Birds are known to be the most mobile hosts and are therefore considered to be hosts with potential
to contribute to the long-distance spread and transmission of tick-borne pathogens. In the present
study, ticks were collected from a hornbill nest at Chaiyaphum Province, Thailand. They were screened
for the presence of Coxiella bacteria using conventional PCR. The evolutionary relationships of positive
Coxiella-like bacteria (CLB) were analysed based on the gene sequences of 16S rRNA, groEL and rpoB.
Among all 22 tested ticks, CLB infections were found in 2 Haemaphysalis wellingtoni individuals. In a
phylogenetic analysis, the Coxiella 16S rRNA gene detected in this study formed a separate clade from
sequences found in ticks of the same genus. In contrast, the phylogenetic relationships based on groEL
and rpoB revealed that these two genes from H. wellingtoni ticks grouped with CLB from the same
tick genus (Haemaphysalis). This study is the first to report the presence of CLB in H. wellingtoni ticks
associated with the Great Hornbill, Buceros bicornis in Thailand. Three genes of CLB studied herein
were grouped separately with Coxiella burnetii (pathogenic strain). The effects of CLB in the ticks and
Buceros bicornis require further investigation.