A Study of The Genetic Variability of Blastocystis hominis Isolates in Hamadan, West of Iran

Abstract

Blastocystis hominis is a common protozoan parasite in the human and many other animals intestine. The parasite pathogenicity is still controversial. A few studies have been conducted on prevalence of B. hominis subtypes in Iran. The results of present study improve our knowledge on B. hominis subtypes in Iran and therefore we can do more investigations on pathogenicity potential of these subtypes in the future. Background:Blastocystis is a common protozoan parasite in mammals, birds, amphibians, reptiles, fish, arthropods, and annelids. This parasite has some subtypes, which pathogenicity status of them still remained controversial. Some of Blastocystis subtypes are potentially pathogenic to human. Objectives: This study has identified the Blastocystis hominis subtypes and their prevalence rates in Hamadan. Materials and Methods: During two months of summer 2011, a total number of 250 human fecal samples referred for parasitology examination to Beasat Hospital and a few clinical laboratories of Hamadan city were collected. The samples were examined by direct method and formalin-ether. 41 samples exhibited positive results for B. hominis thereby were cultured in Locke-egg medium. After the growth and in order to genotype identification, B. hominis isolates were amplified by PCR, using seven pairs of sequencestagged site primers. Results: In this study, three subtypes of B. hominis consisted of one [SB83], two [SB340] and three [SB227] were identified. The most dominant genotype was SB83 with 56.1 % frequency. The prevalence rate of genotype SB227 and SB340 were 22 % and 7.3 %, respectively. Coexistence of genotypes SB83 and SB227 was detected in 14.6 % of positive cases. Conclusions: This is the first study in Hamadan on genotyping of B. hominis, which may trigger other epidemiologic and zoonotic studies on different subtypes and hence control clinical manifestations of infection.

Prevalence and subtype identification of Blastocystis isolated from human in Shiraz city, southern Iran

“…isolated from humans, 19,21,[23][24][25] whereas two studies reported a higher incidence of subtype 1 in humans. 20,26 In contrast to our study, Khoshnood et al reported the ST4 was the most prevalent subtype in human samples. 22 Generally, subtypes 3 has been identified as the most common subtype in human.…”

“…Molecular studies on Blastocystis previously conducted in Iran showed ST1, ST2, ST3, ST4, ST5, ST6 and ST7 in humans, and ST3 was reported in all studies performed in Iran. [19][20][21][22][23][24][25][26][27] The subtype 3 was the most prevalent subtype of Blastocystis in our study, which is similar to the several studies performed in Iran about the subtype distribution of Blastocystis sp. isolated from humans, 19,21,[23][24][25] whereas two studies reported a higher incidence of subtype 1 in humans.…”

“…16 The molecular studies conducted for the genotype identification of Blastocystis isolated from humans in Iran have reported the ST1, ST2, ST3, ST4, ST5, ST6 and ST7 genotypes. [19][20][21][22][23][24][25][26][27] The result of many studies https://doi.org/10.1016/j.cegh.2020.02.010 Received 11 September 2019; Received in revised form 2 January 2020; Accepted 14 February 2020 that were performed in Iran have showed that subtype 3 is the most common subtype of Blastocystis. 19,21,[23][24][25]27 Considering the fact that different subtypes of Blastocystis may be associated with geographical distribution, hosts and pathogenicity of parasite, 19,28 therefore, identification of the subtypes of Blastocystis is necessary for epidemiological studies.…”

Genetic Diversity of Blastocystis Isolated From Cattle in Khorramabad, Iran

“…Three subtypes, including ST1 (56.1%), ST3 (22%) and ST2 (7.3%) were characterized. Coexistence of ST1 and ST3 was detected in 14.6% of cases ( 22 ). In another study in Iran, 100 Blastocystis isolates were characterized using seven pairs of STS primers.…”

Determining intestinal parasitic infections (IPIs) in inmates from Kajang Prison, Selangor, Malaysia for improved prison management

“…subtype 1 (ST1) following ST3 was not surprising. There were various reports which showed ST1 was the common subtype found in human, together with ST2, ST3 and ST4 [ 39 , 41 , 42 ]. The single infection of Blastocystis subtype 6 (ST6) may reflect zoonotic transmission, as this subtype has been reported among the avians [ 43 , 44 ].…”