In this study, we identified two Haemaphysalis species present at the Khao Yai National Park in Thailand and investigated the presence of rickettsia in these ticks. A total of 166 Haemaphysalis specimens were collected randomly under leaves along visitor paths at five locations in the park. Male and female adults of two different Haemaphysalis species, H. shimoga and H. lagrangei, were identified. Polymerase chain reaction (PCR) analysis revealed Rickettsia bacteria in these two Haemaphysalis species; this study represents the first time such presence has been reported in Thailand. The infection rates of Rickettsia were in both H. shimoga (7.41%) and H. lagrangei (10.17%) at these locations in addition to two pools of Haemahysalis nymphs (28.57%). Furthermore, 25.93% of H. shimoga showed positive results that matched Haemaphysalis longicornis symbionts (92% sequence identity) and the Coxeilla burnetti 16S ribosomal RNA gene (90% sequence identity). We propose that this is a novel H. shimoga symbiont bacterium in Thailand and might be a novel Coxeilla-like agent or Coxeilla sp. found in H. shimoga. In contrast, we did not observe any Wolbachia bacteria, which also belong to the order Rickettsiales, in the same group of Haemaphysalis ticks. Furthermore, PCR was used to detect three other genera of bacteria, Anaplasma, Ehrlichia and Borrelia, none of which were identified in the Haemaphysalis ticks studied.

We collected a total of 169 adult hard ticks and 120 nymphs from under the leaves of plants located along tourist nature trails in ten localities. The results present data examining the vector competence of ticks of different genera and the presence of Rickettsia and Anaplasma species. The ticks belonged to three genera, Amblyomma, Dermacentor, and Haemaphysalis, comprising 11 species. Rickettsia bacteria were detected at three collection sites, while Anaplasma bacteria were detected at only one site. Phylogenetic analysis revealed new rickettsia genotypes from Thailand that were closely related to Rickettsia tamurae, Rickettsia monacensis, and Rickettsia montana. This study was also the first to show that Anaplasma bacteria are found in Haemaphysalis shimoga ticks and are closely related evolutionarily to Anaplasma bovis. These results provide additional information for the geographical distribution of tick species and tick-borne bacteria in Thailand and can therefore be applied for ecotourism management. Journal of Vector Ecology 40 (2): 262-268. 2015.