Evaluation of three different cell cultures for tachyzoite and DNA production of Toxoplasma gondii

Background: Toxoplasma gondii is one of the most prevalent zeonotic protozoa that
has been farther considered with concern to the increasing prevalence of AIDS during
the last two decades. Cell culture is an important and necessary tool for molecular
and cell biology of Toxoplasma gondii as well as maintaining stock and routine
laboratory works. This study was performed to evaluate different cell lines and select
an appropriate one for Toxoplasma gondii culture, tachyzoite production and DNA
preparation.
Methods and Materials: Three different fibroblast mono layers were assayed by
inoculation of two strains including RH and Beverley, the representatives of virulent
and avirulent phenotypes, respectively.
Results: The results showed that the viability of propagated parasites in the HFF
cultured flasks was higher than that of the other two cell cultures. The pH of culture
medium was more stable in the HFF flasks, whereas it was likely to become acidic in
the HEL and MRC5 flasks. Total parasite yield in RH strain cultures comparing to the
Beverley cultures in all three cell lines was significantly higher. However,
comparison of the Beverley strain tachyzoite yield in different cultures showed a
higher parasite quantity in the HFF line. Total amount of extracted and purified DNA
was 31 to 33 μgr/flask for the RH strain and 20 to 25 μgr/flask for the Beverley
strain.
Conclusions: It was concluded that the HFF is the most suitable cell line for
routine and continuous subculture as well as DNA production from most Toxoplasma
strains.