2.2. Pla-som preparation and the effect of fermentation time on the viability
of OVMC
Pla-som was prepared by a traditional method in both experiments.
Approximately 2 kg of fish was firstwashed briefly in running tapwater.
After opening the body cavity of each fish and removing the intestines,
the fish was mixed thoroughly with 75 g of glutinous rice, 105 g of
minced garlic and 150 g of table salt. After mixing well, fish were
divided equally into 7 groups (approximately 0.33 kg, each), put into
separate plastic bags, tightly packed, and stored at room temperature
for 1 to 7 days. After fermentation at the designated time point, each
group of pla-som was taken for OVMC isolation and then the viability
of metacercariae was observed under a stereomicroscope.
The pH level of the pla-som was measured using a pH meter
(500 series; Beckman Coulter, Brea, CA, USA).