ABSTRACT
Tuberculosis (TB) is the leading cause of death among infectious diseases worldwide. Among the estimated cases of drug-resistant TB, approximately 60% occur in the BRICS countries (Brazil, Russia, India, China and South Africa). Among Brazilian states, primary and acquired multidrug-resistant TB (MDR-TB) rates were the highest in Rio Grande do Sul (RS). This study aimed to perform molecular characterisation of MDR-TB in the State of RS, a high-burden Brazilian state. We performed molecular characterisation of MDR-TB cases in RS, defined by drug susceptibility testing, using 131 Mycobacterium tuberculosis (M.tb) DNA samples from the Central Laboratory. We carried out MIRU-VNTR 24loci, spoligotyping, sequencing of the katG, inhA and rpoB genes and RDRio sublineage identification. The most frequent families found were LAM (65.6%) and Haarlem (22.1%). RDRio deletion was observed in 42 (32%) of the M.tb isolates. Among MDR-TB cases, eight (6.1%) did not present mutations in the studied genes. In 116 (88.5%) M.tb isolates, we found mutations associated with rifampicin (RIF) resistance in rpoB gene, and in 112 isolates (85.5%), we observed mutations related to isoniazid resistance in katG and inhA genes. An insertion of 12 nucleotides (CCAGAACAACCC) at the 516 codon in the rpoB gene, possibly responsible for a decreased interaction of RIF and RNA polymerase, was found in 19/131 of the isolates, belonging mostly to LAM and Haarlem families. These results enable a better understanding of the dynamics of transmission and evolution of MDR-TB in the region.
Subject(s)
Bacterial Proteins/genetics , Drug Resistance, Multiple, Bacterial/genetics , Mycobacterium tuberculosis/drug effects , Tuberculosis, Multidrug-Resistant/epidemiology , Tuberculosis, Multidrug-Resistant/genetics , Adolescent , Adult , Age Distribution , Antitubercular Agents/therapeutic use , Brazil/epidemiology , Cost of Illness , DNA-Directed RNA Polymerases/genetics , Databases, Factual , Drug Resistance, Multiple, Bacterial/drug effects , Female , Genotype , Humans , Incidence , Male , Microbial Sensitivity Tests , Middle Aged , Minisatellite Repeats/genetics , Mycobacterium tuberculosis/isolation & purification , Retrospective Studies , Risk Assessment , Sex Distribution , Tuberculosis, Multidrug-Resistant/drug therapy , Young AdultABSTRACT
Herein, we intended to perform flow-cytometric analyses of peripheral blood NK-cell subsets in patients with active tuberculosis (TB) and those putative resistant subjects displaying positive tuberculin skin test (TST+) and compared with TST- healthy controls. Our findings demonstrated distinct phenotypic features in TST+ as compared with TB. While lower values of NK-cells with increased frequency of CD3-CD16+ CD56- and CD3-CD16-CD56+ subsets besides lower frequency of CD3-CD16+ CD56+ NK-cells was observed in TST+, unaltered levels of NK-cells with increased levels of CD3-CD16+ CD56- NK-cells with lower frequency of CD3-CD16+ CD56+ NK-cells was found in TB. Additional analysis highlighted a shift towards increased levels of CD3-CD16-/+CD56bright NK-cells as the hallmark of TST+, whereas unaltered frequency was observed in TB. Increased levels of CD3+CD56+ cells were observed in both TST+ and TB. Further focusing on the monocyte/NK-cell network, we have reported that enhanced frequency of CD14+ CD16+ monocytes particularly observed in TST+. Outstanding were the distinct correlation profiles observed between CD3-CD16-CD56+ NK-cells and CD3+ CD56+ cells CD14+ CD16+ monocytes for TST+ and TB. These data suggested that high levels of CD3-CD16-CD56+ NK-cells aside CD14+ CD16+ monocytes as well as non-concurrent increment of CD3+ CD56+ cells, may be involved in protective mechanisms in putative tuberculosis-resistant individuals. On the other hand, the basal levels of macrophage-like monocytes despite its positive correlation with increased levels of CD3+ CD56+ cells may count for the lack of the protective immunity in patients with active tuberculosis. Further studies focusing on the cytokine profiling of peripheral blood innate immunity cells before and after chemotherapeutic treatment are currently under evaluation.
Subject(s)
Killer Cells, Natural/immunology , Lymphocyte Subsets/immunology , Tuberculosis/immunology , Adult , Female , Flow Cytometry , Humans , Immunophenotyping , Male , Middle Aged , Mycobacterium tuberculosis/immunology , Tuberculin TestABSTRACT
Foi comparado o rendimento diagnóstico de tuberculose obtido em estudo propesctivo do líquido pleural de 80 pacientes e em análise retrospectiva de 105 prontuários médicos. Na série prospectiva foi introduzido o controle de qualidade, quando atençäo especial foi dada à colheita, transporte e processamento (precedido ou näo de descontaminaçäo) do líquido pleural. Na série retrospectiva utilizou-se a rotina do Serviço de Bacteriologia da Tuberculose, que consistia em descontaminaçäo de todos os materiais. Na abordagem prospectiva, 97 por cento dos pacientes tiveram seu diagnóstico confirmado. Este foi obtido histopatologicamente em 87 por cento e bacteriologicamente em 56 por cento dos casos. No estudo retrospectivo, a confirmaçäo diagnóstica ocorreu em 94 por cento dos casos. Na série prospectiva, a sensibilidade da cultura no líquido pleural näo precedida de descontaminaçäo (36 por cento) foi superior àquela observada no material submetido a descontaminaçäo (29 por cento) (p = 0,02). O rendimento da cultura do líquido pleural submetido a descontaminaçäo foi de 29 por cento e o oservado no exame bacteriológico do fragmento pleural, de 42 por cento (p < 0,02). Entretanto, na ausência de descontaminaçäo, o rendimento bacteriológico do líquido pleural (36 por cento) e o do fragmento pleural (42 por cento) foram semelhantes (p = 0,22). O controle de qualidade introduzido na série prospectiva aumentou o rendimento da cultura do líquido pleural de 26 por cento para 29 por cento.
