Molecular screening of Anaplasma, Ehrlichia, and Brucella in ticks (Acari: Ixodidae) infesting farm ruminants in Peninsular Malaysia.

Abstract

Ticks are obligate hematophagous arachnids that parasitize both humans and animals. While considerable research in Malaysia has focused on bacterial detection in ticks, knowledge of tick-borne Anaplasma, Ehrlichia and Brucella in farm ruminants remains limited. In this study, 1,241 ticks comprising of four species (Rhipicephalus microplus, Rhipicephalus haemaphysaloides, Haemaphysalis bispinosa, and Haemaphysalis wellingtoni) were collected from 674 farm ruminants across Peninsular Malaysia. The ticks were pooled and molecularly screened for Anaplasma and Ehrlichia using 16S rRNA gene primers, and Brucella using the BSCP31 gene primer. Out of 130 tick pools, five (3.85%) tested positive for Anaplasma and two (1.54%) for Ehrlichia. No Brucella DNA was detected in all four tick species. All positive pools consisted exclusively of R. microplus, with no pathogens identified in the other three tick species. BLAST analysis revealed that the Anaplasma sequences were identical to Anaplasma marginale, A. platys, and Candidatus "Anaplasma boleense", while the Ehrlichia sequences were identical to Ehrlichia ewingii. This study represents the first screening for Anaplasma, Ehrlichia, and Brucella in ticks infesting farm ruminants in Peninsular Malaysia.