Discovery of a Novel Mycobacterium tuberculosis Lineage That Is a Major Cause of Tuberculosis in Rio de Janeiro, Brazil

• Published in: Journal of Clinical Microbiology Vol. 45; no. 12; pp. 3891 - 3902
• Main Authors: Lazzarini, Luiz Claudio Oliveira, Huard, Richard C, Boechat, Neio L, Gomes, Harrison M, Oelemann, Maranibia C, Kurepina, Natalia, Shashkina, Elena, Mello, Fernanda C.Q, Gibson, Andrea L, Virginio, Milena J, Marsico, Ana Grazia, Butler, W. Ray, Kreiswirth, Barry N, Suffys, Philip N, Lapa e Silva, Jose Roberto, Ho, John L
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for Microbiology 01.12.2007; American Society for Microbiology (ASM)
• Subjects: Animals; Bacterial diseases; Bacteriology; Biological and medical sciences; Brazil - epidemiology; Cluster Analysis; DNA Fingerprinting; DNA Transposable Elements - genetics; DNA, Bacterial - genetics; Fundamental and applied biological sciences. Psychology; Genotype; Human bacterial diseases; Humans; Infectious diseases; Medical sciences; Microbiology; Minisatellite Repeats - genetics; Miscellaneous; Mycobacteriology and Aerobic Actinomycetes; Mycobacterium; Mycobacterium tuberculosis; Mycobacterium tuberculosis - classification; Mycobacterium tuberculosis - genetics; Mycobacterium tuberculosis - isolation & purification; Mycobacterium tuberculosis - pathogenicity; Phylogeny; Polymerase Chain Reaction - methods; Polymorphism, Genetic; Polymorphism, Restriction Fragment Length; Recombination, Genetic; Sequence Deletion; Tuberculosis - epidemiology; Tuberculosis - microbiology; Tuberculosis - pathology; Tuberculosis - physiopathology; Tuberculosis and atypical mycobacterial infections; South America; Brazil; America; Infection; Tuberculosis; Mycobacterium tuberculosis; Mycobacteriales; Bacteriosis; Mycobacteriaceae; Bacteria; Actinomycetes; Mycobacterial infection
• ISSN: 0095-1137; 1098-660X; 1098-5530
• DOI: 10.1128/JCM.01394-07

The current study evaluated Mycobacterium tuberculosis isolates from Rio de Janeiro, Brazil, for genomic deletions. One locus in our panel of PCR targets failed to amplify in ~30% of strains. A single novel long sequence polymorphism (>26.3 kb) was characterized and designated RDRio. Homologous recombination between two similar protein-coding genes is proposed as the mechanism for deleting or modifying 10 genes, including two potentially immunogenic PPE proteins. The flanking regions of the RDRio locus were identical in all strains bearing the deletion. Genetic testing by principal genetic group, spoligotyping, variable-number tandem repeats of mycobacterial interspersed repetitive units (MIRU-VNTR), and IS6110-based restriction fragment length polymorphism analysis cumulatively support the idea that RDRio strains are derived from a common ancestor belonging solely to the Latin American-Mediterranean spoligotype family. The RDRio lineage is therefore the predominant clade causing tuberculosis (TB) in Rio de Janeiro and, as indicated by genotypic clustering in MIRU-VNTR analysis, the most significant source of recent transmission. Limited retrospective reviews of bacteriological and patient records showed a lack of association with multidrug resistance or specific risk factors for TB. However, trends in the data did suggest that RDRio strains may cause a form of TB with a distinct clinical presentation. Overall, the high prevalence of this genotype may be related to enhanced virulence, transmissibility, and/or specific adaptation to a Euro-Latin American host population. The identification of RDRio strains outside of Brazil points to the ongoing intercontinental dissemination of this important genotype. Further studies are needed to determine the differential strain-specific features, pathobiology, and worldwide prevalence of RDRio M. tuberculosis.