Comparison of Some Molecular Markers for Tick Species Identification

BACKGROUND: Ticks are obligate blood-sucking ectoparasites of vertebrates. Since many tick identification studies are based on the analysis of 16S rDNA, 12S rDNA and ITS-1, 2 rDNA genes, we aimed to compare the performance of these molecular markers of common use for the identification of ticks, under a diagnostic laboratory environment. METHODS: Overall, 192 tick specimens were collected through the state of Texas from January 2014 to August 2015 and the species was determined by both morphology and molecular amplification using the 16S rDNA, 12S rDNA, ITS1 and ITS2. RESULTS: The species collected were identified by molecular techniques as Dermacentor albipictus, D. variabilis, Amblyomma americanum, Ixodes scapularis, A. cajennense, Rhipicephalus sanguineus and Carios capensis. ITS1 and ITS2 were not able to prove consistent amplification and therefore have been considered as potential markers for tick identification. CONCLUSION: The use of mitochondrial genes in tick identification showed to provide more consistent results in the diagnostic environment.