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.The intestinal protozoan Giardia lamblia (synonyms, G. intestinalis and G. duodenalis [1]) is a cosmopolitan parasite frequently involved in human parasitic gastroenteritis throughout the world. Transmission of the G. lamblia cyst to humans occurs mainly following ingestion of contaminated water. Clinical manifestations of symptomatic giardiasis include greasy stools, flatulence, diarrhea, and abdominal cramps (9). However, the majority of cases are asymptomatic or minimally symptomatic in immunocompetent individuals.Among the six species identified in the Giardia genus, only G. lamblia infects humans and numerous other mammals as well (1,25). Moreover, isolates of G. lamblia are classified into seven assemblages, based on the characterization of the glutamate dehydrogenase (gdh), small-subunit (SSU) rRNA, and triosephosphate isomerase (tpi) genes (12,18,20,21). Assemblages A and B infect humans and a broad range of other hosts, including livestock, cats, dogs, and wild mammals. The assemblage A isolates have been further grouped into subgroups I and II. The assemblage B isolates have been separated into subgroups III and IV (17,24). Genetic assemblages C, D, E, F, and G appear to be host restricted to domestic animals, livestock, and wild animals (19, 21).At present, antigen detection immunoassays for Giardia are used as the routine diagnostic procedure of choice in many hospitals and public health laboratories (8,13,27). However, these methods are unable to differentiate between the genetic asemblages of Giardia lamblia. Molecular detection methods based on PCR have been developed to detect G. lamblia cysts in feces. These techniques have numerous ad...

The ATP-binding cassette (ABC) transporter ABCB1, or P-glycoprotein, is a transmembrane efflux pump well known for its implication in drug transport and chemoresistance. ABCB1 substrates include either drugs, such as antiretrovirals and immunomodulators, or physiological molecules like phospholipids. Pharmacogenetic analysis of ABCB1 polymorphisms, in addition to other xenobiotic metabolizing enzymes, might help to personalize and optimize drug therapy. Indeed, some polymorphisms of ABCB1 have been implicated in susceptibility to diseases, changes in drug pharmacokinetics, and in variation of the biological response to drug treatment. In addition, variant and haplotype distributions differ depending on ethnicity. Thus, some ethnies may be at higher risk for adverse events, inefficacy of treatment or prevalence of pathologies. This study aimed to determine frequencies of ABCB1 polymorphisms and haplotypes in a sample of French healthy individuals. DNA was isolated from blood-EDTA. Polymerase chain reaction-restriction fragment length polymorphism and TaqMan single nucleotide polymorphism genotyping assays were used to genotype 227 individuals for T-129C, G-1A, A61G, G1199A, C1236T, T-76A, G2677T/A and C3435T polymorphisms. The observed frequencies of the variant allele for these eight polymorphisms are 0.04, 0.08, 0.09, 0.06, 0.42, 0.46, 0.45 and 0.46 respectively. These polymorphisms are in linkage disequilibrium and haplotype frequencies were determined, the most frequent haplotype being the one with variants at position 1236, 2677 and 3435 and wild-type alleles at the other positions. Finally, the frequencies of these eight ABCB1 polymorphisms in our French individuals supposed to be healthy population are quite similar to those described in other Caucasian populations except for the C3435T polymorphism.

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