Cattle lice are obligatory blood-sucking parasites, which is the cause of animal health problems worldwide. Recently, several studies have revealed that pathogenic bacteria could be found in cattle lice, and it can act as a potential vector for transmitting louse-borne diseases. However, the cattle lice and their pathogenic bacteria in Thailand have never been evaluated. In the present study, we aim to determine the presence of bacterial pathogens in cattle lice collected from three localities of Thailand. Total genomic DNA was extracted from 109 cattle louse samples and the Polymerase Chain Reaction (PCR) of 18S rRNA was developed to identify the cattle louse. Moreover, PCR was used for screening Bartonella spp., Acinetobacter spp., and Rickettsia spp. in cattle louse samples. The positive PCR products were cloned and sequenced. The phylogenetic tree based on the partial 18S rRNA sequences demonstrated that cattle lice species in this study are classified into two groups according to reference sequences; Haematopinus quadripertusus and Haematopinus spp. closely related to H. tuberculatus. The pathogen detection revealed that Bartonella spp. DNA of gltA and rpoB were detected in 25 of 109 samples (22.93%) both egg and adult stages, whereas Acinetobacter spp. and Rickettsia spp. were not detected in all cattle lice DNA samples. The gltA and rpoB sequences showed that the Bartonella spp. DNA was found in both H. quadripertusus and Haematopinus spp. closely related to H. tuberculatus. This study is the first report of the Bartonella spp. detected in cattle lice from Thailand. The finding obtained from this study could be used to determine whether the cattle lice can serve as a potential vector to transmit these pathogenic bacteria among cattle and may affect animal to human health.
Keywords: 18S rRNA; Bartonella spp.; Thailand; cattle louse; gltA; rpoB.