histopathologic alterations between echinococcus granulosus sensu stricto and e. canadensis genotypes of human cystic echinococcosis cysts in shiraz, iran

Background: we aimed to determine the genotypes of echinococcus granulosus sensu lato (s.l.)using dna regions within the nadh dehydrogenase subunit-1 (nad1) mitochondrial genes informalin-fixed paraffin-embedded (ffpe) isolates of human cystic echinococcosis cysts(ce cysts) and compare their histopathologic alterations.methods: out of 135 samples, 21 high-quality pcr positive samples were selected for sequencingand were deposited into genbank database. moreover, histopathological changesof e. granulosus sensu stricto (g1 genotype) and e. canadensis (g6 genotype) cases were alsocompared.results: based on the sequencing results, 16 cases were diagnosed as e. granulosus s.s. (g1-g3 genotype) and 5 cases as e. canadensis (g6 genotype). five haplotypes of e. granulosuswere identified from 21 nad1 sequences. the histopathological alterations in both genotypesshowed laminated layer of ce without inflammatory cells. in a few cases of the g6 genotype,neutrophils in the outer cuticular layer with mild vascular and congestion were observed.cell debris with multiple areas of necrosis, as well as scanty lymphoplasma cells inthe outer cuticular layer were observed in g1-g3 genotype cases. so, the histopathologicaldifferences between the two genotypes are not noticeable enough to be differentiated bymicroscopical observations.conclusion: e. granulosus s.s. (g1-g3) and e. canadensis (g6 genotype) are prevalent amongce patients. in general, five haplotypes were identified by nad1 genes analysis. the histopathologicaldifferences between the two genotypes have not been so big to be differentiatedby microscopic observations.