Survey of the vectorial competence of ticks in an endemic area of spotted fever group rickettsioses in Fukui Prefecture, Japan.
The prevalence of SFGR in ixodid ticks in the Mt. Arashima-dake area in the northern part of Fukui Prefecture was surveyed, because of strong suspicions that the first case identified in this Prefecture had become infected with R. helvetica in this region. The ticks identified consisted of three genera and six species; I.ovatus, I. persulcatus, I. monospinosus, H. flava, H. japonica and D. taiwanensis. Of all 222 ticks collected, only I. monospinosus ticks (8 of 32 examined) were positive for SFGR isolates, which were genetically identified as R. helvetica. Ticks (157 of all 222) positive for SFGR-DNA fragments consisted of I. monospinosus (14 of 32), I. persulcatus (11 of 55), I. ovatus (3 of 38), H. flava (5 of 21) and H. japonica (2 of 9). Of these, thirteen I. monospinosus, eight I. persulcatus, three I. ovatus, two H. flava and one H. japonica were identified by nucleotide sequences as positive for R. helvetica. DNA fragments from three H. flava and one H. japonica showed greater homology to R. japonica than to R. helvetica or R. asiatica. The present results indicate that it is most likely that the vector tick of R. helvetica infection in Fukui Prefecture is I. monospinosus.
Ishiguro
Fubito
F
Fukui Prefectural Institute of Health and Environmental Science, Fukui, Fuku 910-8551, Japan. ishigurofubito@fklab.fukui.fukui.jp
Takada
Nobuhiro
N
Fujita
Hiromi
H
Noji
Yoshihiro
Y
Yano
Yasuhiro
Y
Iwasaki
Hiromichi
H
D000818:Animals; D001096:Arachnid Vectors / Q000145:classification* / Q000382:microbiology; D004269:DNA, Bacterial / Q000235:genetics; D004784:Environmental Monitoring; D062665:Epidemiological Monitoring; D005260:Female; D026863:Ixodidae / Q000145:classification* / Q000382:microbiology; D007564:Japan / Q000453:epidemiology; D008297:Male; D016133:Polymerase Chain Reaction; D012281:Rickettsia / Q000235:genetics / Q000302:isolation & purification; D012282:Rickettsia Infections / Q000453:epidemiology*
D004269:DNA, Bacterial