Molecular detection and characterization of spotted fever group <i>Rickettsia</i> and <i>Anaplasma</i> in ticks from Pakistan

The present study was designed to report the prevalence of spotted fever group <i>Rickettsia</i> and <i>Anaplasma</i> in ticks from Pakistan. To address this knowledge gap, ticks were collected from October 2019 to November 2020 from livestock hosts. Three hundred ninety ticks from Punjab, Khyber Pakhtunkhwa and Islamabad were investigated for the presence of <i>Rickettsia</i> and <i>Anaplasma</i>. The collected ticks were subjected to molecular studies for detection and characterization of spotted fever group <i>Rickettsia</i> and <i>Anaplasma</i> in ticks from Pakistan. PCR amplification of the <i>ompA</i> gene was used for detection of <i>Rickettsia</i> and portions of the <i>16S</i> rDNA gene for detection of <i>Anaplasma.</i> Nine species of ticks were tested. Of the 390 ticks tested, 7 (2.58%) ticks were positive for <i>Rickettsia. Rickettsia spp.</i> were detected in <i>Haemaphysalis punctata, Hyalomma anatolicum, Hyalomma scupense, Rhipicephalus microplus</i> and <i>Rhipicephalus sanguineus.</i> Unknown <i>Rickettsia</i> was detected in <i>Hy. scupense</i>. Fifty-seven (14.6%) ticks were also positive for <i>Anaplasma spp. Anaplasma ovis</i> was detected in <i>Hy. anatolicum, Hy. scupense, Hy. excavatum, Rhipicephalus decoloratus, R. microplus and R. sanguineus. Anaplasma marginale</i> was detected in <i>Hy. anatolicum, Hy. scupense, R. microplus, R. decoloratus</i> and <i>R. sanguineus</i>. The <i>Anaplasma</i> sequences obtained from this experiment were 99-100% similar to those of the documented strains. This study provides information and confirms the presence of spotted fever group <i>Rickettsia</i> and <i>Anaplasma spp.</i> in different tick species. It also highlights the need for control programs to prevent health risks. Further investigation to determine the prevalence and disease burden of these pathogens in Pakistan is necessary.