Kakaire, Dr. Michael (1997) Development of A Latex Slide Agglutination Test and its use for Serodiagnosis of Heart Water (Cowdria Ruminantium Infection ) In Small Ruminants. PhD thesis, University of Nairobi.
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PDF (Development Of A Latex Slide Agglutination Test And Its Use For Serodiagnosis of Heartwater (Cowdria Ruminantium Infection ) In Small Ruminants)
KAKAIRE M. N. M.SC._VET. PATH. AND MICROB._1997.pdf - Accepted Version Restricted to Repository staff only Download (2MB) | Request a copy |
Abstract
Heartwater is a febrile tick-borne disease of domestic and wild ruminants. The serological tests, for example, 1FAT, ELISA and nucleic acid based tests which are currently used for diagnosis of heartwater require sophisticated laboratory equipment and trained personnel to be performed and are therefore not suitable for routine field use. This means that there is need for a simple rapid and specific test that can be used in the field for routine diagnosis of heartwater.The possibility of detecting C. ruminantium antibodies and antigens circulating in sera and plasma of experimentally infected goats, using latex beads coated with crude Cowdria antigen (latex slide agglutination antibody test) and latex beads coated with anti-MAP2 immunoglobulin fraction (latex slide agglutination antigen test) was investigated. The crude Cowdria antigen was prepared from C. ruminantium organisms cultivated in bovine pulmonary artery endothelial cells (BPA). The anti- MAP2 immunoglobulin fraction was precipitated by use of 50% saturated ammonium sulphate solution from sera obtained from rabbits which had been immunised with recombinant Cowdria MAP2 antigen. Sera and plasma collected from experimentally infected goats were tested for Cowdria antibodies and antigen respectively. Four sera from goats that sutfered an acute and fatal heartwater disease tested negative for Cowdria antibodies, using latex agglutination antibody test based on whole Cowdria antigen, while 2 sera from goats that suffered a non-acute and non-fatal disease started testing positive for Cowdna antibodies during the 6**1 week after inoculation. In addition latex beads were coated with recombinant Cowdria MAP2 antigen and used to test 81 random field goat serum samples for Cowdria antibodies Of the 81 random field goat serum samples tested, 19 (23.4 %) were positive, 11 (13.6 %) weak positive (border line) and 51 were negative. It was not possible to detect Cowdria antigen in plasma of the infected goats with the Latex slide agglutination antigen test. The latex slide agglutination antigen test failed to detect Cowdna antigen in the plasma of the sick goats probably because of either low rickettsemia, low levels qf MAP2 from lysed elementary bodies (EBs) in circulation, coating of circulating EBs with host proteins or the Latex slide agglutination antigen test was not sensitive enough. In addition, failure to detect elementary bodies could be attributed to the fact that MAP2 is an internal and not an integral membrane protein as was demonstrated by the phase partitioning of MAP2 in the aqueous phase. Therefore, MAP2 in the intact elementary bodies was inaccessible to the monospecific rabbit anti-MAP2 antibodies. To test this hypothesis, intact and solubilized elementary bodies were examined by use of latex beads coated with rabbit anti-MAP2 antibodies. A weak agglutination reaction was observed with the solubilized elementary bodies and no agglutination was observed with the intact elementary bodies, thus indicating that solubilization of elementary bodies exposed epitopes recognised by the rabbit anti-MAP2 antibodies.In the present study, sensitivity and specificity parameters of the latex slide agglutination antibody test were not investigated, but it was demonstrated that the latex slide agglutination antibody test is a potential diagnostic tool for detection of C. rummantium antibodies in sera of animals that suffer a non-acute and non-fatal heartwater disease. However, there is need to identity a specific Cowdria surface protein to which antibodies can be raised and coated on latex beads to be able to detect Cowdria antigen in the plasma of sick animals.
| Item Type: | Thesis (PhD) |
|---|---|
| Subjects: | Q Science > QR Microbiology S Agriculture > SF Animal culture |
| Divisions: | Africana |
| Depositing User: | Geoffrey Obatsa |
| Date Deposited: | 27 Sep 2016 09:43 |
| Last Modified: | 24 Oct 2016 14:04 |
| URI: | http://thesisbank.jhia.ac.ke/id/eprint/1092 |
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