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Objective To improve the diagnosis of tuberculosis ( TB) by analyzing Mycobacterium infection in fine-needle aspiration biopsy specimens from children with tuberculous lymphadenitis .Methods Fine-needle aspiration biopsy was performed on 269 children with tuberculous lymphadenitis diagnosed by Shanghai Public Health Clinical Center from January 2011 to September 2013 .The needle aspiration biopsy specimens were processed for acid-fast bacillus (AFB) smear test, mycobacterial culture and Mycobacterium identification ( p-nitrobenzoic acid inhibition test ) .Results Cytological diagnosis of tuberculous lymphade-nitis was made for 269 patients.The positive results by AFB smear test were detected in 63.19% of 269 specimens (n=170) and 40.15%(n=108) specimens were positive in mycobacterial culture .The differ-ence between the two tests were significant (P<0.01).The positive rate of Mycobacterium detected by using BACTEC MGIT 960 automated system and L?wenstein-Jensen culture method were 38 .66% ( n=104 ) and 28.99%(n=78), respectively, showing the significant difference between two tests (P<0.05).AFB smear test in combination with mycobacterial culture could precisely diagnose 70.63% of tuberculous lym-phadenitis in children.Of the 108 clinical isolates, 105 strains (97.2%) were Mycobacterium tuberculosis complex and the rest were non-tuberculous Mycobacterium strains (2.8%).Conclusion The positive rate by AFB smear test was significantly increased in fine needle aspiration biopsy specimens after a series of treatments including sample digestion , centrifugation and precipitation , but the positive rate of mycobacterial culture was reduced .Diagnostic accuracy could be significantly improved by using BACTEC MGIT 960 sys-tem.Mycobacterium tuberculosis complex was the predominant pathogenic bacterium in children with tubercu-lous lymphadenitis .
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[Abstract] Objective To evaluate the effect of Mycobacterium tuberculosis Direct Assay (MTD) for rapid detecting Mycobacterium tuberculosis rRNA and Multi-locus PCR for M.bovis BCG strain typing in patients with suspected extra-pulmonary tuberculosis.Methods From June 2010 to December 2011,47 children and 75 adult patients with suspected extra-pulmonary tuberculosis in Shanghai public health clinical center were recruited.Also 48 non-tuberculosis patients were taken as a negative control.Clinical specimens from these patients were collected.Acid fast stain,solid culture,liquid culture,and MTD were used to detect all clinical specimens simultaneously.Screen tuberculosis strains of the culture isolates by MPT64 antigen assay and use Multi-locus PCR for the BCG strain genotyping of the isolates without MPT64 antigen.SPSS16.0 was used to analyse the results.Results The sensitivity for acid fast stain,solid culture,liquid culture and MTD test was 10.7％ (13/122),11.5％ (14/122),16.4％ (20/122) and 37.7％ (46/122),respectively.And the specificity of MTD was 100.0％.Six clinical isolates from children were identified as BCG by Multi-locus PCR typing,the same with chemical tests.Conclusions The MTD assay and the MGIT960 liquid culture are effective and reliable method for diagnosing extra-pulmonary tuberculosis.And Multi-locus PCR can be assisted for the early diagnosis of extra-pulmonary tuberculosis patients with suspected BCG infection.
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ObjectiveTo analyze the characterstics of phenotype and genotype of multidrug resistant tuberculosis (MDR-TB) and extensively drug resistant tuberculosis (XDR-TB) by molecular line probe assay and liquid culture with MGIT960.MethodsGenoType MTBDR Kits were used for identifying the types of the first-line and second-line antituberculosis drug resistant genes partly and BD MGIT960 was used for detecting the chug susceptibility.Results( 1 ) Out of 94 MDR-TB strains,the rate of drug resistant to EMB,AMK,OFX and MFX by BD MGIT960 assay were 36.2%,17.0%,54.3% and 55.3%,respectively.Among these isolates,13 were extensively drug resistant tuberculosis (XDR-TB).(2) Compared with MGIT960,the concordance rate of GenoType MTBDRplus was 86.2% and 95.7% respectively.Taking MGIT960 results as reference,the sensitivity of GenoType MTBDRsl detecting the susceptibility of EMB,AMK,OFX and MFX to 94 isolates were 47.1%,81.3%,94.1%,94.2%,respectively.The specificity were 75.0%,98.7%,90.7%,92.9%,respectively.(3) Among the rpoB mutation categories,S531L accounts for most.MTB resistant to IFN caused by the mutation of katG chiefly and the S315T1 was in the majority.The gyrA mutation sites located at the ninety-fourth codon most.Out of 94 strains,23 were mixed with 2 kindsof Mycobacterium tuberculosis at least and 7 were undetectable mutations.Conclusion Among the M/XDR-TB,the strains resistant to INH,RFP,AMK,OFX and MFX were caused most by the mutation of katG,rpoB,rrs and gyrA,respectively.The relationship between EMB and embB was not so clear relatively.As a fast detecting drug susceptibility test kit,GenoType MTBDR possess good sensitivity and specificity.So,it could be as an assistant method to guide the therapy on clinic.
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Objective To establish the rapid pathogen identification method for HIV and Mycobac-terium tuberculosis (Mtb)co-infection and the assay for the drug susceptibility. Methods Geneprobe and 16S rDNA sequencing were used to differentiate mycobacterium species and modified microscopic observation drug susceptibility (MODS) was used for the drug susceptibility test. The above assays were compared with acid-fast smear, L-J culture and proportional drug susceptibility tests. Results (1) Thirty-four mycobacte-rial isolates were obtained from 112 samples collected from 68 HIV patients. Among these isolates, the strain species were determined by Geneprobe and 16S rDNA sequencing as the followings: 21 Mtb complex, 10 NTM including 5 M.avium complex, 2 M.gordonae, 2 M.kansasii, 1 M.colombiense, and 3 co-infection. (2) The sensitivity of Mtb to rifampicin, ethambutol, isoniazid and streptomycin were 100%, 100%, 76.2%, 90.5% respectively, while the sensitivity of NTM to rifampicin, ethambutol, isoniazid and strepto-mycin were 40%, 60%, 0%, 30% respectively. There is no significant statistic difference between the two methods, MODS and the reference standard, for the drug susceptibility test. (3) Six to eight weeks are nee-ded for the identification of the species of mycobacteria and the drug susceptibility test by using traditional method. In this study, 5-14 d, 6-15 d and 10-14 d are needed for Geneprobe, 16S rDNA sequencing, and MODS respectively. The time for the testing has been dramatically shortened. Conclusion The identifica-tion of mycobacterial species and the drug susceptibility test using clinical samples could be completed within 15 days by using combined Geneprobe, 16S rDNA sequencing and modified MODS. This combined method can be used for the pathogen identification and drug resistant test in HIV patients who are co-infected by my-cobacteria.