Borrelia turcica sp. nov., isolated from the hard tick Hyalomma aegyptium in Turkey

1 Medical School, Yeditepe University, Istanbul, Turkey 2 Department of Microbiology and COE Program in the 21st Century, University of Shizuoka School of Pharmaceutical Sciences, Shizuoka, 422-8526, Japan 3 Department of Parasitology, Aichi Medical University, Aichi, 480-1195, Japan 4 Department of Microbiology, School of Medicine, Gifu University, Gifu, 500-8705, Japan 5 Department of Bacteriology, National Institute of Infectious Diseases, Tokyo, 162-8640, Japan 6 Department of Food Science, Shizuoka Eiwa Gakuen University Junior College, Shizuoka, 422-8005, Japan Correspondence Toshiyuki Masuzawa masuzawa{at}u-shizuoka-ken.ac.jp Previously, a novel, fast-growing spirochaete was isolated from the hard tick Hyalomma aegyptium , which infests tortoises ( Testudo graeca ), by using Barbour–Stoenner–Kelly (BSK) II medium; the tick samples were taken from the Istanbul area in northwestern Turkey [Güner et al . (2003). Microbiology 149 , 2539–2544]. Here is presented a detailed characterization of the spirochaete. Electron microscopy revealed that strain IST7 T is morphologically similar to other spirochaetes of the genus Borrelia and possesses 15 to 16 flagellae that emerge from both polar regions. PFGE analysis revealed the genome to comprise a linear chromosome of approximately 1 Mb; two large linear plasmids of approximately 145 and 140 kb, and several small plasmids ranging from 50 to 20 kb in size were also found. The 16S rRNA gene sequence of this Borrelia isolate exhibited 99·4 to 99·8 % identity with other strains isolated from H. aegyptium and less than 99 % similarity with those of other Borrelia species. A phylogenetic tree, generated from 16S rRNA gene sequences, demonstrated that the spirochaete isolates from H. aegyptium clustered together and branched off from both Lyme-disease-related and relapsing-fever-associated Borrelia species. A single copy of the rrs gene was detected in the genome of strain IST7 T by Southern hybridization. DNA–DNA hybridization results showed that strain IST7 T was distinct from Lyme-disease-related Borrelia , Borrelia burgdorferi and the relapsing-fever-associated species Borrelia hermsii . The G+C content of strain IST7 T is 30·0 mol%. From these genetic features, a novel Borrelia species, Borrelia turcica sp. nov., is proposed; the type strain is IST7 T (=JCM 11958 T =DSM 16138 T ). Abbreviations: BSK, Barbour–Stoenner–Kelly; CFE, constant-field electrophoresis The GenBank/EMBL/DDBJ accession numbers for the 16S r