Strains of Entamoeba histolytica isolated in Brazil were
characterized using the Low-Stringency Single Specific Primer
PCR (LSSP–PCR), that detects single or multiple mutations in gene size
DNA fragments. Using this technique, a 482-bp genomic DNA fragment from a
structural gene in 8 strains and 2 clones of E. histolytica, isolated
from symptomatic
and asymptomatic patients in Brazil, including pathogenic and non-pathogenic
zymodemes were studied. The results
obtained indicate that LSSP–PCR is a valuable method for
differentiating strains of E. histolytica. Moreover, the results
are consistent with the concept that pathogenic and non-pathogenic strains of
E. histolytica may represent distinct species
or subspecies and are in accord with phenotypically characteristic
isoenzyme patterns.