scholarly journals Multicenter Evaluation of the BACTEC MGIT 960 System for Recovery of Mycobacteria

1999 ◽  
Vol 37 (3) ◽  
pp. 748-752 ◽  
Author(s):  
Bruce A. Hanna ◽  
Adeleh Ebrahimzadeh ◽  
L. Bruce Elliott ◽  
Margie A. Morgan ◽  
Susan M. Novak ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Liquid Medium ◽  
Mycobacterium Avium ◽  
Culture Systems ◽  
Solid Media ◽  
Lowenstein Jensen ◽  
The Mean

We evaluated the BACTEC MGIT 960 system, which is a fully automated, noninvasive system for the growth and detection of mycobacteria with a capacity to incubate and continuously monitor 960 7-ml culture tubes. We studied 3,330 specimens, 2,210 respiratory and 1,120 nonrespiratory specimens, collected from 2,346 patients treated at six sites. Processed specimens were inoculated into the BACTEC MGIT 960 and BACTEC 460 TB systems, as well as onto Lowenstein-Jensen slants and Middlebrook 7H11/7H11 selective plates. From all culture systems, a total of 362 isolates of mycobacteria were recovered; these were recovered from 353 specimens collected from 247 patients. The greatest number of isolates of mycobacteria (289, or 80% of the 362 isolates) was recovered with the BACTEC MGIT 960, followed by the BACTEC 460 TB (271, or 75%) and solid media (250, or 69%). From all culture systems a total of 132 isolates of Mycobacterium tuberculosiscomplex were recovered. The greatest number of isolates of M. tuberculosis complex was recovered when liquid medium was combined with conventional solid media; the number recovered with BACTEC 460 TB plus solid media was 128 (97%), that recovered with BACTEC MGIT 960 plus solid media was 121 (92%), that recovered with BACTEC 460 TB was 119 (90%) and that recovered with all solid media combined was 105 (79%). The recovery with BACTEC MGIT 960 alone was 102 (77%). The mean times to detection (TTD) for M. tuberculosis complex were 14.4 days for BACTEC MGIT, 15.2 days for BACTEC 460 TB, and 24.1 days for solid media. The numbers of isolates of Mycobacterium avium complex (MAC) recovered were 172 (100%) for all systems, 147 (85%) for BACTEC MGIT 960, 123 (72%) for BACTEC 460 TB, and 106 (62%) for all solid media combined. The TTD for MAC in each system were 10.0 days for BACTEC MGIT 960, 10.4 days for BACTEC 460 TB, and 25.9 days for solid media. Breakthrough contamination rates (percentages of isolates) for each of the systems were 8.1% for BACTEC MGIT 960, 4.9% for BACTEC 460 TB, and 21.1% for all solid media combined.

Determination some Immunological Aspects in Pulmonary Tuberculosis Patients in Qadisiyah Province

2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Syoof Khowman Alramahy ◽  
Akram Hadi Hamza
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Pulmonary Tuberculosis ◽  
Statistical Difference ◽  
Positive Culture ◽  
Control Group ◽  
Tuberculosis Patients ◽  
Significant Difference ◽  
Lowenstein Jensen ◽  
The Mean ◽  
Igg Level

This study was carried out to study of some immunological aspects among the pulmonary Tuberculosis patients infected with causative agent, Mycobacterium tuberculosis. A Total of 200 sputum samples were collected from patients attending the consultant Clinic for Chest and Respiratory disease center, Diwaniya. Control group (No=15) also included. According to acid fast stain of sputum, the patients were classified as positive (No=91,45.5%) and negative (No=109,54.5, Lowenstein Jensen medium used for the cultivation of samples, on which 70% of sputum samples where positive culture for this microorganism. The grown microorganism were identified as M. tuberculosis, based on positive A.F.B, Niacin producers ,negative for catlase at 68c. The mean IgG level was l184.053±76.684 mg/100 ml in tuberculosis group compared with 1016.533 ± 44.882 mg/100ml in control group, rendering the statistical difference significant. For IgA and IgM levels, they were at mean of 315.880±38.552 mg/100 ml and 119.527±8.464 mg/100 ml in control group compared with 396.358±38.776 mg/100 ml and 134.207±11.696 mg/100 ml in patients group respectively with significant difference

scholarly journals Multicenter Laboratory Validation of Susceptibility Testing of Mycobacterium tuberculosis against Classical Second-Line and Newer Antimicrobial Drugs by Using the Radiometric BACTEC 460 Technique and the Proportion Method with Solid Media

1999 ◽  
Vol 37 (10) ◽  
pp. 3179-3186 ◽  
Author(s):  
Gaby E. Pfyffer ◽  
Donald A. Bonato ◽  
Adeleh Ebrahimzadeh ◽  
Wendy Gross ◽  
Jacqueline Hotaling ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Liquid Medium ◽  
Susceptibility Testing ◽  
The United States ◽  
Second Line ◽  
Antimicrobial Drugs ◽  
Critical Concentrations ◽  
Solid Media ◽  
Proportion Method ◽  
Study Sites

In a large multicenter study involving six major study sites in the United States, Canada, and Europe, the susceptibilities of 272Mycobacterium tuberculosis strains to classical second-line antituberculosis (anti-TB) drugs (capreomycin, cycloserine, ethionamide, and kanamycin) and newer compounds (amikacin, clofazimine, ofloxacin, and rifabutin) were determined by the radiometric BACTEC 460 procedure and the conventional proportion method on Middlebrook 7H10 agar. Previously established critical concentrations for classical second-line anti-TB drugs were compared with several concentrations in liquid medium to establish equivalence. MICs of newer compounds determined in liquid medium were either the same or up to four times lower than those determined in agar medium. After establishing critical concentrations (breakpoints) in the extended testing of clinical isolates, we obtained an excellent overall correlation between the two systems, with no errors with amikacin, kanamycin, and ofloxacin and very few major or very major errors with the other drugs; however, for cycloserine, no breakpoint concentration could be recommended due to repeatedly inconsistent results by both methods. Based on these data we conclude that the BACTEC 460 procedure is a simple and rapid method requiring 4 to 8 days on average to generate accurate antimicrobial susceptibility testing (AST) results for eight anti-TB drugs other than those considered primary ones. These data not only fill a major gap of knowledge regarding the critical test concentrations of secondary anti-TB drugs but also provide a baseline for future evaluations ofM. tuberculosis AST with the more recently developed, nonradiometric broth-based culture systems.

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.

scholarly journals Comparison of Methods for Processing Drinking Water Samples for the Isolation of Mycobacterium avium and Mycobacterium intracellulare

2008 ◽  
Vol 74 (10) ◽  
pp. 3094-3098 ◽  
Author(s):  
Rachel Thomson ◽  
Robyn Carter ◽  
Chris Gilpin ◽  
Chris Coulter ◽  
Megan Hargreaves
Keyword(s):  
Mycobacterium Avium ◽  
Water Samples ◽  
Culture Media ◽  
Tap Water ◽  
Cetylpyridinium Chloride ◽  
Sodium Thiosulfate ◽  
Mycobacterium Intracellulare ◽  
Solid Media ◽  
Lowenstein Jensen ◽  
Mycobacterial Growth

ABSTRACT Several protocols for isolation of mycobacteria from water exist, but there is no established standard method. This study compared methods of processing potable water samples for the isolation of Mycobacterium avium and Mycobacterium intracellulare using spiked sterilized water and tap water decontaminated using 0.005% cetylpyridinium chloride (CPC). Samples were concentrated by centrifugation or filtration and inoculated onto Middlebrook 7H10 and 7H11 plates and Lowenstein-Jensen slants and into mycobacterial growth indicator tubes with or without polymyxin, azlocillin, nalidixic acid, trimethoprim, and amphotericin B. The solid media were incubated at 32°C, at 35°C, and at 35°C with CO2 and read weekly. The results suggest that filtration of water for the isolation of mycobacteria is a more sensitive method for concentration than centrifugation. The addition of sodium thiosulfate may not be necessary and may reduce the yield. Middlebrook M7H10 and 7H11 were equally sensitive culture media. CPC decontamination, while effective for reducing growth of contaminants, also significantly reduces mycobacterial numbers. There was no difference at 3 weeks between the different incubation temperatures.

scholarly journals Phenotypically Adapted Mycobacterium tuberculosis Populations from Sputum Are Tolerant to First-Line Drugs

2016 ◽  
Vol 60 (4) ◽  
pp. 2476-2483 ◽  
Author(s):  
Obolbek Turapov ◽  
Benjamin D. O'Connor ◽  
Asel A. Sarybaeva ◽  
Caroline Williams ◽  
Hemu Patel ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Liquid Medium ◽  
Culture Supernatant ◽  
Ex Vivo ◽  
First Line ◽  
Content Type ◽  
Host Environment ◽  
Solid Media ◽  
Bactericidal Effects

ABSTRACTTuberculous sputum contains multipleMycobacterium tuberculosispopulations with different requirements for isolationin vitro. These include cells that form colonies on solid media (plateableM. tuberculosis), cells requiring standard liquid medium for growth (nonplateableM. tuberculosis), and cells requiring supplementation of liquid medium with culture supernatant (SN) for growth (SN-dependentM. tuberculosis). Here, we describe protocols for the cryopreservation and direct assessment of antimicrobial tolerance of theseM. tuberculosispopulations within sputum. Our results show that first-line drugs achieved only modest bactericidal effects on all three populations over 7 days (1 to 2.5 log10reductions), and SN-dependentM. tuberculosiswas more tolerant to streptomycin and isoniazid than the plateable and nonplateableM. tuberculosisstrains. Susceptibility of plateableM. tuberculosisto bactericidal drugs was significantly increased after passagein vitro; thus, tolerance observed in the sputum samples from the population groups was likely associated with mycobacterial adaptation to the host environment at some time prior to expectoration. Our findings support the use of a simpleex vivosystem for testing drug efficacies against mycobacteria that have phenotypically adapted during tuberculosis infection.

scholarly journals Thin layer agar-based direct phenotypic drug-susceptibility testing on sputum in Eswatini rapidly detects Mycobacterium tuberculosis growth and rifampicin resistance, otherwise missed by WHO endorsed diagnostic tests.

2021 ◽  
Author(s):  
E. Ardizzoni ◽  
E. Ariza ◽  
D. Mulengwa ◽  
Q. Mpala ◽  
R. de La Tour ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Thin Layer ◽  
Susceptibility Testing ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Field Conditions ◽  
Reference Laboratory ◽  
Solid Media ◽  
Specific Setting ◽  
Lowenstein Jensen

BACKGROUND: Xpert®MTB/RIF rapidly detects resistance to rifampicin (RR), however this test misses the I491F-RR conferring rpoB mutation, common in Southern Africa. In addition, Xpert®MTB/RIF does not distinguish between viable and dead Mycobacterium tuberculosis (MTB). OBJECTIVE: To investigate the ability of thin layer agar (TLA) direct drug-susceptibility testing (DST) to detect MTB and its drug-resistance profiles in field conditions in Eswatini. DESIGN: Consecutive samples were tested in parallel with Xpert®MTB/RIF and TLA for rifampicin (1.0 μg/ml) and ofloxacin (2.0 μg/ml). TLA results were compared at the Reference Laboratory in Antwerp with indirect DST on Löwenstein-Jensen or 7H11 solid media and additional phenotypic and genotypic testing to resolve discordance. RESULTS: TLA showed a positivity rate for MTB detection of 7.1% versus 10.0% for Xpert®MTB/RIF. Of a total of 4547 samples included in the study, 200 isolates were available for comparison to the composite reference. Within a median of 18.4 days, TLA detected RR with 93.0% sensitivity (CI-77.4-98.0) and 99.4% specificity (CI 96.7-99.9), versus 62.5% (CI 42.7-78.8) and 99.3% (CI 96.2-99.9) for Xpert®MTB/RIF. Eight isolates, 28.6% of all RR confirmed isolates, carried the I491F mutation, all detected by TLA. TLA also correctly identified 183 of the 184 ofloxacin-S isolates (99.5% specificity, CI 97.0-99.9). CONCLUSIONS: In field conditions, TLA rapidly detects RR, and in this specific setting contributed to detection of additional RR patients over Xpert®MTB/RIF, mainly but not exclusively due to I491F. TLA also accurately excluded fluoroquinolones resistance.

scholarly journals Nitrate reductase assay for detection of drug resistance in Mycobacterium tuberculosis: simple and inexpensive method for low-resource laboratories

2006 ◽  
Vol 55 (7) ◽  
pp. 861-863 ◽  
Author(s):  
Dihadenys Lemus ◽  
Ernesto Montoro ◽  
Miguel Echemendía ◽  
Anandi Martin ◽  
Françoise Portaels ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Nitrate Reductase ◽  
Accurate Determination ◽  
Low Resource ◽  
Nitrate Reductase Assay ◽  
Lowenstein Jensen ◽  
Proportion Method ◽  
The Mean ◽  
Mean Time

The nitrate reductase assay (NRA) was used as an alternative method for detection of resistance to the first-line antituberculous drugs isoniazid, rifampicin, ethambutol and streptomycin. A total of 320 strains of Mycobacterium tuberculosis were studied and the results compared with the proportion method (PM) on Löwenstein–Jensen medium. The mean time to obtain results was 10 days and the overall agreement between the NRA and PM was 98.8 %. The NRA was easy to perform and represents a useful tool for rapid and accurate determination of drug-resistant M. tuberculosis strains in low-resource countries.

scholarly journals Use of amplified Mycobacterium tuberculosis direct test in respiratory samples from HIV-infected patients in Brazil

2014 ◽  
Vol 40 (2) ◽  
pp. 148-154 ◽  
Author(s):  
Leonardo Bruno Paz Ferreira Barreto ◽  
Maria Cristina da Silva Lourenço ◽  
Valéria Cavalcanti Rolla ◽  
Valdiléia Gonçalves Veloso ◽  
Gisele Huf
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Predictive Value ◽  
Laboratory Diagnosis ◽  
Test Results ◽  
Tuberculosis Complex ◽  
Indicator Tube ◽  
Lowenstein Jensen ◽  
The Mean ◽  
Sensitivity Specificity ◽  
The City

OBJECTIVE: To compare the accuracy of the amplified Mycobacterium tuberculosis direct (AMTD) test with reference methods for the laboratory diagnosis of tuberculosis in HIV-infected patients. METHODS: This was a study of diagnostic accuracy comparing AMTD test results with those obtained by culture on Löwenstein-Jensen (LJ) medium and by the BACTEC Mycobacteria Growth Indicator Tube 960 (BACTEC MGIT 960) system in respiratory samples analyzed at the Bioassay and Bacteriology Laboratory of the Oswaldo Cruz Foundation Evandro Chagas Clinical Research Institute in the city of Rio de Janeiro, Brazil. RESULTS: We analyzed respiratory samples collected from 118 patients, of whom 88 (74.4%) were male. The mean age was 36.6 ± 10.6 years. Using the AMTD test, the BACTEC MGIT 960 system, and LJ culture, we identified M. tuberculosis complex in 31.0%, 29.7%, and 27.1% of the samples, respectively. In comparison with LJ culture, the AMTD test had a sensitivity, specificity, positive predictive value, and negative predictive value of 87.5%, 89.4%, 75.7%, and 95.0%, respectively, for LJ culture, whereas, in comparison with the BACTEC MGIT 960 system, it showed values of 88.6%, 92.4%, 83.8%, and 94.8%, respectively. CONCLUSIONS: The AMTD test showed good sensitivity and specificity in the population studied, enabling the laboratory detection of M. tuberculosis complex in paucibacillary respiratory specimens.

Two Liquid Medium Systems, Mycobacteria Growth Indicator Tube and MB Redox Tube, for Mycobacterium tuberculosis Isolation from Sputum Specimens

2000 ◽  
Vol 38 (3) ◽  
pp. 1227-1230 ◽  
Author(s):  
L. Heifets ◽  
T. Linder ◽  
T. Sanchez ◽  
D. Spencer ◽  
J. Brennan
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Liquid Medium ◽  
Growth Index ◽  
Indicator Tube ◽  
Solid Media ◽  
Valuable Element ◽  
Time To Detection ◽  
Culture Positive ◽  
Laboratory Protocol ◽  
Growth Indicator

Two manual liquid medium systems, the Mycobacteria Growth Indicator Tube (MGIT) and MB Redox tube systems, were evaluated in comparison to the radiometric BACTEC-460 semiautomated system for recovery ofMycobacterium tuberculosis from sputum specimens. The highest level of recovery, from a total of 77 culture-positive specimens, occurred with the BACTEC-460 system (92.2%), followed by the MB Redox tube (80.5%) and the MGIT (63.6%) systems. The shortest time to detection was observed also among the cultures in BACTEC-460: a mean of 12 days to a growth index (GI) of 10 and 15 days to a GI of 500. The mean times for the other systems were 16 days for the MB Redox tube system and 17.4 days for the MGIT system. The proportion of cultures grown after more than 3 weeks of incubation was only 2.8 or 8.4% in BACTEC-460 (for a GI of 10 or 500) but 17.7% in MB Redox and 22.5% in MGIT. Despite these differences in comparison to the BACTEC-460 system and some differences between the MGIT and MB Redox tube systems, either of the two manual liquid medium systems presents a reasonable alternative to the BACTEC-460 system, especially for laboratories with a limited workload, and a valuable element in the laboratory protocol, in conjunction with solid media, for obtaining rapid detection of growth from about 80% of culture-positive specimens and for better overall recovery of M. tuberculosis.

scholarly journals Mutations in fbiD (Rv2983) as a Novel Determinant of Resistance to Pretomanid and Delamanid in Mycobacterium tuberculosis

2020 ◽  
Vol 65 (1) ◽  
pp. e01948-20
Author(s):  
Dalin Rifat ◽  
Si-Yang Li ◽  
Thomas Ioerger ◽  
Keshav Shah ◽  
Jean-Philippe Lanoix ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Clinical Evidence ◽  
Clinical Samples ◽  
Loss Of Function ◽  
Wild Type ◽  
Content Type ◽  
Solid Media ◽  
High Level ◽  
Level Resistance

ABSTRACTThe nitroimidazole prodrugs delamanid and pretomanid comprise one of only two new antimicrobial classes approved to treat tuberculosis (TB) in 50 years. Prior in vitro studies suggest a relatively low barrier to nitroimidazole resistance in Mycobacterium tuberculosis, but clinical evidence is limited to date. We selected pretomanid-resistant M. tuberculosis mutants in two mouse models of TB using a range of pretomanid doses. The frequency of spontaneous resistance was approximately 10−5 CFU. Whole-genome sequencing of 161 resistant isolates from 47 mice revealed 99 unique mutations, of which 91% occurred in 1 of 5 genes previously associated with nitroimidazole activation and resistance, namely, fbiC (56%), fbiA (15%), ddn (12%), fgd (4%), and fbiB (4%). Nearly all mutations were unique to a single mouse and not previously identified. The remaining 9% of resistant mutants harbored mutations in Rv2983 (fbiD), a gene not previously associated with nitroimidazole resistance but recently shown to be a guanylyltransferase necessary for cofactor F420 synthesis. Most mutants exhibited high-level resistance to pretomanid and delamanid, although Rv2983 and fbiB mutants exhibited high-level pretomanid resistance but relatively small changes in delamanid susceptibility. Complementing an Rv2983 mutant with wild-type Rv2983 restored susceptibility to pretomanid and delamanid. By quantifying intracellular F420 and its precursor Fo in overexpressing and loss-of-function mutants, we provide further evidence that Rv2983 is necessary for F420 biosynthesis. Finally, Rv2983 mutants and other F420H2-deficient mutants displayed hypersusceptibility to some antibiotics and to concentrations of malachite green found in solid media used to isolate and propagate mycobacteria from clinical samples.

Sign in / Sign up

Export Citation Format

Share Document