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Brucella

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Axel Cloeckaert – 1st expert on this subject based on the ideXlab platform

  • Brucella vulpis sp nov isolated from mandibular lymph nodes of red foxes vulpes vulpes
    International Journal of Systematic and Evolutionary Microbiology, 2016
    Co-Authors: Holger C Scholz, Adrian M. Whatmore, Mark S. Koylass, Axel Cloeckaert, Sascha Al Dahouk, Michel S Zygmunt, Sandra Revillafernandez, Jens A Hammerl, Jochen Blom

    Abstract:

    Two slow-growing, Gram-negative, non-motile, non-spore-forming, coccoid bacteria (strains F60T and F965), isolated in Austria from mandibular lymph nodes of two red foxes (Vulpes vulpes), were subjected to a polyphasic taxonomic analysis. In a recent study, both isolates were assigned to the genus Brucella but could not be attributed to any of the existing species. Hence, we have analysed both strains in further detail to determine their exact taxonomic position and genetic relatedness to other members of the genus Brucella. The genome sizes of F60T and F965 were 3 236 779 and 3 237 765 bp, respectively. Each genome consisted of two chromosomes, with a DNA G+C content of 57.2 %. A genome-to-genome distance of >80 %, an average nucleotide identity (ANI) of 97 % and an average amino acid identity (AAI) of 98 % compared with the type species Brucella melitensis confirmed affiliation to the genus. Remarkably, 5 % of the entire genetic information of both strains was of non-Brucella origin, including as-yet uncharacterized bacteriophages and insertion sequences as well as ABC transporters and other genes of metabolic function from various soil-living bacteria. Core-genome-based phylogenetic reconstructions placed the novel species well separated from all hitherto-described species of the genus Brucella, forming a long-branched sister clade to the classical species of Brucella. In summary, based on phenotypic and molecular data, we conclude that strains F60T and F965 are members of a novel species of the genus Brucella, for which the name Brucella vulpis sp. nov. is proposed, with the type strain F60T ( = BCCN 09-2T = DSM 101715T).

  • Brucella papionis sp nov isolated from baboons papio spp
    International Journal of Systematic and Evolutionary Microbiology, 2014
    Co-Authors: Adrian M. Whatmore, Axel Cloeckaert, Sascha Al Dahouk, Michel S Zygmunt, Nicholas J Davison, Simon D Brew, Lorraine L Perrett, Mark S. Koylass

    Abstract:

    Two Gram-negative, non-motile, non-spore-forming coccoid bacteria (strains F8/08-60T and F8/08-61) isolated from clinical specimens obtained from baboons (Papio spp.) that had delivered stillborn offspring were subjected to a polyphasic taxonomic study. On the basis of 16S rRNA gene sequence similarities, both strains, which possessed identical sequences, were assigned to the genus
    Brucella
    . This placement was confirmed by extended multilocus sequence analysis (MLSA), where both strains possessed identical sequences, and whole-genome sequencing of a representative isolate. All of the above analyses suggested that the two strains represent a novel lineage within the genus
    Brucella
    . The strains also possessed a unique profile when subjected to the phenotyping approach classically used to separate species of the genus
    Brucella,
    reacting only with Brucella A monospecific antiserum, being sensitive to the dyes thionin and fuchsin, being lysed by bacteriophage Wb, Bk2 and Fi phage at routine test dilution (RTD) but only partially sensitive to bacteriophage Tb, and with no requirement for CO2 and no production of H2S but strong urease activity. Biochemical profiling revealed a pattern of enzyme activity and metabolic capabilities distinct from existing species of the genus
    Brucella
    . Molecular analysis of the omp2 locus genes showed that both strains had a novel combination of two highly similar omp2b gene copies. The two strains shared a unique fingerprint profile of the multiple-copy Brucella-specific element IS711. Like MLSA, a multilocus variable number of tandem repeat analysis (MLVA) showed that the isolates clustered together very closely, but represent a distinct group within the genus
    Brucella
    . Isolates F8/08-60T and F8/08-61 could be distinguished clearly from all known species of the genus
    Brucella
    and their biovars by both phenotypic and molecular properties. Therefore, by applying the species concept for the genus
    Brucella
    suggested by the ICSP Subcommittee on the Taxonomy of Brucella, they represent a novel species within the genus
    Brucella
    , for which the name Brucella papionis sp. nov. is proposed, with the type strain F8/08-60T ( = NCTC 13660T = CIRMBP 0958T).

  • Mutants in the lipopolysaccharide of Brucella ovis are attenuated and protect against B. ovis infection in mice
    Veterinary Research, 2014
    Co-Authors: Pedro Soler-lloréns, Yolanda Gil-ramírez, Ana Zabalza-baranguá, Maite Iriarte, Raquel Conde-Álvarez, Amaia Zúñiga-ripa, Beatriz San Román, Michel S Zygmunt, Nieves Vizcaíno, Axel Cloeckaert

    Abstract:

    Brucella spp. are Gram-negative bacteria that behave as facultative intracellular parasites of a variety of mammals. This genus includes smooth (S) and rough (R) species that carry S and R lipopolysaccharides (LPS), respectively. S-LPS is a virulence factor, and mutants affected in the S-LPS O-polysaccharide (R mutants), core oligosaccharide or both show attenuation. However, B. ovis is naturally R and is virulent in sheep. We studied the role of B. ovis LPS in virulence by mutating the orthologues of wadA, wadB and wadC, three genes known to encode LPS core glycosyltransferases in S Brucellae. When mapped with antibodies to outer membrane proteins (Omps) and R-LPS, wadB and wadC mutants displayed defects in LPS structure and outer membrane topology but inactivation of wadA had little or no effect. Consistent with these observations, the wadB and wadC but not the wadA mutants were attenuated in mice. When tested as vaccines, the wadB and wadC mutants protected mice against B. ovis challenge. The results demonstrate that the LPS core is a structure essential for survival in vivo not only of S Brucellae but also of a naturally R Brucella pathogenic species, and they confirm our previous hypothesis that the Brucella LPS core is a target for vaccine development. Since vaccine B. melitensis Rev 1 is S and thus interferes in serological testing for S Brucellae, wadB mutant represents a candidate vaccine to be evaluated against B. ovis infection of sheep suitable for areas free of B. melitensis.

Michel S Zygmunt – 2nd expert on this subject based on the ideXlab platform

  • Brucella vulpis sp nov isolated from mandibular lymph nodes of red foxes vulpes vulpes
    International Journal of Systematic and Evolutionary Microbiology, 2016
    Co-Authors: Holger C Scholz, Adrian M. Whatmore, Mark S. Koylass, Axel Cloeckaert, Sascha Al Dahouk, Michel S Zygmunt, Sandra Revillafernandez, Jens A Hammerl, Jochen Blom

    Abstract:

    Two slow-growing, Gram-negative, non-motile, non-spore-forming, coccoid bacteria (strains F60T and F965), isolated in Austria from mandibular lymph nodes of two red foxes (Vulpes vulpes), were subjected to a polyphasic taxonomic analysis. In a recent study, both isolates were assigned to the genus Brucella but could not be attributed to any of the existing species. Hence, we have analysed both strains in further detail to determine their exact taxonomic position and genetic relatedness to other members of the genus Brucella. The genome sizes of F60T and F965 were 3 236 779 and 3 237 765 bp, respectively. Each genome consisted of two chromosomes, with a DNA G+C content of 57.2 %. A genome-to-genome distance of >80 %, an average nucleotide identity (ANI) of 97 % and an average amino acid identity (AAI) of 98 % compared with the type species Brucella melitensis confirmed affiliation to the genus. Remarkably, 5 % of the entire genetic information of both strains was of non-Brucella origin, including as-yet uncharacterized bacteriophages and insertion sequences as well as ABC transporters and other genes of metabolic function from various soil-living bacteria. Core-genome-based phylogenetic reconstructions placed the novel species well separated from all hitherto-described species of the genus Brucella, forming a long-branched sister clade to the classical species of Brucella. In summary, based on phenotypic and molecular data, we conclude that strains F60T and F965 are members of a novel species of the genus Brucella, for which the name Brucella vulpis sp. nov. is proposed, with the type strain F60T ( = BCCN 09-2T = DSM 101715T).

  • Brucella papionis sp nov isolated from baboons papio spp
    International Journal of Systematic and Evolutionary Microbiology, 2014
    Co-Authors: Adrian M. Whatmore, Axel Cloeckaert, Sascha Al Dahouk, Michel S Zygmunt, Nicholas J Davison, Simon D Brew, Lorraine L Perrett, Mark S. Koylass

    Abstract:

    Two Gram-negative, non-motile, non-spore-forming coccoid bacteria (strains F8/08-60T and F8/08-61) isolated from clinical specimens obtained from baboons (Papio spp.) that had delivered stillborn offspring were subjected to a polyphasic taxonomic study. On the basis of 16S rRNA gene sequence similarities, both strains, which possessed identical sequences, were assigned to the genus
    Brucella
    . This placement was confirmed by extended multilocus sequence analysis (MLSA), where both strains possessed identical sequences, and whole-genome sequencing of a representative isolate. All of the above analyses suggested that the two strains represent a novel lineage within the genus
    Brucella
    . The strains also possessed a unique profile when subjected to the phenotyping approach classically used to separate species of the genus
    Brucella,
    reacting only with Brucella A monospecific antiserum, being sensitive to the dyes thionin and fuchsin, being lysed by bacteriophage Wb, Bk2 and Fi phage at routine test dilution (RTD) but only partially sensitive to bacteriophage Tb, and with no requirement for CO2 and no production of H2S but strong urease activity. Biochemical profiling revealed a pattern of enzyme activity and metabolic capabilities distinct from existing species of the genus
    Brucella
    . Molecular analysis of the omp2 locus genes showed that both strains had a novel combination of two highly similar omp2b gene copies. The two strains shared a unique fingerprint profile of the multiple-copy Brucella-specific element IS711. Like MLSA, a multilocus variable number of tandem repeat analysis (MLVA) showed that the isolates clustered together very closely, but represent a distinct group within the genus
    Brucella
    . Isolates F8/08-60T and F8/08-61 could be distinguished clearly from all known species of the genus
    Brucella
    and their biovars by both phenotypic and molecular properties. Therefore, by applying the species concept for the genus
    Brucella
    suggested by the ICSP Subcommittee on the Taxonomy of Brucella, they represent a novel species within the genus
    Brucella
    , for which the name Brucella papionis sp. nov. is proposed, with the type strain F8/08-60T ( = NCTC 13660T = CIRMBP 0958T).

  • Mutants in the lipopolysaccharide of Brucella ovis are attenuated and protect against B. ovis infection in mice
    Veterinary Research, 2014
    Co-Authors: Pedro Soler-lloréns, Yolanda Gil-ramírez, Ana Zabalza-baranguá, Maite Iriarte, Raquel Conde-Álvarez, Amaia Zúñiga-ripa, Beatriz San Román, Michel S Zygmunt, Nieves Vizcaíno, Axel Cloeckaert

    Abstract:

    Brucella spp. are Gram-negative bacteria that behave as facultative intracellular parasites of a variety of mammals. This genus includes smooth (S) and rough (R) species that carry S and R lipopolysaccharides (LPS), respectively. S-LPS is a virulence factor, and mutants affected in the S-LPS O-polysaccharide (R mutants), core oligosaccharide or both show attenuation. However, B. ovis is naturally R and is virulent in sheep. We studied the role of B. ovis LPS in virulence by mutating the orthologues of wadA, wadB and wadC, three genes known to encode LPS core glycosyltransferases in S Brucellae. When mapped with antibodies to outer membrane proteins (Omps) and R-LPS, wadB and wadC mutants displayed defects in LPS structure and outer membrane topology but inactivation of wadA had little or no effect. Consistent with these observations, the wadB and wadC but not the wadA mutants were attenuated in mice. When tested as vaccines, the wadB and wadC mutants protected mice against B. ovis challenge. The results demonstrate that the LPS core is a structure essential for survival in vivo not only of S Brucellae but also of a naturally R Brucella pathogenic species, and they confirm our previous hypothesis that the Brucella LPS core is a target for vaccine development. Since vaccine B. melitensis Rev 1 is S and thus interferes in serological testing for S Brucellae, wadB mutant represents a candidate vaccine to be evaluated against B. ovis infection of sheep suitable for areas free of B. melitensis.

Sascha Al Dahouk – 3rd expert on this subject based on the ideXlab platform

  • Brucella vulpis sp nov isolated from mandibular lymph nodes of red foxes vulpes vulpes
    International Journal of Systematic and Evolutionary Microbiology, 2016
    Co-Authors: Holger C Scholz, Adrian M. Whatmore, Mark S. Koylass, Axel Cloeckaert, Sascha Al Dahouk, Michel S Zygmunt, Sandra Revillafernandez, Jens A Hammerl, Jochen Blom

    Abstract:

    Two slow-growing, Gram-negative, non-motile, non-spore-forming, coccoid bacteria (strains F60T and F965), isolated in Austria from mandibular lymph nodes of two red foxes (Vulpes vulpes), were subjected to a polyphasic taxonomic analysis. In a recent study, both isolates were assigned to the genus Brucella but could not be attributed to any of the existing species. Hence, we have analysed both strains in further detail to determine their exact taxonomic position and genetic relatedness to other members of the genus Brucella. The genome sizes of F60T and F965 were 3 236 779 and 3 237 765 bp, respectively. Each genome consisted of two chromosomes, with a DNA G+C content of 57.2 %. A genome-to-genome distance of >80 %, an average nucleotide identity (ANI) of 97 % and an average amino acid identity (AAI) of 98 % compared with the type species Brucella melitensis confirmed affiliation to the genus. Remarkably, 5 % of the entire genetic information of both strains was of non-Brucella origin, including as-yet uncharacterized bacteriophages and insertion sequences as well as ABC transporters and other genes of metabolic function from various soil-living bacteria. Core-genome-based phylogenetic reconstructions placed the novel species well separated from all hitherto-described species of the genus Brucella, forming a long-branched sister clade to the classical species of Brucella. In summary, based on phenotypic and molecular data, we conclude that strains F60T and F965 are members of a novel species of the genus Brucella, for which the name Brucella vulpis sp. nov. is proposed, with the type strain F60T ( = BCCN 09-2T = DSM 101715T).

  • Brucella papionis sp nov isolated from baboons papio spp
    International Journal of Systematic and Evolutionary Microbiology, 2014
    Co-Authors: Adrian M. Whatmore, Axel Cloeckaert, Sascha Al Dahouk, Michel S Zygmunt, Nicholas J Davison, Simon D Brew, Lorraine L Perrett, Mark S. Koylass

    Abstract:

    Two Gram-negative, non-motile, non-spore-forming coccoid bacteria (strains F8/08-60T and F8/08-61) isolated from clinical specimens obtained from baboons (Papio spp.) that had delivered stillborn offspring were subjected to a polyphasic taxonomic study. On the basis of 16S rRNA gene sequence similarities, both strains, which possessed identical sequences, were assigned to the genus
    Brucella
    . This placement was confirmed by extended multilocus sequence analysis (MLSA), where both strains possessed identical sequences, and whole-genome sequencing of a representative isolate. All of the above analyses suggested that the two strains represent a novel lineage within the genus
    Brucella
    . The strains also possessed a unique profile when subjected to the phenotyping approach classically used to separate species of the genus
    Brucella,
    reacting only with Brucella A monospecific antiserum, being sensitive to the dyes thionin and fuchsin, being lysed by bacteriophage Wb, Bk2 and Fi phage at routine test dilution (RTD) but only partially sensitive to bacteriophage Tb, and with no requirement for CO2 and no production of H2S but strong urease activity. Biochemical profiling revealed a pattern of enzyme activity and metabolic capabilities distinct from existing species of the genus
    Brucella
    . Molecular analysis of the omp2 locus genes showed that both strains had a novel combination of two highly similar omp2b gene copies. The two strains shared a unique fingerprint profile of the multiple-copy Brucella-specific element IS711. Like MLSA, a multilocus variable number of tandem repeat analysis (MLVA) showed that the isolates clustered together very closely, but represent a distinct group within the genus
    Brucella
    . Isolates F8/08-60T and F8/08-61 could be distinguished clearly from all known species of the genus
    Brucella
    and their biovars by both phenotypic and molecular properties. Therefore, by applying the species concept for the genus
    Brucella
    suggested by the ICSP Subcommittee on the Taxonomy of Brucella, they represent a novel species within the genus
    Brucella
    , for which the name Brucella papionis sp. nov. is proposed, with the type strain F8/08-60T ( = NCTC 13660T = CIRMBP 0958T).

  • Brucella inopinata sp nov isolated from a breast implant infection
    International Journal of Systematic and Evolutionary Microbiology, 2010
    Co-Authors: Holger C Scholz, Axel Cloeckaert, Gilles Vergnaud, Herbert Tomaso, Sascha Al Dahouk, Peter Kampfer, K Nockler, Cornelia Gollner, Peter Bahn, Marianne Maquart

    Abstract:

    A Gram-negative, non-motile, non-spore-forming coccoid bacterium (strain BO1T) has recently been isolated from a breast implant wound of a 71-year-old female patient with clinical signs of brucellosis. Affiliation of strain BO1T to the genus Brucella was confirmed by polyamine pattern, polar lipid profile, fatty acid profile, quinone system, DNA-DNA hybridization studies, and by insertion sequence 711 (IS711)-specific PCR. Strain BO1T harboured four to five copies of the Brucella specific insertion element IS711, displaying a unique banding pattern and exhibited a unique 16S rRNA gene sequence and also grouped separately in MLST analysis. Strain BO1T reacted with Brucella M-monospecific antiserum. Incomplete lysis was detected with bacteriophages Tb, F1, and F25. Biochemical profiling revealed a high degree of enzymatic activity and metabolic capabilities. In multilocus VNTR (variable-number tandem-repeat) analysis (MLVA), strain BO1T showed a very distinctive profile and clustered with the other ‘exotic’ Brucella strains, including strains isolated from marine mammals, and B. microti, B. suis biovar 5 and B. neotomae. Comparative omp2a and omp2b gene sequence analysis revealed the most divergent omp2 sequences identified to date for a Brucella strain. The recA gene sequence of strain BO1T differed in seven nucleotides from the Brucella recA consensus sequence. Using the Brucella species-specific Multiplex PCR assay, strain BO1T displayed a unique banding pattern not observed in other Brucella species. From the phenotypic and molecular analysis it became evident that strain BO1T was clearly different from all other Brucella species, and therefore represents a novel species within the genus Brucella. Because of its unexpected isolation, the name Brucella inopinata with the type strain BO1T (= BCCN 09-01T = CPAM 6436T) is proposed