OBJECTIVETo compare the performance of MTBDRplus V2 and Xpert MTB/RIF for detecting smear negative pulmonary tuberculosis (PTB).

METHODSClinical PTB suspects were enrolled consecutively in Anhui Chest Hospital and Xi'an Chest Hospital from January to December in 2014. The sputum samples of smear negative PTB suspects were collected and decontaminated. The sediment was used to conduct MTBDRplus V2, Xpert MTB/RIF and drug susceptibility test (DST). All the samples with discrepant drug susceptibility result between molecular methods and phenotypic method were confirmed by DNA sequencing.

RESULTSA total of 1973 cases were enrolled in this study. The detection rates of Mycobacterium tuberculosis complex (MTBC) by MTBDRplus V2 and Xpert MTB/RIF were 27.67% and 27.98%, respectively. When setting MGIT culture result as a gold standard, the sensitivity and specificity of MTBDRplus V2 were 86.74% and 93.84%, and the sensitivity and specificity of Xpert MTB/RIF were 86.55% and 93.43%, respectively. For the detection of the resistance to rifampin, the sensitivity and specificity of MTBDRplus V2 were 94.34% and 96.62%, and the sensitivity and specificity of Xpert MTB/RIF were 88.68% and 95.96%, respectively. For the detection of the resistance to isoniazid, the sensitivity and specificity of MTBDRplus V2 were 77.38% and 98.02%, respectively.

CONCLUSIONMTBDRplus V2 and Xpert MTB/RIF can be used to detect MTBC in smear negative samples with satisfactory performance.

Antitubercular Agents ; pharmacology ; Bacteriological Techniques ; methods ; Drug Resistance, Bacterial ; Humans ; Isoniazid ; pharmacology ; Mycobacterium tuberculosis ; drug effects ; isolation & purification ; Sensitivity and Specificity ; Tuberculosis, Pulmonary ; diagnosis ; microbiology

OBJECTIVETo evaluate microscopic observation drug susceptibility (MODS) for mycobacterium tuberculosis drug susceptibility in smear-positive sputum.

METHODSDrug susceptibility of mycobacterium tuberculosis in 275 smear-positive sputum samples collected from TB patients were detected directly by MODS. The susceptibility of seven antimicrobials including streptomycin, isoniazid, rifampicin, ethambutol, levofloxacin, amikacin and capromycin were detected MODS. At the same time the sputum sample were cultured in MGIT 960 tube and the positive isolates were tested for drug susceptibility by MGIT 960 system. The results of MODS were analyzed and compared with that of MGIT 960.

RESULTSOf 275 smear-positive sputum, MODS detected 235 (85.45%). Results of MODS were obtained in a median time of 18 days (5 - 39 d). For the 235 MODS-positive samples, the compliance rates of MODS to MGIT of 7 drugs were 90.21% (212/235), 88.09% (207/235), 93.62% (220/235), 87.23% (205/235), 92.34% (217/235), 88.51% (208/235) and 86.81% (204/235) respectively. The sensitivity of MODS method were 83.33% (90/108), 85.11% (120/141), 90.74% (98/108), 85.71% (78/91), 86.73% (85/98), 76.92% (40/52) and 77.08% (37/48). The specificities of MODS method were 96.06% (122/127), 92.55% (87/94), 96.06% (122/127), 88.19% (127/144), 96.35% (132/137), 91.80% (168/183) and 89.30% (167/187) respectively.

CONCLUSIONMODS is an optimal alternative method for direct and rapid drug susceptibility of sputum with high accuracy in a timely and affordable way in resource-limited settings.

Antitubercular Agents ; pharmacology ; Drug Resistance, Multiple, Bacterial ; Humans ; Microbial Sensitivity Tests ; methods ; Microscopy ; Mycobacterium tuberculosis ; drug effects ; isolation & purification ; Sputum ; microbiology ; Tuberculosis, Multidrug-Resistant ; microbiology

Antitubercular Agents ; pharmacology ; Drug Resistance, Bacterial ; Humans ; Microbial Sensitivity Tests ; Mycobacterium tuberculosis ; drug effects ; isolation & purification ; Tuberculosis, Multidrug-Resistant ; diagnosis ; microbiology

OBJECTIVETo explore the correlation between Beijing genotype (Beijing family) strains of Mycobacterium tuberculosis (MTB) and drug resistance.

METHODSA computer retrieval of Medline, Embase, SCI, EBSCO, CNKI, Weipu and Wanfang databases from 1990 to 2010 was conducted. A total of 525 articles exploring the relationship of Beijing genotype of MTB and drug resistance were found through literature search. Following the inclusion and exclusion criteria, a Meta-subgroup analysis was conducted in Beijing genotype of MTB and drug resistance.

RESULTSA total of 38 articles were selected, including 22 articles on isoniazid resistance, 24 articles on rifampin resistance, 19 articles on ethambutol resistance, 18 articles on ethambutol resistance, 26 articles on multi-drug resistance (MDR). Meta-subgroup analysis showed that in China, there was an association between Beijing genotype and resistance to rifampin, ethambutol and MDR: rifampin (OR = 1.62, 95%CI: 1.13 - 2.31), ethambutol (OR = 1.67, 95%CI: 1.16 - 2.40), MDR (OR = 1.79, 95%CI: 1.20 - 2.68); in Russia, there was an association between Beijing genotype and resistance to isoniazid, rifampin, ethambutol and MDR: isoniazid (OR = 4.82, 95%CI: 3.19 - 7.29), rifampin (OR = 4.84, 95%CI: 3.84 - 6.10), ethambutol (OR = 3.32, 95%CI: 2.51 - 4.40), MDR (OR = 5.42, 95%CI: 3.36 - 8.74); in Vietnam, there was an association between Beijing genotype and resistance to isoniazid, rifampin, ethambutol and MDR: isoniazid (OR = 2.12, 95%CI: 1.55 - 2.91), rifampin (OR = 4.71, 95%CI: 3.01 - 7.36), ethambutol (OR = 3.78, 95%CI: 1.63 - 8.77), MDR (OR = 4.21, 95%CI: 1.58 - 11.18); in other countries, there was an association between Beijing genotype and resistance to isoniazid, rifampin, ethambutol and MDR: isoniazid (OR = 1.69, 95%CI: 1.19 - 2.42), rifampin (OR = 2.48, 95%CI: 1.92 - 3.19), ethambutol (OR = 3.04, 95%CI: 2.13 - 4.33), MDR (OR = 2.36, 95%CI: 1.52 - 3.68).

CONCLUSIONBeijing genotype of MTB was positively associated with three kinds of first-line anti-tuberculosis drugs (isoniazid, rifampin, ethambutol) and MDR, and the relationship intensity was different in different countries.

Antitubercular Agents ; pharmacology ; China ; DNA, Bacterial ; Drug Resistance, Multiple, Bacterial ; Genotype ; Humans ; Mycobacterium tuberculosis ; drug effects ; genetics ; isolation & purification ; Russia ; Tuberculosis, Multidrug-Resistant ; genetics ; microbiology ; Vietnam

In order to evaluate the performance of a molecular Hain line probe assay (Hain LPA) for rapid detection of rifampicin and isoniazid resistance of Mycobacterium tuberculosis in China, 1612 smear positive patients were consecutively enrolled in this study. Smear positive sputum specimens were collected for Hain LPA and conventional drug susceptibility testing (DST). The sensitivity and specificity of Hain LPA were analyzed by using conventional DST as golden reference. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for rifampicin resistance detection were 88.33%, 97.66%, 81.54%, and 98.62%, respectively. The sensitivity, specificity, PPV and NPV for isoniazid resistance detection were 80.25%, 98.07%, 87.25%, and 96.78%, respectively. These findings suggested that Hain LPA can be an effective method worthy of broader use in China.
China ; Genotyping Techniques ; methods ; Humans ; Isoniazid ; pharmacology ; Mycobacterium tuberculosis ; drug effects ; genetics ; isolation & purification ; Rifampin ; pharmacology ; Tuberculosis, Multidrug-Resistant ; diagnosis ; microbiology

70 clinical Mycobacterium tuberculosis strains isolated from AIDS patients in two HIV/AIDS referral hospitals in Beijing were used in this study. M. tuberculosis and non-tuberculosis mycobacterium (NTM) were identified by using multi-locus PCR. M. tuberculosis was genotyped by using 15-locus MIRU-VNTR technique and spoligotyping afterwards. Meanwhile, the drug susceptibilities of the strains to the four first-line anti TB drugs (rifampin, isoniazid, streptomycin, and ethambutol) and the four second-line anti-TB drugs (capreomycin, kanamycin, ofloxacin, and ethionanide) were tested with proportional method. In this study, M. tuberculosis and NTM strains isolated from AIDS patients with TB-like symptoms were identified and genotyping analysis indicated that Beijing genotype was the predominant genotype. In addition, the prevalence of drug-resistant TB, especially the prevalence of XDR-TB, was higher than that in TB patients without HIV infection.
AIDS-Related Opportunistic Infections ; microbiology ; Antitubercular Agents ; pharmacology ; China ; Humans ; Microbial Sensitivity Tests ; Mycobacterium tuberculosis ; classification ; drug effects ; isolation & purification ; Phylogeny ; Tuberculosis ; complications ; microbiology

OBJECTIVETo understand the characteristics of pncA gene in multidrug-resistant Mycobacterium tuberculosis isolates and its correlation with drug resistance to pyrazinamide.

METHODSA total of 127 clinical isolates of multidrug-resistant mycobacterium tuberculosis were collected from Shenzhen from year 2007 to 2009. PZA susceptibility was determined by the BACTEC MGIT 960 PZA method. Pyrazinamidase (PZase) activity testing and pncA gene sequencing were performed in all the isolates. The type and frequency of mutations in pncA were determined. Correlation analysis among PZA susceptibility and PZase activity, pncA mutation was performed.

RESULTSAmong the 127 isolates, 62 isolates (48.8%) were found resistance to PZA. Among the 62 PZA resistant isolates, 45 isolates which had various pncA mutations were negative for PZase. Mutation rate was 77.4% (48/62) in total PZA resistance isolates. Different types of 48 resistant isolates were identified in the pncA gene, including base substitution (33 isolates), frame shift mutation (12 isolates) and codon mutation (3 isolates). No mutations except one isolate (N11D) existed in all PZA-susceptibility isolates which were positive for PZase. A total of 5 mutations which have not been described previously were found as follows: H57P, P62Q, G108R, D110Y and G162V. The correlation among the PZA susceptibility and the PZase activity (r = 0.895, P < 0.05), the pncA mutation (r = 0.779, P < 0.05) were significant in 127 multidrug-resistant isolates.

CONCLUSIONA high diversity of pncA gene mutation was found among PZA resistant strains of MTB. This study revealed five new mutations of the pncA gene that were not previously described, which scattered in the hot-spot regions located in the metal coordination site and active site of the enzyme. Mutations had a high correlation with the PZA resistance.

Antitubercular Agents ; pharmacology ; DNA, Bacterial ; genetics ; Humans ; Mutation ; Mycobacterium tuberculosis ; drug effects ; genetics ; isolation & purification ; Pyrazinamide ; pharmacology ; Tuberculosis, Multidrug-Resistant ; genetics ; microbiology

OBJECTIVETo understand the characteristics of embB gene mutation of Mycobacterium tuberculosis (MTB) isolates from tuberculosis patients in Chongqing, and the value of embB306 as a molecular marker used to diagnose ethambutol (EMB)-resistant MTB strains.

METHODSDirect sequencing was used to analyze the polymorphism of embB mutation in 51 EMB-resistant MTB strains and 50 EMB-sensitive MTB strains. And diagnostic testing was used to evaluate the value of embB306 as a molecular marker of EMB -resistant MTB strains as compared with the traditional sensitivity test.

RESULTSAll 34 of 51 EMB-resistant strains (66.7%) and 3 of 51 EMB-sensitive strains (6%) had had embB306 mutation. The embB306 mutation rate in EMB-resistant strains coming from previously treated case was 87.5%, showing significantly higher than that from new cases (48.1%, P < 0.01); embB306 mutation rate was increased with the number of the resistant drugs; embB306 mutation serving as a marker to diagnose EMB-resistant MTB strains comparing with the traditional sensitivity test, had the rate of sensitivity = 66.7%, specificity = 94.0%, accuracy = 80.2% and Youden index = 60.7%.

CONCLUSIONembB306 mutation should be the main mechanism of MTB resistance to EMB in Chongqing, showing an association with the history of the treated and numbers of the resistant drugs. embB306 mutation should be a good marker to diagnose EMB-resistant MTB strains.

China ; DNA Mutational Analysis ; DNA, Bacterial ; genetics ; Genes, Bacterial ; Humans ; Mutation ; Mycobacterium tuberculosis ; drug effects ; genetics ; isolation & purification ; Pentosyltransferases ; genetics ; Tuberculosis, Multidrug-Resistant ; microbiology

OBJECTIVETo investigate the composition and resistance of main pathogens isolated form Lower respiratory tract in coalminer's pneumoconiosis patients complicated with infection to provide the basis for clinical treatment.

METHODCoalminer's pneumoconiosis patients complicated with infection during 2009 to 2010 were divided into mechanical ventilation group and non mechanical ventilation group. Specimens were obtained from lower respiratory tract by fibrobronchoscopy with protected specimen brush in patients of both groups to perform isolation, culture, identification and susceptibility test of pathogen.

RESULTTotal 111 patients were enrolled, 36 of them in mechanical ventilation group and 75 patients in non mechanical ventilation group. The pathogenic bacteria detection rate of patients in mechanical ventilation group was significantly higher than that of patients in non mechanical ventilation group (88.9% vs. 46.7%, P < 0.01). In non mechanical ventilation group, Mycobacterium tuberculosis was detected in 3 patients, and 27 strains of G- bacilli, 3 strains of G+ coccus, and 2 strains of fungus; and 26 strains of G- bacilli, 3 strains of G+ coccus, and 3 strains of fungus were detected in mechanical ventilation group. There was no significant difference in term of strains between the two groups (P > 0.05). Rate of resistance to main antibiotics of patients in mechanical ventilation group was higher than that of patients in non mechanical ventilation group.

CONCLUSIONResistance of pathogenic bacteria isolated from lower respiratory tract was severe in coalminer's pneumoconiosis patients complicated with infection, which was higher in patients treated with mechanical ventilation than patients without mechanical ventilation. Mycobacterium tuberculosis and fungal infection and increasing resistance prompted that clinicians must attach importance to rational drug use and keep to monitoring bacterial resistance.

Aged ; Aged, 80 and over ; Anthracosis ; microbiology ; Drug Resistance, Bacterial ; Humans ; Male ; Middle Aged ; Mycobacterium tuberculosis ; drug effects ; isolation & purification ; Respiration, Artificial ; adverse effects ; Respiratory Tract Infections ; microbiology

OBJECTIVETo improve evidence-based care in the management of tuberculosis, we retrospectively analyzed the bacterial types and drug sensitivity test results of mycobacteria in Guangzhou over the past twelve years (from July 1998 to March 2010).

METHODSOver these twelve years, a total of 14 095 mycobacterial strains isolated from different samples were subjected to type identification and drug sensitivity tests according to the Standard Protocols of Laboratory Diagnostics for Tuberculosis by the Chinese Antituberculosis Association. Chi-square test was performed for statistical analyses for comparisons between groups.

RESULTSOf 14 095 strains of mycobacteria isolated, 10 844 strains (76.84%) were MTB, and 3251 strains (23.16%) were non-tuberculosis mycobacteria (NTM). Compared with the result of the fourth national survey of tuberculosis epidemiology, which showed 11.1% of NTM, the one of our study was significantly different (χ(2) = 69.79, P < 0.001). Drug sensitivity tests of MTB showed tolerance rates of 28.99% (2729/9413), 21.75% (2047/9413), 17.45% (1643/9413) and 11.53% (1085/9413) against isoniazid, rifampin, streptomycin and ethambutol, respectively.

CONCLUSIONAn increasing trend was observed in MTB drug tolerance against streptomycin, rifampin and isoniazid, whereas more and more NTM strains were isolated in recent years. These findings are worthy of note for clinicians.

Antitubercular Agents ; pharmacology ; Bacterial Typing Techniques ; China ; epidemiology ; Drug Resistance, Bacterial ; Humans ; Microbial Sensitivity Tests ; Mycobacterium ; classification ; drug effects ; isolation & purification ; Tuberculosis ; epidemiology ; microbiology