Two vancomycin-resistant, strictly anaerobic, Gram-positive, rod-shaped, spore-forming organisms (strains CCRI-9842T and CCRI-9929) isolated from human faecal specimens in Québec, Canada, and Australia were characterized using phenotypic, biochemical and molecular taxonomic methods. Pairwise analysis of the 16S rRNA gene sequences showed that both strains were closely related to each other genetically (displaying 99.2 % sequence similarity) and represented a previously unknown subline within the Clostridium coccoides rRNA group of organisms (rRNA cluster XIVa of the genus Clostridium). Strains CCRI-9842T and CCRI-9929 used carbohydrates as fermentable substrates, producing acetic acid as the major product of glucose metabolism. The novel strains were most closely related to Clostridium asparagiforme, Clostridium bolteae and Clostridium clostridioforme, but morphological, biochemical and phylogenetic studies demonstrated that they represent a previously unidentified species of the genus Clostridium. This was confirmed by the unique cellular fatty acid composition of strains CCRI-9842T and CCRI-9929. Therefore, on the basis of data from the polyphasic taxonomic analysis, it is proposed that strains CCRI-9842T and CCRI-9929 represent a novel species of the genus Clostridium, for which the name Clostridium lavalense sp. nov. is proposed. The type strain is CCRI-9842T (=CCUG 54291T=JCM 14986T=NML 03-A-015T).
Biochemical and molecular genetic studies were performed on an unknown Gram-positive, catalase-negative, coccus-shaped organism isolated from clinical samples from pigs. On the basis of the results of cellular morphological and biochemical tests, the organism was identified as a streptococcal species. 16S rRNA gene sequence comparisons confirmed its identification as a member of the genus Streptococcus, but the organism was distinct from any recognized species of this genus. The closest phylogenetic relative of the unknown organism corresponded to Streptococcus suis NCTC 10234T (97.2 % 16S rRNA gene sequence similarity) and this phylogenetic position was confirmed by analysis of rpoB and sodA sequences. DNA–DNA hybridization studies showed that the unidentified organism produced a DNA reassociation value of 36.6 % with respect to S. suis NCTC 10234T. The novel bacterium was distinguished from S. suis and other Streptococcus species using biochemical tests. On the basis of phenotypic and phylogenetic data, the unidentified organism represents a novel species of the genus Streptococcus, for which the name Streptococcus plurextorum sp. nov. is proposed. The type strain is 1956-02T (=CECT 7308T=CCUG 52972T).
Two strains of xylanase-producing bacteria, S3-4AT and MX2-3T, isolated from soils in Thailand, were characterized on the basis of their phenotypic and chemotaxonomic characteristics, DNA–DNA relatedness and 16S rRNA gene sequences. The novel strains were Gram-positive, facultatively anaerobic, spore-forming, rod-shaped bacteria. They contained meso-diaminopimelic acid as the diagnostic diamino acid in the cell-wall peptidoglycan. The DNA G+C contents of strains S3-4AT and MX2-3T were 52.7 and 52.9 mol%, respectively. The major isoprenoid quinone was MK-7. The dominant cellular fatty acids were anteiso-C15 : 0 and iso-C16 : 0. Phylogenetic analyses using 16S rRNA gene sequences showed that both novel strains were affiliated to the genus Paenibacillus. Strains S3-4AT and MX2-3T were closely related to Paenibacillus agaridevorans DSM 1355T with 97 % and 97.3 % gene sequence similarities, respectively. The DNA–DNA relatedness between strains S3-4AT, MX2-3T and P. agaridevorans DSM 1355T was low (6.0–30.3 %). The novel strains could be clearly distinguished from P. agaridevorans DSM 1355T by physiological and biochemical characteristics. Therefore, these two strains represent novel species of the genus Paenibacillus, for which the names Paenibacillus thailandensis sp. nov. (type strain S3-4AT=KCTC 13043T=PCU 275T=TISTR 1827T) and Paenibacillus nanensis sp. nov. (type strain MX2-3T=KCTC 13044T=PCU 276T=TISTR 1828T) are proposed.
The taxonomic status of Pediococcus dextrinicus is described and transfer of the species to the genus Lactobacillus, with the name Lactobacillus dextrinicus comb. nov., is proposed. This reclassification is supported by multilocus sequence analysis of the 16S rRNA gene and Cpn60, PheS, RecA and RpoA proteins. The mode of cell division and existing phenotypic information also show that P. dextrinicus does not belong to the genus Pediococcus, but rather to the genus Lactobacillus. As such, we propose that Pediococcus dextrinicus is reclassified as Lactobacillus dextrinicus comb. nov. (type strain ATCC 33087T=DSM 20335T=JCM 5887T=LMG 11485T=NCDO 1561T).