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Cultivation
and multiplication of viable axenic Trypanosoma vivax
in vitro and in vivo
O. A. Idowu,
A. B. Idowu, C. F. Mafiana and S. O. Sam-Wobo*
Parasitology Laboratory, Department of
Biological Sciences, University of Agriculture, Abeokuta,
Nigeria.
*Corresponding author. E-mail:
sam_wobo@yahoo.com
Accepted 13 April, 2006 |
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Trypanosoma vivax
was isolated from the blood of an infected
laboratory mouse, washed and introduced into the prepared
culture media, ME-99 and minimum essential medium (MEM),
both containing laboratory prepared (commercial) horse serum
and antibiotics (streptomycin and penicillin). The cultures
were monitored in vitro for 12 days. There was an
initial decline in parasitaemia in the first 48 h in both
media, which later picked up to reach the peak of about 1.10
x 102 parasites/ml in ME-99 on day 5 and 6.2 x 10
parasites/ml in MEM on day 4. Thereafter, the parasites
number tapered off to reach zero on day 9 in ME-99 and day
10 in MEM. No growth was recorded in the control, which
contained normal saline (pH 7), horse serum and antibiotics.
The result of the in vivo culture showed a different
trend when compared to the in vitro. Multiplication
was tremendous with a peak of about 3 x 10 parasites/ml of
blood on day 22 (high inoculum) and day 24 (low inoculum)
post infection. The slender trypomastigote parasites
recovered in the in vitro culture was short and had a
long, free flagellum and measured 23-25 um while that of the
in vivo culture was long, slender, clongated, torpedo
shaped body measuring between 30 and 32 um. During the
course of the in vivo culture congenital transmission
of trypanosomes was observed. The in vitro
attenuated parasite conferred a degree of protection to 25%
of the mice that were later infected with viable parasites
indicating possible prophylactic effect of in vitro
attenuated parasites. The study showed that T. vivax
could not be cultured in large numbers on their own
axenically in MEM and ME-99. However, ME-99 can be said to
be more suitable compared to MEM for axenic cultivation of
T. vivax as a result of the additional nutrients
supplied by the tissue culture medium 199 present in medium
ME-99. Also, the parasites multiplied better in vivo
compared to the in vitro study, which could mean that
the best means of culturing trypanosomes still remains the
in vivo method.
Key words:
Trypanosoma vivax, parasite cultivation, in vitro
and in vivo cultures. |
