Survey of tick-borne pathogens in Rhipicephalus microplus ticks from livestock in the Northern Punjab Province, Pakistan

Ticks are worldwide distributed hematophagous ectoparasites that can act as vectors of numerous zoonotic pathogens of concern for human and veterinary health. In this study, we investigated the presence and abundance of bacterial and protozoan tick-borne pathogens in livestock-associated ticks from Northern Punjab, Pakistan. A total of 374 ticks were collected by convenience sampling in 40 villages and were morphologically and molecularly characterized, with all of them being identified as <i>Rhipicephalus microplus</i>. Out of 121 adult female ticks that were tested by PCR, 57 (47.1%) were positive for <i>Ehrlichia canis</i>, 16 (13.2%) for <i>Anaplasma marginale</i>, 13 (10.7%) for <i>Theileria orientalis</i>, 3 (2.5%) for <i>Ehrlichia muris</i>, and none for <i>Rickettsia</i> spp. Phylogenetic analyses indicated a high proximity of the newly characterized pathogens with conspecifics from other countries, thus suggesting possible recent long-distance spread of ticks and tick-borne pathogens. Moreover, the investigated pathogens showed seasonal variations in ticks, being more abundant during summer. The higher temperature and lower humidity of this season may represent favourable conditions for tick and pathogen survival and spread. The present findings provide an updated report of the distribution of ticks and tick-borne pathogens associated with livestock in Punjab. This highlights the need for further research to monitor the presence and dissemination of these pathogens, and to develop local and general epidemiological control strategies.