RESUMO
Passive surveillance of ticks on horses in Saskatchewan revealed that the horses were parasitized by 3 species, Dermacentor albipictus, D. andersoni, and D. variabilis. The nymphs and adults of D. albipictus occurred on horses earlier in the year than did adults of the 2 other species.
Surveillance passive des tiques sur des chevaux en Saskatchewan. Une surveillance passive des tiques chez des chevaux de la Saskatchewan a révélé que les chevaux étaient affectés par des parasites de trois espèces: Dermacentor albipictus, D. andersoni et D. variabilis. Les nymphes et les adultes de D. albipictus se présentaient chez les chevaux plus tôt dans l'année que les adultes des deux autres espèces.(Traduit par Isabelle Vallières).
Assuntos
Doenças dos Cavalos/parasitologia , Ixodes/classificação , Infestações por Carrapato/veterinária , Animais , Doenças dos Cavalos/epidemiologia , Cavalos , Ninfa/classificação , Vigilância da População , Saskatchewan/epidemiologia , Estações do Ano , Especificidade da Espécie , Infestações por Carrapato/diagnóstico , Infestações por Carrapato/epidemiologia , Fatores de TempoRESUMO
It is often difficult to distinguish morphologically between closely related species of fleas (Siphonaptera). Morphological identification of fleas often requires microscopic examination of internal structures in specimens cleared using caustic solutions. This process degrades DNA and/or inhibits DNA extraction from specimens, which limits molecular-based studies on individual fleas and their microbiomes. Our objective was to distinguish between Oropsylla rupestris (Jordan), Oropsylla tuberculata (Baker), Oropsylla bruneri (Baker), and Oropsylla labis (Jordan & Rothschild) (Ceratophyllidae) using PCR-based single strand conformation polymorphism (SSCP) analyses and DNA sequencing. A 446 bp region of the nuclear 28S ribosomal RNA (rRNA) gene was used as the genetic marker. The results obtained for 36 reference specimens (i.e., fleas that were morphologically identified to species) revealed no intraspecific variation in DNA sequence, whereas the DNA sequences of the four species of Oropsylla differed from one another at two to six nucleotide positions. Each flea species also had a unique SSCP banding pattern. SSCP analyses were then used to identify another 84 fleas that had not been identified morphologically. DNA sequencing data confirmed the species identity of fleas subjected to SSCP. This demonstrates that PCR-SSCP combined with DNA sequencing of the 28S rRNA gene is a very effective approach for the delineation of four closely related species of flea.