title: Mixed infections of Mycobacterium tuberculosis in tuberculosis patients in Shanghai, China.
abstract: We applied a 7 loci Variable-Number-Tandem-Repeats (VNTR-7) analysis method to identify mixed infections of Mycobacterium tuberculosis and to estimate the rate of mixed infections among pulmonary tuberculosis patients in Shanghai, China. We validated the VNTR-7 method and used it to genotype an isolate from each of the 249 from pulmonary tuberculosis patients reported from the Songjiang and Chongming districts in Shanghai during 2006. We identified 14 patients with mixed infections, and the estimated rate of mixed infections was 5.6% (14/249) (95% CI 3.1%-9.2%). Mixed infections were observed more frequently among tuberculosis patients undergoing retreatment (15.6%) than among new cases (4.1%) (p<0.05), and among tuberculosis patients whose disease was caused by non-Beijing genotype strains (12.5%) versus Beijing genotype strains (3.5%) (p<0.05). The VNTR-7 method is a highly sensitive, practical tool with relatively high discriminatory power, making it useful for studying mixed infections.
authors.affiliation: Shanghai Institutes of Preventive Medicine, Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China.
authors.forename: Rendong
authors.initials: R
authors.lastname: Fang
authors.forename: Xia
authors.initials: X
authors.lastname: Li
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Jie
authors.initials: J
authors.lastname: Wu
authors.forename: Xin
authors.initials: X
authors.lastname: Shen
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Gui
authors.forename: Kathryn
authors.initials: K
authors.lastname: DeRiemer
authors.forename: Li
authors.initials: L
authors.lastname: Liu
authors.forename: Jian
authors.initials: J
authors.lastname: Mei
authors.forename: Qian
authors.initials: Q
authors.lastname: Gao
mesh_terms: D002681:China; D004269:DNA, Bacterial / Q000302:isolation & purification; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D018598:Minisatellite Repeats / Q000235:genetics*; D009169:Mycobacterium tuberculosis / Q000235:genetics* / Q000302:isolation & purification; D016133:Polymerase Chain Reaction / Q000379:methods; D032581:Tuberculosis Vaccines; D018088:Tuberculosis, Multidrug-Resistant / Q000382:microbiology*; D014397:Tuberculosis, Pulmonary / Q000382:microbiology* / Q000517:prevention & control
chemical_list: D004269:DNA, Bacterial; D032581:Tuberculosis Vaccines