'Candidatus Borrelia texasensis', from the American dog tick Dermacentor variabilis.
TXW-1, a Borrelia strain isolated in March 1998 from an adult male Dermacentor variabilis tick feeding on a coyote from Webb county, Texas, USA, was characterized by using randomly amplified polymorphic DNA (RAPD) analysis, RFLP and sequence analysis of flaB and rrs (16S rRNA gene), DNA-DNA hybridization analysis, SDS-PAGE and Western blotting with mAbs. It shows different banding patterns in RFLP analysis of flaB and forms distinct branches in phylogenetic analysis derived from flaB and rrs genes. It differs from other borreliae based on the banding patterns obtained by RAPD analysis. This strain contains a small, 38-kDa endoflagellar protein. DNA-DNA hybridization experiments revealed that the levels of DNA reassociation between TXW-1 and previously described relapsing fever borreliae were 38.64 % (Borrelia turicatae), 38.40 % (Borrelia parkeri), 7.39 % (Borrelia hermsii) and 18.30 % (Borrelia coriaceae). However, the level of DNA relatedness between B. parkeri and B. turicatae was 78.78 %. Sequence analyses of flaB and rrs genes indicate that the similarities of nucleotide sequences among TXW-1 and B. turicatae or B. parkeri are less than that between B. turicatae and B. parkeri, and that the genetic distances among TXW-1 and B. turicatae or B. parkeri are greater than that between B. turicatae and B. parkeri. TXW-1 lacks an ospC gene. Electron microscope observations showed that this spirochaete had different morphological structures compared to previously described relapsing fever borreliae. All the results obtained from the above-mentioned analyses indicate that TXW-1 is different from other described Borrelia species and that it represents a novel species of Borrelia. We have been unable to revive frozen cultures and so can not meet the requirements of the Bacteriological Code to deposit viable type material at two different culture collections. Therefore we use the Candidatus designation; based on these results, the species 'Candidatus Borrelia texasensis' is proposed.
Lin
Tao
T
Institute of Arthropodology and Parasitology, Georgia Southern University, Statesboro, GA 30460-8056, USA.
Gao
Lihui
L
Institute of Arthropodology and Parasitology, Georgia Southern University, Statesboro, GA 30460-8056, USA.
Seyfang
Andreas
A
Laboratory of Molecular Parasitology and Medical Microbiology, Department of Biochemistry and Molecular Biology, Medical College of Georgia, Augusta, GA 30912-2100, USA.
Oliver
James H
JH
Institute of Arthropodology and Parasitology, Georgia Southern University, Statesboro, GA 30460-8056, USA.
D000818:Animals; D001898:Borrelia / Q000737:chemistry / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D046029:Coyotes / Q000469:parasitology; D004269:DNA, Bacterial / Q000032:analysis; D003870:Dermacentor / Q000382:microbiology* / Q000502:physiology; D004285:Dogs / Q000469:parasitology; D005408:Flagellin / Q000235:genetics; D020459:Genes, rRNA; D008297:Male; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010641:Phenotype; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D019105:Random Amplified Polymorphic DNA Technique; D012061:Relapsing Fever / Q000382:microbiology; D017422:Sequence Analysis, DNA; D013781:Texas
D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D005408:Flagellin; C416532:flaB flagellin