RESUMEN
In a previous study, 50 of 132 soil samples collected throughout Japan were found to be Leptospira-positive. In the present study, three strains identified in the collected specimens, three, E8, E18 and YH101, were found to be divergent from previously described Leptospira species according to 16S ribosomal RNA gene sequence analysis. These three strains have a helical shape similar to that of typical Leptospira and were not re-isolated from experimental mice inoculated with the cultured strains. Upon 16S ribosomal RNA gene sequence analysis, E8 was found to belong to the intermediate Leptospira species clade and E18 and YH101 to belong to the saprophytic Leptospira species clade. Based on analyses of genome-to-genome distances and average nucleotide identity in silico using whole genome sequences and DNA-DNA hybridization in vitro, these isolates were found to be distinct from previously described Leptospira species. Therefore, these three isolates represent novel species of the genus Leptospira for which the names Leptospira johnsonii sp. nov., (type strain E8 T , = JCM 32515 T = CIP111620 T ), Leptospira ellinghausenii sp. nov., (type strain E18 T , = JCM 32516 T = CIP111618 T ) and Leptospira ryugenii sp. nov., (type strain YH101 T , = JCM 32518 T = CIP111617 T ) are proposed.
Asunto(s)
Leptospira/clasificación , Leptospira/aislamiento & purificación , Microbiología del Suelo , Animales , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Genoma Bacteriano/genética , Japón , Leptospira/genética , Masculino , Ratones , Ratones Transgénicos , Filogenia , ARN Ribosómico 16S/genética , Microbiología del Agua , Secuenciación Completa del GenomaRESUMEN
Borrelia miyamotoi, a hard tick-borne relapsing fever agent, was sampled in Ixodes ricinus and Ixodes persulcatus ticks from the Tver province in Russia (a sympatric region of both tick species) and examined by TaqMan-PCR targeting the 16S rRNA gene. Borrelia was detected in 4 out of 168 ticks: 2 out of 58 I. ricinus ticks (infection rate 2.9%) and 2 out of 110 I. persulcatus ticks (1.8%). The agent was identified as B. miyamotoi on the basis of the 16S and 23S rDNA intergenic spacer and glycerophosphodiester phosphodiesterase gene sequencing analyses. Interestingly, the genes sequences detected from one I. ricinus tick were identical to those of Asian-type B. miyamotoi from I. persulcatus. This tick was identified as I. ricinus by sequencing analysis of internal transcribed spacer 2 and mitochondrial cytochrome oxidase subunit 1. The results suggest that the I. ricinus ticks were infected with Asian-type B. miyamotoi in a sympatric region for I. ricinus and I. persulcatus.