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Objective To evaluate the clinical value of the isothermal RNA amplification assay (SAT) for detection of Mycobacterium tuberculosis in sputum samples.Methods Sputum specimens from 230 patients with diagnosed tuberculosis and 78 cases of other respiratory diseases during September to December 2011 were detected using SAT,BD960 culture,LowenStein-Jensen( L-J ) culture and concentrated smear simultaneously.The samples with different results between SAT and BD960 culture were tested by Mycobacterium tuberculosis PCR fluorescence diagnosis kits.Strains were identified by amplification and sequencing the BD960 culture-positive isolates and SAT amplification products.Positive detection rate of SAT and other three methods for patients with tuberculosis were compared by chi-square test.Results Using the results of BD960 culture as the golden standard (7 cases of pollution bacteria in BD960 culture was rejected ),the sensitivity,specificity,positive predictive value,and negative predictive value of SAT was 90.5％ (95/105),84.2％ (165/196),75.4％ (95/126),94.3％ (165/175),respectively.The agreement rate of SAT and BD960 culture was 86.4％ (260/301).For 223 tuberculosis patients,the positive detection rate of SAT,BD960 culture,L-J culture and concentrated smear was 56.5％ ( 126/223 ),45.7％ ( 102/223 ),41.7％ ( 93/223 ) and 37.2％ ( 83/223 ) respectively.The positive detection rate of SAT is significantly higher than the other three methods (x2 =4.087,P ＜ 0.05 ).Conclusion SAT,as a new technology for laboratory diagnosis of TB,has high specificity and sensitivity.The operation is fast and simple,and the pollution rate is low.It is a promising laboratory diagnosis method.
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OBJECTIVE To examine the prevalence and trends of drug resistance of nontuberculous mycobacteria(NTM)in Shanghai.METHODS All NTM strains isolated between 1998 and 2004 in Shanghai were identified with conventional biochemical tests.Antimicrobial susceptibility test for all NTM was performed by standard absolute concentration method.RESULTS The prevalence rate was determined as 1.49%,1.17%,1.98%,2.46%,2.66%,2.72% and 3.0% among mycobacteria culture positive patients per year in 1998,1999,2000,2001,2002,2003,and in 2004,respectively.These data indicated the prevalence rate has continuously increased.Distribution of NTM isolates was Group Ⅰ18.7%,Group Ⅱ 5.1%,Group Ⅲ 25.1%,and Group Ⅳ 51.1% accordingly.Group Ⅳ rapidly growing NTM accounted for majority of them.Most of NTM showed high drug resistance to general antituberculotic drug.In particular Group Ⅳ Mycobacterium chelonae and M.fortuitum appeared multi-drug resistance.CONCLUSIONS The prevalence rate of NTM in Shanghai shows increased tendency.Most of NTM isolates are Group Ⅳ rapidly growing NTM.NTM shows high drug resistance to first line antituberculotic substance.
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Objective To understand the bacteriology and the association between drug susceptibility and clinical features from recent hospitalization of tuberculosis(TB)patients with positive tuberculosis bacilli culture.Methods We collected the clinical data of inpatients due to tuberculosis or pulmonary disease with positive tuberculosis bacilli by BACTEC960 culture auto-analysis system and possessing anti-tuberculosis drug susceptibility testing results from January 2008 to November 2008.All isolated strains were tested with first-line drugs included Streptomycin(S),Isoniazid(H),Rifampicin(R)and Ethambutol(E).Some isolate strains were used to test Amikacin(Am),Capreomycin(Cm)and Ofloxacin(Ofx).We recorded the drug-tested results and clinical data and retrospectively analyzed them.The patients with pulmonary disease from nontuberculosis mycobacteria(NTM)were excluded.Results (1)There were 417 patients with positive culture of tuberculosis bacilli (included 294 male and 123 female).The mean age was(47.8 18.1)years(ranging from 6 to 91 years).There were 68 cases complicated with endobronchial tuberculosis(EBTB)and 56 cases with type 2 diabetes mellitus.(2)There were 271 cases for initial treatment and 146 cases of relapsing tuberculosis.The total drug resistant rate was 53.5 percent,and of oflx was as high as 31.86 percent.The initial drug resistant rate was S 22.5%,H 25.8%,R 17.3%,E 21.0%,Am 6.3%,Cm 10.0%,Ofx 16.6% respectively and the required rate was 67.8%,82.9%,68.5%,68.5%,19.9%,25.3%,58.2% respectively.(3)There were 143 patients with multi-drug resistant TB(MDR-TB).The mean age 44.59?16.31 was significantly younger than of other patients(P