Leptospira idonii sp. nov., isolated from environmental water

Mitsumasa Saito, Sharon Y. A. M. Villanueva, Yoshiaki Kawamura, Ken-ichiro Iida, Junko Tomida, Takaaki Kanemaru, Eri Kohno, Satoshi Miyahara, Akiko Umeda, Kazunobu Amako, Nina G. Gloriani, Shin-ichi Yoshida

¹Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan

²Department of Microbiology, Aichigakuin University, School of Pharmacy, 1-100 Kusumoto-cho, Nagoya 464-8650, Japan

³Department of Morphology Core Unit, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan

⁴Department of Basic Laboratory Sciences, Graduate School of Medicine, Yamaguchi University, 1-1-1 Minami-Kogushi, Ube, Yamaguchi 755-8505, Japan

⁵Department of Medical Microbiology, College of Public Health, University of the Philippines-Manila, 625 Pedro Gil St, Ermita, 1000, Manila, The Philippines

Correspondence
Mitsumasa Saito msaito{at}bact.med.kyushu-u.ac.jp

International Journal of Systematic and Evolutionary Microbiology 2013; 63(Pt 7):2457–2462 · https://doi.org/10.1099/ijs.0.047233-0

Abstract

Strain Eri-1^T was isolated from a water sample on the campus of Kyushu University, Fukuoka, Japan. The motility and morphology of the isolate were similar to those of members of the genus Leptospira, but the spiral structure of the isolate was sharper under dark-field microscopy. Cells were 10.6±1.3 µm long and 0.2 µm in diameter, with a wavelength of 0.9 µm and an amplitude of 0.4 µm. Strain Eri-1^T grew in Korthof’s medium at both 13 and 30 °C, and also in the presence of 8-azaguanine. 16S rRNA gene-based phylogenetic analysis placed strain Eri-1^T within the radiation of the genus Leptospira where it formed a unique lineage within the clade of the known saprophytic species of the genus Leptospira. The strain was not pathogenic to hamsters. Strain Eri-1^T exhibited low levels (11.2–12.6 %) of similarity by DNA–DNA hybridization to the three most closely related species of the genus Leptospira. The DNA G+C content of the genome of strain Eri-1^T was 42.5±0.1 mol%. These results suggest that strain Eri-1^T represents a novel species of the genus Leptospira, for which the name Leptospira idonii sp. nov. is proposed. The type strain is Eri-1^T ( = DSM 26084^T = JCM 18486^T).