Erwinia piriflorinigrans sp. nov., a novel pathogen that causes necrosis of pear blossoms.

Eight Erwinia strains, isolated from necrotic pear blossoms in València, Spain, were compared with reference strains of Erwinia amylovora and Erwinia pyrifoliae, both of which are pathogenic to species of pear tree, and to other species of the family Enterobacteriaceae using a polyphasic approach. Phenotypic analyses clustered the novel isolates into one phenon, distinct from other species of the genus Erwinia, showing that the novel isolates constituted a homogeneous phenotypic group. Rep-PCR profiles, PCR products obtained with different pairs of primers and plasmid contents determined by restriction analysis showed differences between the novel strains and reference strains of E.

Description of the Bacterium Causing Blight of Leek as Pseudomonas syringae pv. porri (pv. nov.).

ABSTRACT Forty bacterial strains isolated from leek blight (Allium porrum) in France and other countries were studied by conventional biochemical methods, serological reactions, numerical taxonomy, DNA-DNA hybridization, and ice nucleation activity, as well as by pathogenicity on leek and other host plants. They were compared with reference strains of Pseudomonas, mainly pathotype strains of P. syringae pathovars and strains of P.

The Relationship of Host Range, Physiology, and Genotype to Virulence on Cantaloupe in Pseudomonas syringae from Cantaloupe Blight Epidemics in France.

ABSTRACT In 1993, a bacterial blight caused important losses of cantaloupe (Cucumis melo var. cantalupensis) in southwestern France and has now been reported in all cantaloupe-growing regions of France. The causal agent of this blight is Pseudomonas syringae, although on a worldwide basis this bacterium has not been a major pathogen of melon for over 50 years.

Classification, nomenclature, and plant pathogenic bacteria - a clarification.

ABSTRACT In a recent Letter to the Editor of Phytopathology, proposals were made for endorsement and for rejection of selected names of plant pathogenic Pseudomonas spp. and Xanthomonas spp. We believe that support for, and rejection of, several names was based on misconceptions concerning the Approved Lists of Bacterial Names and entails misinterpretations of several Rules of the International Code of Nomenclature of Bacteria.

Streptomyces turgidiscabies and Streptomyces reticuliscabiei: one genomic species, two pathogenic groups.

Three strains of Streptomyces reticuliscabiei and two strains of Streptomyces turgidiscabies were analysed, together with reference and type strains of other Streptomyces species, for phenotypic traits, DNA-DNA relatedness, comparison of 16S rRNA gene sequences and presence of necrotic protein gene (nec1) homologues in order to clarify their phylogenetic relationships. A numerical analysis of phenotypic characteristics showed that S. reticuliscabiei and S.

Nitrogen-fixing sinorhizobia with Medicago laciniata constitute a novel biovar (bv. medicaginis) of S. meliloti.

Sixty-eight new rhizobial isolates were obtained from root-nodules of Medicago laciniata and from Mediterranean soils in Tunisia and France. All of them were identified as Sinorhizobium meliloti on the basis of PCR-RFLP analyses of 16S rDNA and the intergenic spacer sequence between 16S and 23S rDNAs. DNA/DNA hybridization, phenotypic characterization and 16S rRNA gene sequencing led to the conclusion that they belong the same taxon.

Transfer of Pectobacterium chrysanthemi (Burkholder et al. 1953) Brenner et al. 1973 and Brenneria paradisiaca to the genus Dickeya gen. nov. as Dickeya chrysanthemi comb. nov. and Dickeya paradisiaca comb. nov. and delineation of four novel species, Dickeya dadantii sp. nov., Dickeya dianthicola sp. nov., Dickeya dieffenbachiae sp. nov. and Dickeya zeae sp. nov.

A collection of 75 strains of Pectobacterium chrysanthemi (including all biovars and pathovars) and the type strains of Brenneria paradisiaca (CFBP 4178(T)) and Pectobacterium cypripedii (CFBP 3613(T)) were studied by DNA-DNA hybridization, numerical taxonomy of 121 phenotypic characteristics, serology and 16S rRNA gene-based phylogenetic analyses. From analysis of 16S rRNA gene sequences, it was deduced that P. chrysanthemi strains and B.

Erwinia papayae sp. nov., a pathogen of papaya (Carica papaya).

Bacterial canker of papaya (Carica papaya) emerged during the 1980s in different islands of the Caribbean. Nineteen strains of Gram-negative, rod-shaped, non-spore-forming bacteria isolated from papaya were compared to 38 reference and type strains of phytopathogenic Enterobacteriaceae and related bacteria. Phylogenetic analysis of 16S rRNA gene sequences showed that the papaya strains belonged to the genus Erwinia.

Polyphasic characterization of xanthomonads isolated from onion, garlic and Welsh onion (Allium spp.) and their relatedness to different Xanthomonas species.

Bacterial blight is an emerging disease that affects primarily onion, but also garlic and Welsh onion. The present study was undertaken to characterize the causative xanthomonad(s) by a polyphasic approach using a worldwide collection of 33 bacterial strains. Analysis of 16S rRNA gene sequence similarities indicated that the causal agent belongs to the campestris core in the genus Xanthomonas, which is in agreement with results of phenotypic characterization (analyses of carbon source utilization and fatty acid methyl esters).

Acidovorax valerianellae sp. nov., a novel pathogen of lamb's lettuce [Valerianella locusta (L.) Laterr].

Bacterial spot disease of lamb's lettuce [Valerianella locusta (L.) Laterr.] was first observed in fields in 1991.

Elevation of three subspecies of Pectobacterium carotovorum to species level: Pectobacterium atrosepticum sp. nov., Pectobacterium betavasculorum sp. nov. and Pectobacterium wasabiae sp. nov.

A collection of 42 strains belonging to the five subspecies of Pectobacterium carotovorum (subspecies atrosepticum, betavasculorum, carotovorum, odoriferum and wasabiae) and 11 reference and type strains of biovars of Pectobacterium chrysanthemi, Pectobacterium cacticidum and Brenneria paradisiaca were studied by DNA-DNA hybridization, numerical taxonomy of 120 phenotypic characteristics, serology and new phylogenetic analysis of previously reported sequences from a database of aligned 16S rDNA sequences. The P. carotovorum subspecies formed a clade according to neighbour-joining methods, but they formed two paraphyletic clusters according to maximum-likelihood and maximum-parsimony.

Pseudomonas salomonii sp. nov., pathogenic on garlic, and Pseudomonas palleroniana sp. nov., isolated from rice.

A total of 26 strains, including 15 strains isolated from garlic plants with the typical symptoms of 'Café au lait' disease and 11 strains isolated from diseased or healthy rice seeds and sheaths infested by Pseudomonas fuscovaginae, were compared with 70 type or reference strains of oxidase-positive pathogenic or non-pathogenic fluorescent pseudomonads. The strains were characterized by using a polyphasic taxonomic approach. Numerical taxonomy of phenotypic characteristics showed that the garlic and rice strains were related to each other.

Pseudomonas costantinii sp. nov., another causal agent of brown blotch disease, isolated from cultivated mushroom sporophores in Finland.

Pathogenic bacteria are frequently associated with mushroom sporophores exhibiting brown blotch disease symptoms. These bacteria belong mainly to Pseudomonas tolaasii or occasionally to 'Pseudomonas reactans'. Although a group of isolates originating from some Finnish mushroom farms satisfied the two characteristic criteria for diagnosis of infection with P.

Phenotypic and genomic evidence for the revision of Pseudomonas corrugata and proposal of Pseudomonas mediterranea sp. nov.

To re-examine the taxonomic status of Pseudomonas corrugata, 27 strains of this species were studied using a polyphasic approach. Numerical analysis of phenotypic data revealed two phena, A (including the P. corrugata type strain) and B, which could be clearly differentiated by the assimilation of mesotartrate, 2-ketogluconate and histamine.

Siderophore typing, a powerful tool for the identification of fluorescent and nonfluorescent pseudomonads.

A total of 301 strains of fluorescent pseudomonads previously characterized by conventional phenotypic and/or genomic taxonomic methods were analyzed through siderotyping, i.e., by the isoelectrophoretic characterization of their main siderophores and pyoverdines and determination of the pyoverdine-mediated iron uptake specificity of the strains.

Pseudomonas lini sp. nov., a novel species from bulk and rhizospheric soils.

The taxonomic position of eight fluorescent Pseudomonas strains isolated from bulk and rhizospheric soils, and from water was examined. These eight strains clustered in one phenon together with Pseudomomas mandelii (CFBP 4844T), but could still be differentiated from this type strain by four phenotypic features. The eight stains exhibited internal DNA-DNA hybridization values ranging from 60 to 100%, with deltaTm below 5 degrees C (3.

The structure of the pyoverdin isolated from various Pseudomonas syringae pathovars.

From seven different pathovars of Pseudomonas syringae representing various genetic subgroups, and one strain of Pseudomonas viridiflava the same pyoverdin siderophore (1) was isolated, probably identical with the pyoverdin whose amino acid composition (but not their sequence) had been reported before. 1 is the first pyoverdin where two of the ligands for Fe3+ are beta-hydroxy Asp units. Its remarkably high complexing constant for Fe3+ at pH 5 as compared with other pyoverdins offers a definite advantage in plant infection.

Samsonia erythrinae gen. nov., sp. nov., isolated from bark necrotic lesions of Erythrina sp., and discrimination of plant-pathogenic Enterobacteriaceae by phenotypic features.

Bacterial strains isolated from diseased erythrina (Erythrina sp.) trees in Martinique (French West Indies) were studied using phenotypic tests, 16S rDNA sequence analysis and DNA-DNA hybridization. Numerical analysis of phenotypic characteristics showed that these strains formed an homogeneous phenon among plant-pathogenic Enterobacteriaceae, and gave useful and updated information for the identification of these bacteria.

Enumeration and characterization of cellulolytic bacteria from refuse of a landfill.

Enumeration and phenotypic characterization of aerobic cellulolytic bacteria were performed on fresh, 1 year old and 5 years old refuse samples of a French landfill site. Numbers of cellulolytic bacteria ranged from 1.1x10(6) to 2.

Isolation of fluorescent pseudomonads from the rhizosphere of banana plants antagonistic towards root necrosing fungi.

Total aerobic bacteria and fluorescent pseudomonads were counted in bulk and rhizospheric soils of banana plants of 14 plantations in Martinique (French West Indies). Fluorescent Pseudomonas isolates were then identified and investigated for in vitro antagonism towards Cylindrocladium sp., a fungal pathogen of banana roots.

Genomic and phenotypic characterization of Xanthomonas cynarae sp. nov., a new species that causes bacterial bract spot of artichoke (Cynara scolymus L.).

A bacterial disease of artichoke (Cynara scolymus L.) was first observed in 1954 in Brittany and the Loire Valley, France. This disease causes water-soaked spots on bracts and depreciates marketability of the harvest.

Acidovorax anthurii sp. nov., a new phytopathogenic bacterium which causes bacterial leaf-spot of anthurium.

The bacterial leaf-spot of anthurium emerged during the 1980s, in the French West Indies and Trinidad. This new bacterial disease is presently wide spread and constitutes a serious limiting factor for commercial anthurium production. Twenty-nine strains isolated from leaf-spots of naturally infected anthurium were characterized and compared with reference strains belonging to the Comamonadaceae family, the genera Ralstonia and Burkholderia, and representative fluorescent pseudomonads.

DNA relatedness among strains of Streptomyces pathogenic to potato in France: description of three new species, S. europaeiscabiei sp. nov. and S. stelliscabiei sp. nov. associated with common scab, and S. reticuliscabiei sp. nov. associated with netted scab.

The genomic relatedness was evaluated by DNA-DNA hybridization for 23 strains (21 were pathogenic and two were saprophytic strains) isolated from lesions of common and netted scab in France and 19 strains from other countries, including type strains of Streptomyces species. Three genomospecies were defined within the conventional species of Streptomyces scabies, and these genomospecies were different from other pathogenic described species (Streptomyces acidiscabies, Streptomyces caviscabies) based on previously published phenotypic data. Two of these genomospecies (1 and 3) correspond to new species, for which the names Streptomyces europaeiscabiei sp.

Pseudomonas brassicacearum sp. nov. and Pseudomonas thivervalensis sp. nov., two root-associated bacteria isolated from Brassica napus and Arabidopsis thaliana.

Bacteria isolates phenotypically related to Pseudomonas corrugata have frequently been isolated from the rhizosphere of Arabidopsis thaliana and Brassica napus grown on different soils. 16S rDNA (rrs) gene sequencing, DNA-DNA hybridization, biochemical characterization and siderophore typing showed that these isolates belong to two different species that are distinct from other species of the genus Pseudomonas, including P. corrugata.

Characterization of plasmid-borne and chromosome-encoded traits of Agrobacterium biovar 1, 2, and 3 strains from France.

We collected 111 Agrobacterium isolates from galls of various origins (most of them from France) and analyzed both their plasmid-borne and chromosome-encoded traits. Phenotypic analysis of these strains allowed their classification in three phena which exactly matched the delineation of biovars 1, 2, and 3. A fourth phenon was identified which comprises three atypical strains.