Highlight Activities 2019: Etiological agents of tortoise tick in Thailand

Several species of bacteria and protozoa can cause infection or infestation of ticks collected from Indotestudo tortoises. This study surveyed etiological agents found in tortoise ticks in Thailand, which possibly could cause harm to humans, and to study the evolutionary relationships of microorganisms detected. Twenty-six Amblyomma geoemydae ticks were collected from three Indotestudo elongata: one from Satun and two from Uthai Thani provinces. Ticks were morphologically and molecularly identified. Based on PCR techniques, Ehrlichia and Francisella bacteria and Hemolivia protozoa were identified in A.  geoemydae.  Phylogenetic  analysis  indicated Hemolivia 18S rDNA sequences belonged to a distinct clade from genus Hepatozoon but related to H. mauritanica and H. mariae, and analysis of Ehrlichia 16S rDNA sequences revealed they formed a unique clade of E. ruminantium while Francisella 16S rDNA sequences belonged to the same group. These data will be of use in further investigations of the roles of these etiological agents in human and animal hosts.


Ahantarig A, Hirunkanokpun S, Naksatit A, Ongin T, Baimai V, Trinachartvanit W. Etiological agents of tortoise tick in Thailand. Southeast Asian J Trop Med Public Health 2019; 50: 79–85