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Tapeworms of the species complex of Echinococcus granulosus sensu lato (s. l.) are the cause of a severe zoonotic disease – cystic echinococcosis, which is listed among the most severe parasitic diseases in humans and is prioritized by the World Health Organization. A stable taxonomy of E. granulosus s. l. is essential to the medical and veterinary communities for accurate and effective communication of the role of different species in this complex on human and animal health. E. granulosus s. l. displays high genetic diversity and has been divided into different species and genotypes. Despite several decades of research, the taxonomy of E. granulosus s. l. has remained controversial, especially the species status of genotypes G6–G10. Here the Bayesian phylogeny based on six nuclear loci (7387 bp in total) demonstrated, with very high support, the clustering of G6/G7 and G8/G10 into two separate clades. According to the evolutionary species concept, G6/G7 and G8/G10 can be regarded as two distinct species. Species differentiation can be attributed to the association with distinct host species, largely separate geographical distribution and low level of cross-fertilization. These factors have limited the gene flow between genotypic groups G6/G7 and G8/G10, resulting in the formation of distinct species. We discuss ecological and epidemiological differences that support the validity of these species. [ABSTRACT FROM AUTHOR]

Cystic echinococcosis (CE) is a severe parasitic disease caused by the species complex Echinococcus granulosus sensu lato. Human infections are most commonly associated with E. granulosus sensu stricto (s.s.), comprising genotypes G1 and G3. The objective of the current study was to provide first insight into the genetic diversity and phylogeography of genotype G3. Despite the epidemiological importance of the genotype, it has remained poorly explored due to the ambiguity in the definition of the genotype. However, it was recently demonstrated that long sequences of mitochondrial DNA (mtDNA) provide a reliable method to discriminate G1 and G3 from each other. Therefore, we sequenced near-complete mtDNA of 39 G3 samples, covering most of the known distribution range and host spectra of the genotype. The phylogenetic network revealed high genetic variation within E. granulosus s.s. G3 and while G3 is significantly less prevalent worldwide than G1, the genetic diversity of both of the genotypes is equally high. We also present the results of the Bayesian phylogeographic analysis, which yielded several well-supported diffusion routes of genotype G3 originating from Turkey and Iran, suggesting the Middle East as the origin of the genotype. [ABSTRACT FROM AUTHOR]

Background: Stray dogs are considered potential reservoirs for zoonotic diseases. Previous helminthic surveys in Iran, have accounted for mainly species of nematodes and cestodes, and rarely digeneans. Methods: We accessed 42 car-crashed stray dogs from the Farah Abad Region in the Mazandaran Province (North Iran) between Oct 2012 and Dec 2013, to be inspected for parasites. Helminths were collected from the intestine and they were morphologically studied. Results: We found five adult digeneans from the family Brachylaimidae, identified as Brachylaima sp. Worms were assigned to the genus based on the shape of the body, the position of genital pore, cirrus sac and testes, and the extension of the vitellarium. Absence of additional information on the developmental stages of the parasite precluded its specific identification. As the geographic distribution of species of Brachylaima is restricted to the Mediterranean region, we raise the hypothesis that dogs may become infected with parasites through the consumption of helicid snails when searching for food on the street. Conclusion: This is the second report of a species of Brachylaima in Iran and the third digenean species from stray dogs in the area. We want to raise the attention of researchers to helminthic surveys in potential zoonotic reservoirs like stray dogs. [ABSTRACT FROM AUTHOR]

The present study aimed to evaluate the histologic, histochemical, and immunohistochemical changes in buffalo livers with cystic echinococcosis. Noninfected and infected livers were collected from the freshly slaughtered buffalo at the Aligarh abattoir. Small pieces of both infected and noninfected livers ( n = 5) were cut and processed for histologic and histochemical studies. Immunohistochemistry was performed using rabbit anti-CD3, CD19, and CD117 antibodies. The results revealed the presence of brood capsules and germinal and laminated membranes surrounded by a fibrous adventitial layer, followed by moderate and diffused infiltration of eosinophils, monocytes, neutrophils, lymphocytes, and marked focal infiltration of mast cells. The infected livers also had mild dilation of central veins and sinusoids, mild and focal necrosis of hepatic tissue, and congestion of central and portal veins. Periodic acid-Schiff reaction revealed marked glycogen depletion in the infected liver. Masson's trichrome stain showed marked deposition of collagen fibers in the portal area, adventitial layer, and between the hepatocytes compared with the noninfected liver, where deposition was found only in the portal area. The T-cell response was more pronounced than the B-cell response in infected liver. Thus, it can be concluded that hydatid cyst infection causes several pathological and biochemical changes and increased infiltration of inflammatory cells in the infected livers, suggesting the involvement of nonspecific immune responses against hydatid cysts. The T-cell response was more pronounced than B-cells, indicating the involvement of cell-mediated immunity against cystic echinococcosis. These findings may help to understand the local immune responses to cystic echinococcosis., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.