title: Prospective genotyping of Mycobacterium tuberculosis from fresh clinical samples.
abstract: Shorter time-to-result is key for improving molecular-guided epidemiological investigation of tuberculosis (TB) cases. We performed a prospective study to evaluate the use of standardized MIRU-VNTR (mycobacterial interspersed repetitive-unit-variable-number tandem-repeat) typing of Mycobacterium tuberculosis directly on 79 fresh clinical samples from 26 TB patients consecutively enrolled over a 17-month period. Overall, complete 24-locus types were obtained for 18 out of the 26 (69.2%) patients and 14 of the 16 grade 3+ and grade 2+ samples (87.5%). The degree of completion of the genotypes obtained significantly correlated with smear microscopy grade both for 26 first samples (p = 0.0003) and for 53 follow-up samples (p = 0.002). For 20 of the 26 patients for whom complete or even incomplete M. tuberculosis isolate genotypes were obtained, typing applied to the clinical samples allowed the same unambiguous conclusions regarding case clustering or uniqueness as those that could have been drawn based on the corresponding cultured isolates. Standard 24 locus MIRU-VNTR typing of M. tuberculosis can be applied directly to fresh clinical samples, with typeability depending on the bacterial load in the sample.
authors.affiliation: Laboratory for Mycobacteria, University Clinic of Respiratory and Allergic Diseases, Golnik, Slovenia.
authors.forename: Urška
authors.initials: U
authors.lastname: Bidovec-Stojkovič
authors.affiliation: University of Ljubljana, Faculty of Medicine, Institute of Microbiology and Immunology, Ljubljana, Slovenia.
authors.forename: Katja
authors.initials: K
authors.lastname: Seme
authors.affiliation: Laboratory for Mycobacteria, University Clinic of Respiratory and Allergic Diseases, Golnik, Slovenia.
authors.forename: Manca
authors.initials: M
authors.lastname: Žolnir-Dovč
authors.affiliation: INSERM U1019, Lille, France; CNRS UMR 8204, Lille, France; University of Lille Nord de France, Lille, France; Institut Pasteur de Lille, Center for Infection and Immunity of Lille, Lille, France; Genoscreen, Lille, France.
authors.forename: Philip
authors.initials: P
authors.lastname: Supply
mesh_terms: D000483:Alleles; D004269:DNA, Bacterial / Q000378:metabolism; D056426:Genetic Loci; D005838:Genotype; D006801:Humans; D018598:Minisatellite Repeats / Q000235:genetics; D009169:Mycobacterium tuberculosis / Q000235:genetics* / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D012720:Severity of Illness Index; D014376:Tuberculosis / Q000382:microbiology* / Q000473:pathology
chemical_list: D004269:DNA, Bacterial