Quantification of Theileria parva in Rhipicephalus appendiculatus (Acari: Ixodidae) Confirms differences in infection between selected tick strains
Theileria parva is the etiologic agent of East Coast fever, an economically important disease of cattle in sub-Saharan Africa. This protozoan parasite is biologically transmitted by Rhipicephalus appendiculatus (Neumann) (Acari: Ixodidae). An understanding of the vector—parasite interaction may aid...
| Autores principales: | , , , , , |
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| Formato: | Journal Article |
| Lenguaje: | Inglés |
| Publicado: |
Oxford University Press
2009
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| Materias: | |
| Acceso en línea: | https://hdl.handle.net/10568/307 |
| _version_ | 1855532713692364800 |
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| author | Odongo, David O. Ueti, M.W. Mwaura, S.N. Knowles, Donald P. Bishop, Richard P. Scoles, Glen A. |
| author_browse | Bishop, Richard P. Knowles, Donald P. Mwaura, S.N. Odongo, David O. Scoles, Glen A. Ueti, M.W. |
| author_facet | Odongo, David O. Ueti, M.W. Mwaura, S.N. Knowles, Donald P. Bishop, Richard P. Scoles, Glen A. |
| author_sort | Odongo, David O. |
| collection | Repository of Agricultural Research Outputs (CGSpace) |
| description | Theileria parva is the etiologic agent of East Coast fever, an economically important disease of cattle in sub-Saharan Africa. This protozoan parasite is biologically transmitted by Rhipicephalus appendiculatus (Neumann) (Acari: Ixodidae). An understanding of the vector—parasite interaction may aid the development of improved methods for controlling transmission. We developed quantitative polymerase chain reaction (qPCR) and nested PCR (nPCR) assays targeting the T. parva-specific p104 gene to study T. parva pathogenesis in two strains of R. appendiculatus that had previously been selected to be relatively more (Kiambu) or less (Muguga) susceptible to infection. Nymphs from both strains were fed simultaneously to repletion on acutely infected calves. Nymphs from the Kiambu strain showed significantly higher engorgement weights compared with Muguga strain nymphs. Immediately after engorgement qPCR confirmed that nymphal Kiambu ticks had significantly higher parasite loads at repletion than Muguga nymphs. By 12 d postengorgement, parasites were below quantifiable levels but could be detected by nPCR in 83–87% (Muguga and Kiambu, respectively) of nymphs. After the molt, adult feeding on naïve cattle stimulated parasite replication in the salivary glands. PCR detected significantly more infected ticks than microscopy, and there was a significant difference between the two tick strains both in the proportion of ticks that develop salivary gland infections, and in the number of parasites within infected salivary glands. These data confirm that although both tick strains were competent vectors, Kiambu is both a significantly more susceptible and a more efficient host for T. parva than Muguga. The mechanisms that contribute to the levels of susceptibility and efficiency are unknown; however, this study lays the groundwork for a comparison of the transcriptome of these tick strains, the next step toward discovering the genes involved in the tick-parasite interaction. |
| format | Journal Article |
| id | CGSpace307 |
| institution | CGIAR Consortium |
| language | Inglés |
| publishDate | 2009 |
| publishDateRange | 2009 |
| publishDateSort | 2009 |
| publisher | Oxford University Press |
| publisherStr | Oxford University Press |
| record_format | dspace |
| spelling | CGSpace3072023-12-08T19:36:04Z Quantification of Theileria parva in Rhipicephalus appendiculatus (Acari: Ixodidae) Confirms differences in infection between selected tick strains Odongo, David O. Ueti, M.W. Mwaura, S.N. Knowles, Donald P. Bishop, Richard P. Scoles, Glen A. theileria parva rhipicephalus appendiculatus Theileria parva is the etiologic agent of East Coast fever, an economically important disease of cattle in sub-Saharan Africa. This protozoan parasite is biologically transmitted by Rhipicephalus appendiculatus (Neumann) (Acari: Ixodidae). An understanding of the vector—parasite interaction may aid the development of improved methods for controlling transmission. We developed quantitative polymerase chain reaction (qPCR) and nested PCR (nPCR) assays targeting the T. parva-specific p104 gene to study T. parva pathogenesis in two strains of R. appendiculatus that had previously been selected to be relatively more (Kiambu) or less (Muguga) susceptible to infection. Nymphs from both strains were fed simultaneously to repletion on acutely infected calves. Nymphs from the Kiambu strain showed significantly higher engorgement weights compared with Muguga strain nymphs. Immediately after engorgement qPCR confirmed that nymphal Kiambu ticks had significantly higher parasite loads at repletion than Muguga nymphs. By 12 d postengorgement, parasites were below quantifiable levels but could be detected by nPCR in 83–87% (Muguga and Kiambu, respectively) of nymphs. After the molt, adult feeding on naïve cattle stimulated parasite replication in the salivary glands. PCR detected significantly more infected ticks than microscopy, and there was a significant difference between the two tick strains both in the proportion of ticks that develop salivary gland infections, and in the number of parasites within infected salivary glands. These data confirm that although both tick strains were competent vectors, Kiambu is both a significantly more susceptible and a more efficient host for T. parva than Muguga. The mechanisms that contribute to the levels of susceptibility and efficiency are unknown; however, this study lays the groundwork for a comparison of the transcriptome of these tick strains, the next step toward discovering the genes involved in the tick-parasite interaction. 2009-07-01 2009-12-30T08:59:06Z 2009-12-30T08:59:06Z Journal Article https://hdl.handle.net/10568/307 en Open Access Oxford University Press Odongo, D.O.; Ueti, M.W.; Mwaura, S.N.; Knowles, D.P.; Bishop, R.P.; Scoles, G.A. 2009. Quantification of Theileria parva in Rhipicephalus appendiculatus (Acari: Ixodidae) Confirms differences in infection between selected tick strains. Journal of Medical Entomology. v. 46(4). p. 888-894. |
| spellingShingle | theileria parva rhipicephalus appendiculatus Odongo, David O. Ueti, M.W. Mwaura, S.N. Knowles, Donald P. Bishop, Richard P. Scoles, Glen A. Quantification of Theileria parva in Rhipicephalus appendiculatus (Acari: Ixodidae) Confirms differences in infection between selected tick strains |
| title | Quantification of Theileria parva in Rhipicephalus appendiculatus (Acari: Ixodidae) Confirms differences in infection between selected tick strains |
| title_full | Quantification of Theileria parva in Rhipicephalus appendiculatus (Acari: Ixodidae) Confirms differences in infection between selected tick strains |
| title_fullStr | Quantification of Theileria parva in Rhipicephalus appendiculatus (Acari: Ixodidae) Confirms differences in infection between selected tick strains |
| title_full_unstemmed | Quantification of Theileria parva in Rhipicephalus appendiculatus (Acari: Ixodidae) Confirms differences in infection between selected tick strains |
| title_short | Quantification of Theileria parva in Rhipicephalus appendiculatus (Acari: Ixodidae) Confirms differences in infection between selected tick strains |
| title_sort | quantification of theileria parva in rhipicephalus appendiculatus acari ixodidae confirms differences in infection between selected tick strains |
| topic | theileria parva rhipicephalus appendiculatus |
| url | https://hdl.handle.net/10568/307 |
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