This paper reports on a Leptospira isolate of bovine origin and its identification as belonging to a previously unknown serovar, for which the name Topaz is proposed. The isolate (94-79970/3) was cultured from bovine urine from a north Queensland dairy farm in Australia. Strain 94-79970/3 grew at 30 °C in Ellinghausen McCullough Johnson Harris (EMJH) medium but failed to grow at 13 °C in EMJH medium or in the presence of 8-azaguanine. Serologically, strain 94-79970/3 produced titres against the Leptospira borgpetersenii serovar Tarassovi, the reference strain for the Tarassovi serogroup; however, no significant titres to any other serovars within the serogroup were obtained. Using 16S rRNA and DNA gyrase subunit B gene analysis, strain 94-79970/3 was identified as a member of the species Leptospira weilii. We propose that the serovar be named Topaz, after the location where the original isolate was obtained. The reference strain for this serovar is 94-79970/3 (=KIT 94-79970/3=LT722).
A novel thermophilic, anaerobic bacterium, strain RASENT, was isolated from a deep-sea hydrothermal vent chimney sample collected in the Iheya North field, Okinawa Trough, Japan, at a water depth of 982 m. The cells were motile, Gram-negative and helical with hooked ends, 0.23–0.28×15–27 μm in size with an approximate wavelength of 1.1–1.5 μm. Growth of the strain was observed at 37–60 °C (optimum 50 °C), in 2.5–3.5 % (w/v) NaCl (optimum 2.5–3 % NaCl) and at pH 6.0–7.5 (optimum pH 7.0). The strain grew on yeast extract only of the substrates examined in this study. The G+C content of the genomic DNA was 27.1 mol%. Major fatty acids for the strain were C16 : 0, C18 : 1(Δ9) trans, C18 : 0 and C18 : 1(Δ9) cis. Based on comparative 16S rRNA gene sequence analysis, strain RASENT formed a deeply branching lineage within the phylum Spirochaetes and had only low levels of sequence similarity with other species of the phylum (range of similarity 72.1–80.6 %). Hence, we propose the name Exilispira thermophila gen. nov., sp. nov. The type strain of Exilispira thermophila is strain RASENT (=JCM 14728T =NBRC 103205T =KCTC 5595T).
A single Leptospira strain (designated Khorat-H2T) was isolated from the urine of an adult male patient with suspected leptospirosis from the province of Nakornrachasima, Thailand. The isolate showed typical Leptospira motility and morphology under dark-field microscopy. Cells were 10–13 μm long and 0.2 μm in diameter, with a wavelength of 0.5 μm and an amplitude of approximately 0.3 μm. Phenotypically, strain Khorat-H2T did not grow at 13 °C but grew at 30 and 37 °C and in the presence of 8-azaguanine. Serological identification using the microscopic agglutination test revealed that strain Khorat-H2T had no cross-reaction with any recognized Leptospira serogroups. Phylogenetic analysis of the 16S rRNA gene sequence placed the novel strain within the radiation of the genus Leptospira, with sequence similarities of 88.1–97.7 % to recognized Leptospira species. DNA–DNA hybridization against the type strains of the three most closely related Leptospira species was used to confirm the results of the 16S rRNA sequence analysis. The G+C content of strain Khorat-H2T was 41.8 mol%. On the basis of phenotypic, serological and phylogenetic data, strain Khorat-H2T represents a novel species of the genus Leptospira, for which the name Leptospira wolffii sp. nov. is proposed. The type strain is Khorat-H2T (=WHO LT1686T =KIT Khorat-H2T).
The taxonomic positions of two environmental isolates from South Korea were established using a combination of genotypic and phenotypic data. The organisms, designated PB314T and Ho-08T, were Gram-negative, rod-shaped and non-spore-forming and had chemotaxonomic properties consistent with their classification in the genus Deinococcus 16S rRNA gene tree, the highest sequence similarities being shown to the type strains of Deinococcus grandis (96.3–96.7 %) and Deinococcus indicus (96.3–96.4 %). The isolates shared relatively high 16S rRNA gene sequence similarity (98.1 %) but had a DNA–DNA relatedness value of only 22 %. Chemotaxonomic data revealed that both strains possess quinone system MK-8 as the predominant compound, C16 : 1 ω7c and C16 : 0 as major fatty acids and ornithine as a diamino acid in the peptidoglycan structure, corroborating our assignment of the strains to the genus Deinococcus. The results of phylogenetic analyses based on 16S rRNA gene sequences, DNA–DNA relatedness values and physiological and biochemical tests clearly demonstrated that the two strains represent distinct species. On the basis of these data, two novel species, Deinococcus aquaticus sp. nov. (type strain PB314T =KCTC 12552T =NBRC 101311T) and Deinococcus caeni sp. nov. (type strain Ho-08T =KCTC 12553T =NBRC 101312T), are proposed.