zahra babaei

Taenia multiceps is a widely distributed zoonotic tapeworm of canids. The larval stage of the parasite (Coenurus) occurs in sheep, goat and cattle and has been rarely reported from humans. This study investigated genetic variability of two mitochondrial genes in 102 isolates of T. multiceps. Metacestodes were collected from brains and hearts of sheep in Tehran and Qom provinces of Iran. DNA of each isolate was extracted and used for PCR amplification of cytochrome c oxidase subunit I (CO1) and 12S ribosomal DNA (12S rRNA) genes. All amplicons were sequenced and the sequence data were analyzed using NCBI Blast and BioEdit. Phylogenetic trees and pairwise calculations were obtained by using Mega5 software. In total 7 and 25 representative haplotypes were differentiated for CO1 and 12S rRNA genes, respectively. For CO1 sequences 11 segregation sites within 7 haplotypes were observed. For 12S rRNA sequences a total of 32 segregation sites were observed in 25 haplotypes. CO1 gene displayed lower diversity than 12S rRNA gene with an overall nucleotide variation of 3.0% for CO1 vs. 7.2% for 12S rRNA. Pairwise comparisons among 7 haplotypes in CO1 and 12S rRNA genes showed the level of nucleotide differences 0.3-2.5% and 0.2-4.0%, respectively. A high degree of genetic variation was found in the isolates of T. multiceps in Iran. Additional molecular studies are required on the parasite from other intermediate hosts.

Reliable and rapid genotyping of large number of Echinococcus granulosus sensu lato isolates is crucial for understanding the epidemiology and transmission of cystic echinococcosis. We have developed a method for distinguishing and discriminating common genotypes of E. granulosus s.l. (G1, G3, and G6) in Iran. This method is based on polymerase chain reaction coupled with high resolution melting curve (HRM), ramping from 70 to 86 °C with fluorescence data acquisition set at 0.1 °C increments and continuous fluorescence monitoring. Consistency of this technique was assessed by inter- and intra-assays. Assessment of intra- and inter-assay variability showed low and acceptable coefficient of variations ranging from 0.09 to 0.17 %. Two hundred and eighty E. granulosus s.l. isolates from sheep, cattle, and camel were used to evaluate the applicability and accuracy of the method. The isolates were categorized as G1 (93, 94, and 25 %), G3 (7, 4, and 4 %), and G6 (0, 2, and 71 %) for sheep, cattle, and camel, respectively. HRM results were completely compatible with those obtained from sequencing and rostellar hook measurement. This method proved to be a valuable screening tool for large-scale molecular epidemiological studies.

Free-living amoebae (FLA) are a group of ubiquitous protozoan, which are distributed in the natural and artificial environment sources. The main aim of the current study was to identify the presence of FLA in the recreational hot springs of Sarein in Ardebil Province of Iran. Seven recreational hot springs were selected in Sarein City and 28 water samples (four from each hot spring) were collected using 500 ml sterile plastic bottles during three month. Filtration of water samples was performed, and culture was done in non-nutrient agar medium enriched with Escherichia coli. Identification of the FLA was based on morphological criteria of cysts and trophozoites. Genotype identification of Acanthamoeba positive samples were also performed using sequencing based method. Overall, 12 out of 28 (42.9%) samples were positive for FLA which Acanthamoeba and Vahlkampfiid amoebae were found in one (3.6%) and 11 (39.3%) samples, respectively. Sequence analysis of the single isolate of Acanthamoeba revealed potentially pathogenic T(4) genotype corresponding to A. castellanii. Contamination of hot springs to FLA, such as Acanthamoeba T(4) genotype (A. castellanii) and Vahlkampfiid amoebae, could present a sanitary risk for high risk people, and health authorities must be aware of FLA presence.