FALLAH M, HAGHIGHI A, TACHIBANA H. PRELIMINARY COMPARATIVE STUDY OF ENTAMOEBA HISTOLYTICA AND ENTAMOEBA DISPAR BY PCR TECHNIQUE IN IRAN. Med J Islam Repub Iran 2001; 14 (4) :369-372
URL:
http://mjiri.iums.ac.ir/article-1-841-en.html
From the Department of Parasitology, School of Medicine, Hamadan University of Medical Sciences, Hamadan
Abstract: (4112 Views)
It has been suggested that two distinct species exist within what was originally
known as Entamoeba histolytica and E. dispar. These are Entamoeba dispar
for the nonpathogenic and E. histolytica for the pathogenic fonn. Differentiation
of these two organisms is of great clinical importance since they are morphologically
indistinguishable and both fonns can infect the human intestinal cavity. A
study was carried out to differentiate E. histolytica from E. dispar by polymerase
chain reaction (PCR) using two sets of primers (p11plus p12 and p13 plus p14)
specific for either species of ameba. The extracted DNA was used for the identification
of the species in the stool and culture media by PCR. A total of 16 samples,
cysts and trophozoites, were analyzed. In all, 15 samples reacted with E. dispar
primers, resulting in the expected 10 I-bp PCR products however, none of these
reacted with E. histolytica primers. Only one sample reacted with E. histolytica
primers. Because of high sensitivity of the PCR method and the high risk of laboratory
contamination during processing and extracting DNA and its polymerization,
and because of many existing cultures of E. histolytica in the same laboratory,
the chance of contamination can not be ruled out in the single case of E.
histolytica. This preliminary study could be an introduction for a PCR -based epidemiological
study to detennine the importance of E. histolytica in Iran.