Ticks and tick-borne pathogens in ruminant farms of Peninsular Malaysia: First molecular evidence of Borrelia theileri in Rhipicephalus microplus (Acari: Ixodidae).

To shed light on the importance of tick-borne diseases, especially in farm animals that often contact with farm workers, this study aimed to identify ticks and tick-borne pathogens in ruminants in Malaysia. Accordingly, specimen collection was conducted across Peninsular Malaysia yielded a total of 1241 ticks collected from 674 farm ruminants. Among these, four tick species were identified, with Rhipicephalus microplus being the most prevalent, constituting 99.03 % of the total tick population. Analysis of 130 tick pools revealed three positives for Borrelia. BLAST analyses of the flaB and 16S rRNA genes revealed high similarities to Borrelia theileri, ranging from 98.78 to 100 % for flaB and 99.23–99.45 % for 16S rRNA. These results align with the phylogenetic trees, where sequences from both genes clustered together with B. theileri, further supporting this identification. No Rickettsia and Bartonella bacteria were detected. This study represents the first occurrence of B. theileri in R. microplus in Malaysia.