Molecular detection of spotted fever group rickettsia in ixodid ticks from Pakistan

Background: Ticks are vectors for several species of spotted fever group rickettsiae (SFGR), which can be transmitted to vertebrate host during blood meals. In this study the prevalence of SFG Rickettsia occurring within Pakistani ticks was examined.

Methodology/Principal Findings: Ticks (n=574) were collected from different host from five provinces in Pakistan including Sindh, Punjab, Kashmir, Northern region, and Baluchistan. The ticks were identified and samples were screened for SFGR by molecular detection using outer membrane protein (OmpA). Further validation of SFGR positive samples species confirmed with the amplification of citrate synthase (gltA) and a 17kDa (hrtA).  A variety of tick genera were sampled including Hyalomma, Haemaphysalis, and Rhipicephalus. Positive samples have been subjected to BLAST analysis and were submitted to GenBank. Sequence identity has revealed homology to a variety of Rickettsial species such as Rickettsia africae, Rickettsia conorii, and many other Rickettsial endosymbionts.

Conclusion/Significance:  These results demonstrated the prevalence of SFGR associated with ticks collected from Pakistan.  Additionally, the detection of SFGR in Ixodid ticks is important for future studies to test the infection in humans.