Page 65 - VHSA - Onderstepoort 100 Years - Part 3

Protozo R.D. BIGALKE AND
TIntroduction
he first protozoa to be discovered were the free- living, motile and relatively large ciliates or infu- soria by A. van Leeuwenhoek, who had observed them microscopically as early as 1674. In the latter
half of the 19th century the French chemist Louis Pasteur used the improved microscope and newly developed staining technology to discover a host of living organisms, especially bacteria and yeasts, that were important to the wellbeing and health of humans and animals. It was not until 1880 that the first parasitic protozoan parasites were discovered and associated with ill health in their hosts. The
ONDERSTEPOORT 100
human malaria parasite, Plasmodium, was
first seen microscopically in blood smears by
A. Laveran in 1880 in Algeria. In the same
year, in Punjab, India, G. Evans incriminated
a trypanosome, later called Trypanosoma
evansi, as the cause of surra, an Asian and
North African disease of a wide variety of
animal species, notably equids, dogs, camels
and elephants. In 1887 V. Babes blamed an
intra-erythrocytic parasite as the cause of haemoglobinaemia in cattle in Romania,
later named Babesia in his honour. D. Bruce
incriminated tsetse-borne trypanosomes as
the cause of nagana in Natal in 1895.
He was apparently dealing with a mixed
infection. One of the species he isolated was
named Trypanosoma brucei and for a long
time it was regarded as the only cause of the disease. T. Smith & F.L. Kilborne, working on Texas fever (= redwater) in the
“Arnold Theiler just happened to have come to a continent ‘blessed’ with a multitude of yet undiscovered diseases of livestock, some of which were caused by parasitic protozoa and other micro- organisms with a similar life style, such as many of the rickettsias.”
Antique microscope, ca 1750, probably based on a Van Leeuwenhoek design
USA discovered, between 1889 and 1893, that the Piroplasma/Babesia responsible for the disease was transmitted by ticks, thus introducing arthropod vectors, other than insects, onto the scientific horizon.
When Arnold Theiler arrived in what is now South Africa in 1891 the scientific atmosphere was saturated with all these fascinating discoveries relating to proto- zoology. He just happened to have come to a continent ‘blessed’ with a multitude of yet undiscovered diseases of livestock,
some of which were caused by parasitic protozoa and other micro-organisms with a similar life style, such as many of the rickettsias. Moreover, his enquiring mind and forceful personality were ready to grasp all the scientific opportunities that crossed his path. Theiler’s initial research on redwater (babesiosis) and East Coast fever (Theileria parva infection) of cattle and biliary fever of horses was conducted, with the able assistance of Theo Meyer as laboratory assistant and W.F. Averre as stockman, at his Daspoort laboratory in the early 1900s before the research institute at Onderstepoort had come into being (for details see Part 1). It was also Theiler who identified, in 1908, that Trypanosoma congolense, first described in 1904 by Broden, was the main cause of nagana in Zululand.
Early days at Onderstepoort (1908-1929)
When the existence of the new laboratory at Onderstepoort was formally announced on 8 October 1908 it contained bacteriological and pathological laboratories as well as rooms
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Painting of a blood smear showing Theileria parva tick-transmitted parasite causing East Coast fever in cattle
, a protozoan
Protozoology
1908-2008
Years