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

Abstract

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 [Gü ner et al. (2003). Microbiology 149, 2539Microbiology 149, -2544. Here is presented a detailed characterization of the spirochaete. Electron microscopy revealed that strain IST7T 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 ).

Detection of a Borrelia species in questing Gulf Coast ticks, Amblyomma maculatum

“…Phylogenetic analyses of the flaB and 16S rRNA partial gene sequences identified in this study placed these A. maculatum associated Borrelia sequences in a clade with or as a sister group to the reptile-associated borreliae, and distinct from the relapsing fever group and Lyme disease groups. These results are consistent with the GenBank query results which showed closest flaB sequence identity (89%) to the B. turcica isolates Tortoise 7S1 and 7S2 from the hard tick, Hyalomma aegyptium , removed from a tortoise in Turkey (Güner et al, 2004), and closest 16S rRNA gene sequence identity (98%) to species including B. turcica . That the sequences identified here are closest to reptile-associated Borrelia species is curious considering A. maculatum are not known to feed on reptiles, and opens additional questions.…”

“…The third recently proposed group of borreliae consists of reptile-associated Borrelia spp. found in hard ticks of the genera Amblyomma and Hyalomma (Güner et al, 2004; Takano et al, 2011). Phylogenetic analyses of the flaB and 16S rRNA partial gene sequences identified in this study placed these A. maculatum associated Borrelia sequences in a clade with or as a sister group to the reptile-associated borreliae, and distinct from the relapsing fever group and Lyme disease groups.…”

Zoonotic pathogens associated with Hyalomma aegyptium in endangered tortoises: evidence for host-switching behaviour in ticks?

“…Determining the vectorial capacity of a tick to a certain pathogen is questionable if based only on pathogen detection (mainly by PCR), without experimental trials [11]. Several pathogens were detected in H. aegyptium : Theileria annulata [12], Borrelia turcica [13], Rickettsia spp. and Borrelia burgdorferi s.l.…”

Ticks biting humans in the urban area of Istanbul

“…The reports of tick on humans raise the question about its importance as a vector of pathogens. A spirochete, Borrelia turcica, has been detected on ticks of this species collected from turtles in the same area (Guner et al 2004). Neither implications as human pathogen nor the reservoir hosts for that spirochete have been reported so far.…”