Mycobacterial Growth Indicator Tube Versus the Proportion Method on L�wenstein-Jensen Medium for Antibiotic Susceptibility Testing of Mycobacterium tuberculosis

2000 ◽  
Vol 19 (12) ◽  
pp. 938-942 ◽  
Author(s):  
E. Cambau ◽  
C. Truffot-Pernot ◽  
F. Boulahbal ◽  
C. Wichlacz ◽  
J. Grosset ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Antibiotic Susceptibility ◽  
Susceptibility Testing ◽  
Antibiotic Susceptibility Testing ◽  
Indicator Tube ◽  
Proportion Method ◽  
Tube Versus ◽  
Mycobacterial Growth ◽  
Mycobacterial Growth Indicator Tube ◽  
Growth Indicator

Evaluation of the BBL MGIT (Mycobacterial Growth Indicator Tube) AST SIRE System for Antimycobacterial Susceptibility Testing of Mycobacterium tuberculosis to 4 Primary Antituberculous Drugs

2000 ◽  
Vol 124 (1) ◽  
pp. 82-86
Author(s):  
John S. Bergmann ◽  
Geoffrey Fish ◽  
Gail L. Woods
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Susceptibility Testing ◽  
Clinical Isolates ◽  
Indicator Tube ◽  
The Mean ◽  
Inoculum Preparation ◽  
Mycobacterial Growth ◽  
Mean Time ◽  
Mycobacterial Growth Indicator Tube ◽  
Growth Indicator

Abstract Objective.—To evaluate the performance of the BBL MGIT (Mycobacterial Growth Indicator Tube) AST SIRE system for the antimycobacterial susceptibility testing of Mycobacterium tuberculosis to isoniazid (at a concentration equivalent to the lower concentration used for testing by the method of proportion), rifampin, ethambutol, and streptomycin. Design.—Thirty-one clinical isolates and 30 challenge strains provided by the Centers for Disease Control and Prevention (CDC) were tested by MGIT AST SIRE using 2 methods of inoculum preparation, and results were compared with those of the method of proportion, which was considered the reference method. Clinical isolates for which the results of the 2 methods were discordant also were tested at 2 reference laboratories. Results.—Based on data from our site and the reference laboratories, agreement rates between initial MGIT AST SIRE results and the method of proportion for the clinical isolates with the inoculum prepared from a McFarland equivalent and from a positive MGIT tube, respectively, were 100% and 96.8% for isoniazid, 100% and 100% for rifampin, 96.8% and 100% for ethambutol, and 100% and 100% for streptomycin, excluding the isolate for which the discordant streptomycin result could not be resolved. For the 30 challenge isolates, agreement rates between MGIT AST SIRE and expected results and between method of proportion and expected results, respectively, were 96.7% and 93.3% for isoniazid, 93.3% and 100% for rifampin, 83.3% and 100% for ethambutol, and 93.3% and 100% for streptomycin. For the clinical isolates, the mean time to an MGIT AST SIRE result of susceptible was 6.15 ± 0.13 days (range, 5–8 days). For a result of resistant, the mean time overall was 5.00 ± 0.24 days (range, 3–8 days). Conclusion.—These data suggest that the MGIT AST SIRE system, using either method of inoculum preparation, is an acceptable alternative to the BACTEC 460 TB method of susceptibility testing of clinical isolates of M tuberculosis to isoniazid, rifampin, ethambutol, and streptomycin. Reasons for the lower agreement with the CDC challenge isolates should be investigated. Further evaluation of the MGIT AST SIRE system using a concentration of isoniazid equivalent to the higher concentration tested by the method of proportion would be useful, because the decision concerning use of this agent generally is based on the susceptibility test result at the higher concentration.

scholarly journals Occurrence ofrpoBMutations in Isoniazid-Resistant but Rifampin-Susceptible Mycobacterium tuberculosis Isolates from Germany

2013 ◽  
Vol 58 (1) ◽  
pp. 590-592 ◽  
Author(s):  
Sönke Andres ◽  
Doris Hillemann ◽  
Sabine Rüsch-Gerdes ◽  
Elvira Richter
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Susceptibility Testing ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Content Type ◽  
Indicator Tube ◽  
Lowenstein Jensen ◽  
Proportion Method ◽  
Rifampin Resistance ◽  
Growth Indicator

ABSTRACTFour out of 143 phenotypically isoniazid-resistant but rifampin-susceptibleMycobacterium tuberculosisstrains that were isolated from patients in Germany in 2011 had mutations in the rifampin resistance-determining region ofrpoB. After performing drug susceptibility testing (DST) with two methods, the proportion method on Löwenstein-Jensen medium and using the Bactec 960 Mycobacteria Growth Indicator Tube system, we conclude that the two methods are equally reliable for phenotypic DST and MIC determination.

scholarly journals Comparison of MGIT and Myco/F Lytic Liquid-Based Blood Culture Systems for Recovery of Mycobacterium tuberculosis from Pleural Fluid

2015 ◽  
Vol 53 (4) ◽  
pp. 1391-1394 ◽  
Author(s):  
Elizabeth Harausz ◽  
John Kafuluma Lusiba ◽  
Mary Nsereko ◽  
John L. Johnson ◽  
Zahra Toossi ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Pleural Fluid ◽  
Culture System ◽  
Liquid Culture ◽  
Content Type ◽  
Indicator Tube ◽  
Liquid Culture System ◽  
Mycobacterial Growth ◽  
Mycobacterial Growth Indicator Tube ◽  
Growth Indicator

The specificities and sensitivities of the Bactec mycobacterial growth indicator tube (MGIT) system for the recovery ofMycobacterium tuberculosisfrom pleural fluid are not statistically different than those of the Myco/F lytic liquid culture system. The time to positivity is shorter in the MGIT system (12.7 versus 20.7 days, respectively;P= 0.007). The Myco/F lytic culture system may be an alternative to the MGIT system for diagnosing pleural tuberculosis.

scholarly journals Kanamycin Susceptibility Testing of Mycobacterium tuberculosis Using Mycobacterium Growth Indicator Tube and a Colorimetric Method

2001 ◽  
Vol 45 (6) ◽  
pp. 1934-1936 ◽  
Author(s):  
Ivan Bastian ◽  
Leen Rigouts ◽  
Juan Carlos Palomino ◽  
Françoise Portaels
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Susceptibility Testing ◽  
Colorimetric Method ◽  
Alamar Blue ◽  
Mycobacterium Growth Indicator Tube ◽  
Indicator Tube ◽  
Proportion Method ◽  
Susceptibility Tests ◽  
Growth Indicator

ABSTRACT Two novel systems were evaluated for performing indirect kanamycin susceptibility tests on 72 strains of Mycobacterium tuberculosis. The microplate Alamar blue colorimetric method (breakpoint, 2.5 μg/ml) and the Mycobacterium Growth Indicator Tube (MGIT) system (breakpoint, 5.0 μg/ml) both produced 98.6% agreement when compared with the conventional proportion method performed on 7H10 agar using 5.0 μg of kanamycin/ml. Both systems provided results within an average of 1 week.

scholarly journals Multicenter Evaluation of the Mycobacteria Growth Indicator Tube for Testing Susceptibility of Mycobacterium tuberculosis to First-Line Drugs

1999 ◽  
Vol 37 (1) ◽  
pp. 45-48 ◽  
Author(s):  
Sabine Rüsch-Gerdes ◽  
Cornelia Domehl ◽  
Giampietro Nardi ◽  
Maria Rita Gismondo ◽  
Hans-Martin Welscher ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Susceptibility Testing ◽  
Solid Medium ◽  
First Line ◽  
Indicator Tube ◽  
Significant Difference ◽  
Testing Susceptibility ◽  
Proportion Method ◽  
Test Cultures ◽  
Growth Indicator

In a multicenter study involving three reference centers for mycobacteria, the reliability of the Mycobacteria Growth Indicator Tube (MGIT) for rapid antimicrobial susceptibility testing (AST) ofMycobacterium tuberculosis was evaluated and compared to the radiometric method (BACTEC 460TB). Test cultures for which the results of the MGIT and BACTEC 460TB tests were discordant were checked by the conventional proportion method on solid medium. Four hundred forty-one isolates have been tested for susceptibility to isoniazid (INH), rifampin (RMP), ethambutol (EMB), and streptomycin (SM). Discrepant results were obtained for three isolates (0.7%) with INH (susceptible by MGIT, resistant by BACTEC 460TB), for four isolates (0.9%) with RMP (susceptible by MGIT, resistant by BACTEC 460TB), for six isolates (1.9%) with EMB (four susceptible by MGIT, resistant by BACTEC 460TB; two resistant by MGIT, susceptible by BACTEC 460TB), and for four isolates (0.9%) with SM (two susceptible by MGIT, resistant by BACTEC 460TB; two resistant by MGIT, susceptible by BACTEC 460TB). When cultures with discordant results were tested by the conventional proportion method, about half of the cultures yielded results similar to the BACTEC 460TB results, while the other half yielded results similar to the MGIT results. Turnaround times were 3 to 14 days (median, 8.8 days) for MGIT and 3 to 15 days (median, 7.8 days) for BACTEC 460TB. There was no statistically significant difference between the susceptibility testing results of the two methods (P > 0.05). These data demonstrate that the MGIT system is an accurate, nonradiometric alternative to the BACTEC 460TB method for rapid susceptibility testing of M. tuberculosis.

scholarly journals Accuracy of Xpert Ultra in Diagnosis of Pulmonary Tuberculosis among Children in Uganda: a Substudy from the SHINE Trial

2020 ◽  
Vol 58 (9) ◽  
Author(s):  
Willy Ssengooba ◽  
Jean de Dieu Iragena ◽  
Lydia Nakiyingi ◽  
Serestine Mujumbi ◽  
Eric Wobudeya ◽  
...  
Keyword(s):  
Positive Result ◽  
Diagnostic Challenge ◽  
Indicator Tube ◽  
Lowenstein Jensen ◽  
Mgit Culture ◽  
Mycobacterial Growth ◽  
Culture Positive ◽  
Mycobacterial Growth Indicator Tube ◽  
Higher Sensitivity ◽  
Growth Indicator

ABSTRACT Childhood tuberculosis (TB) presents significant diagnostic challenges associated with paucibacillary disease and requires a more sensitive test. We evaluated the diagnostic accuracy of Xpert MTB/RIF Ultra (Ultra) compared to other microbiological tests using respiratory samples from Ugandan children in the SHINE trial. SHINE is a randomized trial evaluating shorter treatment in 1,204 children with minimal TB disease in Africa and India. Among 352 samples and one cervical lymph node fine needle aspirate, one sample was randomly selected per patient and tested with the Xpert MTB/RIF assay (Xpert) and with Lowenstein-Jensen medium (LJ) and liquid mycobacterial growth indicator tube (MGIT) cultures. We selected only uncontaminated stored sample pellets for Ultra testing. We estimated the sensitivity of Xpert and Ultra against culture and a composite microbiological reference standard (any positive result). Of 398 children, 353 (89%) had culture, Xpert, and Ultra results. The median age was 2.8 years (interquartile range [IQR], 1.3 to 5.3); 8.5% (30/353) were HIV infected, and 54.4% (192/353) were male. Of the 353, 31 (9%) were positive by LJ and/or MGIT culture, 36 (10%) by Ultra, and 16 (5%) by Xpert. Sensitivities (95% confidence intervals [CI]) were 58% (39 to 65% [18/31]) for Ultra and 45% (27 to 64% [14/31]) for Xpert against any culture-positive result, with false positives of <1% and 5.5% for Xpert and Ultra. Against a composite microbiological reference, sensitivities were 72% (58 to 84% [36/50]) for Ultra and 32% (20 to 47% [16/50]) for Xpert. However, there were 17 samples that were positive only with Ultra (majority trace). Among children screened for minimal TB in Uganda, Ultra has higher sensitivity than Xpert. This represents an important advance for a condition which has posed a diagnostic challenge for decades.

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