title: Subtyping of Blastocystis sp. isolated from symptomatic and asymptomatic individuals in Makkah, Saudi Arabia.
abstract: BACKGROUND
  Blastocystis is a group of cosmopolitan gastrointestinal parasite of humans and a wide variety of animals. These anaerobic protozoans include more than 17 specific small-subunit ribosomal RNA subtypes, of which nine are found in humans with a variable geographical distribution. Until now, no study has described the Blastocystis subtypes present in Saudi Arabia.
  
  
  METHODS
  In total, 1,262 faecal samples were collected from patients with gastrointestinal complaints and asymptomatic individuals visiting two major hospitals. All samples were analysed by F1/R1 diagnostic PCR, microscopy and culture methods. The subtypes of Blastocystis sp. isolates were determined by the sequenced-tagged site (STS)-based method.
  
  
  RESULTS
  One-hundred-thirty-three positive cases were detected by F1/R1 diagnostic PCR, of which 122 were also positive by the culture method and 83 by direct microscopy. The sensitivities of direct microscopy and the culture method were 62% and 92%, respectively. Subtype (ST3) was the most prevalent (80.5%), followed by ST1 (14.5%) and ST2 (5%). ST4, ST5, ST6 and ST7 were not detected in this study. ST3 infections were significantly predominant (P < 0.05) among symptomatic patients.
  
  
  CONCLUSIONS
  To our knowledge, this study provides the first run-through information on Blastocystis sp. epidemiology in Makkah city, revealing a rather moderate prevalence of 10.5% and the presence of three subtypes, ST1, ST2, and ST3. ST3 was the most predominant, particularly among symptomatic patients.
authors.affiliation: Department of Medical Parasitology, Faculty of Medicine, Umm Al-Qura University, Makkah, Saudi Arabia. rtmakhlof@uqu.edu.sa.|Department of Medical Parasitology, Faculty of Medicine, El-Minia University, El-Minia, Egypt. rtmakhlof@uqu.edu.sa.
authors.forename: Raafat T
authors.initials: RT
authors.lastname: Mohamed
authors.affiliation: Department of Medical Parasitology, Faculty of Medicine, Umm Al-Qura University, Makkah, Saudi Arabia.
authors.forename: Mohammed A
authors.initials: MA
authors.lastname: El-Bali
authors.affiliation: Department of Medical Parasitology, Faculty of Medicine, Umm Al-Qura University, Makkah, Saudi Arabia.|Department of Medical Parasitology, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
authors.forename: Anhar A
authors.initials: AA
authors.lastname: Mohamed
authors.affiliation: Department of Medical Parasitology, Faculty of Medicine, Ain Shams University, Cairo, Egypt.|Microbiology Laboratory, King Abdellah Medical City, Makkah, Saudi Arabia.
authors.forename: Mona A
authors.initials: MA
authors.lastname: Abdel-Fatah
authors.affiliation: Department of Medical Parasitology, Faculty of Medicine, Umm Al-Qura University, Makkah, Saudi Arabia.|Department of Medical Parasitology, Faculty of Medicine, Mansoura University, Mansoura, Egypt.
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: El-Malky
authors.affiliation: Department of Medical Parasitology, Faculty of Medicine, Umm Al-Qura University, Makkah, Saudi Arabia.|Department of Medical Parasitology, Faculty of Medicine, El-Minia University, El-Minia, Egypt.
authors.forename: Nawras M
authors.initials: NM
authors.lastname: Mowafy
authors.affiliation: Laboratory and Blood Bank Department, Al-Noor Specialist Hospital, Makkah, Saudi Arabia.|Department of Medical Parasitology, Faculty of Medicine, Assiut University, Assiut, Egypt.
authors.forename: Dina A
authors.initials: DA
authors.lastname: Zaghlool
authors.affiliation: Department of Medical Parasitology, Faculty of Medicine, Umm Al-Qura University, Makkah, Saudi Arabia.
authors.forename: Rowaida A
authors.initials: RA
authors.lastname: Bakri
authors.affiliation: Department of Medical Parasitology, Faculty of Medicine, Umm Al-Qura University, Makkah, Saudi Arabia.
authors.forename: Saeed A
authors.initials: SA
authors.lastname: Al-Harthi
mesh_terms: D058345:Asymptomatic Infections; D016844:Blastocystis / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D016776:Blastocystis Infections / Q000469:parasitology*; D016054:DNA, Protozoan / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D005243:Feces / Q000469:parasitology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012529:Saudi Arabia
chemical_list: D016054:DNA, Protozoan; D004275:DNA, Ribosomal
keywords: Blastocystis sp; Makkah city; Sequence-Tagged Sites (STS) PCR; Subtyping