Genetic variation and phylogenetic relationship of Hypoderaeum conoideum(Bloch, 1782) Dietz, 1909(Trematoda: Echinostomatidae) inferred from nuclear and mitochondrial DNA sequences

Objective:To explore genetic variations of Hypoderaeum conoideum collected from domestic ducks from 12 different localities in Thailand and Lao PDR,as well as their phylogenetic relationship with American and European isolates.Methods:The nucleotide sequences of their nuclear ribosomal DNA(ITS),mitochondrial cytochrome c oxidase subunit 1(CO1),and NADH dehydrogenase subunit 1(ND1)were used to analyze genetic diversity indices.Results:We found relatively high levels of nucleotide polymorphism in ND1(4.02%),whereas moderate and low levels were observed in CO1(2.11%)and ITS(0.96%),respectively.Based on these polymorphisms,the 20 ND1,12 CO1,and 18 ITS haplotypes were classified,and several common haplotypes were observed in all samples.At least three major lineages,namely American,European and Asian lineages,have been classified by phylogenetic analyses based on ND1 sequences.Conclusions:Our report demonstrates that the ND1 gene is the most suitable genetic marker to explore genetic variation and phylogenetic relationship of Hypoderaeum conoideum.However,a combination of all loci for ND1,CO1 and ITS would be of great value toward further genetic investigation of this endemic worldwide parasite.Thus,comprehensive molecular genetic analyses of Hypoderaeum conoideum from its worldwide distribution is needed to further understanding of the evolutionary and systematic relationships of this parasite.

Prevalence and genotype distribution of Enterobius vermicularis among kindergarteners in Shiraz and Khorramabad cities, Iran

Objective: To study the prevalence and genotype of Enterobius(E.)vermicularis from adhesive tape samples in the cities of Shiraz and Khorramabad, Iran. Methods: A total of 1 000 adhesive tape samples from kindergartens in Shiraz(500 samples) and Khorramabad(500 samples) were collected and tested using a microscope to find E. vermicularis egg/s. A questionnaire was filled out for each sample. In order to characterize the genotype of E. vermicularis, the PCR-sequencing method of the mitochondrial cytochrome C oxidase subunit 1(cox1) gene was used. Genomic DNA was extracted from the positive scotch tape samples of E. vermicularis. The cox1 gene was amplified by the polymerase chain reaction and sequenced. The sequence data were aligned using the BioEdit software and compared with the published sequences in GenBank. Phylogenetic analysis was performed using the maximum likelihood method. Results: The parasitological method showed that 15 out of the 500 samples from Shiraz(3.00%) and 12 out of the 500 samples from Khorramabad(2.40%) were infected with E. vermicularis eggs. BLAST analysis indicated that the sequenced isolates belonged to E. vermicularis genotype B while three different haplotypes were also identified. Conclusions: This is the first study on genotyping E. vermicularis in the cities of Shiraz and Khorramabad. Considering the public health importance of the disease, further studies are necessary to characterize the genotype of E. vermicularis in human populations from other regions of Iran.