AUTHOR=Takhampunya Ratree , Sakolvaree Jira , Chanarat Nitima , Youngdech Nittayaphon , Phonjatturas Kritsawan , Promsathaporn Sommai , Tippayachai Bousaraporn , Tachavarong Wirunya , Srinoppawan Kanchit , Poole-Smith Betty K. , McCardle P. Wesley , Chaorattanakawee Suwanna 

TITLE=The Bacterial Community in Questing Ticks From Khao Yai National Park in Thailand

JOURNAL=Frontiers in Veterinary Science

VOLUME=8

YEAR=2021

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2021.764763

DOI=10.3389/fvets.2021.764763

ISSN=2297-1769

ABSTRACT=<p>Ticks are known vectors for a variety of pathogens including bacteria, viruses, fungi, and parasites. In this study, bacterial communities were investigated in active life stages of three tick genera (<italic>Haemaphysalis, Dermacentor</italic>, and <italic>Amblyomma</italic>) collected from Khao Yai National Park in Thailand. Four hundred and thirty-three questing ticks were selected for pathogen detection individually using real-time PCR assays, and 58 of these were subjected to further metagenomics analysis. A total of 62 ticks were found to be infected with pathogenic bacteria, for a 14.3% prevalence rate, with <italic>Amblyomma</italic> spp. exhibiting the highest infection rate (20.5%), followed by <italic>Haemaphysalis</italic> spp. (14.5%) and <italic>Dermacentor</italic> spp. (8.6%). <italic>Rickettsia</italic> spp. were the most prevalent bacteria (7.9%) found, followed by <italic>Ehrlichia</italic> spp. (3.2%), and <italic>Anaplasma</italic> spp. and <italic>Borrelia</italic> spp. each with a similar prevalence of 1.6%. Co-infection between pathogenic bacteria was only detected in three <italic>Haemaphysalis</italic> females, and all co-infections were between <italic>Rickettsia</italic> spp. and Anaplasmataceae (<italic>Ehrlichia</italic> spp. or <italic>Anaplasma</italic> spp.), accounting for 4.6% of infected ticks or 0.7% of all examined questing ticks. The prevalence of the <italic>Coxiella</italic>-like endosymbiont was also investigated. Of ticks tested, 65.8% were positive for the <italic>Coxiella</italic>-like endosymbiont, with the highest infection rate in nymphs (86.7%), followed by females (83.4%). Among tick genera, <italic>Haemaphysalis</italic> exhibited the highest prevalence of infection with the <italic>Coxiella</italic>-like endosymbiont. Ticks harboring the <italic>Coxiella</italic>-like endosymbiont were more likely to be infected with <italic>Ehrlichia</italic> spp. or <italic>Rickettsia</italic> spp. than those without, with statistical significance for <italic>Ehrlichia</italic> spp. infection in particular (<italic>p</italic>-values = 0.003 and 0.917 for <italic>Ehrlichia</italic> spp. and <italic>Rickettsia</italic> spp., respectively). Profiling the bacterial community in ticks using metagenomics revealed distinct, predominant bacterial taxa in tick genera. Alpha and beta diversities analyses showed that the bacterial community diversity and composition in <italic>Haemaphysalis</italic> spp. was significantly different from <italic>Amblyomma</italic> spp. However, when examining bacterial diversity among tick life stages (larva, nymph, and adult) in <italic>Haemaphysalis</italic> spp., no significant difference among life stages was detected. These results provide valuable information on the bacterial community composition and co-infection rates in questing ticks in Thailand, with implications for animal and human health.</p>