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. 1993 Feb;110(1):95–104. doi: 10.1017/s095026880005072x

Detection of Cowdria ruminantium by means of a DNA probe, pCS20 in infected bont ticks, Amblyomma hebraeum, the major vector of heartwater in southern Africa.

C E Yunker 1, S M Mahan 1, S D Waghela 1, T C McGuire 1, F R Rurangirwa 1, A F Barbet 1, L A Wassink 1
PMCID: PMC2271963  PMID: 8432329

Abstract

A DNA probe, pCS20, previously described for use in detection of Cowdria ruminantium infections in Amblyomma variegatum (the principal vector of heartwater) hybridized with C. ruminantium DNA in organs of laboratory-infected A. hebraeum adult ticks (the major southern African vector of heartwater). The probe hybridized with C. ruminantium DNA in 46/49 midguts from male ticks and 26/29 from females, thus indicating infection. Corresponding salivary glands were less heavily infected, but infections were more numerous in glands from males. Infection in ticks was confirmed by transmission of the disease to susceptible goats. The probe did not hybridize with DNA from uninfected ticks or with DNA from a spotted fever group rickettsia commonly associated with A. hebraeum in Zimbabwe. The C. ruminantium specific pCS20 DNA probe can be applied to determine accurately the infection rates in the two major vectors of heartwater and the risk of exposure of ruminants in endemic areas.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Byrom B., Yunker C. E. Improved culture conditions for Cowdria ruminantium (Rickettsiales), the agent of heartwater disease of domestic ruminants. Cytotechnology. 1990 Nov;4(3):285–290. doi: 10.1007/BF00563789. [DOI] [PubMed] [Google Scholar]
  2. Du Plessis J. L. A method for determining the Cowdria ruminantium infection rate of Amblyomma hebraeum: effects in mice injected with tick homogenates. Onderstepoort J Vet Res. 1985 Jun;52(2):55–61. [PubMed] [Google Scholar]
  3. Friedhoff K. T. Interaction between parasite and tick vector. Int J Parasitol. 1990 Jul;20(4):525–535. doi: 10.1016/0020-7519(90)90200-7. [DOI] [PubMed] [Google Scholar]
  4. Kelly P. J., Mason P. R. Transmission of a spotted fever group rickettsia by Amblyomma hebraeum (Acari: Ixodidae). J Med Entomol. 1991 Sep;28(5):598–600. doi: 10.1093/jmedent/28.5.598. [DOI] [PubMed] [Google Scholar]
  5. Kocan K. M., Bezuidenhout J. D. Morphology and development of Cowdria ruminantium in Amblyomma ticks. Onderstepoort J Vet Res. 1987 Sep;54(3):177–182. [PubMed] [Google Scholar]
  6. Mahan S. M., Waghela S. D., McGuire T. C., Rurangirwa F. R., Wassink L. A., Barbet A. F. A cloned DNA probe for Cowdria ruminantium hybridizes with eight heartwater strains and detects infected sheep. J Clin Microbiol. 1992 Apr;30(4):981–986. doi: 10.1128/jcm.30.4.981-986.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Norval R. A., Andrew H. R., Yunker C. E. Infection rates with Cowdria ruminantium of nymphs and adults of the bont tick Amblyomma hebraeum collected in the field in Zimbabwe. Vet Parasitol. 1990 Jul;36(3-4):277–283. doi: 10.1016/0304-4017(90)90039-e. [DOI] [PubMed] [Google Scholar]
  8. Oberem P. T., Bezuidenhout J. D. Heartwater in hosts other than domestic ruminants. Onderstepoort J Vet Res. 1987 Sep;54(3):271–275. [PubMed] [Google Scholar]
  9. Provost A., Bezuidenhout J. D. The historical background and global importance of heartwater. Onderstepoort J Vet Res. 1987 Sep;54(3):165–169. [PubMed] [Google Scholar]
  10. Synge B. A. Brain biopsy for the diagnosis of heartwater. Trop Anim Health Prod. 1978 Feb;10(1):45–48. doi: 10.1007/BF02235303. [DOI] [PubMed] [Google Scholar]
  11. Uilenberg G. Experimental transmission of Cowdria ruminantium by the Gulf coast tick Amblyomma maculatum: danger of introducing heartwater and benign African theileriasis onto the American mainland. Am J Vet Res. 1982 Jul;43(7):1279–1282. [PubMed] [Google Scholar]
  12. Uilenberg G. Heartwater (Cowdria ruminantium infection): current status. Adv Vet Sci Comp Med. 1983;27:427–480. [PubMed] [Google Scholar]
  13. Van de Pypekamp H. E., Prozesky L. Heartwater. An overview of the clinical signs, susceptibility and differential diagnoses of the disease in domestic ruminants. Onderstepoort J Vet Res. 1987 Sep;54(3):263–266. [PubMed] [Google Scholar]
  14. Waghela S. D., Rurangirwa F. R., Mahan S. M., Yunker C. E., Crawford T. B., Barbet A. F., Burridge M. J., McGuire T. C. A cloned DNA probe identifies Cowdria ruminantium in Amblyomma variegatum ticks. J Clin Microbiol. 1991 Nov;29(11):2571–2577. doi: 10.1128/jcm.29.11.2571-2577.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Walker J. B., Olwage A. The tick vectors of Cowdria ruminantium (Ixodoidea, Ixodidae, genus Amblyomma) and their distribution. Onderstepoort J Vet Res. 1987 Sep;54(3):353–379. [PubMed] [Google Scholar]
  16. Yunker C. E., Kocan K. M., Norval R. A., Burridge M. J. Distinctive staining of colonies of Cowdria ruminantium in midguts of Amblyomma hebraeum. Onderstepoort J Vet Res. 1987 Sep;54(3):183–185. [PubMed] [Google Scholar]

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