Page 44 - VHSA - Onderstepoort 100 Years - Part 1

ONDERSTEPOORT 100
When Cameron left the Institute in 1985, B.J. Erasmus was tasked with the supervision of the vaccine factory in his stead.
Bigalke first became aware of the impact of the discovery of the ‘double helix’ structure of DNA by Watson and Crick in 1953 when he was attending the post-graduate course at the London School of Hygiene and Tropical Medicine mentioned above in 1963/64. He was exposed to the excellent research climate that existed at that institution and was able to superficially acquaint himself with the basic principles of this quantum leap discovery.
As did his predecessors, Jansen and Weiss,
he supported the initiative of Verwoerd
– who would succeed him as director – to
apply molecular biological techniques to
microbiological research and to appoint
and capacitate the manpower required
to empower the discipline. The Institute
thereby acquired a formidable team of
young molecular biologists who were
attracted by Verwoerd’s obvious expertise
and excellent reputation. Names such as H.
(Henk) Huismans, A.A. (Albie) van Dijk, D.F.
(Dennis) York, and G.J. (Gerrit) Viljoen come
to mind. Use of transmission and scanning
electron microscopes, introduced during the
time when Jansen and Weiss were directors,
was also becoming a routine procedure.
Research on the bluetongue virus (BTV) provided considerable excitement when Huismans and co-workers successfully cloned and sequenced genome segments of the
44 virus in 1987 and found that the segments
could be used as diagnostic probes to identify
it directly in blood samples from infected
sheep and in cultured cells. Huismans and
his team also made remarkable progress
with the construction of genome libraries
of viruses in the late 1980s (See Part 3: Biochemistry/Molecular Biology). This did
not mean that the less basic veterinary research was neglected. There were sections such as Toxicology, Virology, Protozoology, Entomology, Pathology, Helminthology, Bacteriology, Food Hygiene and the FMD Laboratory that continued to do excellent research. However, the use of molecular biological techniques started spilling over into these disciplines – a spin off – their research teams in fact often including full-blown molecular biologists.
Although not a geneticist, Bigalke had developed a great interest in the genetic resistance of livestock to indigenous ecto- and endoparasites, with the express view of stimu- lating research at Ondertsepoort on the development of management practices to reduce the existing reliance on the use of pharmaceuticals, to which ticks and nematodes, in particular, were rapidly becoming resistant. In 1983 he
visited Australia where pioneering research was being done on the identification of cattle breeds that were resistant to the blue tick, Boophilus microplus and where the concept of the development of ‘easy care livestock’, which included Merino sheep, was receiving considerable attention. On his return he propagated the concept in his trip report and verbally to the staff. Some good research on the phenomenon of genetic tick resistance in cattle breeds followed (see boxed text opposite page), but it took two decades before the concept was applied to resistance to nematodes in sheep, as
is currently the case.
One of the outstanding research
achievements whilst Bigalke was Director was that of J.D. (Dürr) Bezuidenhout of the in vitro culture of the aetiological agent of heartwater, Cowdria (now Ehrlichia) ruminantium in 1985 in bovine umbilical cord endothelial cells. This did not imme- diately pave the way to the development of a more practical vaccine, as was expected – clearly rather unrealistically – but was a tremendous boost for the sophisticated research on the genome of the organism which followed and is currently receiving much attention. Bezuidenhout’s efforts to produce a heartwater vaccine from ground-up ticks unfortunately had to be shelved because of the fatal anaphylactic reaction that some animals showed to the product.
Bezuidenhout also organized an ex- tremely fruitful international scientific conference on heartwater entitled ‘Heart- water: Past, Present and Future’ which took place in the conference centre at the tourist camp Berg-en-Dal in the Kruger National Park from 8-11 September 1986. The proceedings were published under the names of the various authors as a special issue of the Onderstepoort Journal
of Veterinary Research (1987), Vol. 54; No 3, pp. 161-546. Despite the then existing political isolation of South Africa, the conference was attended by heartwater researchers from all over the world, including several African countries, France and its Caribbean islands, the USA, the UK and Germany. It not only provided a forum for discussion, but the current state of scientific knowledge was catered for by the 59 papers presented. A concluding session concerned future prospects and goal setting had a guiding effect on the future directions that would be followed in heartwater research.
In 1971 J.L. (Jean) Du Plessis and N.A.L. Kümm discovered that white mice were susceptible to infection with a strain of the heartwater agent. This paved the way for the develop- ment, in 1981, of an indirect fluorescent antibody test for the diagnosis of heartwater using peritoneal macrophages of the
PART 1
Onderstepoort Veterinary Institute: General History
1908-2008
Years