First report of Providencia rettgeri, Colpodella spp., Ehrlichia spp., and Rickettsia hoogstraalii in ticks infesting goats of Pakistan

Ticks are the second most important vector of infectious diseases, after mosquitoes, and can transmit several diseases of concern for both human and veterinary health. This study molecularly barcoded ticks collected from goats in Pakistan and screened for associated pathogens. From July 2023 to June 2024, examination of 253 goats (Capra hircus) in the 7th district of Khyber Pakhtunkhwa found 170 goats infested with 1,305 ticks, equating to a mean abundance of 5.15 ticks per goat. A phenol-chloroform technique was used to extract DNA and subsequently amplify the presence of pathogen DNA targeting 16S, 18S gltA, and ompA genes. Tick DNA was also amplified for the molecular confirmation of species using 12S rDNA partial sequence. All collected ticks were identified morphologically and molecularly as Haemaphysalis Punctata (519), Hyalomma anatolicum (380), Hae. sulcata (269), and Hy. excavatum (137), including 361 females, 323 males, 286 larvae and 198 nymphs. This study detected several tick-borne pathogens including Colpodella spp., Ehrlichia spp. and Rickettsia hoogstraalii, as well as detecting the bacteria Providencia rettgeri. Rickettsia hoogstraalii was found in Haemaphysalis punctata collected from Karak District. In contrast, Hy. excavatum from Banuu district were found to carry P. rettgeri. Hyalomma excavatum infesting goats in Buner, Chitral, and Hy. anatolicum form Kohistan, District tested positive only for Colpodella spp. whereas a single species of uncultured Ehrlichia spp. was found in Hae. sulcata collected from Mansehra, and Lakki Marawat district. This research's novel report of human pathogenic microbes detected in ticks has implications for livestock and human health, as well as the role ticks potentially play in zoonotic disease transmission in Pakistan.