Thesis (MSc)--University of Stellenbosch, 2006. / ENGLISH ABSTRACT: Ostrich farming is of significant economical importance in South Africa. Three ostrich mycoplasmas,
Ms01, Ms02 and Ms03 have been identified previously, and were provisionally named ‘Mycoplasma
struthiolus’ (Ms) after their host Struthio camelus. Ostrich mycoplasmas are the major causative
organisms of respiratory diseases, and they cause stock losses, reduced production and
hatchability, and downgrading of carcasses and therefore lead to large economic losses to the
industry. In order to be pathogenic to their host, they need to attach through an attachment
organelle, the so-called tip structure. This structure has been identified in the poultry mycoplasma,
M. gallisepticum, and is made up of the adhesin GapA and adhesin-related CrmA. Currently, no
ostrich mycoplasma vaccine is commercially available and for this reason the need to develop one
has arisen. Therefore the first part of this study was dedicated to the identification and isolation of
vaccine candidate genes in the three ostrich mycoplasmas. Four primer approaches for polymerase
chain reactions (PCR’s), cloning and sequencing, were used for the identification of adhesin or
adhesin-related genes from Ms01, Ms02 and Ms03. The primer approaches revealed that the target
genes could not be identified due to the high diversity of sequences that were generated. Therefore
sequences were also compared with those of other mycoplasma species in BLAST searches.
Results showed that the most significant hit was with the human pathogen M. hominis oppD, which
is located in the same operon as the membrane protein P100 involved in adhesion. Other hits were
with ABC transporters which may also play a role in cytadhesion.
The second part of this study was aimed at testing whether two poultry mycoplasma vaccines, M.
synoviae and M. gallisepticum, can be used in ostriches to elicit immune responses until an ostrich
mycoplasma vaccine has been developed. Ostriches on three farms of different age groups in the
Oudsthoorn district were therefore vaccinated with these vaccines in a vaccine trial. The enzymelinked
immunosorbent assay (ELISA) was used to test the level of antibody response. Results
showed that both vaccines elicited an immune response in all three age groups. A high percentage
of the ostriches reacted positively, which indicates that both vaccines elicit antibody responses and
may therefore give protection against ostrich mycoplasma infections. / AFRIKAANSE OPSOMMING: Volstruisboerdery is ‘n belangrike ekonomiese sektor in Suid-Afrika. Drie volstruismikoplasmas,
Ms01, Ms02 en Ms03, is voorheen geïdentifiseer en voorlopig ‘Mycoplasma struthiolus’ (Ms)
benaam na aanleiding van hul gasheer, Struthio camelus. Volstruismikoplasmas is die grootste
oorsaaklike organismes van respiratoriese siektes, kudde verliese en die afgradering van karkasse
wat lei tot groot ekonomiese verliese in die volstruisbedryf. Ten einde patogenies vir die gasheer te
wees, moet mikoplasmas deur middel van ‘n aanhegtingsmeganisme vasheg – die sogenaamde
puntvormige struktuur. Hierdie struktuur is in die pluimvee mikoplasma M. gallisepticum
geïdentifiseer, en bestaan uit aanhegting proteïen GapA en die aanhegting verwante proteïen
CrmA. Tans is geen volstruismikoplasma entstof kommersieel beskikbaar nie, en derhalwe het die
behoefte ontstaan om so ‘n entstof te ontwikkel. Die eerste gedeelte van hierdie studie is dus gewy
aan die identifisering en isolering van entstof kandidaat gene in al drie volstruismikoplasmas. Vier
inleier benaderings vir polimerase ketting reaksies (PKR), klonering asook geenopeenvolging
bepalings vir die identifisering van aanhegting of aanhegting verwante gene vanuit Ms01, Ms02 en
Ms03 is gebruik. Die inleier benaderings het getoon dat die teikengene nie geïdentifiseer kon word
nie as gevolg van hoë variasie in die gegenereerde geenopeenvolgings. Derhalwe is
geenopeenvolgings met ander mikoplasma spesies deur middel van BLAST soektogte vergelyk.
Resultate het getoon dat die betekenisvolste ooreenstemming dié met die menslike patogeen M.
hominis oppD was, wat deel vorm van die membraan proteïen P100 operon wat betrokke is by
aanhegting. Ander ooreenstemmings sluit ABC transporters in wat moontlik betrokke kan wees by
aanhegting.
Die tweede gedeelte van hierdie studie het ten doel gehad om te toets of twee pluimvee
mikoplasma entstowwe, M. synoviae en M. gallisepticum, gebruik kan word in volstruise om
immuunresponse te ontlok tot tyd en wyl ‘n volstruismikoplasma entstof ontwikkel is. Volstruise
vanaf drie plase in verskillende ouderdomsgroepe in die Oudtshoorn distrik was ingeënt met hierdie
entstowwe in ‘n entstof proefneming. Die ensiem-afhanklike immuno-absorpsie essaï (ELISA) was
gebruik om antiliggaam response te toets. Die resultate het getoon dat beide entstowwe
immuunresponse ontlok het in al drie ouderdomsgroepe. ‘n Groot persentasie van die volstruise het
positief gereageer wat ‘n aanduiding is dat beide entstowwe immuunresponse ontlok het en kan
dus beskerming bied teen volstruismikoplasma infeksies.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/17411 |
| Date | 12 1900 |
| Creators | Van der Merwe, Elizabeth Frances |
| Contributors | Bellstedt, D.U., Stellenbosch University. Faculty of Science. Dept. of Biochemistry. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
| Format | xii, 136 leaves : ill. (some col.) |
| Rights | Stellenbosch University |
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