Characterization of Two Cuban Strains of Rhipicephalus Microplus Ticks

Abstract Background: Rhipicephalus microplus (Canestrini, 1888) is one of the species with medical and economic relevance that had been reported in the list of Cuban tick species. Some morphological characterizations about the R. microplus species in Cuba have been published, however, molecular studies are lacking. Molecular phylogenetic analyses have revealed a common ancestor for R. annulatus , R. australis and three clades of R. microplus within the Boophilus subgenus. These five clades were grouped in a complex named R. microplus . The present study aimed the accurate taxonomic classification of R. microplus tick strains established as colonies in the Cuban National Laboratory of Parasitology. Methods: Morphological characterization of adult specimens from two Cuban strains of the R. microplus ticks were carried out by using Scanning Electron Microscopy. The sequences of three mitochondrial genes: 12S rRNA, 16S rRNA and the subunit I of cytochrome c oxidase gene (COXI) and one nuclear gene: internal transcribed spacer 2 (ITS2) were used for phylogenetic analyses. The life cycle under laboratory conditions for both strains was also characterized. Results: Tick specimens of both strains showed morphologic characteristics which were strongly coincident with those distinctive for the R. microplus species. Phylogenies based on mitochondrial gene sequences identified congruently the Cuban tick strains within the R. microplus clade A together with a Mexican reference strain and tick isolations from Argentina, Bolivia, Brazil, Mozambique, Costa Rica, Panama, Paraguay, Peru, Tanzania, United States, Uruguay and South Africa. Phylogenetic inferences based on nuclear ITS2 sequences also classified both tick strains as belonging to the R. microplus species but did not support the clades A, B and C previously described. The life cycle for both strains under established laboratory conditions averaged 65±5 days and 2422±295 and 2604±304 larvae were obtained for each fully engorged female tick collected from CC and ML strains, respectively. Conclusions: These results placed of Cuban tick strains as Rhipicephalus microplus clade A inside the R. microplus complex. This study constitutes the first molecular characterization of ticks from the R. microplus species in Cuba.