Assuntos
Mycobacterium tuberculosis , Tuberculose Resistente a Múltiplos Medicamentos , Humanos , Mycobacterium tuberculosis/genética , Microesferas , Antituberculosos/farmacologia , Mutação , Testes de Sensibilidade Microbiana , Fluoroquinolonas , Farmacorresistência Bacteriana/genética , Tuberculose Resistente a Múltiplos Medicamentos/microbiologiaRESUMO
OBJECTIVE: To evaluate multidrug resistant loop-mediated isothermal amplification (MDR-LAMP) assay for the early diagnosis of multidrug-resistant tuberculosis and to compare the mutation patterns associated with the rpoB, katG, and inhA genes at the Chinese Center for Disease Control and Prevention. METHODS: MDR-LAMP assay was evaluated using 100 Mycobacterium tuberculosis ( Mtb) isolates obtained from the National Reference Laboratory for Tuberculosis in China. Phenotypic resistance to isoniazid and rifampicin and whole-genome sequencing served as reference standards. RESULTS: The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MDR-LAMP were 85.5%, 93.6%, 96.7%, and 74.4% for the detection of resistance to isoniazid and rifampicin, respectively, and 80.5%, 92.3%, 98.6%, and 41.4% for the detection of Mtb cultured from smear-positive sputum samples, respectively. When DNA sequencing was used as the reference standard, the sensitivity, specificity, PPV, and NPV of MDR-LAMP were 93.1%, 92.3%, 97.2%, and 82.8% for the detection of katG and inhA gene mutations, respectively, and 89.1%, 88.9%, 93.4%, and 81.1% for the detection of rpoB gene mutation, respectively. CONCLUSION: MDR-LAMP is a rapid and accessible assay for the laboratory identification of rifampicin and isoniazid resistance of Mtb isolates.
Assuntos
DNA Bacteriano/análise , Farmacorresistência Bacteriana Múltipla/genética , Técnicas de Diagnóstico Molecular/métodos , Mycobacterium tuberculosis/genética , Técnicas de Amplificação de Ácido Nucleico/métodos , Antituberculosos , Proteínas de Bactérias/genética , Catalase/genética , RNA Polimerases Dirigidas por DNA/genética , Isoniazida , Mutação , Mycobacterium tuberculosis/isolamento & purificação , Oxirredutases/genética , Fenótipo , Rifampina , Sequenciamento Completo do GenomaRESUMO
BACKGROUND: Information on the prevalence and resistance spectrum of nontuberculous mycobacteria (NTM) in China is mainly based on regional or local data. To estimate the proportion of NTM cases in China, a national survey of NTM pulmonary disease was carried out based on acid-fast positive sputum samples collected in 2013. METHODS: Sputum samples collected from enrolled presumptive cases in 72 nationwide tuberculosis surveillance sites from the 31 provinces in the mainland of China were cultured using L-J medium at the National tuberculosis reference laboratory (NTRL). MALDI-TOF MS identified the species of re-cultured strains, and minimal inhibitory concentrations (MICs) were determined to evaluate the drug susceptibility of NTM isolates. Data analysis used statistical software SPSS version 22.0 for Windows statistical package. RESULTS: Of 4917 mycobacterial isolates cultured, 6.4% [317/4917, 95% confidence interval (CI) 5.8%-7.2%] were confirmed as NTM, among which 7.7% (287/3709, 95% CI 6.9%-8.6%) were from the southern region. In inland and coastal China, 87.7% (95% CI 78.7%-93.2%) and 50.0% (95% CI 43.7%-56.3%) of isolates, respectively, were slow-growing mycobacteria (SGM), with the remaining rapid growing mycobacteria (RGM). A total of 29 species were detected, Mycobacterium abscessus had higher clarithromycin-inducible resistance rates than M. massiliense (65.67% vs 2.22%). M. kansasii presented lower resistance rates in linezolid and moxifloxacin than M. avium-intracellulare complex (3.23% vs 66.67%, 0 vs 47.22%) and other SGM (3.23% vs 38%, 0 vs 26%). CONCLUSIONS: More NTM pulmonary disease was observed in the south and coastal China (P < 0.01). SGM was widely distributed, and more RGM are present in southern and coastal China (P < 0.01). The antimicrobial resistance spectrum of different NTM species was significantly different and accurate species identification would be facilitated to NTM pulmonary disease treatment.
Assuntos
Antibacterianos , Micobactérias não Tuberculosas , Antibacterianos/farmacologia , China/epidemiologia , Farmacorresistência Bacteriana , IncidênciaRESUMO
A pot culture experiment was carried out to investigate the accumulation properties of mercury (Hg) in rice grain and cabbage grown in seven soil types (Udic Ferrisols, Mollisol, Periudic Argosols, Latosol, Ustic Cambosols, Calcaric Regosols, and Stagnic Anthrosols) spiked with different concentrations of Hg (CK, 0.25, 0.50, 1.00, 2.00, and 4.00 mg/kg). The results of this study showed that Hg accumulation of plants was significantly affected by soil types. Hg concentration in both rice grain and cabbage increased with soil Hg concentrations, but this increase differed among the seven soils. The stepwise multiple regression analysis showed that pH, Mn(II), particle size distribution, and cation exchange capacity have a close relationship with Hg accumulation in plants, which suggested that physicochemical characteristics of soils can affect the Hg accumulation in rice grain and cabbage. Critical Hg concentrations in seven soils were identified for rice grain and cabbage based on the maximum safe level for daily intake of Hg, dietary habits of the population, and Hg accumulation in plants grown in different soil types. Soil Hg limits for rice grain in Udic Ferrisols, Mollisol, Periudic Argosols, Latosol, Ustic Cambosols, Calcaric Regosols, and Stagnic Anthrosols were 1.10, 2.00, 2.60, 2.78, 1.53, 0.63, and 2.17 mg/kg, respectively, and critical soil Hg levels for cabbage are 0.27, 1.35, 1.80, 1.70, 0.69, 1.68, and 2.60 mg/kg, respectively.
