The distribution of Blastocystis subtypes in isolates from Qatar
التاريخ
2015-09-15البيانات الوصفية
عرض كامل للتسجيلةالملخص
Background: Blastocystis is a common single-celled intestinal parasite of humans and other animals comprising at
least 17 genetically distinct small subunit ribosomal RNA lineages (subtypes (STs)), nine of which have been found
in humans. The geographic distribution of Blastocystis subtypes is variable, but the subtypes present in Qatar are at
present unknown.
Methods: Stool samples were collected from randomly selected, apparently healthy subjects arriving in Qatar for
the first time. Blastocystis subtypes were determined by sequencing of the small subunit rRNA gene (SSU rDNA)
PCR products. Phylogenetic analyses were done using Maximum Composite Likelihood method.
Results: 71.1 % of samples were positive for Blastocystis infection based on PCR-detection methodology compared
to only 6.9 % by microscopy. Prevalence of Blastocystis did not differ between the sexes nor between age classes.
However, there was a regional difference in prevalence with subjects arriving from Africa showing the highest
(87.6 %), those from Western Asia intermediate (68.6 %) and from Eastern Asia the lowest prevalence (67.6 %).
Genetic analysis detected only three STs. ST3 was the most common (69.3 %) and ST2 was the rarest (3.5 %), while
ST1 had a prevalence of 27.2 %. ST2 showed a regional variation, being absent from the 64 Western Asian
Blastocystis-positive subjects. Both ST1 and ST3 showed significant differences in prevalence between the sexes.
Conclusions: This is the first report exploring the distribution of Blastocystis subtypes in our region. We recommend
that stool screening via microscopy for the presence of Blastocystis should be abandoned since it is extremely
insensitive. In future, the prevalence of Blastocystis infections should be based on PCR methodology and we predict
that in the years ahead diagnostic PCR will become the tool of choice. More work is needed to identify the full
range of Blastocystis subtypes that circulate in our region.
المجموعات
- الأبحاث [727 items ]
- العلوم الصحية - كلية الآداب والعلوم (قبل 2016) [152 items ]