Masuzawa Toshiyuki, Saito Mitsumasa, Nakao Ryo, Nikaido Yasuhiko, Matsumoto Masahiro, Ogawa Midori, Yokoyama Mitsuru, Hidaka Yusuke, Tomita Junko, Sakakibara Keiko, Suzuki Kazushi, Yasuda Shima, Sato Hiroki, Yamaguchi Masaya, Yoshida Shin-Ichi, Koizumi Nobuo, Kawamura Yoshiaki
Laboratory of Microbiology and Immunology, Faculty of Pharmaceutical Sciences, Chiba Institute of Science (CIS), Choshi, Chiba.
Department of Microbiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Fukuoka.
Microbiol Immunol. 2019 Mar;63(3-4):89-99. doi: 10.1111/1348-0421.12671. Epub 2019 Mar 29.
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 , = JCM 32515 = CIP111620 ), Leptospira ellinghausenii sp. nov., (type strain E18 , = JCM 32516 = CIP111618 ) and Leptospira ryugenii sp. nov., (type strain YH101 , = JCM 32518 = CIP111617 ) are proposed.
在之前的一项研究中，在日本各地采集的132份土壤样本中有50份被发现钩端螺旋体呈阳性。在本研究中，根据16S核糖体RNA基因序列分析，在所采集的标本中鉴定出的三株菌株，即E8、E18和YH101，被发现与先前描述的钩端螺旋体物种不同。这三株菌株具有与典型钩端螺旋体相似的螺旋形状，并且没有从接种培养菌株的实验小鼠中再次分离出来。经16S核糖体RNA基因序列分析，发现E8属于中间型钩端螺旋体物种分支，E18和YH101属于腐生型钩端螺旋体物种分支。基于使用全基因组序列进行的全基因组距离分析和计算机模拟平均核苷酸同一性分析以及体外DNA-DNA杂交分析，发现这些分离株与先前描述的钩端螺旋体物种不同。因此，这三株分离株代表了钩端螺旋体属的新物种，为此提议将其命名为约翰逊钩端螺旋体新种（模式菌株E8 = JCM 32515 = CIP111620）、埃林豪森钩端螺旋体新种（模式菌株E18 = JCM 32516 = CIP111618）和留根钩端螺旋体新种（模式菌株YH101 = JCM 32518 = CIP111617）。
