Objective To evaluate the diagnostic value of all diagnostic tests detecting the ethambutol resistance in Mycobacterium tuberculosis. Methods PubMed, EMbase, Chinese Biomedical Database (CBM), Chinese Scientific Journals Full-Text Database (CSJD), and Chinese Journal Full-text Database (CJFD) were searched, and QUADAS items were used to evaluate the quality of included studies. Meta-disc software was used to handle data from included studies. Such index as sensitivity, specificity, and SROC were applied to assess the diagnostic value of individual diagnostic test. Results Nine studies were included. The results of meta-analyses showed that compared with proportion method, the summary sensitivity, summary specificity, positive likelihood ratio, negative likelihood ratio, and SROC area under curve of a nitrate reductase assay were 92%, 99%, 30.50, 0.13, and 0.975 2, respectively, while compared with BACTEC 460 TB, the above mentioned indexes of BACTEC MGIT 960 System were 92%, 99%, 6.27, 0.11, and 0.9, respectively. Bacteriophage biological amplification method revealed relative good analysis effectiveness on MB/BacT. Conclusion According to the results, it is recommended that nitrate reductase assay can replace proportion method as screening test of ethambutol resistance in Mycobacterium tuberculosis, and BACTEC MGIT 960 System can replace BACTEC 460 as final diagnostic test of ethambutol resistance in Mycobacterium tuberculosis.
Objective To investigate the initial drug resistance of Mycobacterium tuberculosis ( M.tuberculosis) in patients with culture positive pulmonary tuberculosis. Methods 1184 patients who hospitalized in Shandong Provincial Chest Hospital with culture positive pulmonary tuberculosis were enrolled. The absolute density method was used to assess the drug resistance of M. tuberculosis. Results M.tuberculosis were sensitive to all anti-tuberculosis drugs in 834 cases( 70. 44% ) , and resistant in 350 cases( 29. 56% ) , in which initial resistance and secondary resistance accounted for 44. 86% ( 157/350) and 55. 14% ( 193 /350) respectively. In 157 cases with initial resistance, 53 cases ( 33. 8% ) were mono-drug resistant tuberculosis( MonoDR-TB) , of which 38 cases were resistance to Streptomycin( 24. 2% ) ; 72 cases( 45. 9% ) were polydrug-resistant tuberculosis ( PDR-TB) ; 20 cases ( 12. 7% ) were multidrug-resistant tuberculosis ( MDR-TB) ; 12 cases ( 7. 6% ) were extensively drug resistant tuberculosis ( XDR-TB) . There was no totally drug-resistant tuberculosis ( TDR-TB) . Conclusions The initial drug resistance of M.tuberculosis in patients with pulmonary tuberculosis is still serious. Unified management of TB control programs and full supervision of chemotherapy are very imperative.
Objective To evaluate the diagnostic value of all diagnostic tests for detecting armazide resistance in mycobacterium tuberculosis. Methods We searched PUBMED, EMBASE, CBM, CSJD and CJFD. QUADAS items were used to evaluate the quality of included studies. Meta-disc software was used to handle data from included studies. Results Twelve studies were included. Meta-analyses showed that the summary sensitivity and summary specificity of nitrate reductase assay were 92% and 99%, and those of BACTEC MGIT 960 system were 93% and 96%, respectively. The SROC of nitrate reductase assay and BACTEC MGIT 960 system were 0.9836 and 0.9862, respectively. Conclusion We recommend that proportion method can be replaced by nitrate reductase assay as a screening test for detecting armazide resistance in mycobacterium tuberculosis, and BACTEC 460 can be replaced by BACTEC MGIT 960 system as a final diagnostic test for detecting armazide resistance in mycobacterium tuberculosis.
Objective To evaluate the diagnostic accuracy of LiPA and phage-based assays in detecting rifampicin resistance in Mycobacterium tuberculosis. Methods A fully recursive literature search was conducted in PUBMED, EMBASE, CBMWeb, CSJD and CJFD. QUADAS items were used to evaluate the quality of the included studies. Meta-disc software was used to handle data from the included studies. SEN, SPE and SROC were used to assess the diagnostic accuracy of every individual diagnostic test. Results A total of 42 studies were included finally. (1) LiPA for detection of rifampicin resistant Mycobacterium tuberculosis: 7 studies took BACTEC 460 assay as the reference test, and meta-analysis showed that the summary SEN = 0.98, summary SPE = 0.98, SROC (AUC) = 0.9924; 6 studies chose proportion assay as the reference test, and meta-analysis showed that the summary SEN = 0.97, summary SPE = 1.00, SROC (AUC) = 0.9961; and 3 studies took both BACTEC 460 assay and proportion assay as the reference tests, and meta-analysis showed that the summary SEN = 0.92, summary SPE = 0.98, SROC (AUC) = 0.9842. (2)Seven studies detected the rifampicin resistant Mycobacterium tuberculosis using Phage amplification assays (Commercial), taking BACTEC 460 assay and proportion assay as the reference tests. Meta-analysis showed that the summary SEN = 0.95, summary SPE = 0.95, SROC (AUC) = 0.9842. (3) Seven studies detected the rifampicin resistant Mycobacterium tuberculosis using Phage amplification assays (in-house), taking BACTEC 460 assay, proportion assay and absolute concentration as the reference tests. Meta-analysis showed that the summary SEN = 0.98, summary SPE = 0.98, SROC (AUC) = 0.9949. (4)Seven studies detected the rifampicin resistant Mycobacterium tuberculosis using Luciferase reporter phage assays (In-house), taking BACTEC 460 assay, proportion assay and absolute concentration as the reference tests. Meta-analysis showed that the summary SEN = 0.98, summary SPE = 0.98, SROC (AUC) = 0.9788. Conclusion Current research confirms that Phage assay is a highly sensitive and specific test for the detection of rifampicin resistance in culture isolates and has a potential in improving the diagnostic accuracy of all diagnostic tests in detecting the rifampicin resistant Mycobacterium tuberculosis. LiPA is also a highly sensitive and specific test for the detection of rifampicin resistance, but the sensitivity appears to relatively decrease when it was used directly on clinical specimens. The results mentioned above need to be further confirmed by more high-quality studies.
ObjectiveTo explore distribution characteristics of drug-resistant mutations and analyze drug-resistant genotypes in Mycobacterium tuberculosis in Deyang district, Sichuan. MethodsA total of 257 patients infected with Mycobacterium tuberculosis and positive for mycobacterium tuberculosis DNA who were detected from February 2010 to March 2013 were included in our research. Drug-resistance mutations were detected and analyzed using gene chip technology combining by polymerase chain reaction (PCR) and reverse dot hybridization (RDB). ResultsIn these 257 pulmonary tuberculosis patients, drug-resistance mutations were detected in 49 with pulmonary tuberculosis. Drug-resistance mutation rate at katG 315, rpsL 43, embB 306 and rpoB 531 (S531L) was 11.67% (30/257), 7.00% (18/257), 4.28% (11/257) and 3.89% (10/257), respectively. In 234 initially treated pulmonary tuberculosis patients, the rate of isoniazid-resistant genotype, rifampicin-resistant genotype, ethambutol-resistant genotype, streptomycin-resistant genotype and multi-drug resistant genotype was 9.83%, 4.27%, 3.42%, 5.13% and 2.99%, respectively. In 23 retreated pulmonary tuberculosis patients, these rates was 52.17%, 26.09%, 13.04%, 43.48% and 13.04%, respectively. ConclusionIn Deyang district, Sichuan, drug-resistant genotypes for isoniazid, rifampicin, ethambutol and streptomycin are detected in Mycobacterium tuberculosis. Most of the drug-resistant mutations occur at katG 315, rpsL 43, embB 306 and rpoB 531. The rates of drug-resistant genotypes and multi-drug resistance in initially treated pulmonary tuberculosis patients are lower than those in retreated patients. Multi-drug resistant rate is relatively low in our research.
ObjectiveTo evaluate the clinical values of phage amplified biologically assay (PhaB) for diagnosis of tuberculosis by comparatively analyzing the diagnostic performances of PhaB, acid fast stain and culture. MethodsThe samples of random sputum and morning sputum from 157 tuberculosis patients diagnosed between January and December 2014 were detected by mycobacteria culture, PhaB, acid fast stain and culture method. The differences of diagnostic performances were analyzed by chi-square test. ResultsThe diagnostic sensitivity was 89.8% (mycobacteria culture), 68.2% (PhaB) and 52.2% (acid fast stain); according to the gold standard of culture method, the positive coincident rate was 74.5% and 57.4%, respectively in PhaB and acid fast stain (P<0.05), and the general coincident rate was 75.8% and 60.5% (P<0.05); of those patients with two negative sputum smears, the positive rate was 33.3% (25/75) in PhaB; the detection time was 1 hour (acid fast stain), 46 hours (PhaB) and 9.5 days (mycobacteria culture), respectively. ConclusionBecause of its high sensitivity, high specificity and short turn around time, simple operation, distinguishing dead isolates and live isolates and drug resistance detection, PhaB is a new method for screening test of tuberculosis or as an effective complementary testing for traditional assays.
To screen new tuberculosis diagnostic antigens and vaccine candidates, we predicted the epitopes of Mycobacterium tuberculosis latent infection-associated protein Rv2004c by means of bioinformatics. The homology between Rv2004c protein and human protein sequences was analyzed with BLAST method. The second structures, hydrophilicity, antigenicity, flexibility and surface probability of the protein were analyzed to predict B cell epitopes and T cell epitopes by Protean software of DNAStar software package. The Th epitopes were predicted by RANKPEP and SYFPEITHI supermotif method, the CTL epitopes were predicted by means of combination analyses of SYFPEITHI supermotif method, BIMAS quantitative motif method and NetCTL prediction method. The peptide sequences with higher scores were chosen as the candidate epitopes. Blast analysis showed that Rv2004c protein had low homology with human protein. This protein had abundant secondary structures through analysis of DNAStar software, the peptide segments with high index of hydrophilicity, antigenicity, surface probability and flexibility were widely distributed and were consistent with segments having beta turn or irregular coil. Ten candidates of B cell epitopes were predicted. The Th epitopes of Rv2004c protein were located after the 200th amino acid. Of 37 Th cell epitopes predicted, there were more epitopes of HLA-DRB1*0401 and HLA-DRB1*0701 phenotypes, and the MHC restrictive types of some Th cell epitopes exist cross overlap. Of 10 CTL epitopes predicted, there were more number and higher score of HLA-A2 restricted epitopes. Therefore Mycobacterium tuberculosis Rv2004c protein is a protein antigen with T cell and B cell epitopes, and is expected to be a new target protein candidate for tuberculosis diagnosis and vaccine.
ObjectiveTo systematically review the diagnostic value of PCR-single-strand conformational polymorphism (PCR-SSCP) method for detecting rpoB gene mutation of rifampin-resistant mycobacterium tuberculosis. MethodsSuch databases as PubMed, Web of Science, The Cochrane Library (Issue 2, 2014), CBM, VIP and WanFang Data were electronically and comprehensively searched for relevant studies on the diagnostic value of PCR-SSCP method for detecting rpoB gene mutation of rifampin-resistant mycobacterium tuberculosis from inception to January 1st, 2014. Literature screening according to the inclusion and exclusion criteria, data extraction and methodological quality assessment were completed by two reviewers independently. Meta-analysis was then conducted using Meta-Disc 1.4 and Stata 12.0. ResultsA total of 10 studies were included involving 1 299 cases. The results of meta-analysis showed SEN=0.92 (95%CI 0.90 to 0.94, P=0.019 3), SPE=0.97 (95%CI 0.95 to 0.98, P < 0.000 1), +LR=23.68 (95%CI 8.71 to 64.37, P < 0.000 1), -LR=0.10 (95%CI 0.06 to 0.15, P=0.023 1), DOR=257.16 (95%CI 96.82 to 683.02, P=0.020 0), and SROC area under the curve (AUC) was 0.971 5, and Q* was 0.922 3. The results of sensitivity analysis (after removing studies with sample size less than 100, Chinese studies and QUADAS more than 10 studies) showed that, the results were stable with reliable conclusion. ConclusionPCR-SSCP method has a fairly high value in the diagnosis of rpoB gene mutation of rifampinresistant mycobacterium tuberculosis.