Comparison of two target genes for detection and genotyping of Giardia lamblia in human feces by PCR and PCR-restriction fragment length polymorphism.
A PCR assay targeting the tpi gene was developed to detect and to genotype Giardia lamblia in human feces. Our assay was specific and discriminated between G. lamblia assemblages A and B. G. lamblia cysts isolated from human feces were also analyzed with two previously described PCR-restriction fragment length polymorphism (RFLP) assays, which are based on the detection of tpi or gdh genes. These RFLP analyses distinguished groups I and II within assemblage A or groups III and IV within assemblage B. Among 26 fecal samples from patients with sporadic giardiasis diagnosed by hospital laboratories, the tpi gene was amplified from 25 (96%) with our PCR assay, whereas only 21 (81%) samples were positive when the gdh gene was targeted. Of the 25 positive samples, nine (36%) contained assemblage A and 16 (64%) contained assemblage B. Thus, RFLP analysis classified eight samples (32%) in assemblage A group II, eight (32%) in assemblage B group III, and five (20%) in assemblage B group IV. The group could not be specified for four samples. The tpi and gdh genes of G. lamblia assemblage B were amplified from 14 (93%) of 15 samples collected only from French soldiers coming back from the Ivory Coast. All of these contained assemblage B group III. The PCR method developed is sensitive, simple, and specific and shows that the tpi gene is well adapted for G. lamblia genotyping.
Bertrand
Isabelle
I
LCPME-UMR 7564 CNRS-UHP, Equipe Microbiologie et Physique, Faculté de Pharmacie, 5 rue Albert Lebrun, BP 80 403, 54001 Nancy Cedex, France. Isabelle.Bertrand@pharma.uhp-nancy.fr
Albertini
Laetitia
L
Schwartzbrod
Janine
J
D000293:Adolescent; D000328:Adult; D000818:Animals; D002675:Child, Preschool; D016054:DNA, Protozoan / Q000032:analysis / Q000235:genetics; D005243:Feces / Q000469:parasitology*; D005260:Female; D005838:Genotype; D016829:Giardia lamblia / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D005873:Giardiasis / Q000469:parasitology; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods*; D012150:Polymorphism, Restriction Fragment Length; D012680:Sensitivity and Specificity; D014305:Triose-Phosphate Isomerase / Q000235:genetics*
D016054:DNA, Protozoan; D014305:Triose-Phosphate Isomerase