scholarly journals Comparison of the MB/BacT and BACTEC 460 TB Systems for Recovery of Mycobacteria from Various Clinical Specimens

1999 ◽  
Vol 37 (4) ◽  
pp. 1206-1209 ◽  
Author(s):  
Francesca Brunello ◽  
Flavio Favari ◽  
Roberta Fontana
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Nontuberculous Mycobacteria ◽  
Common Species ◽  
Individual Species ◽  
Mycobacterium Chelonae ◽  
Recovery Rates ◽  
Clinical Specimens ◽  
Lowenstein Jensen ◽  
Smear Negative ◽  
The Difference

A total of 1,830 specimens (75.7% respiratory and 24.3% nonrespiratory) were cultured in parallel with the MB/BacT and BACTEC 460 TB systems and on Lowenstein-Jensen (LJ) medium. Mycobacteria were identified from 173 (6.5%) specimens. The most common species recovered were Mycobacterium tuberculosis complex (65.9%),Mycobacterium avium complex (22.5%), andMycobacterium chelonae (9.2%). The recovery rates by individual systems were 96.5, 99.4, and 95.9% for MB/BacT, BACTEC 460 TB, and LJ medium, respectively, for all mycobacteria; the recovery rates were 99.1, 100, and 98.2%, respectively, for M. tuberculosis complex alone. The difference among the recovery rates for all mycobacteria and those for individual species was not significant. The BACTEC 460 TB system detected M. tuberculosis isolates more rapidly than the MB/BacT system (8 versus 11.8 days for smear-positive specimens [P < 0.01] and 18 versus 21 days for smear-negative specimens [P < 0.05]), whereas the MB/BacT system more rapidly detected the nontuberculous mycobacteria (17.1 versus 12.7 days [P < 0.01]). These results indicate that the nonradiometric MB/BacT system is a rapid, sensitive, and efficient method for the recovery ofM. tuberculosis and nontuberculous mycobacteria from both pulmonary and extrapulmonary clinical specimens.

scholarly journals Comparison of recoveries of Mycobacterium tuberculosis using the automated BACTEC MGIT 960 System and Lowenstein – Jensen medium

2010 ◽  
Vol 9 (1) ◽  
pp. 44
Author(s):  
Mo. A.AL-Mazini, T. Bukeet, and A. Abdul Kareem
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Recovery Rates ◽  
Clinical Specimens ◽  
Indicator Tube ◽  
Lowenstein Jensen ◽  
Bactec System ◽  
Smear Negative ◽  
The Difference ◽  
Growth Indicator

We examined whether the BACTEC/ Mycobacteria Growth Indicator Tube (MGIT) System alone could supplant the use of a supplemental Lowenstein–Jensen (LJ) slant for routine recovery of M. tuberculosis from clinical specimens. A total of 392 specimens of sputum were included in the study, collected from 196 patients. Specimens were processed with standard N-acetyl- L- Cysteine (NALC-NaOH) method, then inoculated onto BACTEC MGIT 960 and onto LJ media. The recovery rates of M.tuberculosis were 100 % (256/256) with BACTEC MGIT 960 and 72.6%(186/256) with LJ. The rates of contamination for each of the system were 4.8%with BACTEC MGIT 960 and 5.3%with LJ. The TTD for M. tuberculosis was 11.3 days with BACTEC System and 30.8 days with LJ. The difference in TTD between smear positive and smear negative specimens for M.tuberculosis with BACTEC MGIT 960 was not statistically significant. This study shows that the BACTEC System demonstrates better sensitivity for the recovery of M. tuberculosis from clinical specimens.

scholarly journals Comparison of MB/BacT and BACTEC 460 TB Systems for Recovery of Mycobacteria in a Routine Diagnostic Laboratory

1999 ◽  
Vol 37 (11) ◽  
pp. 3711-3712 ◽  
Author(s):  
Andreas Roggenkamp ◽  
Mathias W. Hornef ◽  
Adelheid Masch ◽  
Bettina Aigner ◽  
Ingo B. Autenrieth ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Routine Laboratory ◽  
Diagnostic Laboratory ◽  
Recovery Rates ◽  
Clinical Specimens ◽  
Smear Negative

MB/BacT, BACTEC 460 TB, and Löwenstein-Jensen (LJ) medium were evaluated in parallel for recovery of mycobacteria from 3,700 continuous clinical specimens in a routine laboratory. Mycobacteria were identified from 123 (3.3%) specimens. The recovery rates for all mycobacteria by the different systems were 91.0, 73.0, and 53.6% for BACTEC 460 TB, MB/BacT, and LJ medium, respectively. The recovery rates for Mycobacterium tuberculosis complex were 97.1, 80.2, and 67.6%, respectively. The lack of sensitivity of the MB/BacT system was more pronounced with smear-negative specimens and resulted in a failure to detect three patients with infectious tuberculosis.

scholarly journals Clinical Evaluation of COBAS TaqMan PCR for the Detection ofMycobacterium tuberculosisandM. aviumComplex

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Satoshi Ikegame ◽  
Yoritake Sakoda ◽  
Nao Fujino ◽  
Kazuhito Taguchi ◽  
Masayuki Kawasaki ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Observational Study ◽  
Careful Consideration ◽  
Pcr Analysis ◽  
Test Results ◽  
Clinical Specimens ◽  
Cobas Taqman ◽  
Taqman Pcr ◽  
Smear Negative ◽  
Pcr Test

A retrospective observational study was performed to determine the sensitivity and limitation of PCR test for the detection ofMycobacterium tuberculosisandM. aviumcomplex. We obtained clinical specimens collected from the respiratory tract, culturedM. tuberculosisorM. aviumcomplex, and performed PCR analysis. A total of 299 samples (M. tuberculosis, 177;M. avium, 35;M. intracellulare, 87) were analyzed by COBAS TaqMan PCR from April 2007 to March 2011. The PCR positivity rates were 50–55%, 70–100%, 88–98%, and 100% in smear-negative, smear 1+, 2+, and 3+ groups, respectively. The PCR positivity of tuberculosis in smear 1+ was 80.6%, which was statistically significantly (P<0.001) lower than that of smear 2+ (97.3%). From January 2005 to March 2007, we collected an additional 138 samples (M. tuberculosis, 74;M. avium, 21; M. intracellulare, 43), which were analyzed by COBAS Amplicor PCR. The PCR positivity rates obtained using COBAS TaqMan PCR and COBAS Amplicor PCR were not significantly different. The sensitivity of PCR test for mycobacteria is not sufficient in case of smear 1+. Careful consideration must be given to the interpretation of negative PCR test results in smear 1+, because smear-positive tuberculosis is the criterion for isolation.

scholarly journals Evaluation of the Abbott RealTi m e MTB and RealTi m e MTB INH/RIF Assays for Direct Detection of Mycobacterium tuberculosis Complex and Resistance Markers in Respiratory and Extrapulmonary Specimens

2016 ◽  
Vol 54 (12) ◽  
pp. 3022-3027 ◽  
Author(s):  
Sabine Hofmann-Thiel ◽  
Nikolay Molodtsov ◽  
Uladzimir Antonenka ◽  
Harald Hoffmann
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Susceptibility Testing ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Nucleic Acid Amplification ◽  
Content Type ◽  
Clinical Specimens ◽  
Different Types ◽  
Resistance Markers ◽  
Smear Negative

The Abbott RealTi m e MTB (RT MTB) assay is a new automated nucleic acid amplification test for the detection of Mycobacterium tuberculosis complex (MTBC) in clinical specimens. In combination with the RealTi m e MTB INH/RIF (RT MTB INH/RIF) resistance assay, which can be applied to RT MTB-positive specimens as an add-on assay, the tests also indicate the genetic markers of resistance to isoniazid (INH) and rifampin (RIF). We aimed to evaluate the diagnostic sensitivity and specificity of RT MTB using different types of respiratory and extrapulmonary specimens and to compare performance characteristics directly with those of the FluoroType MTB assay. The resistance results obtained by RT MTB INH/RIF were compared to those from the GenoType MTBDR plus and from phenotypic drug susceptibility testing. A total of 715 clinical specimens were analyzed. Compared to culture, the overall sensitivity of RT MTB was 92.1%; the sensitivity rates for smear-positive and smear-negative samples were 100% and 76.2%, respectively. The sensitivities of smear-negative specimens were almost identical for respiratory (76.3%) and extrapulmonary (76%) specimens. Specificity rates were 100% and 95.8% for culture-negative specimens and those that grew nontuberculous mycobacteria, respectively. RT MTB INH/RIF was applied to 233 RT MTB-positive samples and identified resistance markers in 7.7% of samples. Agreement with phenotypic and genotypic drug susceptibility testing was 99.5%. In conclusion, RT MTB and RT MTB INH/RIF allow for the rapid and accurate diagnosis of tuberculosis (TB) in different types of specimens and reliably indicate resistance markers. The strengths of this system are the comparably high sensitivity with paucibacillary specimens, its ability to detect INH and RIF resistance, and its high-throughput capacities.

scholarly journals Comparison of hypertonic saline-sodium hydroxide method with modified Petroff’s method for the decontamination and concentration of sputum samples

2013 ◽  
Vol 2 (3) ◽  
pp. 78-81 ◽  
Author(s):  
SK Chaudhary ◽  
B Mishra
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Sodium Hydroxide ◽  
Hypertonic Saline ◽  
P Value ◽  
Chi Square ◽  
Major Health ◽  
Medical College ◽  
Lowenstein Jensen ◽  
Novel Method ◽  
The Difference

INTRODUCTION: Tuberculosis is one of the major health problems particularly in developing countries. For definitive diagnosis of pulmonary tuberculosis identification of tubercle bacilli in sputum by microscopy and culture is essential. For decontamination and concentration of sputum, the commonly used method in the laboratory is Modified Petroff’s method but the Hypertonic saline–sodium hydroxide (HS-SH) method is known to be better for detection of Mycobacterium tuberculosis by culture. This study was aimed to compare a novel method for the improvement of decontamination and concentration of sputum samples. MATERIALS AND METHODS: A total of 50 confirmed smear positive sputum samples from pulmonary TB patients who visited at St. John’s Medical College and Hospital during 2009 to 2010, were processed for the decontamination process. Each sample was decontaminated by Modified Petroff’s and HS-SH method separately. Treated samples were cultured in Lowenstein-Jensen media in microbiology laboratory. RESULTS: The culture positive percents of Mycobacterium tuberculosis in the L-J medium treated with HS-SH and Modified Petroff’s method were 84.0% and 70.0%, respectively. A notable feature is that by HS-SH method more samples were positive by 4th week, statistically significant (Chi- square value-11.26 with p-value < 0.05) compare to Modified Petroff’s method. The difference for 3+ grades of L-J growths found slightly higher by Modified Petroff’s method but at lower grades of growths HS-SH method performed better. CONCLUSIONS: HS-SH method is better for the detection of Mycobacterium tuberculosis by culture when compared with the Modified Petroff’s method. DOI: http://dx.doi.org/10.3126/ijim.v2i3.8664   Int J Infect Microbiol 2013;2(3):78-81

scholarly journals Improving the Sensitivity of the Xpert MTB/RIF Assay on Sputum Pellets by Decreasing the Amount of Added Sample Reagent: a Laboratory and Clinical Evaluation

2015 ◽  
Vol 53 (4) ◽  
pp. 1258-1263 ◽  
Author(s):  
Nila J. Dharan ◽  
Danielle Amisano ◽  
Gerald Mboowa ◽  
Willy Ssengooba ◽  
Robert Blakemore ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Limit Of Detection ◽  
Smear Microscopy ◽  
Content Type ◽  
Clinical Specimens ◽  
Test Sensitivity ◽  
Smear Negative ◽  
Almost All ◽  
Culture Positive ◽  
Xpert Assay

The Xpert MTB/RIF (Xpert) assay permits rapid near-patient detection ofMycobacterium tuberculosisin sputum; however, the test sensitivity remains suboptimal in paucibacillary specimens that are negative for acid-fast bacilli using smear microscopy. Xpert testing includes dilution with sample reagent, and when processed sputum pellets are tested, the recommended sample reagent/pellet ratio is 3:1. We evaluated whether a decreased sample reagent/pellet ratio of 2:1 increased Xpert sensitivity compared to the recommended 3:1. The limit of detection was determined by inoculating serial dilutions ofM. tuberculosisinto sputum samples, preparing sputum pellets, and testing each pellet by Xpert at both sample reagent ratios. Processed sputum pellets obtained fromM. tuberculosisculture-positive clinical specimens were also tested by Xpert at both ratios. Among spiked sputum pellets, the limit of detection was 1,478 CFU/ml (95% confidence interval [CI], 1,211 to 1,943) at a 3:1 ratio and decreased to 832 CFU/ml (95% CI, 671 to 1,134) at 2:1. The proportion of specimens in whichM. tuberculosiswas detected was greater at 2:1 than at 3:1 for almost all numbers of CFU/ml; this difference was most prominent at lower numbers of CFU/ml. Among 134 concentrated sputum pellets from the clinical study, the sensitivity of Xpert at 2:1 was greater than at 3:1 overall (80% versus 72%;P= 0.03) and for smear-negative specimens (67% versus 58%;P= 0.12). For Xpert testing of sputum pellets, using a lower sample reagent/pellet ratio increasedM. tuberculosisdetection, especially for paucibacillary specimens. Our study supports use of a 2:1 sample reagent/pellet dilution for Xpert testing of sputum pellets.

scholarly journals Multicenter Comparison of ESP Culture System II with BACTEC 460TB and with Lowenstein-Jensen Medium for Recovery of Mycobacteria from Different Clinical Specimens, Including Blood

1998 ◽  
Vol 36 (5) ◽  
pp. 1378-1381 ◽  
Author(s):  
Enrico Tortoli ◽  
Paola Cichero ◽  
M. Gabriella Chirillo ◽  
M. Rita Gismondo ◽  
Letizia Bono ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Mycobacterium Avium ◽  
Culture System ◽  
Solid Medium ◽  
Mycobacterial Species ◽  
Becton Dickinson ◽  
Clinical Specimens ◽  
Lowenstein Jensen ◽  
Bactec System ◽  
The Times

The recently developed ESP Culture System II (AccuMed, Chicago, Ill.) was compared with radiometric BACTEC 460TB (Becton Dickinson, Towson, Md.) and with Lowenstein-Jensen medium for recovery of mycobacteria from over 2,500 clinical specimens both of respiratory and nonrespiratory origin, including blood. The majority of the 219 mycobacterial isolates (129) belonged to the Mycobacterium tuberculosis complex, followed by 37 isolates of theMycobacterium avium complex (MAC) and 53 isolates of eight other mycobacterial species. Rates of recovery obtained with BACTEC, ESP, and Lowenstein-Jensen medium were 89, 79, and 64%, respectively, with such differences being statistically significant. Different media and systems appeared to behave differently when the more frequently detected organisms were considered: M. tuberculosis complex isolates grew better with BACTEC, and MAC isolates grew better with ESP. An analysis of the combinations of Lowenstein-Jensen medium with BACTEC and with ESP did not reveal significant differences in recovery rates. With regard to the times needed for the detection of positive cultures, they were significantly longer on Lowenstein-Jensen medium (average, 28 days) than with the remaining two systems, between which there was no difference (average, 18 days). We conclude, therefore, that the ESP system, when used in combination with a solid medium, performs as well as the thoroughly validated radiometric BACTEC system and offers the advantages of full automation and absence of radioisotopes.

Evaluation of the Enhanced Amplified Mycobacterium Tuberculosis Direct Test for Direct Detection of Mycobacterium tuberculosis Complex in Respiratory Specimens

1999 ◽  
Vol 123 (11) ◽  
pp. 1101-1103 ◽  
Author(s):  
Michael B. Smith ◽  
John S. Bergmann ◽  
Michelle Onoroto ◽  
Greg Mathews ◽  
Gail L. Woods
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Nontuberculous Mycobacteria ◽  
Direct Detection ◽  
Direct Test ◽  
Tuberculosis Complex ◽  
Predictive Values ◽  
Smear Negative ◽  
Sensitivity Specificity ◽  
Culture Positive ◽  
Respiratory Specimens

Abstract Objective.—To evaluate the performance of the enhanced Mycobacterium Tuberculosis Direct Test (E-MTD), for the direct detection of M tuberculosis complex (MTBC) in respiratory specimens. Design.—Two hundred seventy-four respiratory specimens from 151 patients in respiratory isolation were tested with the E-MTD, and the results were compared with the results of mycobacterial smear, culture, and the earlier form of the test, MTD-1. Results.—Forty-one specimens were culture positive for mycobacteria (20 MTBC and 21 nontuberculous mycobacteria), 23 of which were smear positive (16 MTBC, 7 nontuberculous mycobacteria). Twenty-four specimens were positive by E-MTD, and 21 were positive by MTD-1. Of the 20 MTBC culture-positive specimens, 19 were positive by the E-MTD and 19 were positive by the MTD-1. The remaining specimens were MTBC negative by all methods. After resolution of discrepancies, the sensitivity, specificity, and positive and negative predictive values were 95.2%, 100%, 100%, 99.6% for the MTD-1 and 95.2%, 98.8%, 87.0%, and 99.6%, for the E-MTD. For the E-MTD smear-positive and smear-negative specimens, these same values were 93.8%, 100%, 100%, and 87.5% and 100%, 98.8%, 62.5%, and 100%, respectively. Conclusion.—The results suggest that the E-MTD is a reliable method for the direct detection of MTBC in smear-positive respiratory specimens.

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