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Tick surveillance for relapsing fever spirochete Borrelia miyamotoi in Hokkaido, Japan.

Takano A, Toyomane K, Konnai S, Ohashi K, Nakao M, Ito T, Andoh M, Maeda K, Watarai M, Sato K, Kawabata H - PLoS ONE (2014)

Bottom Line: The prevalence in I. persulcatus and I. pavlovskyi ticks were significantly higher than in I. ovatus.Co-infections with Lyme disease-related spirochetes were found in all of the tick species.From these results, B. miyamotoi-infected ticks are widely distributed throughout Hokkaido.

View Article: PubMed Central - PubMed

Affiliation: Department of Veterinary Medicine, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Yamaguchi, Japan; The United Graduate School of Veterinary Science, Yamaguchi University, Yamaguchi, Yamaguchi, Japan.

ABSTRACT
During 2012-2013, a total of 4325 host-seeking adult ticks belonging to the genus Ixodes were collected from various localities of Hokkaido, the northernmost island of Japan. Tick lysates were subjected to real-time PCR assay to detect borrelial infection. The assay was designed for specific detection of the Relapsing fever spirochete Borrelia miyamotoi and for unspecific detection of Lyme disease-related spirochetes. Overall prevalence of B. miyamotoi was 2% (71/3532) in Ixodes persulcatus, 4.3% (5/117) in Ixodes pavlovskyi and 0.1% (1/676) in Ixodes ovatus. The prevalence in I. persulcatus and I. pavlovskyi ticks were significantly higher than in I. ovatus. Co-infections with Lyme disease-related spirochetes were found in all of the tick species. During this investigation, we obtained 6 isolates of B. miyamotoi from I. persulcatus and I. pavlovskyi by culture in BSK-M medium. Phylogenetic trees of B. miyamotoi inferred from each of 3 housekeeping genes (glpQ, 16S rDNA, and flaB) demonstrated that the Hokkaido isolates were clustered with Russian B. miyamotoi, but were distinguishable from North American and European B. miyamotoi. A multilocus sequence analysis using 8 genes (clpA, clpX, nifS, pepX, pyrG, recG, rplB, and uvrA) suggested that all Japanese B. miyamotoi isolates, including past isolates, were genetically clonal, although these were isolated from different tick and vertebrate sources. From these results, B. miyamotoi-infected ticks are widely distributed throughout Hokkaido. Female I. persulcatus are responsible for most human tick-bites, thereby I. persulcatus is likely the most important vector of indigenous relapsing fever from tick bites in Hokkaido.

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Phylogenetic analysis of RF borreliae based on 16 S rDNA of Borrelia spp.The phylogenetic tree of 16 S rDNA was constructed. The phylogenetic branches were supported in >70% by the bootstrap analysis. The bar indicates the percentage of sequence divergence. Sequences in this study were shown in bold type. If possible, clone or strain name, isolation source, and country were described in the case of B. miyamotoi. Numbers in parentheses indicate Accession Numbers in GenBank.
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pone-0104532-g003: Phylogenetic analysis of RF borreliae based on 16 S rDNA of Borrelia spp.The phylogenetic tree of 16 S rDNA was constructed. The phylogenetic branches were supported in >70% by the bootstrap analysis. The bar indicates the percentage of sequence divergence. Sequences in this study were shown in bold type. If possible, clone or strain name, isolation source, and country were described in the case of B. miyamotoi. Numbers in parentheses indicate Accession Numbers in GenBank.

Mentions: In this study, 6 isolates of B. miyamotoi derived from I. persulcatus and I. pavlovskyi were established in culture using BSK-M medium (Table 2). These isolates were utilized for molecular characterization, together with 5 isolates previously established in Hokkaido [1]. In the initial step of molecular analyses, DNA sequences of housekeeping genes (glpQ, 16 S rDNA, and flaB) were determined for all of the Hokkaido isolates, and there were no nucleotide substitutions in all 11 isolates. Therefore, the isolate HT31 (the type strain of B. miyamotoi) was selected as a representative for phylogenetic analysis. Neighbor-joining phylogenetic trees inferred from each of the housekeeping genes clearly showed that HT31 was clustered with B. miyamotoi from Russia, but was distinguishable from B. miyamotoi found in North American and B. miyamotoi detected from most I. ricinus ticks in Europe (Figures 3, S1, and S2). These three clusters of B. miyamotoi were temporally designated as “Siberian,” “American” and “European” types, in this study (Figure 3).


Tick surveillance for relapsing fever spirochete Borrelia miyamotoi in Hokkaido, Japan.

Takano A, Toyomane K, Konnai S, Ohashi K, Nakao M, Ito T, Andoh M, Maeda K, Watarai M, Sato K, Kawabata H - PLoS ONE (2014)

Phylogenetic analysis of RF borreliae based on 16 S rDNA of Borrelia spp.The phylogenetic tree of 16 S rDNA was constructed. The phylogenetic branches were supported in >70% by the bootstrap analysis. The bar indicates the percentage of sequence divergence. Sequences in this study were shown in bold type. If possible, clone or strain name, isolation source, and country were described in the case of B. miyamotoi. Numbers in parentheses indicate Accession Numbers in GenBank.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4128717&req=5

pone-0104532-g003: Phylogenetic analysis of RF borreliae based on 16 S rDNA of Borrelia spp.The phylogenetic tree of 16 S rDNA was constructed. The phylogenetic branches were supported in >70% by the bootstrap analysis. The bar indicates the percentage of sequence divergence. Sequences in this study were shown in bold type. If possible, clone or strain name, isolation source, and country were described in the case of B. miyamotoi. Numbers in parentheses indicate Accession Numbers in GenBank.
Mentions: In this study, 6 isolates of B. miyamotoi derived from I. persulcatus and I. pavlovskyi were established in culture using BSK-M medium (Table 2). These isolates were utilized for molecular characterization, together with 5 isolates previously established in Hokkaido [1]. In the initial step of molecular analyses, DNA sequences of housekeeping genes (glpQ, 16 S rDNA, and flaB) were determined for all of the Hokkaido isolates, and there were no nucleotide substitutions in all 11 isolates. Therefore, the isolate HT31 (the type strain of B. miyamotoi) was selected as a representative for phylogenetic analysis. Neighbor-joining phylogenetic trees inferred from each of the housekeeping genes clearly showed that HT31 was clustered with B. miyamotoi from Russia, but was distinguishable from B. miyamotoi found in North American and B. miyamotoi detected from most I. ricinus ticks in Europe (Figures 3, S1, and S2). These three clusters of B. miyamotoi were temporally designated as “Siberian,” “American” and “European” types, in this study (Figure 3).

Bottom Line: The prevalence in I. persulcatus and I. pavlovskyi ticks were significantly higher than in I. ovatus.Co-infections with Lyme disease-related spirochetes were found in all of the tick species.From these results, B. miyamotoi-infected ticks are widely distributed throughout Hokkaido.

View Article: PubMed Central - PubMed

Affiliation: Department of Veterinary Medicine, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Yamaguchi, Japan; The United Graduate School of Veterinary Science, Yamaguchi University, Yamaguchi, Yamaguchi, Japan.

ABSTRACT
During 2012-2013, a total of 4325 host-seeking adult ticks belonging to the genus Ixodes were collected from various localities of Hokkaido, the northernmost island of Japan. Tick lysates were subjected to real-time PCR assay to detect borrelial infection. The assay was designed for specific detection of the Relapsing fever spirochete Borrelia miyamotoi and for unspecific detection of Lyme disease-related spirochetes. Overall prevalence of B. miyamotoi was 2% (71/3532) in Ixodes persulcatus, 4.3% (5/117) in Ixodes pavlovskyi and 0.1% (1/676) in Ixodes ovatus. The prevalence in I. persulcatus and I. pavlovskyi ticks were significantly higher than in I. ovatus. Co-infections with Lyme disease-related spirochetes were found in all of the tick species. During this investigation, we obtained 6 isolates of B. miyamotoi from I. persulcatus and I. pavlovskyi by culture in BSK-M medium. Phylogenetic trees of B. miyamotoi inferred from each of 3 housekeeping genes (glpQ, 16S rDNA, and flaB) demonstrated that the Hokkaido isolates were clustered with Russian B. miyamotoi, but were distinguishable from North American and European B. miyamotoi. A multilocus sequence analysis using 8 genes (clpA, clpX, nifS, pepX, pyrG, recG, rplB, and uvrA) suggested that all Japanese B. miyamotoi isolates, including past isolates, were genetically clonal, although these were isolated from different tick and vertebrate sources. From these results, B. miyamotoi-infected ticks are widely distributed throughout Hokkaido. Female I. persulcatus are responsible for most human tick-bites, thereby I. persulcatus is likely the most important vector of indigenous relapsing fever from tick bites in Hokkaido.

Show MeSH
Related in: MedlinePlus