International journal of systematic bacteriology最新文献

Conventional phenotypic methods lead to misidentification of the lactic acid bacteria Lactobacillus hilgardii and Lactobacillus brevis. Random amplified polymorphic DNA (RAPD) and repetitive element PCR (REP-PCR) techniques were developed for a molecular study of these two species. The taxonomic relationships were confirmed by analysis of the ribosomal operon. Amplified DNA fragments were chosen to isolate L. hilgardii-specific probes. In addition to rapid molecular methods for identification of L. hilgardii, these results convincingly proved that some strains first identified as L. brevis must be reclassified as L. hilgardii. The data clearly showed that these molecular methods are more efficient than phenotypic or biochemical studies for bacterial identification at the species level.

A strictly anaerobic, halotolerant, spindle-shaped rod, designated strain SEBR 4211T, was isolated from an African saline oil-producing well. Cells stain Gram-positive, which was confirmed by electron microscopy observations. Strain SEBR 4211T was motile by means of one to four peritrichous flagella, had a G+C content of 43 mol% and grew optimally at 37 degrees C, pH 7.3, with 0 to 3% (w/v) NaCl. It utilized a limited number of carbohydrates (cellobiose, glucose, fructose, mannitol and ribose) and produced acetate, butyrate, CO2 and H2 as end products from glucose fermentation. It reduced thiosulfate to sulfide. In the presence of thiosulfate, a decrease in butyrate and an increase in acetate production was observed. Phylogenetically, strain SEBR 4211T was related to members of the low G+C Clostridiales order with Clostridium halophilum as the closest relative (16S rDNA sequence similarity of 90%). On the basis of phenotypic, genotypic and phylogenetic characteristics of the isolate, it is proposed to designate it as a new species of a new genus, Fusibacter gen. nov., as Fusibacter paucivorans sp. nov. The type strain is SEBR 4211T (= DSM 12116T).

On the basis of numerical analysis of 100 phenotypic features, the strains of two species, Staphylococcus carnosus and Staphylococcus piscifermentans, were differentiated into two separate phenons corresponding with the macrorestriction patterns of their genomic DNA, as well as with the results of ribotyping and PCR amplification of enterobacterial repetitive intergenic consensus sequences. One of the S. carnosus strains, the F-2 strain, was shown to be marginal, exhibiting the lowest genomic and phenotypic similarity to the S. carnosus type strain DSM 20501T. Two of the strains studied (strains S. carnosus SK 06 and S. piscifermentans SK 05) were phenotypically convergent, forming a separate phenon. They were phenotypically similar, even though the genomic DNA of one of them was homologous with that of the S. carnosus type strain, whereas that of the other was homologous with the genomic DNA of the S. piscifermentans type strain. In such cases, fingerprinting methods (particularly macrorestriction analysis and ribotyping) served as important correctives, as they allow phenotypically convergent strains to be distinguished on the basis of their genomic profiles. The results of this paper support the proposal for the new species Staphylococcus condimenti as well as the new subspecies Staphylococcus carnosus subsp. utilis.

In order to determine whether morphological criteria are suitable to affiliate myxobacterial strains to species, a phylogenetic analysis of 16S rDNAs was performed on 54 myxobacterial strains that represented morphologically 21 species of the genera Angiococcus, Archangium, Chondromyces, Cystobacter, Melittangium, Myxococcus, Polyangium and Stigmatella, five invalid species and three unclassified isolates. The analysis included 12 previously published sequences. The branching pattern confirmed the deep trifurcation of the order Myxococcales. One lineage is defined by the genera Cystobacter, Angiococcus, Archangium, Melittangium, Myxococcus and Stigmatella. The study confirms the genus status of 'Corallococcus', previously 'Chondrococcus', within the family Myxococcaceae. The second lineage contains the genus Chondromyces and the species Polyangium ('Sorangium') cellulosum, while the third lineage is comprised of Nannocystis and a strain identified as Polyangium vitellinum. With the exception of a small number of strains that did not cluster phylogenetically with members of the genus to which they were assigned by morphological criteria ('Polyangium thaxteri' Pl t3, Polyangium cellulosum ATCC 25531T, Melittangium lichenicola ATCC 25947T and Angiococcus disciformis An d1), the phenotypic classification should provide a sound basis for the description of neotype species in those cases where original strain material is not available or is listed as reference material.

A bacterial strain, D-1/1aT, isolated from a medieval wall painting of the chapel of Herberstein (Styria, Austria) was characterized by a polyphasic approach. Strain D-1/1aT shared 98.1% 16S rRNA sequence similarity to Agrococcus jenensis. The chemotaxonomic characteristics including polar lipid pattern, whole cell sugars, quinone system, polyamine pattern, cell wall composition and fatty acid profile were in good agreement with those of Agrococcus jenensis. The G+C content of the DNA was determined to be 74 mol%. The value of 47% DNA reassociation obtained after DNA-DNA hybridization between DNA of Agrococcus jenensis and strain D-1/1aT as well as differences in the amino acid composition of the peptidoglycan and in physiological characteristics demonstrate that the isolate represents a new species of the genus Agrococcus. The name Agrococcus citreus sp. nov. is proposed for the new species harbouring isolate D-1/1aT. The type strain is DSM 12453T.

Novel Eubacterium-like isolates, strains 12-3T and KV43-B, which were isolated from the periodontal pocket of an adult patient with periodontal disease and necrotic dental pulp, respectively, were studied taxonomically and phylogenetically. The morphological and differential biochemical characteristics of these organisms are also described in this paper. These organisms were Gram-positive, anaerobic, non-spore-forming, rod-shaped bacteria that were inert in most of the conventional biochemical tests and closely resembled members of asaccharolytic oral Eubacterium species. On the other hand, protein profiles of whole cells in SDS-PAGE and Western immunoblotting reaction analysis distinguished these isolates from strains of the previously described genus Eubacterium. The G+C content of the DNAs from the novel isolates was 50 and 51 mol%, respectively. The levels of DNA-DNA relatedness to other asaccharolytic oral Eubacterium species, including Eubacterium brachy, Eubacterium lentum, Eubacterium nodatum, Eubacterium timidum, Eubacterium saphenum, Eubacterium minutum and Eubacterium exiguum, was less than 11%. These organisms also exhibited a very low level of reassociation with the DNA of Eubacterium limosum, the type species of the genus Eubacterium. The results of 16S rDNA sequence comparisons revealed that these organisms represent a novel lineage distinct from all previously described genera of Gram-positive, rod-shaped bacteria. On the basis of our results, it is suggested that strains 12-3T and KV43-B should be classified in a new genus and species, for which the name Cryptobacterium curtum gen. nov., sp. nov. is proposed. The type strain of Cryptobacterium curtum is 12-3T (= ATCC 700683T).

Phenotypic and phylogenetic studies were performed on two strains of a hitherto undescribed Aerococcus-like organism isolated from the human vagina. Comparative 16S rRNA gene sequencing studies demonstrated that the unknown strains constitute a new subline within the genus Aerococcus. The unknown bacterium was readily distinguished from the two currently recognized Aerococcus species, Aerococcus viridans and Aerococcus urinae, by biochemical tests and electrophoretic analysis of whole-cell proteins. On the basis of phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium be classified as Aerococcus christensenii sp. nov. The type strain of A. christensenii is CCUG 28831T.

A Gram-positive, anaerobic, moderate thermophile, strain Wv6T, capable of reducing indigo dye, was isolated from a fermenting woad vat prepared essentially as in medieval Europe. Strain Wv6T formed rod-shaped cells, which occurred singly, in pairs or in chains and produced terminal oval endospores. Strain Wv6T was saccharolytic. Growth occurred at pH 5.9-9.9 (initial pH) with an optimum at 50 degrees C of pH 7.2 +/- 0.2 (constant pH). At pH 7.8, the temperature range for growth was 30-55 degrees C with the optimum at 49-52 degrees C. Comparative 16S rRNA gene sequence analysis demonstrated that the bacterium represents a hitherto unknown subline within rRNA cluster I Clostridium. Based on the results of the phylogenetic analysis and phenotypic criteria, it is proposed that the unknown moderate thermophile should be classified as Clostridium isatidis sp. nov., a new species of the genus Clostridium. The type strain of Clostridium isatidis is strain Wv6T (= NCFB 3071T).

Three strains of moderately thermophilic, sulfur-reducing bacteria were isolated from shallow-water hot vents of the Bay of Plenty (New Zealand) and Matupi Harbour (Papua New Guinea). Cells of all isolates were short, Gram-negative, motile rods with one polar flagellum. All strains were obligate anaerobes and grew optimally at pH 5.8-6.2, 52-54 degrees C and 2.5-3% (w/v) NaCl. Growth substrates were molecular hydrogen, acetate and saturated fatty acids; one of the strains, isolated from Matupi Harbour, was able to utilize ethanol. Elemental sulfur was required for growth. H2S and CO2 were the only growth products. No growth occurred in the absence of 100 mg yeast extract I-1. The G+C content of the DNA determined for the type strain MH2T was 40.4 mol%. Results of 16S rDNA sequencing indicated that these strains represent a distinct lineage most closely related to the genus Desulfurella. On the basis of the results of morphological, physiological and phylogenetic studies, a new genus, Hippea gen. nov., is proposed with the type species Hippea maritima gen. nov., sp. nov., of which the type strain is MH2T (= DSM 10411T).