Viability and infectivity of Toxoplasma gondii tachyzoites exposed to Butanedione monoxime

Abstract

The most important pathogenesis factor in the Apicomplexa parasites is invasion to the host cell. Given the inhibitory role of Butanedione Monoxime (BDM) on myosin-actin interaction, this study aimed to investigate the effects of this molecule on the vitality and infectivity of Toxoplasma tachyzoites in order to provide a new option for vaccine development. The tachyzoites of the RH strain of Toxoplasma gondii were exposed to different concentrations (1, 2, 4, 8, 16, 32, 64, and 128 lg/mL) of BDM, and mortality effect was assessed by flow cytometry. Then, the penetration ability of the tachyzoites was investigated in HeLa and macrophage cell lines. The infectivity of exposed tachyzoites to BDM were also investigated in mice through following up and detecting the etiological factor. The highest percentage of mortality (72.69%) was seen in the tachyzoites exposed to 128 lg/mL of the compound. The tachyzoites exposed to 32, 64, and 128 lg/ mL of BDM began the proliferation in HeLa cells after 48 h, while this proliferation was initiated within 24 h in macrophage cells. All the mice inoculated with the BDMtreated tachyzoites died after 13 days. The mean survival time of the mice receiving tachyzoites exposed to 128 lg/ mL of BDM was 12.4 days, which was significantly different from the negative control group (p = 0.001). BDM, as the inhibitor of myosin-actin interaction, and other substances that block the entry of parasites into cells may be suitable candidates for vaccine production against Toxoplasma. Yet, future studies are required to be conducted on the issue.

Viability of Toxoplasma gondii tachyzoites in different conditions for parasite transportation

“…Several factors, such as temperature, media, pH, and time, may impact the survival of T. gondii tachyzoites [9,13,18]. The present result showed that NS was the best medium for short-term storage (within 6 h) of T. gondii tachyzoites without 5% CO 2 supplementation.…”

Optimization of tools for the detection and identification of Cryptocotyle metacercariae in fish: Digestion method and viability studies

“…Recently, some authors studied both the viability and the infectivity for different pathogens, mixing several techniques in parallel. Bajelan et al (2020) Cryptocotyle metacercariae. The validation of these tools will be a prerequisite before any study on infectivity assessment after either food/culinary treatments or keeping the fish host after its death may be carried out.…”

Introduction of protocols for mass production of Toxoplasma gondii tachyzoites of the genotype II PRU strain

“…17,18 In previous studies, different methods, including trypsin digestion, purification using a 3-lm filter membrane, CF-11 cellulose purification, and Percoll solution purification, were used to separate the tachyzoites of Toxoplasma from in vivo and in vitro culture systems. 11,16,19 The trypsin digestion method showed a high salvage rate for tachyzoites purification, but the viability of the purified tachyzoites was low. This method is suitable for antigen analysis.…”

“…Flasks (75 cm 2 ) were seeded with 9 × 10 5 HeLa cells in a growth medium. When 70% coverage with a HeLa cell monolayer was achieved, the cultures were infected with tachyzoites from immunosuppressed mice (tachyzoite:cell ratios were 1:10), 16 and incubated at 37°C with 5% CO 2 for 6‐8 hours, during which time the active tachyzoites could penetrate the cells. The culture media containing cell debris and inactive tachyzoites were then removed and replaced with fresh culture medium.…”