Tick control on livestock relies principally on the use of acaricides but the development of acaricide resistance and concerns for environmental pollution underscore the need for alternative control methods, for instance through the use of anti-tick vaccines. Two commercial vaccines based on the recombinant Bm86 protein from Rhipicephalus Boophilus microplus ticks were developed. Partial protection of the Bm86 vaccine against other Rhipicephalus Boophilus and Hyalomma tick species suggests that the efficacy of a Bmbased vaccine may be enhanced when based on the orthologous recombinant Bm86 antigen.
We therefore identified and analysed the Bm86 homologues from species representing the main argasid and ixodid tick genera, including two from the prostriate Ixodes ricinus tick species. This second protein was named ATAQ after a part of its signature peptide. Quantitative reverse transcriptase-PCR showed that ATAQ proteins are expressed in both midguts and Malpighian tubules, in contrast to Bm86 orthologues which are expressed exclusively in tick midguts.
Furthermore, expression of this protein over the life stages of R. The vaccine potential of ATAQ proteins against tick infestations is yet to be evaluated. Ticks are obligate hematophagous ectoparasites which can be divided into three families.
The hard ticks or Ixodidae form the largest family which can be further subdivided into two groups, the basal Prostriata which consists of the genus Ixodes , and the more recent genera of the Metastriata. The soft ticks or Argasidae form a smaller family which is considered to be more basal than the Ixodidae. The third family, the Nuttalliellidae, is monotypic Nava et al.
The damage caused by ticks has considerable economic impact, in particular in the tropics and subtropics Jongejan and Uilenberg, Control of ticks worldwide relies principally on the use of acaricides but concerns about environmental pollution, residues in food products and the development of acaricide resistance have resulted in the search for alternative means of tick control such as anti-tick vaccines.
