Aeromonas

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Bianca Habermann - One of the best experts on this subject based on the ideXlab platform.

  • The complete and fully assembled genome sequence of Aeromonas salmonicida subsp. pectinolytica and its comparative analysis with other Aeromonas species: investigation of the mobilome in environmental and pathogenic strains
    BMC Genomics, 2018
    Co-Authors: Friedhelm Pfeiffer, Martin Blettinger, Assa Yeroslaviz, Andreas Dahl, Stephan Gruber, Maria-antonia Zamora-lagos, Bianca Habermann
    Abstract:

    Background: Due to the predominant usage of short-read sequencing to date, most bacterial genome sequences reported in the last years remain at the draft level. This precludes certain types of analyses, such as the in-depth analysis of genome plasticity. Results: Here we report the finalized genome sequence of the environmental strain Aeromonas salmonicida subsp. pectinolytica 34mel, for which only a draft genome with 253 contigs is currently available. Successful completion of the transposon-rich genome critically depended on the PacBio long read sequencing technology. Using finalized genome sequences of A. salmonicida subsp. pectinolytica and other Aeromonads, we report the detailed analysis of the transposon composition of these bacterial species. Mobilome evolution is exemplified by a complex transposon, which has shifted from pathogenicity-related to environmental-related gene content in A. salmonicida subsp. pectinolytica 34mel. Conclusion: Obtaining the complete, circular genome of A. salmonicida subsp. pectinolytica allowed us to perform an in-depth analysis of its mobilome. We demonstrate the mobilome-dependent evolution of this strain’s genetic profile from pathogenic to environmental.

  • the complete and fully assembled genome sequence of Aeromonas salmonicida subsp pectinolytica and its comparative analysis with other Aeromonas species investigation of the mobilome in environmental and pathogenic strains
    BMC Genomics, 2018
    Co-Authors: Friedhelm Pfeiffer, Mariaantonia Zamoralagos, Martin Blettinger, Assa Yeroslaviz, Andreas Dahl, Stephan Gruber, Bianca Habermann
    Abstract:

    Due to the predominant usage of short-read sequencing to date, most bacterial genome sequences reported in the last years remain at the draft level. This precludes certain types of analyses, such as the in-depth analysis of genome plasticity. Here we report the finalized genome sequence of the environmental strain Aeromonas salmonicida subsp. pectinolytica 34mel, for which only a draft genome with 253 contigs is currently available. Successful completion of the transposon-rich genome critically depended on the PacBio long read sequencing technology. Using finalized genome sequences of A. salmonicida subsp. pectinolytica and other Aeromonads, we report the detailed analysis of the transposon composition of these bacterial species. Mobilome evolution is exemplified by a complex transposon, which has shifted from pathogenicity-related to environmental-related gene content in A. salmonicida subsp. pectinolytica 34mel. Obtaining the complete, circular genome of A. salmonicida subsp. pectinolytica allowed us to perform an in-depth analysis of its mobilome. We demonstrate the mobilome-dependent evolution of this strain’s genetic profile from pathogenic to environmental.

Brigitte Lamy - One of the best experts on this subject based on the ideXlab platform.

  • Genome-driven evaluation and redesign of PCR tools for improving the detection of virulence-associated genes in aeromonads
    PLoS ONE, 2018
    Co-Authors: Emilie Talagrand-reboul, Estelle Jumas-bilak, Fadua Latif-eugenín, Roxana Beaz-hidalgo, Sophie Colston, Maria-jose Figueras, Joerg Graf, Brigitte Lamy
    Abstract:

    Many virulence factors have been described for opportunistic pathogens within the genus Aeromonas. Polymerase Chain Reactions (PCRs) are commonly used in population studies of aeromonads to detect virulence-associated genes in order to better understand the epidemiology and emergence of Aeromonas from the environment to host, but their performances have never been thoroughly evaluated. We aimed to determine diagnostic sensitivity and specificity of PCR assays for the detection of virulence-associated genes in a collection of Aeromonas isolates representative for the genetic diversity in the genus. Thirty-nine Aeromonas strains belonging to 27 recognized species were screened by published PCR assays for virulence-associated genes (act, aerA, aexT, alt, ascFG, ascV, ast, lafA, lip, ser, stx1, stx2A). In parallel, homologues of the 12 putative virulence genes were searched from the genomes of the 39 strains. Of the 12 published PCR assays for virulence factors, the comparison of PCR results and genome analysis estimated diagnostic sensitivities ranging from 34% to 100% and diagnostic specificities ranged from 71% to 100% depending upon the gene. To improve the detection of virulence-associated genes in aeromonads, we have designed new primer pairs for aerA/act, ser, lafA, ascFG and ascV, which showed excellent diagnostic sensitivity and specificity. Altogether, the analysis of high quality genomic data, which are more and more easy to obtain, provides significant improvements in the genetic detection of virulence factors in bacterial strains.

  • The Social Life of Aeromonas through Biofilm and Quorum Sensing Systems
    Frontiers in Microbiology, 2017
    Co-Authors: Emilie Talagrand-reboul, Estelle Jumas-bilak, Brigitte Lamy
    Abstract:

    Bacteria of the genus Aeromonas display multicellular behaviors herein referred to as “social life”. Since the 1990s, interest has grown in cell-to-cell communication through quorum sensing signals and biofilm formation. As they are interconnected, these two self-organizing systems deserve to be considered together for a fresh perspective on the natural history and lifestyles of aeromonads. In this review, we focus on the multicellular behaviors of Aeromonas, i.e., its social life. First, we review and discuss the available knowledge at the molecular and cellular levels for biofilm and quorum sensing. We then discuss the complex, subtle, and nested interconnections between the two systems. Finally, we focus on the aeromonad multicellular coordinated behaviors involved in heterotrophy and virulence that represent technological opportunities and applied research challenges.

  • Integrative taxonomy approach for the reappraisal of the species Aeromonas media with the description of Aeromonas alphaquinta sp. nov.
    2015
    Co-Authors: Emilie Talagrand-reboul, Estelle Jumas-bilak, Maria-jose Figueras, Joerg Graf, Sophie M. Colston, Jean-luc Kimper, Hélène Marchandin, Brigitte Lamy
    Abstract:

    Aeromonas media groups bacteria mainly found in aquatic habitats that can act occasionally as opportunistic pathogens in human and animals. The aim of this study is to explore the diversity of the bacteria currently affiliated to the species A. media. Forty strains were included in a population study integrating, multilocus genetics, genomics, phylogenetics as well as lifestyle and evolutionary features. Sixteen gene-based multilocus phylogeny delineated three clades. The emergence of clades was mainly due to mutations even if horizontal gene transfers occurred within and between clades. Data from 14 whole genome sequences showed that clades corresponded to different groups defined by both average nucleotide identity and in silico DNA-DNA Hybridization, i.e. to different genomospecies. DL-lactate utilization, cefoxitin susceptibility and several signatures clearly distinguished two clades/genomospecies, which were proposed as two species: emended A. media and Aeromonas alphaquinta sp. nov. (type strain LMG 13459T = ATCC 51107T = CIP 74.32T). The third clade was proposed as Aeromonas sp. genomospecies Paramedia (reference strain 1086C = CECT 8838 = LMG 28708) awaiting larger number of strains for a robust species description. Data used for polyphasic barcoding that support the description A. alphaquinta sp. nov. and the emendation A. media were further analyzed in an integrative approach giving a more comprehensive knowledge of the two species among aeromonads.

  • Exposure to pairs of Aeromonas strains enhances virulence in the Caenorhabditis elegans infection model
    Frontiers in Microbiology, 2015
    Co-Authors: Thomas Mosser, Emilie Talagrand-reboul, Estelle Jumas-bilak, Joerg Graf, Sophie M. Colston, Maria J. Figueras, Brigitte Lamy
    Abstract:

    Aeromonad virulence remains poorly understood, and is difficult to predict from strain characteristics. In addition, infections are often polymicrobial (i.e., are mixed infections), and 5-10% of such infections include two distinct aeromonads, which has an unknown impact on virulence. In this work, we studied the virulence of aeromonads recovered from human mixed infections. We tested them individually and in association with other strains with the aim of improving our understanding of aeromonosis. Twelve strains that were recovered in pairs from six mixed infections were tested in a virulence model of the worm Caenorhabditis elegans. Nine isolates were weak worm killers (median time to death, TD50, >=7 days) when administered alone. Two pairs showed enhanced virulence, as indicated by a significantly shortened TD50 after co-infection vs. infection with a single strain. Enhanced virulence was also observed for five of the 14 additional experimental pairs, and each of these pairs included one strain from a natural synergistic pair. These experiments indicated that synergistic effects were frequent and were limited to pairs that were composed of strains belonging to different species. The genome content of virulence-associated genes failed to explain virulence synergy, although some virulence-associated genes that were present in some strains were absent from their companion strain (e.g., T3SS). The synergy observed in virulence when two Aeromonas isolates were co-infected stresses the idea that consideration should be given to the fact that infection does not depend only on single strain virulence but is instead the result of a more complex interaction between the microbes involved, the host and the environment. These results are of interest for other diseases in which mixed infections are likely and in particular for water-borne diseases (e.g., legionellosis, vibriosis), in which pathogens may display enhanced virulence in the presence of the right partner. This study contributes to the current shift in infectiology paradigms from a premise that assumes a monomicrobial origin for infection to one more in line with the current pathobiome era.

Emilie Talagrand-reboul - One of the best experts on this subject based on the ideXlab platform.

  • Genome-driven evaluation and redesign of PCR tools for improving the detection of virulence-associated genes in aeromonads
    PLoS ONE, 2018
    Co-Authors: Emilie Talagrand-reboul, Estelle Jumas-bilak, Fadua Latif-eugenín, Roxana Beaz-hidalgo, Sophie Colston, Maria-jose Figueras, Joerg Graf, Brigitte Lamy
    Abstract:

    Many virulence factors have been described for opportunistic pathogens within the genus Aeromonas. Polymerase Chain Reactions (PCRs) are commonly used in population studies of aeromonads to detect virulence-associated genes in order to better understand the epidemiology and emergence of Aeromonas from the environment to host, but their performances have never been thoroughly evaluated. We aimed to determine diagnostic sensitivity and specificity of PCR assays for the detection of virulence-associated genes in a collection of Aeromonas isolates representative for the genetic diversity in the genus. Thirty-nine Aeromonas strains belonging to 27 recognized species were screened by published PCR assays for virulence-associated genes (act, aerA, aexT, alt, ascFG, ascV, ast, lafA, lip, ser, stx1, stx2A). In parallel, homologues of the 12 putative virulence genes were searched from the genomes of the 39 strains. Of the 12 published PCR assays for virulence factors, the comparison of PCR results and genome analysis estimated diagnostic sensitivities ranging from 34% to 100% and diagnostic specificities ranged from 71% to 100% depending upon the gene. To improve the detection of virulence-associated genes in aeromonads, we have designed new primer pairs for aerA/act, ser, lafA, ascFG and ascV, which showed excellent diagnostic sensitivity and specificity. Altogether, the analysis of high quality genomic data, which are more and more easy to obtain, provides significant improvements in the genetic detection of virulence factors in bacterial strains.

  • Delineation of Taxonomic Species within Complex of Species: Aeromonas media and Related Species as a Test Case
    Frontiers in Microbiology, 2017
    Co-Authors: Emilie Talagrand-reboul, Fadua Latif-eugenín, Maria-jose Figueras, Joerg Graf, Sophie M. Colston, Jean-luc Kimper, Hélène Marchandin, Frédéric Roger, Fabienne Petit, Estelle Jumas-bilak
    Abstract:

    Aeromonas media is an opportunistic pathogen for human and animals mainly found in aquatic habitats and which has been noted for significant genomic and phenotypic heterogeneities. We aimed to better understand the population structure and diversity of strains currently affiliated to A. media and the related species A. rivipollensis. Forty-one strains were included in a population study integrating, multilocus genetics, phylogenetics, comparative genomics, as well as phenotypics, lifestyle, and evolutionary features. Sixteen gene-based multilocus phylogeny delineated three clades. Clades corresponded to different genomic groups or genomospecies defined by phylogenomic metrics ANI (average nucleotide identity) and isDDH (in silico DNA-DNA hybridization) on 14 whole genome sequences. DL-lactate utilization, cefoxitin susceptibility, nucleotide signatures, ribosomal multi-operon diversity, and differences in relative effect of recombination and mutation (i.e., in evolution mode) distinguished the two species Aeromonas media and Aeromonas rivipollensis. The description of these two species was emended accordingly. The genome metrics and comparative genomics suggested that a third clade is a distinct genomospecies. Beside the species delineation, genetic and genomic data analysis provided a more comprehensive knowledge of the cladogenesis determinants at the root and inside A. media species complex among aeromonads. Particular lifestyles and phenotypes as well as major differences in evolution modes may represent putative factors associated with lineage emergence and speciation within the A. media complex. Finally, the integrative and populational approach presented in this study is considered broadly in order to conciliate the delineation of taxonomic species and the population structure in bacterial genera organized in species complexes.

  • The Social Life of Aeromonas through Biofilm and Quorum Sensing Systems
    Frontiers in Microbiology, 2017
    Co-Authors: Emilie Talagrand-reboul, Estelle Jumas-bilak, Brigitte Lamy
    Abstract:

    Bacteria of the genus Aeromonas display multicellular behaviors herein referred to as “social life”. Since the 1990s, interest has grown in cell-to-cell communication through quorum sensing signals and biofilm formation. As they are interconnected, these two self-organizing systems deserve to be considered together for a fresh perspective on the natural history and lifestyles of aeromonads. In this review, we focus on the multicellular behaviors of Aeromonas, i.e., its social life. First, we review and discuss the available knowledge at the molecular and cellular levels for biofilm and quorum sensing. We then discuss the complex, subtle, and nested interconnections between the two systems. Finally, we focus on the aeromonad multicellular coordinated behaviors involved in heterotrophy and virulence that represent technological opportunities and applied research challenges.

  • Integrative taxonomy approach for the reappraisal of the species Aeromonas media with the description of Aeromonas alphaquinta sp. nov.
    2015
    Co-Authors: Emilie Talagrand-reboul, Estelle Jumas-bilak, Maria-jose Figueras, Joerg Graf, Sophie M. Colston, Jean-luc Kimper, Hélène Marchandin, Brigitte Lamy
    Abstract:

    Aeromonas media groups bacteria mainly found in aquatic habitats that can act occasionally as opportunistic pathogens in human and animals. The aim of this study is to explore the diversity of the bacteria currently affiliated to the species A. media. Forty strains were included in a population study integrating, multilocus genetics, genomics, phylogenetics as well as lifestyle and evolutionary features. Sixteen gene-based multilocus phylogeny delineated three clades. The emergence of clades was mainly due to mutations even if horizontal gene transfers occurred within and between clades. Data from 14 whole genome sequences showed that clades corresponded to different groups defined by both average nucleotide identity and in silico DNA-DNA Hybridization, i.e. to different genomospecies. DL-lactate utilization, cefoxitin susceptibility and several signatures clearly distinguished two clades/genomospecies, which were proposed as two species: emended A. media and Aeromonas alphaquinta sp. nov. (type strain LMG 13459T = ATCC 51107T = CIP 74.32T). The third clade was proposed as Aeromonas sp. genomospecies Paramedia (reference strain 1086C = CECT 8838 = LMG 28708) awaiting larger number of strains for a robust species description. Data used for polyphasic barcoding that support the description A. alphaquinta sp. nov. and the emendation A. media were further analyzed in an integrative approach giving a more comprehensive knowledge of the two species among aeromonads.

  • Exposure to pairs of Aeromonas strains enhances virulence in the Caenorhabditis elegans infection model
    Frontiers in Microbiology, 2015
    Co-Authors: Thomas Mosser, Emilie Talagrand-reboul, Estelle Jumas-bilak, Joerg Graf, Sophie M. Colston, Maria J. Figueras, Brigitte Lamy
    Abstract:

    Aeromonad virulence remains poorly understood, and is difficult to predict from strain characteristics. In addition, infections are often polymicrobial (i.e., are mixed infections), and 5-10% of such infections include two distinct aeromonads, which has an unknown impact on virulence. In this work, we studied the virulence of aeromonads recovered from human mixed infections. We tested them individually and in association with other strains with the aim of improving our understanding of aeromonosis. Twelve strains that were recovered in pairs from six mixed infections were tested in a virulence model of the worm Caenorhabditis elegans. Nine isolates were weak worm killers (median time to death, TD50, >=7 days) when administered alone. Two pairs showed enhanced virulence, as indicated by a significantly shortened TD50 after co-infection vs. infection with a single strain. Enhanced virulence was also observed for five of the 14 additional experimental pairs, and each of these pairs included one strain from a natural synergistic pair. These experiments indicated that synergistic effects were frequent and were limited to pairs that were composed of strains belonging to different species. The genome content of virulence-associated genes failed to explain virulence synergy, although some virulence-associated genes that were present in some strains were absent from their companion strain (e.g., T3SS). The synergy observed in virulence when two Aeromonas isolates were co-infected stresses the idea that consideration should be given to the fact that infection does not depend only on single strain virulence but is instead the result of a more complex interaction between the microbes involved, the host and the environment. These results are of interest for other diseases in which mixed infections are likely and in particular for water-borne diseases (e.g., legionellosis, vibriosis), in which pathogens may display enhanced virulence in the presence of the right partner. This study contributes to the current shift in infectiology paradigms from a premise that assumes a monomicrobial origin for infection to one more in line with the current pathobiome era.

Estelle Jumas-bilak - One of the best experts on this subject based on the ideXlab platform.

  • Genome-driven evaluation and redesign of PCR tools for improving the detection of virulence-associated genes in aeromonads
    PLoS ONE, 2018
    Co-Authors: Emilie Talagrand-reboul, Estelle Jumas-bilak, Fadua Latif-eugenín, Roxana Beaz-hidalgo, Sophie Colston, Maria-jose Figueras, Joerg Graf, Brigitte Lamy
    Abstract:

    Many virulence factors have been described for opportunistic pathogens within the genus Aeromonas. Polymerase Chain Reactions (PCRs) are commonly used in population studies of aeromonads to detect virulence-associated genes in order to better understand the epidemiology and emergence of Aeromonas from the environment to host, but their performances have never been thoroughly evaluated. We aimed to determine diagnostic sensitivity and specificity of PCR assays for the detection of virulence-associated genes in a collection of Aeromonas isolates representative for the genetic diversity in the genus. Thirty-nine Aeromonas strains belonging to 27 recognized species were screened by published PCR assays for virulence-associated genes (act, aerA, aexT, alt, ascFG, ascV, ast, lafA, lip, ser, stx1, stx2A). In parallel, homologues of the 12 putative virulence genes were searched from the genomes of the 39 strains. Of the 12 published PCR assays for virulence factors, the comparison of PCR results and genome analysis estimated diagnostic sensitivities ranging from 34% to 100% and diagnostic specificities ranged from 71% to 100% depending upon the gene. To improve the detection of virulence-associated genes in aeromonads, we have designed new primer pairs for aerA/act, ser, lafA, ascFG and ascV, which showed excellent diagnostic sensitivity and specificity. Altogether, the analysis of high quality genomic data, which are more and more easy to obtain, provides significant improvements in the genetic detection of virulence factors in bacterial strains.

  • Delineation of Taxonomic Species within Complex of Species: Aeromonas media and Related Species as a Test Case
    Frontiers in Microbiology, 2017
    Co-Authors: Emilie Talagrand-reboul, Fadua Latif-eugenín, Maria-jose Figueras, Joerg Graf, Sophie M. Colston, Jean-luc Kimper, Hélène Marchandin, Frédéric Roger, Fabienne Petit, Estelle Jumas-bilak
    Abstract:

    Aeromonas media is an opportunistic pathogen for human and animals mainly found in aquatic habitats and which has been noted for significant genomic and phenotypic heterogeneities. We aimed to better understand the population structure and diversity of strains currently affiliated to A. media and the related species A. rivipollensis. Forty-one strains were included in a population study integrating, multilocus genetics, phylogenetics, comparative genomics, as well as phenotypics, lifestyle, and evolutionary features. Sixteen gene-based multilocus phylogeny delineated three clades. Clades corresponded to different genomic groups or genomospecies defined by phylogenomic metrics ANI (average nucleotide identity) and isDDH (in silico DNA-DNA hybridization) on 14 whole genome sequences. DL-lactate utilization, cefoxitin susceptibility, nucleotide signatures, ribosomal multi-operon diversity, and differences in relative effect of recombination and mutation (i.e., in evolution mode) distinguished the two species Aeromonas media and Aeromonas rivipollensis. The description of these two species was emended accordingly. The genome metrics and comparative genomics suggested that a third clade is a distinct genomospecies. Beside the species delineation, genetic and genomic data analysis provided a more comprehensive knowledge of the cladogenesis determinants at the root and inside A. media species complex among aeromonads. Particular lifestyles and phenotypes as well as major differences in evolution modes may represent putative factors associated with lineage emergence and speciation within the A. media complex. Finally, the integrative and populational approach presented in this study is considered broadly in order to conciliate the delineation of taxonomic species and the population structure in bacterial genera organized in species complexes.

  • The Social Life of Aeromonas through Biofilm and Quorum Sensing Systems
    Frontiers in Microbiology, 2017
    Co-Authors: Emilie Talagrand-reboul, Estelle Jumas-bilak, Brigitte Lamy
    Abstract:

    Bacteria of the genus Aeromonas display multicellular behaviors herein referred to as “social life”. Since the 1990s, interest has grown in cell-to-cell communication through quorum sensing signals and biofilm formation. As they are interconnected, these two self-organizing systems deserve to be considered together for a fresh perspective on the natural history and lifestyles of aeromonads. In this review, we focus on the multicellular behaviors of Aeromonas, i.e., its social life. First, we review and discuss the available knowledge at the molecular and cellular levels for biofilm and quorum sensing. We then discuss the complex, subtle, and nested interconnections between the two systems. Finally, we focus on the aeromonad multicellular coordinated behaviors involved in heterotrophy and virulence that represent technological opportunities and applied research challenges.

  • Integrative taxonomy approach for the reappraisal of the species Aeromonas media with the description of Aeromonas alphaquinta sp. nov.
    2015
    Co-Authors: Emilie Talagrand-reboul, Estelle Jumas-bilak, Maria-jose Figueras, Joerg Graf, Sophie M. Colston, Jean-luc Kimper, Hélène Marchandin, Brigitte Lamy
    Abstract:

    Aeromonas media groups bacteria mainly found in aquatic habitats that can act occasionally as opportunistic pathogens in human and animals. The aim of this study is to explore the diversity of the bacteria currently affiliated to the species A. media. Forty strains were included in a population study integrating, multilocus genetics, genomics, phylogenetics as well as lifestyle and evolutionary features. Sixteen gene-based multilocus phylogeny delineated three clades. The emergence of clades was mainly due to mutations even if horizontal gene transfers occurred within and between clades. Data from 14 whole genome sequences showed that clades corresponded to different groups defined by both average nucleotide identity and in silico DNA-DNA Hybridization, i.e. to different genomospecies. DL-lactate utilization, cefoxitin susceptibility and several signatures clearly distinguished two clades/genomospecies, which were proposed as two species: emended A. media and Aeromonas alphaquinta sp. nov. (type strain LMG 13459T = ATCC 51107T = CIP 74.32T). The third clade was proposed as Aeromonas sp. genomospecies Paramedia (reference strain 1086C = CECT 8838 = LMG 28708) awaiting larger number of strains for a robust species description. Data used for polyphasic barcoding that support the description A. alphaquinta sp. nov. and the emendation A. media were further analyzed in an integrative approach giving a more comprehensive knowledge of the two species among aeromonads.

  • Exposure to pairs of Aeromonas strains enhances virulence in the Caenorhabditis elegans infection model
    Frontiers in Microbiology, 2015
    Co-Authors: Thomas Mosser, Emilie Talagrand-reboul, Estelle Jumas-bilak, Joerg Graf, Sophie M. Colston, Maria J. Figueras, Brigitte Lamy
    Abstract:

    Aeromonad virulence remains poorly understood, and is difficult to predict from strain characteristics. In addition, infections are often polymicrobial (i.e., are mixed infections), and 5-10% of such infections include two distinct aeromonads, which has an unknown impact on virulence. In this work, we studied the virulence of aeromonads recovered from human mixed infections. We tested them individually and in association with other strains with the aim of improving our understanding of aeromonosis. Twelve strains that were recovered in pairs from six mixed infections were tested in a virulence model of the worm Caenorhabditis elegans. Nine isolates were weak worm killers (median time to death, TD50, >=7 days) when administered alone. Two pairs showed enhanced virulence, as indicated by a significantly shortened TD50 after co-infection vs. infection with a single strain. Enhanced virulence was also observed for five of the 14 additional experimental pairs, and each of these pairs included one strain from a natural synergistic pair. These experiments indicated that synergistic effects were frequent and were limited to pairs that were composed of strains belonging to different species. The genome content of virulence-associated genes failed to explain virulence synergy, although some virulence-associated genes that were present in some strains were absent from their companion strain (e.g., T3SS). The synergy observed in virulence when two Aeromonas isolates were co-infected stresses the idea that consideration should be given to the fact that infection does not depend only on single strain virulence but is instead the result of a more complex interaction between the microbes involved, the host and the environment. These results are of interest for other diseases in which mixed infections are likely and in particular for water-borne diseases (e.g., legionellosis, vibriosis), in which pathogens may display enhanced virulence in the presence of the right partner. This study contributes to the current shift in infectiology paradigms from a premise that assumes a monomicrobial origin for infection to one more in line with the current pathobiome era.

Stephan Gruber - One of the best experts on this subject based on the ideXlab platform.

  • The complete and fully assembled genome sequence of Aeromonas salmonicida subsp. pectinolytica and its comparative analysis with other Aeromonas species: investigation of the mobilome in environmental and pathogenic strains
    BMC Genomics, 2018
    Co-Authors: Friedhelm Pfeiffer, Martin Blettinger, Assa Yeroslaviz, Andreas Dahl, Stephan Gruber, Maria-antonia Zamora-lagos, Bianca Habermann
    Abstract:

    Background: Due to the predominant usage of short-read sequencing to date, most bacterial genome sequences reported in the last years remain at the draft level. This precludes certain types of analyses, such as the in-depth analysis of genome plasticity. Results: Here we report the finalized genome sequence of the environmental strain Aeromonas salmonicida subsp. pectinolytica 34mel, for which only a draft genome with 253 contigs is currently available. Successful completion of the transposon-rich genome critically depended on the PacBio long read sequencing technology. Using finalized genome sequences of A. salmonicida subsp. pectinolytica and other Aeromonads, we report the detailed analysis of the transposon composition of these bacterial species. Mobilome evolution is exemplified by a complex transposon, which has shifted from pathogenicity-related to environmental-related gene content in A. salmonicida subsp. pectinolytica 34mel. Conclusion: Obtaining the complete, circular genome of A. salmonicida subsp. pectinolytica allowed us to perform an in-depth analysis of its mobilome. We demonstrate the mobilome-dependent evolution of this strain’s genetic profile from pathogenic to environmental.

  • the complete and fully assembled genome sequence of Aeromonas salmonicida subsp pectinolytica and its comparative analysis with other Aeromonas species investigation of the mobilome in environmental and pathogenic strains
    BMC Genomics, 2018
    Co-Authors: Friedhelm Pfeiffer, Mariaantonia Zamoralagos, Martin Blettinger, Assa Yeroslaviz, Andreas Dahl, Stephan Gruber, Bianca Habermann
    Abstract:

    Due to the predominant usage of short-read sequencing to date, most bacterial genome sequences reported in the last years remain at the draft level. This precludes certain types of analyses, such as the in-depth analysis of genome plasticity. Here we report the finalized genome sequence of the environmental strain Aeromonas salmonicida subsp. pectinolytica 34mel, for which only a draft genome with 253 contigs is currently available. Successful completion of the transposon-rich genome critically depended on the PacBio long read sequencing technology. Using finalized genome sequences of A. salmonicida subsp. pectinolytica and other Aeromonads, we report the detailed analysis of the transposon composition of these bacterial species. Mobilome evolution is exemplified by a complex transposon, which has shifted from pathogenicity-related to environmental-related gene content in A. salmonicida subsp. pectinolytica 34mel. Obtaining the complete, circular genome of A. salmonicida subsp. pectinolytica allowed us to perform an in-depth analysis of its mobilome. We demonstrate the mobilome-dependent evolution of this strain’s genetic profile from pathogenic to environmental.