Evaluation of DNA vaccines developed against Mycoplasma struthionis sp. nov. str. Ms01 in ostriches

De Wet, Bertus (2016-03)

Thesis (MSc)--Stellenbosch University, 2016.

Thesis

ENGLISH ABSTRACT: The vast demand for ostrich meat has made South Africa the leader in not only the production of ostrich meat but also ostrich associated products such as feathers and leather. Ostrich specific mycoplasmas (referred to as Ms01, Ms02 and Ms03) cause respiratory tract infections with subsequent reduction in physical growth rate and therefore reduced production. To date no vaccines are available to combat these infections in ostriches. In this laboratory three DNA vaccines (pCI-neo, VR1012 and VR1020) have been developed with each containing the Ms01 oppA gene as antigen. The aim of this study was to evaluate these developed DNA vaccines in a mammalian cell culture based system as well as an ostrich vaccination trial. COS-1 cells were transfected with the three developed DNA vaccines. Transcription of the oppA gene was proven for all the plasmids. Translation into the OppA protein was shown to be limited to the VR1020_oppA plasmid. The protein was visualised by SDS-PAGE and detected by western blot using chemiluminescence. Two of the vaccines, VR1020_oppA and pCI-neo_oppA, were administered in three concentrations (100 μg/ml, 300 μg/ml and 600 μg/ml) to ostriches during a vaccination trial followed by a booster injection. The ability of the vaccines to elicit anti-OppA antibodies was measured using ELISA. The pCI-neo_oppA vaccine failed to induce an immune response against the antigen after both the first and booster vaccinations. The VR1020_oppA vaccine on the other hand was able to elicit an anti-OppA immune response.

AFRIKAANSE OPSOMMING: Die groot aanvraag vir volstruisvleis het Suid-Afrika die leier in nie net die produksie van volstruisvleis nie, maar ook volstruis-geassosieerde produkte soos vere en leer gemaak. Volstruis-spesifieke mikoplasmas (verwys na as Ms01, Ms02 en Ms03) veroorsaak lugweginfeksies wat lei tot ‘n afname in fisiese groei tempo en gevolglike daling in produksie. Tot op hede is daar geen entstowwe beskikbaar om hierdie infeksies in volstruise te bekamp nie. In hierdie laboratorium is drie DNS-entstowwe (pCI-neo, VR1012 en VR1020) ontwikkel wat elk die Ms01 oppA geen bevat as antigeen. Die doel van hierdie studie was om hierdie DNS-entstowwe in 'n selkultuur-gebaseerde sisteem, sowel as 'n volstruis inentingproef te evalueer. COS-1-selle was getransfekteer met die drie DNS-entstowwe. Transkripsie van die oppA geen is bewys vir al die plasmiede. Translasie na die OppA proteïen was getoon, maar was beperk tot die VR1020_oppA plasmied. Die protein was gevisualiseer deur middel van SDS-PAGE en opgespoor deur middel van western-klad met behulp van chemiluminessensie. Twee van die entstowwe, VR1020_oppA en pCI-neo_oppA, was toegedien in drie konsentrasies (100 μg/ml, 300 μg/ml en 600 μg/ml) in volstruise tydens 'n inentingsproef, gevolg deur 'n skraagdosis. Die vermoë van die entstowwe om anti-OppA teenliggame te ontlok is gemeet deur middel van ELISA. Die pCI-neo_oppA entstof was nie daartoe in staat om na beide die eerste en skraag inentings 'n immuunrespons teen die antigeen te induseer nie. Die VR1020_oppA entstof daarenteen, was daartoe in staat om 'n anti-OppA immuunrespons te ontlok.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/98280
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