial Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA, 30333, USA
| | - Brian Emery
- Special Bacteriology Reference Laboratory, Bacterial Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA, 30333, USA
| | - Melissa Bell
- Special Bacteriology Reference Laboratory, Bacterial Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA, 30333, USA
| | - Vladimir Loparev
- Division of Scientific Resources, Centers for Disease Control and Prevention, Atlanta, GA, 30333, USA
| | - Phalasy Juieng
- Division of Scientific Resources, Centers for Disease Control and Prevention, Atlanta, GA, 30333, USA
| | - Jarrett Gartin
- Special Bacteriology Reference Laboratory, Bacterial Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA, 30333, USA
| | - Chantal Bizet
- Microbiology Department, Institut Pasteur, Collection de L'Institut Pasteur (CIP), Paris, France
| | - Dominique Clermont
- Microbiology Department, Institut Pasteur, Collection de L'Institut Pasteur (CIP), Paris, France
| | - Alexis Criscuolo
- Institut Pasteur - Bioinformatics and Biostatistics Hub - C3BI, USR 3756 IP CNRS, Paris, France
| | - Sylvain Brisse
- Microbial Evolutionary Genomics, Institut Pasteur, Paris, France.,CNRS, UMR 3525, Paris, France.,Institut Pasteur, Biodiversity and Epidemiology of Bacterial Pathogens, Paris, France
| | - John R McQuiston
- Special Bacteriology Reference Laboratory, Bacterial Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA, 30333, USA
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29
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Mahato NK, Gupta V, Singh P, Kumari R, Verma H, Tripathi C, Rani P, Sharma A, Singhvi N, Sood U, Hira P, Kohli P, Nayyar N, Puri A, Bajaj A, Kumar R, Negi V, Talwar C, Khurana H, Nagar S, Sharma M, Mishra H, Singh AK, Dhingra G, Negi RK, Shakarad M, Singh Y, Lal R. Microbial taxonomy in the era of OMICS: application of DNA sequences, computational tools and techniques. Antonie van Leeuwenhoek 2017; 110:1357-1371. [PMID: 28831610 DOI: 10.1007/s10482-017-0928-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 08/10/2017] [Indexed: 02/06/2023]
Abstract
The current prokaryotic taxonomy classifies phenotypically and genotypically diverse microorganisms using a polyphasic approach. With advances in the next-generation sequencing technologies and computational tools for analysis of genomes, the traditional polyphasic method is complemented with genomic data to delineate and classify bacterial genera and species as an alternative to cumbersome and error-prone laboratory tests. This review discusses the applications of sequence-based tools and techniques for bacterial classification and provides a scheme for more robust and reproducible bacterial classification based on genomic data. The present review highlights promising tools and techniques such as ortho-Average Nucleotide Identity, Genome to Genome Distance Calculator and Multi Locus Sequence Analysis, which can be validly employed for characterizing novel microorganisms and assessing phylogenetic relationships. In addition, the review discusses the possibility of employing metagenomic data to assess the phylogenetic associations of uncultured microorganisms. Through this article, we present a review of genomic approaches that can be included in the scheme of taxonomy of bacteria and archaea based on computational and in silico advances to boost the credibility of taxonomic classification in this genomic era.
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Affiliation(s)
| | - Vipin Gupta
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Priya Singh
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Rashmi Kumari
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | | | - Charu Tripathi
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Pooja Rani
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Anukriti Sharma
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Nirjara Singhvi
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Utkarsh Sood
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Princy Hira
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Puneet Kohli
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Namita Nayyar
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Akshita Puri
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Abhay Bajaj
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Roshan Kumar
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Vivek Negi
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Chandni Talwar
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Himani Khurana
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Shekhar Nagar
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Monika Sharma
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Harshita Mishra
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Amit Kumar Singh
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Gauri Dhingra
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Ram Krishan Negi
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | | | - Yogendra Singh
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Rup Lal
- Department of Zoology, University of Delhi, Delhi, 110007, India.
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30
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Uncultivated microbes in need of their own taxonomy. ISME JOURNAL 2017; 11:2399-2406. [PMID: 28731467 DOI: 10.1038/ismej.2017.113] [Citation(s) in RCA: 431] [Impact Index Per Article: 61.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 05/18/2017] [Accepted: 05/23/2017] [Indexed: 01/16/2023]
Abstract
The great majority of microbial species remains uncultured, severely limiting their taxonomic characterization and thus communication among scientists. Although Candidatus was devised as a provisional category to classify uncultured taxa, it has not been widely accepted owing to technical limitations and lack of priority of Candidatus names in the official nomenclature. High-throughput sequencing provides the potential for data-rich taxonomic descriptions of uncultivated microbes, comparable in quality to those of cultured organisms. In order to fully realize this potential, standards and guidelines on how to perform these descriptions are needed. Here we aimed to outline these standards and draw the roadmap for a new genome-based taxonomy that, at least initially, would be parallel but highly convergent to the one in existence for isolates. In particular, we recommend the use of DNA genome sequences, recovered by population binning or single-cell techniques, as the basis for (i) identification and phylogenetic placement, (ii) bioinformatics-based functional and thus phenotypic predictions, as well as (iii) type material. We also recommend the implementation of an independent nomenclatural system for uncultivated taxa, following the same nomenclature rules as those for cultured Bacteria and Archaea but with its own list of validly published names. If widely adopted, this system will not only facilitate a comprehensive characterization of the 'uncultivated majority', but also provide a unified catalogue of validly published names, thereby avoiding synonyms and confusion. We also suggest that a committee of experts, supported by an international microbiological society, should be formed to govern the new classification system.
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31
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Alvarenga DO, Fiore MF, Varani AM. A Metagenomic Approach to Cyanobacterial Genomics. Front Microbiol 2017; 8:809. [PMID: 28536564 PMCID: PMC5422444 DOI: 10.3389/fmicb.2017.00809] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 04/20/2017] [Indexed: 01/08/2023] Open
Abstract
Cyanobacteria, or oxyphotobacteria, are primary producers that establish ecological interactions with a wide variety of organisms. Although their associations with eukaryotes have received most attention, interactions with bacterial and archaeal symbionts have also been occurring for billions of years. Due to these associations, obtaining axenic cultures of cyanobacteria is usually difficult, and most isolation efforts result in unicyanobacterial cultures containing a number of associated microbes, hence composing a microbial consortium. With rising numbers of cyanobacterial blooms due to climate change, demand for genomic evaluations of these microorganisms is increasing. However, standard genomic techniques call for the sequencing of axenic cultures, an approach that not only adds months or even years for culture purification, but also appears to be impossible for some cyanobacteria, which is reflected in the relatively low number of publicly available genomic sequences of this phylum. Under the framework of metagenomics, on the other hand, cumbersome techniques for achieving axenic growth can be circumvented and individual genomes can be successfully obtained from microbial consortia. This review focuses on approaches for the genomic and metagenomic assessment of non-axenic cyanobacterial cultures that bypass requirements for axenity. These methods enable researchers to achieve faster and less costly genomic characterizations of cyanobacterial strains and raise additional information about their associated microorganisms. While non-axenic cultures may have been previously frowned upon in cyanobacteriology, latest advancements in metagenomics have provided new possibilities for in vitro studies of oxyphotobacteria, renewing the value of microbial consortia as a reliable and functional resource for the rapid assessment of bloom-forming cyanobacteria.
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Affiliation(s)
- Danillo O. Alvarenga
- Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista (UNESP)Jaboticabal, Brazil
- Centro de Energia Nuclear na Agricultura, Universidade de São Paulo (USP)Piracicaba, Brazil
| | - Marli F. Fiore
- Centro de Energia Nuclear na Agricultura, Universidade de São Paulo (USP)Piracicaba, Brazil
| | - Alessandro M. Varani
- Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista (UNESP)Jaboticabal, Brazil
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32
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Venter SN, Palmer M, Beukes CW, Chan WY, Shin G, van Zyl E, Seale T, Coutinho TA, Steenkamp ET. Practically delineating bacterial species with genealogical concordance. Antonie van Leeuwenhoek 2017; 110:1311-1325. [DOI: 10.1007/s10482-017-0869-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 03/30/2017] [Indexed: 10/19/2022]
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Abdallah RA, Beye M, Diop A, Bakour S, Raoult D, Fournier PE. The impact of culturomics on taxonomy in clinical microbiology. Antonie van Leeuwenhoek 2017; 110:1327-1337. [PMID: 28389704 DOI: 10.1007/s10482-017-0871-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 04/04/2017] [Indexed: 02/06/2023]
Abstract
Over the past decade, new culture methods coupled to genome and metagenome sequencing have enabled the number of isolated bacterial species with standing in nomenclature to rise to more than 15,000 whereas it was only 1791 in 1980. 'Culturomics', a new approach based on the diversification of culture conditions, has enabled the isolation of more than 1000 distinct human-associated bacterial species since 2012, including 247 new species. This strategy was demonstrated to be complementary to metagenome sequencing for the exhaustive study of the human microbiota and its roles in health and diseases. However, by identifying a large number of new bacterial species in a short time, culturomics has highlighted a need for taxonomic approaches adapted to clinical microbiology that would include the use of modern and reproducible tools, including high throughput genomic and proteomic analyses. Herein, we review the development of culturomics and genomics in the clinical microbiology field and their impact on bacterial taxonomy.
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Affiliation(s)
- Rita Abou Abdallah
- Unité de recherche sur les maladies infectieuses et tropicales émergentes (URMITE), UM 63CNRS 7278IRD 198Inserm 1095IHU Méditerranée Infection, Faculté de Médecine, Aix-Marseille Université, 27 Bd Jean Moulin, 13385, Marseille Cedex5, France
| | - Mamadou Beye
- Unité de recherche sur les maladies infectieuses et tropicales émergentes (URMITE), UM 63CNRS 7278IRD 198Inserm 1095IHU Méditerranée Infection, Faculté de Médecine, Aix-Marseille Université, 27 Bd Jean Moulin, 13385, Marseille Cedex5, France
| | - Awa Diop
- Unité de recherche sur les maladies infectieuses et tropicales émergentes (URMITE), UM 63CNRS 7278IRD 198Inserm 1095IHU Méditerranée Infection, Faculté de Médecine, Aix-Marseille Université, 27 Bd Jean Moulin, 13385, Marseille Cedex5, France
| | - Sofiane Bakour
- Unité de recherche sur les maladies infectieuses et tropicales émergentes (URMITE), UM 63CNRS 7278IRD 198Inserm 1095IHU Méditerranée Infection, Faculté de Médecine, Aix-Marseille Université, 27 Bd Jean Moulin, 13385, Marseille Cedex5, France
| | - Didier Raoult
- Unité de recherche sur les maladies infectieuses et tropicales émergentes (URMITE), UM 63CNRS 7278IRD 198Inserm 1095IHU Méditerranée Infection, Faculté de Médecine, Aix-Marseille Université, 27 Bd Jean Moulin, 13385, Marseille Cedex5, France
| | - Pierre-Edouard Fournier
- Unité de recherche sur les maladies infectieuses et tropicales émergentes (URMITE), UM 63CNRS 7278IRD 198Inserm 1095IHU Méditerranée Infection, Faculté de Médecine, Aix-Marseille Université, 27 Bd Jean Moulin, 13385, Marseille Cedex5, France.
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Sangal V, Goodfellow M, Jones AL, Schwalbe EC, Blom J, Hoskisson PA, Sutcliffe IC. Next-generation systematics: An innovative approach to resolve the structure of complex prokaryotic taxa. Sci Rep 2016; 6:38392. [PMID: 27924912 PMCID: PMC5141411 DOI: 10.1038/srep38392] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 11/08/2016] [Indexed: 01/14/2023] Open
Abstract
Prokaryotic systematics provides the fundamental framework for microbiological research but remains a discipline that relies on a labour- and time-intensive polyphasic taxonomic approach, including DNA-DNA hybridization, variation in 16S rRNA gene sequence and phenotypic characteristics. These techniques suffer from poor resolution in distinguishing between closely related species and often result in misclassification and misidentification of strains. Moreover, guidelines are unclear for the delineation of bacterial genera. Here, we have applied an innovative phylogenetic and taxogenomic approach to a heterogeneous actinobacterial taxon, Rhodococcus, to identify boundaries for intrageneric and supraspecific classification. Seven species-groups were identified within the genus Rhodococcus that are as distantly related to one another as they are to representatives of other mycolic acid containing actinobacteria and can thus be equated with the rank of genus. It was also evident that strains assigned to rhodococcal species-groups are underspeciated with many misclassified using conventional taxonomic criteria. The phylogenetic and taxogenomic methods used in this study provide data of theoretical value for the circumscription of generic and species boundaries and are also of practical significance as they provide a robust basis for the classification and identification of rhodococci of agricultural, industrial and medical/veterinary significance.
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Affiliation(s)
- Vartul Sangal
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne NE1 8ST, UK
| | - Michael Goodfellow
- School of Biology, University of Newcastle, Newcastle upon Tyne NE1 7RU, UK
| | - Amanda L Jones
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne NE1 8ST, UK
| | - Edward C Schwalbe
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne NE1 8ST, UK
| | - Jochen Blom
- Heinrich-Buff-Ring 58, Justus-Liebig-Universität, 35392 Gießen, Germany
| | - Paul A Hoskisson
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK
| | - Iain C Sutcliffe
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne NE1 8ST, UK
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35
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Gupta RS. Impact of genomics on the understanding of microbial evolution and classification: the importance of Darwin's views on classification. FEMS Microbiol Rev 2016; 40:520-53. [PMID: 27279642 DOI: 10.1093/femsre/fuw011] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/14/2016] [Indexed: 12/24/2022] Open
Abstract
Analyses of genome sequences, by some approaches, suggest that the widespread occurrence of horizontal gene transfers (HGTs) in prokaryotes disguises their evolutionary relationships and have led to questioning of the Darwinian model of evolution for prokaryotes. These inferences are critically examined in the light of comparative genome analysis, characteristic synapomorphies, phylogenetic trees and Darwin's views on examining evolutionary relationships. Genome sequences are enabling discovery of numerous molecular markers (synapomorphies) such as conserved signature indels (CSIs) and conserved signature proteins (CSPs), which are distinctive characteristics of different prokaryotic taxa. Based on these molecular markers, exhibiting high degree of specificity and predictive ability, numerous prokaryotic taxa of different ranks, currently identified based on the 16S rRNA gene trees, can now be reliably demarcated in molecular terms. Within all studied groups, multiple CSIs and CSPs have been identified for successive nested clades providing reliable information regarding their hierarchical relationships and these inferences are not affected by HGTs. These results strongly support Darwin's views on evolution and classification and supplement the current phylogenetic framework based on 16S rRNA in important respects. The identified molecular markers provide important means for developing novel diagnostics, therapeutics and for functional studies providing important insights regarding prokaryotic taxa.
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Affiliation(s)
- Radhey S Gupta
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
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36
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Gupta RS, Naushad S, Fabros R, Adeolu M. A phylogenomic reappraisal of family-level divisions within the class Halobacteria: proposal to divide the order Halobacteriales into the families Halobacteriaceae, Haloarculaceae fam. nov., and Halococcaceae fam. nov., and the order Haloferacales into the families, Haloferacaceae and Halorubraceae fam nov. Antonie van Leeuwenhoek 2016; 109:565-87. [PMID: 26837779 DOI: 10.1007/s10482-016-0660-2] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 01/28/2016] [Indexed: 12/11/2022]
Abstract
The evolutionary interrelationships between the archaeal organisms which comprise the class Halobacteria have proven difficult to elucidate using traditional phylogenetic tools. The class currently contains three orders. However, little is known about the family level relationships within these orders. In this work, we have completed a comprehensive comparative analysis of 129 sequenced genomes from members of the class Halobacteria in order to identify shared molecular characteristics, in the forms of conserved signature insertions/deletions (CSIs) and conserved signature proteins (CSPs), which can provide reliable evidence, independent of phylogenetic trees, that the species from the groups in which they are found are specifically related to each other due to common ancestry. Here we present 20 CSIs and 31 CSPs which are unique characteristics of infra-order level groups of genera within the class Halobacteria. We also present 40 CSIs and 234 CSPs which are characteristic of Haloarcula, Halococcus, Haloferax, or Halorubrum. Importantly, the CSIs and CSPs identified here provide evidence that the order Haloferacales contains two main groups, one consisting of Haloferax and related genera supported by four CSIs and five CSPs and the other consisting of Halorubrum and related genera supported by four CSPs. We have also identified molecular characteristics that suggest that the polyphyletic order Halobacteriales contains at least two large monophyletic clusters of organisms in addition to the polyphyletic members of the order, one cluster consisting of Haloarcula and related genera supported by ten CSIs and nineteen CSPs and the other group consisting of the members of the genus Halococcus supported by nine CSIs and 23 CSPs. We have also produced a highly robust phylogenetic tree based on the concatenated sequences of 766 proteins which provide additional support for the relationships identified by the CSIs and CSPs. On the basis of the phylogenetic analyses and the identified conserved molecular characteristics presented here, we propose a division of the order Haloferacales into two families, an emended family Haloferacaceae and Halorubraceae fam. nov. and a division of the order Halobacteriales into three families, an emended family Halobacteriaceae, Haloarculaceae fam. nov., and Halococcaceae fam. nov.
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Affiliation(s)
- Radhey S Gupta
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, L8N 3Z5, Canada.
| | - Sohail Naushad
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, L8N 3Z5, Canada
| | - Reena Fabros
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, L8N 3Z5, Canada
| | - Mobolaji Adeolu
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, L8N 3Z5, Canada
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37
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Fournier PE, Lagier JC, Dubourg G, Raoult D. From culturomics to taxonomogenomics: A need to change the taxonomy of prokaryotes in clinical microbiology. Anaerobe 2015; 36:73-8. [DOI: 10.1016/j.anaerobe.2015.10.011] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 10/06/2015] [Accepted: 10/23/2015] [Indexed: 01/07/2023]
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