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1.
Artigo em Inglês | MEDLINE | ID: mdl-31898799

RESUMO

The aim of our study was to evaluate the performance of conventional drug susceptibility testing (DST) among the tuberculosis (TB)-specialized hospitals in China. A total of 40 hospitals participated in the external quality assurance program for assessment of DST results from each hospital. The sensitivity, specificity, and accuracy of DST were analyzed. The mean accuracy was 96.5% for isoniazid (INH), 95.8% for rifampin (RIF), 97.0% for ethambutol (EMB), 96.8% for ofloxacin (OFX), 97.1% for kanamycin (KAN), 96.1% for amikacin (AMK), and 93.6% for capreomycin (CAP), respectively. Of the 40 participating laboratories, 4 (10.0%) and 6 (15%) failed to achieve 90% accuracy for INH and RIF, respectively. In addition, six hospitals (15%) were confirmed as certified to provide reliable DST results for both first-line and second-line drugs. The certified proportion for DST dropped from 73.9% in the non-western region to 59.2% in the western region. The significant difference was observed in the certified proportion for first-line drugs between the western and non-western region (P = 0.013). Our results demonstrate that the quality of phenotypical DST is frequently unsatisfactory, with approximately one-third of participated laboratories failing to produce certified phenotypical DST results. In addition, the uncertified laboratories majorly come from the western region in China.

2.
Chest ; 157(2): 268-275, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31437432

RESUMO

BACKGROUND: The Xpert MTB/RIF (Xpert) assay has greatly improved the diagnosis of TB and identification of resistance to rifampicin (RIF). However, sensitivity of Xpert remains poor for pleural fluid detection. This study evaluated the performance of the novel next-generation Xpert MTB/RIF Ultra (Xpert Ultra) in comparison with Xpert for pleural TB diagnosis. METHODS: Patients with suspected pleural TB were enrolled consecutively in four hospitals, and pleural fluids were subjected to smear, culture, and Xpert. Defrosted pleural fluid (-80°C) was examined using Xpert Ultra. Drug susceptibility testing (DST) was conducted for all of the recovered isolates. RESULTS: In total, 317 individuals with suspected pleural TB were recruited; 208 of them were diagnosed with pleural TB according to the composite reference standard, which was composed of clinical, laboratory, histopathologic, and radiologic examination features and ≥ 12 months of follow-up data. The direct head-to-head comparison for Mycobacterium tuberculosis detection showed that Xpert Ultra (44.23%, 92 of 208) produced a higher sensitivity than culture (26.44%, 55 of 208, P < .001), Xpert (19.23%, 40 of 208, P < .001), and smear (1.44%, three of 208, P < .001). When Xpert Ultra outcomes were integrated, the percentage of definite pleural TB cases increased from 56.25% (117 of 208) to 64.90% (135 of 208). The specificities of smear, culture, Xpert, and Xpert Ultra were 100% (84 of 84), 100% (84 of 84), 98.67% (83 of 84), and 98.67% (83 of 84), respectively. Xpert Ultra was 100% concordant with phenotype DST for the detection of RIF resistance. CONCLUSIONS: Xpert Ultra has great potential in diagnosis of pleural TB and its RIF resistance, which could speed up the initiation of appropriate treatment.

3.
J Infect ; 79(2): 153-158, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31207324

RESUMO

OBJECTIVES: The diagnosis of osteoarticular tuberculosis (TB) remains challenging and results in under- or over-diagnosis. The aim of the present study was to evaluate performance of the novel next-generation Xpert MTB/RIF Ultra (Xpert Ultra) in comparison to culture and Xpert MTB/RIF (Xpert) for osteoarticular TB diagnosis in high burden settings. METHODS: Osteoarticular TB suspected cases were enrolled consecutively during June 2017 to June 2018 at Beijing Chest Hospital and their pus specimens were subjected to smear, culture, Xpert and Xpert Ultra. Drug susceptibility testing (DST) was conducted for all of the recovered isolates. The performances of Xpert Ultra and Xpert were evaluated using composite reference standard (CRS) as gold standard, which included clinical, laboratory, histopathological, radiological and ≥6 months' follow-up data. RESULTS: In total, 186 patients were recruited, and 132 of them were diagnosed with osteoarticular TB according to CRS. The direct head-to-head performance comparison for M. tuberculosis detection showed that Xpert Ultra (90.91%, 120/132) produced a higher sensitivity than Xpert (78.79%, 104/132, P = 0.006) and culture (39.39%, 52/132, P < 0.001). When Xpert Ultra outcomes were integrated, the percentage of confirmed osteoarticular TB case increased from 84.09% (111/132) to 93.94% (124/132). The specificities of Xpert and Xpert Ultra were 100% (34/34) and 97.06% (33/34), respectively. Both Xpert Ultra and Xpert accurately identified all of the 9 rifampicin (RIF)-resistant and 38 RIF-sensitive cases defined by phenotypic DST. Therefore, Xpert Ultra was 100% concordant with phenotypic DST for the detection of RIF resistance. CONCLUSIONS: Xpert Ultra detected significantly more osteoarticular TB cases than Xpert or culture, making it a useful tool for rapid diagnosis of osteoarticular TB.

4.
Infect Drug Resist ; 12: 825-829, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31114264

RESUMO

Background: The purpose of this work was to assess the activity of para-aminosalicylic acid (PAS) in combination with isoniazid (INH) against clinical isolates of Mycobacterium tuberculosis (MTB). Materials and methods: A total of 72 MTB isolates with differential in vitro drug susceptibilities were included in this study, comprising 24 pan-susceptible, 24 MDR-TB, and 24 extensively drug-resistant (XDR) isolates. A microplate alamarBlue assay was performed to identify the minimal inhibitory concentrations (MICs) of MTB isolates. Results: The MIC50 of INH was 4 mg/L, and that of PAS was 0.063 mg/L against MTB isolates when single drug used. The combined use of INH and PAS resulted in 16-fold and 8-fold decrease in MIC50 for INH and PAS, respectively. The INH-PAS revealed synergistic activity in 94.4% of the isolates. In addition, there was no significant difference in the FIC index of the INH-PAS combination among individual isolates harboring different susceptibility pattern (P>0.05). Conclusion: The synergy between INH and PAS is demonstrated using non-multidrug-resistant (non-MDR) and MDR-TB strains, which will provide clinicians with useful hints to reuse this combination for treatment of TB patients in clinical practice.

5.
J Infect ; 78(4): 311-316, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30796951

RESUMO

OBJECTIVES: We assessed the diagnostic performance of Xpert MTB/RIF Ultra (Xpert Ultra) in comparison to Xpert MTB/RIF (Xpert) for the detection of paucibacillary tuberculosis (TB). METHODS: Smear-negative sputum, pleural fluid and cerebrospinal fluid (CSF) were collected from TB suspects at Beijing Chest Hospital (Beijing, China) and were examined using smear, Xpert and culture. Xpert Ultra was tested using specimens stored at -80 °C. Drug susceptibility testing (DST) was conducted for all of the isolates recovered. The performances of Xpert Ultra and Xpert were evaluated using composite reference standard (CRS) as gold standard, which included clinical, laboratory, histopathological, radiological and follow-up features. RESULTS: Totally 689 cases were included. The direct head-to-head diagnostic performance comparison showed higher sensitivity of Xpert Ultra in contrast with Xpert among 292 smear-negative pulmonary TB (PTB) (70.89% vs 57.88%, P = 0.001), 108 tuberculous pleurisy (61.11% vs 34.26%, P<0.001), and 43 tuberculous meningitis (44.19% vs 18.60%, P = 0.011). The percentage of definite PTB, tuberculous pleurisy and tuberculous meningitis increased from 67.12% to 78.77%, 61.11% to 69.44% and 23.26% to 51.16%, respectively after integrating Xpert Ultra outcomes. The specificity of Xpert Ultra and Xpert was 96.75% (238/246) and 98.37% (242/246), respectively. Xpert Ultra and Xpert performed similarly in detecting rifampicin resistance. CONCLUSION: Xpert Ultra has higher sensitivity but relatively reduced specificity compared with Xpert in diagnosis of paucibacillary TB. Performing Xpert Ultra would improve the definite diagnosis of smear-negative pulmonary tuberculosis, tuberculous pleurisy and tuberculous meningitis.

6.
Clin Infect Dis ; 69(3): 405-413, 2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-30321294

RESUMO

BACKGROUND: The increase in multidrug-resistant tuberculosis (MDR-TB) severely hampers tuberculosis prevention and control in China, a country with the second highest MDR-TB burden globally. The first nationwide drug-resistant tuberculosis surveillance program provides an opportunity to comprehensively investigate the epidemiological/drug-resistance characteristics, potential drug-resistance mutations, and effective population changes of Chinese MDR-TB. METHODS: We sequenced 357 MDR strains from 4600 representative tuberculosis-positive sputum samples collected during the survey (70 counties in 31 provinces). Drug-susceptibility testing was performed using 18 anti-tuberculosis drugs, representing the most comprehensive drug-resistance profile to date. We used 3 statistical and 1 machine-learning methods to identify drug-resistance genes/single-nucleotide polymorphisms (SNPs). We used Bayesian skyline analysis to investigate changes in effective population size. RESULTS: Epidemiological/drug-resistance characteristics showed different MDR profiles, co-resistance patterns, preferred drug combination/use, and recommended regimens among 7 Chinese administrative regions. These factors not only reflected the serious multidrug co-resistance and drug misuse but they were also potentially significant in facilitating the development of appropriate regimens for MDR-TB treatment in China. Further investigation identified 86 drug-resistance genes/intergenic regions/SNPs (58 new), providing potential targets for MDR-TB diagnosis and treatment. In addition, the effective population of Chinese MDR-TB displayed a strong expansion during 1993-2000, reflecting socioeconomic transition within the country. The phenomenon of expansion was restrained after 2000, likely attributable to the advances in diagnosis/treatment technologies and government support. CONCLUSIONS: Our findings provide an important reference and improved understanding of MDR-TB in China, which are potentially significant in achieving the goal of precision medicine with respect to MDR-TB prevention and treatment.

7.
Front Microbiol ; 9: 1858, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30154770

RESUMO

Tuberculosis (TB) recurrence can result from either relapse of an original infection or exogenous reinfection with a new strain of Mycobacterium tuberculosis (MTB). The aim of this study was to assess the roles of relapse and reinfection among recurrent TB cases characterized by a high prevalence rate of drug-resistant TB within a hospital setting. After 58 paired recurrent TB cases were genotyped to distinguish relapse from reinfection, 37 (63.8%) were demonstrated to be relapse cases, while the remaining 21 were classified as reinfection cases. Statistical analysis revealed that male gender was a risk factor for TB reinfection, odds ratios and 95% confidence interval (OR [95% CI]: 4.188[1.012-17.392], P = 0.049). Of MTB isolates obtained from the 37 relapse cases, 11 exhibited conversion from susceptible to resistance to at least one antibiotic, with the most frequent emergence of drug resistance observed to be levofloxacin. For reinfection cases, reemergence of rifampicin-resistant isolates harboring double gene mutations, of codon 531 of rpoB and codon 306 of embB, were observed. In conclusion, our data demonstrate that relapse is a major mechanism leading to TB recurrence in Beijing Chest Hospital, a national hospital specialized in TB treatment. Moreover, male patients are at higher risk for reinfection. The extremely high rate of multidrug-resistant tuberculosis (MDR-TB) among reinfection cases reflects more successful transmission of MDR-TB strains versus non-resistant strains overall.

8.
Emerg Microbes Infect ; 7(1): 109, 2018 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-29921972

RESUMO

Early diagnosis of spinal tuberculosis (TB) is hampered by the flaws of conventional tests. The aim of this study was to assess the value of new and existing molecular tests in a prospective, head-to-head cohort study. Specimens were consecutively collected from spinal TB suspects in four hospitals in Beijing, China. Smear, culture, histopathology, Xpert MTB/RIF (Xpert), and MeltPro TB assays were performed in parallel using the same specimen from each patient. Drug-susceptibility testing (DST) was conducted on the isolates recovered. In total, 438 suspects were recruited; 319 of them were diagnosed with spinal TB according to the composite reference standard (CRS), which was composed of clinical, laboratory, histopathological, and radiological examinations and 18 months of follow-up. Based on conventional testing, 74.29% of patients were classified as confirmed cases, which increased to 90.6% when Xpert outcomes were integrated. Further, 76.60% of probable and 45.71% of possible cases were re-classified as confirmed cases with Xpert. Xpert (85.27%) produced higher sensitivity than histopathology (73.04%), MeltPro TB (57.68%), culture (51.72%) and smear (24.45%) (all P <0.001). Xpert was 100% concordant with phenotypic DST regarding rifampicin resistance detection. The sensitivity and specificity of MeltPro TB for rifampicin resistance detection were 100% and 97.96%, respectively, and 95.00% and 93.88% for isoniazid resistance detection. New molecular tests demonstrated excellent efficiency for spinal TB diagnosis in this cohort study, so their application as initial diagnostic tools would greatly increase the proportion of confirmed cases and dramatically reduce the delay of appropriate treatment. An updated laboratory testing algorithm of the disease is desirable.


Assuntos
Técnicas de Diagnóstico Molecular/métodos , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose da Coluna Vertebral/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antituberculosos/farmacologia , China , Farmacorresistência Bacteriana , Feminino , Seguimentos , Humanos , Isoniazida/farmacologia , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/genética , Estudos Prospectivos , Rifampina/farmacologia , Tuberculose da Coluna Vertebral/microbiologia , Adulto Jovem
9.
J Thorac Dis ; 10(3): 1689-1695, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29707322

RESUMO

Background: Due to the non-homogeneity of specimens collected from tuberculosis (TB) suspects, repeated Xpert MTB/RIF (Xpert) may have potential clinical benefits. Incremental cost-effectiveness was analyzed for the second Xpert assay to detect Mycobacterium tuberculosis (Mtb) and rifampicin (RIF) resistance. Methods: Specimens were collected from 1,063 pulmonary TB (PTB) and 398 extrapulmonary TB (EPTB) suspects, who had two Xpert tests sequentially within one week. The specimens were subjected to smear, culture, Xpert and drug susceptibility testing. Incremental cost-effectiveness of the serial Xpert assays was evaluated. Results: Among 813 Xpert-positive TB patients, 755 (92.87%) were identified by the first assay whereas the additional 58 (7.13%) were identified by the second assay. The second Xpert assay had higher incremental yield for smear-negative than for smear-positive specimens (12.07% vs. 1.84%, P<0.001), and higher incremental yield for EPTB than for PTB (10.71% vs. 4.65%, P=0.003). About 94.48% (137/145) of the RIF-resistant patients were identified by the first Xpert assay and 5.52% (8/145) were identified by the second Xpert assay. After the first assay, the incremental cost of performing a second Xpert was huge: US$22.82 vs. US$467.72 (P<0.001) and US$35.02 vs. US$291.87 (P<0.001) for PTB and EPTB, respectively. The incremental cost of performing a second Xpert is lower in smear-negative than in smear-positive group in both PTB and EPTB. Conclusions: One Xpert assay is sufficient for smear-positive cases, and a second Xpert assay is beneficial not only for Mtb detection but also for RIF-resistant diagnosis for smear-negative TB suspects, whereas the incremental cost for the second Xpert is huge.

10.
Artigo em Inglês | MEDLINE | ID: mdl-29760127

RESUMO

Due to the natural resistance of nontuberculous mycobacteria (NTM) to many antibiotics, the treatment of diseases caused by NTM is often long-term but unsuccessful. The main goal of this study was to evaluate the in vitro susceptibilities to clofazimine of 209 isolates consisting of different NTM species isolated in Beijing, China. Furthermore, 47 reference strains were also tested, including 30 rapidly growing mycobacterium (RGM) species and 17 slowly growing mycobacterium (SGM) species. The potential molecular mechanism contributing to clofazimine resistance of NTM was investigated as well. Clofazimine exhibited excellent activity against both reference strains and clinical isolates of different SGM species, and most of the strains had MICs far below 1 µg/ml. Although the majority of the clinical isolates of Mycobacterium abscessus and Mycobacterium fortuitum had MICs higher than 2 µg/ml, 17 out of the 30 reference strains of different RGM species had MICs below 1 µg/ml in vitro According to the MIC distributions, the tentative epidemiological cutoff (ECOFF) values for Mycobacterium kansasii, Mycobacterium avium, and Mycobacterium intracellulare were defined at 0.5 µg/ml, 1 µg/ml, and 2 µg/ml, respectively. Intriguingly, single-direction cross-resistance between bedaquiline- and clofazimine (Cfz)-resistant isolates was observed among the tested NTM species. This study demonstrates that clofazimine had strong activity against most SGM species in vitro, as well as some RGM species. The data provide important insights into the possible clinical application of Cfz to treat NTM infections.


Assuntos
Antibacterianos/farmacologia , Clofazimina/farmacologia , Micobactérias não Tuberculosas/efeitos dos fármacos , Sequência de Aminoácidos , China , Farmacorresistência Bacteriana Múltipla , Humanos , Testes de Sensibilidade Microbiana , Infecções por Micobactéria não Tuberculosa/tratamento farmacológico , Mycobacterium abscessus/efeitos dos fármacos , Complexo Mycobacterium avium/efeitos dos fármacos , Mycobacterium fortuitum/efeitos dos fármacos , Mycobacterium kansasii/efeitos dos fármacos , Micobactérias não Tuberculosas/isolamento & purificação , Alinhamento de Sequência
11.
Front Microbiol ; 8: 1768, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28959248

RESUMO

The objective of this study was to investigate the cross-resistance between rifampin (RIF) and rifabutin (RFB) among clinical Mycobacterium tuberculosis (MTB) isolates, and the correlations between specific rpoB mutations and the minimum inhibitory concentrations (MICs) of RIF and RFB. A total of 256 RIF-resistant isolates were included from the National Tuberculosis Clinical Laboratory in China. The MICs of MTB isolates against RIF and RFB were determined by using a microplate alamarBlue assay. In addition, all the MTB isolates were sequenced for mutations in rpoB gene. 204 out of 256 isolates (79.7%) were resistant to RFB, whereas 52 (20.3%) were susceptible to RFB. RIF-resistant/INH-susceptible (RR) group had a significant lower proportion of RFB-resistance than MDR- (P = 0.04) and XDR-TB group (P < 0.01). DNA sequencing revealed that there were 218 isolates (85.2%) with a single mutation, 26 (10.1%) with double mutations, and 12 (4.7%) without mutation in rpoB gene. Notably, although the single substitution of Leu511Pro, Asp516Gly, and His526Asn did not result in RFB resistance, 77.8% (7/9) of the MTB isolates with these double mutations became resistant to RFB. Compared with RR group (38.9%, 7/18), MDR-TB (63.5%, 106/167) had significantly higher proportion of isolates with mutations in codon 531 of rpoB gene (P = 0.04). Our data demonstrate that various rpoB mutations are associated with differential resistance to RIF and RFB. A single specific mutation in codons 511, 516, 526, and 533 was linked to the susceptibility to RFB for MTB, while the strains with these double mutations irrelevantly conferring RFB resistance produced RFB-resistant phenotype.

12.
Sci Rep ; 7(1): 6181, 2017 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-28733605

RESUMO

Conventional bacteriological methods are not generally helpful in diagnosing urinary tuberculosis (UTB). GeneXpert is endorsed for the detection of pulmonary tuberculosis, whereas the data on its utility for urine specimens is limited. In this study, we aimed to evaluate its performance on urine specimens in a country with high TB incidence. A total of 163 suspected UTB patients were consecutively enrolled in the analysis, including 37 (22.7%) culture-positive and 44 (27.0%) clinically diagnosed UTB cases. Compared with conventional culture, the sensitivity of GeneXpert (94.6%) was significantly higher than that of smear microscopy (40.5%, P < 0.001). When setting clinical diagnosis as gold standard, 51 out of 81 clinically diagnosed UTB cases were detected by GeneXpert, demonstrating a sensitivity of 63.0%, which was significantly higher than that of smear microscopy (18.5%, P < 0.001) and culture (45.7%, P = 0.027), respectively. In addition, the proportion of UTB cases in the migrant population was significantly higher than that in the resident population (P = 0.019). To conclude, our data demonstrate that GeneXpert outperforms AFB smear and culture for the detection of MTB in urine samples, which provides an alternative for the diagnosis of UTB. The migrant population and previously diagnosed TB cases are high risk factors for developing UTB cases.


Assuntos
Tipagem Molecular/métodos , Mycobacterium tuberculosis/genética , Tuberculose Urogenital/diagnóstico , Adulto , Idoso , Carga Bacteriana , Técnicas Bacteriológicas/métodos , Feminino , Humanos , Masculino , Microscopia , Pessoa de Meia-Idade , Estudos Prospectivos , Sensibilidade e Especificidade , Adulto Jovem
13.
Sci Rep ; 6: 37757, 2016 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-27876877

RESUMO

The diagnosis of extrapulmonary tuberculosis (EPTB) is challenging due to non-specific symptoms, invasive approach for specimen collection and most importantly, the paucibacillary status. The objective of this assay was to evaluate the efficacy of Myco/F lytic system, BACTEC Mycobacteria Growth Indicator Tube (MGIT) 960 system and Lowenstein-Jensen (L-J) medium for recovery of bacilli from sterile body fluids. 214 specimens (114 pleural fluid and 100 pus) from clinically diagnosed EPTB patients were collected and subjected to Ziehl-Neelsen (ZN) smear microscopy, L-J culture, MGIT 960 culture and Myco/F lytic culture.103 out of the 214 sterile body fluid samples yielded positive culture outcomes by any of the three methods. Among all the culture positive specimens, the recovery rate was 86.41% for Myco/F lytic, 75.73% for MGIT 960, and 42.72% for L-J medium. The mean time to positivity (TTP) was 27.06 ± 8.03 days for Myco/F lytic, 22.20 ± 7.84 days for MGIT960 and 42 ± 8.84 days for L-J medium. The rates of contamination were 6.54%, 3.74% and 2.80% for Myco/F lytic, MGIT960 and L-J medium respectively. Both Myco/F lytic and MGIT960 system were superior to L-J medium for recovery of bacilli from sterile body fluids. Myco/F lytic system was more favorable than MGIT960 regarding recovery rate and cost-effectiveness, thus can be considered as a promising alternative to MGIT960 system for diagnosing EPTB.


Assuntos
Técnicas Bacteriológicas/métodos , Líquidos Corporais/microbiologia , Meios de Cultura/química , Mycobacterium tuberculosis/isolamento & purificação , Humanos , Fatores de Tempo
14.
Front Microbiol ; 7: 922, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27379052

RESUMO

A novel method for detecting drug resistance in Mycobacterium tuberculosis using mycobacteriophage Φ (2) GFP10 was evaluated with clinical isolates. The phage facilitates microscopic fluorescence detection due to the high expression of green fluorescence protein which also simplifies the operative protocol as well. A total of 128 clinical isolates were tested by the phage assay for isoniazid (INH), rifampin (RIF), and streptomycin (STR) resistance while conventional drug susceptibility test, by MGIT960, was used as reference. The sensitivities of Φ (2) GFP10 assay for INH, RIF, and STR resistance detection were 100, 98.2, and 89.3%, respectively while their specificities were 85.1, 98.6, and 95.8%, respectively. The agreement between phage and conventional assay for detecting INH, RIF, and STR resistance was 92.2, 98.4, and 93.0%, respectively. The Φ (2) GFP10-phage results could be available in 2 days for RIF and STR, while it takes 3 days for INH, with an estimated cost of less than $2 to test all the three antibiotics. The Φ (2) GFP10-phage method has the potential to be a valuable, rapid and economical screening method for detecting drug-resistant tuberculosis.

15.
Diagn Microbiol Infect Dis ; 84(3): 207-11, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26775806

RESUMO

Our study was aimed to identify the phenotypic and genotypic pyrazinamide (PZA) resistance features among multidrug-resistant (MDR) isolates in a national tuberculosis (TB) referral center of China. PZA susceptibility test was performed for a total of 142 MDR-TB clinical isolates using the MGIT 960 PZA kits, and the pncA, rpsA, and panD genes were sequenced. Extensively drug-resistant (XDR) and pre-XDR strains had higher PZA resistance rate than that of MDR strains which were still sensitive to fluoroquinolone and aminoglycoside (42.9%, 24/56) (χ(2)=8.922, P=0.012). No panD mutation was detected among the PZA resistant strains with wild-type pncA and rpsA genes. Our study indicates that PZA-resistant frequency increases with TB drug resistance level; pncA, rpsA, and panD mutations had strong, low, and no correlation with PZA resistance, and rapid molecular assay will facilitate the timely identification of the PZA-sensitive MDR-TB.


Assuntos
Farmacorresistência Bacteriana , Genes Bacterianos , Mutação , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/genética , Pirazinamida/farmacologia , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Adulto , Idoso , Substituição de Aminoácidos , Antituberculosos/farmacologia , China/epidemiologia , Códon , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Fases de Leitura Aberta , Regiões Promotoras Genéticas , Análise de Sequência de DNA , Adulto Jovem
16.
Biomed Res Int ; 2015: 501847, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26618171

RESUMO

BACKGROUND: The viable mycobacterial bacilli can sometimes form granules in the Mycobacterium Growth Indicator Tube (MGIT) to produce instrument-negative outcomes when BACTEC MGIT 960 culture is performed. The cause of this phenomenon has never been analyzed. METHODS: Thirty-one instrument-negative, granule presenting MGIT vials were collected for conducting acid-fast staining and also liquid and solid subculture. Species identification and drug susceptibility test were performed with the recovered strains. Cultivation test was done by inoculating small amount of bacilli into the MGIT vials. RESULTS: Twenty-four and twenty-nine of the tested MGIT vials were smear and culture positive, respectively. In total, 18, 4, and 7 of the cultivated strains were identified as Mycobacterium tuberculosis complex, M. intracellulare, and M. xenopi, respectively. When a limited amount of bacilli was inoculated, the granule formation was observed for M. xenopi strains in the MGIT system. CONCLUSIONS: The granules observed in the instrument-negative MGIT vials consisted of viable bacilli, which emphasized the need of visual inspection to increase recovery rate. Limited bacterial load and specific species might be the cause of granule forming.


Assuntos
Técnicas Bacteriológicas/métodos , Mycobacterium tuberculosis/crescimento & desenvolvimento , Meios de Cultura/metabolismo , Reações Falso-Negativas , Kit de Reagentes para Diagnóstico
17.
Sci Rep ; 5: 8538, 2015 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-25736338

RESUMO

The epidemiology of Mycobacterium bovis infection in humans in China is unknown. In this study, pulmonary tuberculosis caused by M. bovis in China was studied. A total of 4069 clinical strains isolated from sputa during the 2007-2009 nationwide surveillance of drug-resistant tuberculosis in China were analyzed. M. bovis was identified by para-nitrobenzoic acid and thiophen-2-carboxylic acid hydrazide growth tests, spoligotyping and multiplex PCR amplification. In addition, a total of 1828 clinical specimens were recruited from Beijing Chest Hospital (Beijing, China) for Löwenstein-Jensen (LJ) culture, both on standard LJ medium and LJ medium containing 4.5 mg/ml(W/V) sodium pyruvate, the latter being the preferred medium for M. bovis growth. The isolates which demonstrated more vigorous on pyruvate containing medium than on standard LJ medium were then identified by multiplex PCR amplification. Only 1 isolate from the nationwide surveillance was confirmed as M. bovis-BCG. The isolate belonged to a predominant spoligotype SB0120 (ST482). In addition, no M. bovis isolate was acquired by the continuous screening step in Beijing Chest Hospital. M. bovis has a negligible contribution to pulmonary tuberculosis in China, so neither laboratory identification nor clinical treatment of M. bovis infection need be considered in routine work.


Assuntos
Mycobacterium bovis/fisiologia , Escarro/microbiologia , Tuberculose Pulmonar/epidemiologia , Tuberculose Pulmonar/microbiologia , Proteínas de Bactérias/genética , Técnicas de Tipagem Bacteriana/métodos , Técnicas Bacteriológicas/métodos , China/epidemiologia , Elementos de DNA Transponíveis/genética , Interações Hospedeiro-Patógeno , Humanos , Reação em Cadeia da Polimerase Multiplex/métodos , Mycobacterium bovis/classificação , Mycobacterium bovis/genética , RNA Ribossômico 16S/genética
19.
Glob Health Action ; 7: 24022, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24845213

RESUMO

BACKGROUND: China has a high burden of drug-resistant tuberculosis (TB) and diabetes mellitus (DM). OBJECTIVE: The objectives of this study were to determine the following in patients with culture-confirmed TB: 1) demographic characteristics and disease patterns in relation to the presence or absence of type 2 diabetes and 2) presence or absence of drug resistance to isoniazid (INH), rifampicin (RMP) or both in relation to duration of diabetes and control of diabetes. DESIGN: This is a cross-sectional and retrospective study involving record reviews. RESULTS: There were 621 patients with culture-positive TB, of whom 187 (30%) had previously known or new type 2 diabetes. In those with diabetes, there was a significantly higher proportion of males, persons aged ≥35 years and patients registered with new TB (p<0.05). Prevalence of multidrug-resistant TB (MDR-TB) was 6.2% in new patients (N=422) and 62.3% in previously treated patients (N=199), with no significant differences between those with and without diabetes. In patients with diabetes, there was no association of drug resistance with diabetes duration or disease control [assessed by fasting blood glucose (FBG) at 1 week]. CONCLUSION: A high proportion of patients with TB in a tertiary health facility, Beijing, China, had diabetes, but there was no association between type 2 diabetes and drug-resistant TB. Further prospective studies are needed to confirm these findings.


Assuntos
Antituberculosos/uso terapêutico , Diabetes Mellitus Tipo 2/epidemiologia , Tuberculose Pulmonar/tratamento farmacológico , Adolescente , Adulto , Fatores Etários , China/epidemiologia , Estudos Transversais , Farmacorresistência Bacteriana Múltipla , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Sistema de Registros , Estudos Retrospectivos , Fatores Sexuais , Tuberculose Pulmonar/epidemiologia , Adulto Jovem
20.
Zhonghua Jie He He Hu Xi Za Zhi ; 36(5): 360-2, 2013 May.
Artigo em Chinês | MEDLINE | ID: mdl-24047811

RESUMO

OBJECTIVE: To evaluate the reliability of thiophen-2-carboxylic acid hydrazine (TCH) test for identification of Mycobacterium bovis (M. bovis). METHODS: A total of 4069 clinically isolated strains were identified by P-Nitrobenzoic acid medium (500 mg/L) and TCH medium (5 mg/L). Mycobacterium tuberculosis (M. tuberculosis) complex strains susceptible to 5 mg/L TCH were further tested for susceptibility to 2 mg/L TCH. Spacer oligonucleotide typing (spoligotyping) and multi-loci PCR were also performed to identify TCH susceptible strains. RESULTS: Among the 4069 isolated strains there were 3929 strains belonging to M. tuberculosis complex (MTBC) of which 245 were susceptible to 5 mg/L TCH. Of these 245 strains, 20 were also susceptible to 2 mg/L TCH, while only 1 strain was identified to be M. bovis by both spoligotyping and multi-loci PCR. CONCLUSION: TCH susceptibility test (either 5 mg/L or 2 mg/L) is not a reliable method for identification of M. bovis.


Assuntos
Mycobacterium bovis/classificação , Mycobacterium tuberculosis/classificação , Tiofenos/farmacologia , Animais , Técnicas de Tipagem Bacteriana , Bovinos , DNA Bacteriano/genética , Testes de Sensibilidade Microbiana , Mycobacterium bovis/genética , Mycobacterium bovis/isolamento & purificação , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/isolamento & purificação , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase , Tiofenos/administração & dosagem , Tuberculose/microbiologia
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