evaluation of a single pcr assays on cp5 gene for differentiation of entamoeba histolytica and e. dispar

background: we examined a molecular method with a single-pcr for amplification of a part of cp5 gene enabling us to differen­tiate the pathogenic species, entamoeba histolytica , from the non-pathogenic species, e. dispar . methods: we developed a single pcr method for this purpose.  after investigation of genbank, primer pairs were de­signed from highly conserved regions of cysteine proteinase (cp5) gene. the primers were utilized in pcr using isolated ge­nomic dna template of e. histolytica and the pcr products were then sequenced. the same primer and method for pcr was used for isolated genomic dna template of e. dispar . results: a fragment of about 950 bp was isolated in pcr by using dna from e. histolytica , however, no banding pattern was produced by using the same primers for e. dispar . we characterized cp5 gene at molecular level in e. histolytica iso­lates from 22 positive; including 20 non-dysentery samples isolated from both cities as well as two dysentery samples iso­lated only from tabriz. nucleotide sequence comparison in gene data banks (ncbi, nih) revealed significant homology with cp5 gene in e. histolytica isolates conclusion: we developed a pcr method, which could detect simply and rapidly e. histolytica by amplifying a specific pcr fragment.