Diagnostic Tests, Routine ; methods ; Humans ; Mycobacterium tuberculosis ; isolation & purification ; Sensitivity and Specificity ; Tuberculosis, Pulmonary ; diagnosis ; microbiology

We evaluate the performance of Xpert MTB/RIF for the diagnosis of extrapulmonary tuberculosis (EPTB) in China. The performance of Xpert was evaluated compared to the composite reference standard (CRS), drug susceptibility testing (DST), and imaging examination. The overall sensitivity and specificity of Xpert were 64.1% (195/304) and 100% (24/24), respectively, using CRS as the gold standard. The sensitivity was significantly higher than that of culture for pus (P<0.05). The proportion of EPTB-positive cases diagnosed by imaging was two times more than that diagnosed using Xpert; however, 6 out of 19 cases may have been overdiagnosed by imaging. Compared to phenotypic DST, the sensitivity and specificity of Xpert were 80% (12/15) and 100% (75/75), respectively. Considering its high sensitivity and specificity, Xpert MTB/RIF may be used as a rapid initial test for EPTB diagnosis, and may also support a quicker decision on the treatment regimen. The combination of imaging and Xpert testing could provide high efficiency and accurate diagnosis of suspected EPTB.
Bacterial Proteins ; genetics ; metabolism ; China ; DNA-Directed RNA Polymerases ; genetics ; metabolism ; Diagnostic Tests, Routine ; instrumentation ; methods ; Drug Resistance, Bacterial ; Humans ; Microbial Sensitivity Tests ; Mycobacterium tuberculosis ; drug effects ; genetics ; isolation & purification ; metabolism ; Retrospective Studies ; Rifampin ; pharmacology ; Sensitivity and Specificity ; Sputum ; Tuberculosis ; Tuberculosis, Pulmonary ; diagnosis ; microbiology

OBJECTIVETo establish a laboratory method for detection of Mycobacterium tuberculosis in sputum based on variable number tandem repeat (VNTR).

METHODSMycobacterium tuberculosis was tested by VNTR and fluorescent quantitative reverse transcription polymerase chain reaction (FQ-PCR) in 130 sputum samples from patients with pulmonary tuberculosis and 200 specimens from patients with other lung diseases. According to the amplification conditions and clinical detection needs, MTUB21, MUTB04, QUB18, QUB26, QUB11b, MIRU31, MIRU10 and MIRU26 were selected as test targets. The results of VNTR and FQ-PCR were compared with Lowenstein-Jensen culture and clinical diagnosis, and analyzed by chi-square test.

RESULTSWith the results of L-J culture as the standard, the sensitivity and specificity of VNTR were 93.1% (108/116) and 97.7% (209/214), and those of FQ-PCR were 94.0% (109/116) and 96.7% (207/214), respectively; no significant difference was observed between two groups (χ2=0.352, P=0.569). Using the clinical diagnosis as the standard, the sensitivity and specificity of VNTR were 86.9% (113/130) and 100% (200/200), and those of FQ-PCR were 87.7% (114/130) and 99.0% (198/200), respectively; the difference was not statistically significant (χ2=0.030, P=0.862). In 113 VNTR positive samples, the molecular codes differed from each other in 98.2% samples (111/113); only 2 samples had identical code (5-4-6-8-5-5-3-8).

CONCLUSIONThe study suggests that VNTR provides a promising method for diagnosis of clinical tuberculosis.

Humans ; Minisatellite Repeats ; Mycobacterium tuberculosis ; isolation & purification ; Polymerase Chain Reaction ; Sensitivity and Specificity ; Sputum ; microbiology ; Tuberculosis, Pulmonary ; diagnosis

A worsening scenario of drug-resistant tuberculosis has increased the need for new treatment strategies to tackle this worldwide emergency. There is a pressing need to simplify and shorten the current 6-month treatment regimen for drug-susceptible tuberculosis. Rifamycins and fluoroquinolones, as well as several new drugs, are potential candidates under evaluation. At the same time, treatment outcomes of patients with drug-resistant tuberculosis should be improved through optimizing the use of fluoroquinolones, repurposed agents and newly developed drugs. In this context, the safety and tolerance of new therapeutic approaches must be addressed.
Animals ; Antitubercular Agents/adverse effects/*therapeutic use ; *Drug Discovery ; *Drug Repositioning ; Drug Resistance, Bacterial ; Drug Therapy, Combination ; Extensively Drug-Resistant Tuberculosis/drug therapy/microbiology ; Humans ; Lung/*drug effects/microbiology ; Mycobacterium tuberculosis/*drug effects/pathogenicity ; Treatment Outcome ; Tuberculosis, Multidrug-Resistant/diagnosis/*drug therapy/microbiology ; Tuberculosis, Pulmonary/diagnosis/*drug therapy/microbiology

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

PURPOSE: To evaluate the diagnostic utility and predictors for determinate results of an enzyme-linked immunospot assay using induced sputum cells (IS ELISPOT) for a rapid diagnosis of pulmonary tuberculosis (TB). MATERIALS AND METHODS: Subjects suspected of pulmonary TB who had either sputum acid fast bacilli smear-negative or not producing sputum spontaneously were prospectively enrolled. ELISPOT assay was performed using cells from induced sputum. RESULTS: A total of 43 subjects, including 25 with TB (TB group) and 18 with non-TB disease (non-TB group) were enrolled. Results of IS ELISPOT were determinate in only 17/43 (39%) subjects, but all of determinate results were consistent with the final diagnosis. Of the 43 sputum samples, 11 (26%) were inadequate to perform IS ELISPOT. Of 32 adequate sputum samples, the proportion of determinate results was significantly higher in the TB group (75%, 15/20) than in the non-TB group (17%, 2/12) (p=0.002). The status of active TB was a unique predictor but smear positivity was not a significant predictor for determinate results. In addition, sensitivity of IS ELISPOT (75%, 9/12) in smear negative TB was higher than that of TB-polymerase chain reaction (25%, 3/12). CONCLUSION: IS ELISPOT showed relatively high diagnostic value and accuracy in the TB group, independent of smear positivity. IS ELISPOT may provide additional diagnostic yield for microbiological tools in the rapid diagnosis of smear-negative TB.
Adult ; Aged ; *Enzyme-Linked Immunospot Assay ; Female ; Humans ; Immunologic Tests/*methods ; Male ; Middle Aged ; Mycobacterium tuberculosis/*isolation & purification ; Predictive Value of Tests ; Prospective Studies ; Reproducibility of Results ; Risk Factors ; Sensitivity and Specificity ; Sputum/*microbiology ; Tuberculosis, Pulmonary/*diagnosis/microbiology

No abstract available.
Adult ; Antineoplastic Agents/*adverse effects ; Antitubercular Agents/therapeutic use ; Biopsy ; Female ; Gastrointestinal Stromal Tumors/*drug therapy/pathology/surgery ; Humans ; Imatinib Mesylate/*adverse effects ; Lung Diseases, Interstitial/*chemically induced/diagnosis ; Mycobacterium tuberculosis/*isolation & purification ; Protein Kinase Inhibitors/*adverse effects ; Rectal Neoplasms/*drug therapy/pathology/surgery ; Tomography, X-Ray Computed ; Tuberculosis, Pulmonary/diagnosis/drug therapy/*microbiology

BACKGROUND/AIMS: We evaluated the trend in the rates of drug-resistant tuberculosis (TB) over time, as well as the difference in the drug-resistance pattern between pulmonary tuberculosis (PTB) and extrapulmonary tuberculosis (EPTB) at a private referral center in South Korea. METHODS: All patients with culture-confirmed TB from 2006 to 2013 were included. RESULTS: In total, 1,745 patients were included: 1,431 (82.0%) were new cases, and 314 (18.0%) were cases treated previously; 1,610 (92.3%) were diagnosed with PTB, and 135 (7.7%) were diagnosed with EPTB. Multidrug-resistant (MDR) and extensively drug-resistant (XDR) TB were detected in 5.8% and 2.0% of new cases and in 20.1% and 8.6% of previously treated cases, respectively. The MDR TB rate during the study period decreased remarkably, whereas the MDR and XDR TB rates decreased significantly in previously treated cases. No difference in the drug-resistance rate was detected between PTB and EPTB. CONCLUSIONS: The TB drug-resistance rate, particularly that of MDR TB, remained high at a private referral hospital, and the drug-resistance rate did not decrease significantly from 2006 to 2013. This finding underscores the need for a national survey regarding the prevalence of drug-resistant TB to obtain the most accurate and current drug-resistance status in South Korea, including the private sector.
Adult ; Aged ; Antitubercular Agents/*therapeutic use ; *Drug Resistance, Multiple, Bacterial ; Extensively Drug-Resistant Tuberculosis/drug therapy/microbiology ; Female ; Hospitals, Private ; Humans ; Male ; Microbial Sensitivity Tests ; Middle Aged ; Mycobacterium tuberculosis/*drug effects/isolation & purification ; Prevalence ; Republic of Korea/epidemiology ; Retrospective Studies ; *Tertiary Care Centers ; Time Factors ; Treatment Outcome ; Tuberculosis, Multidrug-Resistant/diagnosis/*drug therapy/epidemiology/*microbiology ; Tuberculosis, Pulmonary/diagnosis/*drug therapy/epidemiology/*microbiology

The evaluation of the quality of a sputum specimen prior to bacterial culture has been an accepted practice. However, optimal sputum criteria for pulmonary tuberculosis (TB) are not well established. We investigated indicators for sputum acceptability in tuberculosis cultures and acid-fast bacilli (AFB) smear. A post-hoc analysis of a randomized trial with 228 sputum specimens from 77 patients was conducted. In the trial, pulmonary TB suspects were requested for collecting three sputum specimens. We performed both TB study (AFB smear and M. tuberculosis culture) and Gram staining in each specimen. By using generalized estimating equations, the association between sputum characteristics and positive TB testings were analyzed. Although acceptable specimens for bacterial pneumonia showed higher TB-culture positive rates than unacceptable specimens (adjusted odds ratio [aOR]=1.66; 95% confidence interval [CI]=1.11-2.49), a specimen with > or =25 white blood cells/low-power field was the better predictor for positive M. tuberculosis cultures (aOR=2.30; 95% CI=1.48-3.58) and acid-fast bacilli smears (aOR=1.85; 95% CI=1.05-3.25). Sputum leukocytosis could be an indicator of sputum acceptability for diagnosing pulmonary tuberculosis.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Bacteriological Techniques/*methods ; Female ; Humans ; Male ; Middle Aged ; Mycobacterium tuberculosis/*isolation & purification ; Reproducibility of Results ; Sensitivity and Specificity ; Sputum/cytology/*microbiology ; Tuberculosis, Pulmonary/*diagnosis/*microbiology/pathology ; Young Adult

PURPOSE: We investigated the value of an interferon-gamma release assay (IGRA) for the diagnosis of active pulmonary tuberculosis (PTB) among sputum smear negative PTB suspects in an environment with intermediate burden of PTB and high Bacillus Calmette-Guerin (BCG) vaccination rate. MATERIALS AND METHODS: We retrospectively reviewed IGRA, medical records, chest PA and CT scan of PTB suspects seen at Gangnam Severance Hospital, Seoul, Korea from Oct. 2007 to Apr. 2013. "Active PTB" was diagnosed when 1) M. tuberculosis culture positive, 2) confirmation by pathologic examination; or 3) clinical findings compatible with TB. RESULTS: Of 224 sputum smear negative PTB suspects, 94 were confirmed as having active PTB. There were no statistically significant differences in the diagnostic yield of IGRA between immunocompromised and immunocompetent sputum smear negative PTB suspects. IGRA did show superior sensitivity [81.9%, 95% confidence interval (CI); 74.13-89.70%] in the diagnosis of sputum smear negative PTB when compared with chest high-resolution computed tomography (HRCT), tuberculin skin test (TST), and chest X-ray (p<0.001). Also, IGRA showed highest negative predictive value (82.7%, 95% CI; 75.16-90.15%) when compared with HRCT, TST and chest X-ray (p=0.023). However, combining the results of IGRA with those of HRCT, TST, or both did not increase any diagnostic parameters. CONCLUSION: Failure to increase diagnostic yields by combination with other diagnostic modalities suggests that additional enforcement with IGRA may be insufficient to exclude other diagnoses in sputum smear negative PTB suspects and to screen active PTB in an environment with intermediate TB prevalence and a high BCG vaccination rate.
Adult ; Aged ; Female ; Humans ; Interferon-gamma Release Tests/*methods ; Male ; Middle Aged ; Retrospective Studies ; Sputum/*microbiology ; Tuberculosis, Pulmonary/blood/*diagnosis/metabolism