四川省炉霍县牦牛源蜱传斑点热群立克次体和无形体分子检测及遗传进化分析.

【Objective】The present paper aimed to investigate the species of parasitic ticks on the surface of yaks in Luhuo county, Sichuan province, and the infection status of Rickettsia (SFGR) and invisible ticks.【Method】Ticks were collected from the surface of yaks in six villages in Luhuo county. After preliminary morphological identification, tick genomic DNA was extracted. PCR technology was used to amplify partial fragments of tick ITS-2, SFGR OmpB, and amorphous 16S rRNA genes. The positive products were sequenced, compared, and an evolutionary tree was constructed to determine the species of ticks and their infection status with SFGR and anaplasma.【Result】A total of 820 adult ticks were collected with only Haemaphysalis qinghaiensisus (29/820) and Rhipicephalus microplus (791/820) found. Rickettsia spp. were detected in all six villages and total infection rate was 49.8% (408/820) with only Candidatus R. longicornii detected. The infection rates of SFGR in six villages were statistically significant (χ² = 111.524, P = 0.000 ＜ 0.01). The infection rates of SFGR in H. qinghaiensisus and R. microplus were 44.8% (13/29) and 49.9% (395/791), respectively with no significant differences (χ² = 0.292, P = 0.589 ＞ 0.5). Anaplasma spp. (including A. bovis, A. marginale, A. platys, and A. phagocytophilum) were detected in five villages, with a total infection rate of 30.9% (253/820). The infection rates of Anaplasma in five villages were statistically significant (χ² = 139.825, P = 0.000 ＜ 0.01). Also, the infection rates of Anaplasma between H. qinghaiensisus and R. microplus were statistically significant (χ² = 8.087, P = 0.004 ＜ 0.01). Co-infection of SFGR and Anaplasma was observed with the infection rate of 18.8% (154/820).【Conclusion】There are Qinghai blood tick and micro fanhead tick in Luhuo county, which also carry SFGR and various intangible organisms. Therefore, it is necessary to do a good job in the prevention and control of local tick borne spotted fever group rickettsia and intangible organisms. [ABSTRACT FROM AUTHOR]