Bacterial community in Haemaphysalis ticks of domesticated animals from the Orang Asli communities in Malaysia

Abstract

Ticks are vectors in the transmission of many important infectious diseases in human and animals. Ticks can be readily found in the semi-forested areas such as the settlements of the indigenous people in Malaysia, the Orang Asli. There is still minimal information available on the bacterial agents associated with ticks found in Malaysia. We performed a survey of the bacterial communities associated with ticks collected from domestic animals found in two Orang Asli villages in Malaysia. We collected 62 ticks, microscopically and molecularly identified as related to Haemaphysalis wellingtoni, Haemaphysalis hystricis and Haemaphysalis bispinosa. Bacterial 16s rRNA hypervariable region (V6) amplicon libraries prepared from the tick samples were sequenced on the Ion Torrent PGM platform. We detected a total of 392 possible bacterial genera after pooling and sequencing 20 samples, indicating a diverse bacterial community profile. Dominant taxa include the potential tick endosymbiont, Coxiella. Other dominant taxa include the tick-associated pathogen, Rickettsia, and environmental bacteria such as Bacillus, Mycobacterium, Sphingomonas and Pseudomonas. Other known tick-associated bacteria were also detected, including Anaplasma, Ehrlichia, Rickettsiella and Wolbachia, albeit at very low abundance. Specific PCR was performed on selected samples to identify Rickettsia and Coxiella. Sequence of Rickettsia felis, which causes spotted fever in human and cats, was identified in one sample. Coxiella endosymbionts were detected in three samples. This study provides the baseline knowledge of the microbiome of ticks in Malaysia, focusing on tick-associated bacteria affecting the Orang Asli communities. The role of the herein found Coxiella and Rickettsia in tick physiology or disease transmission merits further investigation.

Coxiella Detection in Ticks from Wildlife and Livestock in Malaysia

“…It is, however, important to note that Coxiella -like bacteria were not detected in all Haemaphysalis tick species examined in the prior study (Arthan et al 2015). Similar observations were made in our previous attempt to study the bacterial communities in Haemaphysalis ticks in Malaysia (Khoo et al 2016). We observed nonuniform relative abundance of Coxiella in all of the Haemaphysalis ticks tested.…”

“…Swabs were taken and amplification of bacterial 16s rRNA sequences was performed to ensure no residual genomic material remained (Khoo et al 2016). Tick samples were ground in liquid nitrogen using chilled mortar and pestle in a biosafety cabinet, using separate sets of mortar and pestle for each sample.…”

“…Samples exhibiting the amplification of all fragments during nested PCR were considered as positive for the presence of the Coxiella DNA. Samples displaying no amplification of the Coxiella -specific 16s rRNA fragment were subjected to additional PCR amplification of nonspecific bacterial 16s rRNA gene as described in an earlier study (Khoo et al 2016). The partial sequence of the rpoB gene from selected samples was amplified using previously described primers and protocols (Duron et al 2015).…”

Diversity of bacteriome associated with Phlebotomus chinensis (Diptera: Psychodidae) sand flies in two wild populations from China

“…Spiroplasma as endosymbionts has been identified in Drosophila 39404142, ticks4344 and mosquitoes45. Diplorickettsia , Coxiella and Rickettsiella are obligate endosymbionts that have been identified in ticks28464748 and leafhoppers49. Here, we reported for the first time the presence of Spiroplasma and taxa related to Diplorickettsia and Rickettsiella in Ph.…”

Phenotypic and genotypic identification of hard ticks of the genus Haemaphysalis (Acari: Ixodidae) in Peninsular Malaysia

“…Its distribution occurs throughout the Australasian, Oriental, subtropical and temperate belt of Eastern Asia including Malaysia (Yamaguti et al 1971). The species is a putative vector of pathogens such as Ehrlichia , Coxiella , Trypanosoma and Rickettsia spp., that may cause spotted fever group (SFG), ehrlichiosis and rickettsiosis (Parola et al 2003; Ando et al 2010; Arthan et al 2015; Khoo et al 2016). Despite its local abundance in Malaysia, most of the information regarding this tick species were published decades ago and little attention has been given to its medical importance and vectorial role.…”