Dna quantities and qualities from various stages of some trematodes using optical and HAT-RAPD methods.

The aim of this experiment was to minimize DNA quantity and quality for detection by optical (spectrophotometer at 260 nm and 280 nm) and HAT-RAPD methods. Total DNA from different stages, adult, metacercaria and eggs of 6 trematode species were isolated for analysis. In this experiment, the adult trematodes were classified into 3 groups by size: small, Haplorchis taichui and Stellantchasmus falcatus; medium, Opisthorchis viverrini and Ganeo tigrinus; and large, Paramphistomum epiclitum and Fischoederius elongatus. The adult minimal DNA quantities and qualities of all specimen samples detected by optical method were 97.22,72.28, 3,167.00, 1,490.62, 21,382.66, and 27,321.77 ng; eggs were 3.92, 3.57, 3.72, 6.23, 17.53, and 14.01 ng, respectively; and metacercarial stages 50.70 and 40.98 ng in H. taichui and S. falcatus. In addition, the HAT-RAPD technique was chosen to amplify the minimal DNA qualities and quantities of all trematode specimens. Total DNA was 1-1 x 10(-12) ng; DNA templates in each dilution were used for amplification by primer OPA-09. DNA concentrations ranging between 1 x 10(-8) and 1 x 10(-11) ng were amplified with high polymorphism. Our experiment concluded that only a single specimen of each egg, metacercaria, or adult stage could be amplified with distinct bands.

Investigation of Stellantchasmus falcatus metacercariae in half-beaked fish, Dermogenus pusillus from four districts of Chiang Mai Province, Thailand.

Half-beaked fish, Dermogenus pusillus, collected from Mueang, Hang Dong, Doi Saket and Saraphi Districts, Chiang Mai Province, were examined for their infection status with Stellantchasmus falcatus (Digenea: Heterophyidae) metacercariae. The infection rate of the fish was 100%. Fish in three of four districts were found only to have metacercariae of S. falcatus, whereas those in Saraphi District had mixed infections with metacercariae of Posthodiplostomum sp. The intensity of S. falcatus infection per fish varied; 652-1,342 (mean 999.5), 562-2,422 (1,323.1), 185-2,492 (502.6), and 22-550 (210.4) in Mueang, Hang Dong, Saraphi, and Doi Saket Districts, respectively. The body portions of the fish with the heaviest metacercarial infection were the muscles, in all districts. The present study confirms that half-beaked fish in Chiang Mai Province are heavily infected with S. falcatus metacercariae.