RESUMO
General proteins and 14 enzymes from metacercariae of Paragonimus heterotremus, P. siamensis and P. westermani were determined by vertical polyacrylamide gel electrophoresis. The isoenzyme profiles showed considerable interspecific polymorphism for general protein (PT), malate dehydrogenase (MDH), malic enzyme (ME) and tetrazolium oxidase (TO) while those of glucose phosphate isomerase (GPI) and phosphoglucomutase (PGM) showed similarity. The Pt-6 and To-I loci can be used as identification markers for these three species. The preliminary study of the molecular biology of Paragonimus heterotremus P. siamensis and P. westermani was based on analysis of metacercarial genomic DNA with restriction endonuclease Pst I. Agarose gel electrophoresis revealed restriction fragment length differences among the three species studied. The DNA restriction fragments were approximately 4-6 fragments, ranging from 5.35 to 14.67 kb. Among these. P westermani shared two homologous fragments with P. siamensis, ie, 5.35 and 7.22 kh, none with P. heterotremus, while P. heterotremus shared only one with P. siamensis, ie, 8.16 kb. Thus, the DNA restriction fragment length differences can be used to differentiate among these three species.