Histopathologic Alterations between Echinococcus granulosus sensu stricto and E. canadensis Genotypes of Human Cystic Echinococcosis Cysts in Shiraz, Iran

Enayat  Darabi; Seyed Mahmoud  Sadjjadi; Tahereh  Mohammadzadeh; Mehdi  Karamian; Seyed Mohammad  Owji; Bahareh  Sedaghat

doi:10.18502/ijpa.v20i1.18102

Enayat Darabi Department of Parasitology and Mycology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
Seyed Mahmoud Sadjjadi Department of Parasitology and Mycology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
Tahereh Mohammadzadeh Applied Microbiology Research Center, Systems Biology and Poisoning Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
Mehdi Karamian Department of Parasitology and Mycology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
Seyed Mohammad Owji Department of Pathology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
Bahareh Sedaghat Department of Parasitology and Mycology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran

DOI: https://doi.org/10.18502/ijpa.v20i1.18102

Keywords: Cystic echinococcosis; Iran; Parasitology; Histopathology; Genotyping; Haplotyping

Abstract

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 in formalin-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 sequencing and were deposited into GenBank database. Moreover, histopathological changes of E. granulosus sensu stricto (G1 genotype) and E. canadensis (G6 genotype) cases were also compared.

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. granulosus were identified from 21 nad1 sequences. The histopathological alterations in both genotypes showed 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 in the outer cuticular layer were observed in G1-G3 genotype cases. So, the histopathological differences between the two genotypes are not noticeable enough to be differentiated by microscopical observations.

Conclusion: E. granulosus s.s. (G1-G3) and E. canadensis (G6 genotype) are prevalent among CE patients. In general, five haplotypes were identified by nad1 genes analysis. The histopathological differences between the two genotypes have not been so big to be differentiated by microscopic observations.