Cysteine-proteinase of Entamoeba histolytica have been considered implicated like important virulence factors in the pathogenesis of amebiasis. On the basis of the differences in ethnic gene that encodes to 30 kDa proteinase. The present study validated a strategy to differentiate strains of pathogenic and non-pathogenic Entamoeba histolytica by restriction patterns.
Materials and methods: Thirteen stool samples with Entamoeba histolytica cyst from 4 asymptomatic and 9 symptomatic patients ages and sex different into Robinson' medium were used. DNA obtained was used by amplified gene ethnic and it was cut with restriction enzyme Taq I and Hinf I.
Results: All strains were cultivated into Robinson's medium. A 530 bp fragment which hybridated with probe for Entamoeba histolytica was obtained. By the way valuation by restriction patterns with Taq I and Hinf I show that two of four samples of asymptomatic patients belong to pathogenic strain. It agrees with control strain positive HM-1:IMSS. Last 9 belonged to symptomatic patients with pathogenic strain.
Conclusions: These results indicate that ethnic amplified by polymerase chain reaction is insufficiently to establish differential diagnostic. Therefore is necessary carry out enzyme digestion to identify pathogenic strain.