Avibacterium paragallinarum is an avian pathogen that causes the upper respiratory disease Infectious coryza (IC) in chickens. This disease has the ability to cause vast economic losses due to a decrease in egg production. To date the factors contributing to pathogenicity, immunogenicity and serotyping are still not clearly understood.
Vaccine failures are a major problem that occurs due to no or poor cross-protection occurring especially between the C-serovars of A. paragallinarum. This problem will be overcome by having a more accurate serotyping technique available for the diagnosis of IC. Therefore one of the aims of this study was the development of a molecular serotyping technique, where a serotyping PCR was developed which distinguished between the Modesto (C-2) and SA-3 (C-3) A. paragallinarum isolates which is the major cause of IC in South Africa.
Reported in a recently published article was the presence of a HP2-like and Mu-like phage within the genome of the Modesto (C-2) strain of A. paragallinarum. Therefore another major question addressed during this study was whether there are prophage genes present in all of the reference isolates as well as in field isolates of A. paragallinarum and what the effect of these phages might be on the virulence and pathogenicity of these isolates. Phage genes that are important during lysogeny were selected and screened for by means of PCR. From the results it was able to determine that some of these genes are present in some of these isolates but no discernible patterns were detected in terms of the effect on pathogenicity. Therefore future studies will be conducted to mainly focus on the effect these phages might have on the virulence and pathogenicity as well as whether these phages are responsible for the occurrence of different A. paragallinarum serovars.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ufs/oai:etd.uovs.ac.za:etd-08082014-104137 |
| Date | 08 August 2014 |
| Creators | Coetsee, Elke |
| Contributors | Ms CE Boucher, Prof RR Bragg |
| Publisher | University of the Free State |
| Source Sets | South African National ETD Portal |
| Language | en-uk |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.uovs.ac.za//theses/available/etd-08082014-104137/restricted/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University Free State or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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