title: Molecular characterization of Giardia duodenalis in Yemen.
abstract: Giardia duodenalis is an important intestinal protozoan in Yemen with infection rates ranging from 18% to 27%. To date, there has been no genotyping study to provide a better understanding of the transmission dynamic. This study was conducted to genotype and subtype G. duodenalis in Yemen. Stool samples were collected from 503 Yemeni outpatients between 1 and 80 years old, including 219 males and 284 females. Giardia cysts were detected via microscopy after the formal-ether concentration. Genotyping of Giardia was carried out using PCR and sequence analysis of the 16s rRNA and b-giardin genes. Of the 89 microscopy-positive Giardia samples, 65 were successfully sequenced, of which 66% (43 of 65) were identified as G. duodenalis assemblage A and 34% (22 of 65) as assemblage B. Further subtyping analysis based on b-giardin gene identified the presence of subtypes A2 and A3, which belong to the anthroponotic sub-assemblage AII. Data of the study suggest that anthroponotic transmission played a potential role in the transmission of giardiasis in the community. However, further genotyping and subtyping studies of specimens from humans and animals living in the same households are needed for a more definitive understanding of giardiasis transmission in Yemen.
authors.affiliation: Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Naela A
authors.initials: NA
authors.lastname: Alyousefi
authors.forename: Mohammed A K
authors.initials: MA
authors.lastname: Mahdy
authors.forename: Lihua
authors.initials: L
authors.lastname: Xiao
authors.forename: Rohela
authors.initials: R
authors.lastname: Mahmud
authors.forename: Yvonne A L
authors.initials: YA
authors.lastname: Lim
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001483:Base Sequence; D002648:Child; D002675:Child, Preschool; D003598:Cytoskeletal Proteins / Q000235:genetics; D016054:DNA, Protozoan / Q000737:chemistry; D005243:Feces / Q000469:parasitology; D005260:Female; D005838:Genotype; D060005:Genotyping Techniques; D016829:Giardia lamblia / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D005873:Giardiasis / Q000453:epidemiology / Q000469:parasitology* / Q000635:transmission; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D010802:Phylogeny; D015800:Protozoan Proteins / Q000235:genetics; D016415:Sequence Alignment; D012959:Socioeconomic Factors; D015006:Yemen / Q000453:epidemiology; D055815:Young Adult
chemical_list: D003598:Cytoskeletal Proteins; D016054:DNA, Protozoan; D015800:Protozoan Proteins; C038207:giardin protein, Giardia lamblia