Raafat Taha Mohamed Makhlof
Umm Al-Qura University, KSA
Title: Genetic diversity of human Blastocystis isolates in Makkah, Saudi Arabia
Biography
Biography: Raafat Taha Mohamed Makhlof
Abstract
Blastocystis spp. is commonly found in the feces of human worldwide. Infection has been reported as asymptomatic, acute symptomatic and chronic symptomatic. This wide range of responses to infection could be related to the genetic diversity. Since the genotype of human Blastocystis hominis isolates is highly polymorphic, PCR-based genotype classification using known sequence-tagged site (STS) primers would allow the identification or classification of different genotype. This study was done on 650 stool samples collected from patients referred to two major hospitals in Makkah city, Saudi Arabia in 2014-2015. All microscopically positive samples were subjected to in vitro culture using D-MEM media with 20% horse serum and antibiotics with incubation at 37 oC anaerobically. The screening of Blastocystis organisms in 3 to 4 days old cultures was done observing the typical vascular or granular forms, then sub-culturing more than 2 times and freezing for DNA extraction. PCR was done using seven kinds of STS primers. One hundred forty isolates were confirmed positive using diagnostic primers. Ninety-nine out of 140 isolates were identified as subtype-I genotype (ST1) followed by 24 isolates identified as subtype-II genotype (ST2) while 14 isolates identified as subtype-III genotype (ST3). Only two isolates were negative with all the STS primers, the phylogenetic position was inferred from the small subunit rRNA (SSU rRNA) genes with the known sequence data of 20 Blastocystis isolates. In conclusion, the ST1 is the predominant genotype among Saudi patients.