Use of the BacT/Alert MB Mycobacterial Blood Culture System for Detection of Mycobacteria in Sterile Body Fluids Other than Blood (original) (raw)
Utility of the BACTEC Myco/F lytic medium for the detection of mycobacteria in blood
Diagnostic Microbiology and Infectious Disease, 2000
This study aims to evaluate the performance of a new vial (Myco/F Lytic) for the detection of mycobacteria from blood specimens. This vial is monitored in the BACTEC 9000 blood culture system. We compared it with the traditional method routinely used in our laboratory, which is a lysis-centrifugation based procedure. Of 275 samples tested in parallel by both methods, 23 from 20 patients grew mycobacteria (18 Mycobacterium avium complex, 4 M. tuberculosis and 1 M. simiae); 11 isolates were recovered using both systems, 12 were isolated with the Myco/F Lytic medium only, and none were isolated using the traditional method only (p Ͻ 0.05). Blood was the diagnostic sample for 12 patients with the Myco/F Lytic system and only 7 with the traditional system. The mean time to detection of mycobacteria with Myco/F Lytic medium was 17 days, whereas it was 44 days with the traditional method (p Ͻ 0.001). Identification by DNA probes was performed directly from the Myco/F Lytic bottle. Myco/F Lytic is a rapid, simple, safe and highly reliable diagnostic method for the detection of mycobacteria in blood.
Clinical Microbiology and Infection, 1998
Methods: In this prospective study, all blood cultures submitted for mycobacteria detection, taken mainly from HIV-infected patients, were incubated for 12 weeks. The clinical impact of a late positive blood culture result was assessed retrospectively.Methods: In this prospective study, all blood cultures submitted for mycobacteria detection, taken mainly from HIV-infected patients, were incubated for 12 weeks. The clinical impact of a late positive blood culture result was assessed retrospectively.Results: From a total of 750 blood cultures, 68 had a growth index (GI) >10 due to the presence of mycobacteria. Of 545 negative blood cultures with a GI <10 within 12 weeks examined by Ziehl—Neelsen, one bottle revealed acid-fast bacilli further identified as Mycobacterium genavense by PCR-restriction fragment length polymorphism analysis of the hsp65 gene. For six of 39 patients with positive blood cultures, the delay to positivity was > 6 weeks (one M. tuberculosis, three M. genavense, two M. avium intracellulare complex). The prolonged incubation and the systematic terminal Ziehl—Neelsen increased the recovery of M. genavense from 5% to 14.5%. However, for only three patients did the late microbiological result lead to the introduction of antimycobacterial therapy.From a total of 750 blood cultures, 68 had a growth index (GI) >10 due to the presence of mycobacteria. Of 545 negative blood cultures with a GI <10 within 12 weeks examined by Ziehl—Neelsen, one bottle revealed acid-fast bacilli further identified as Mycobacterium genavense by PCR-restriction fragment length polymorphism analysis of the hsp65 gene. For six of 39 patients with positive blood cultures, the delay to positivity was > 6 weeks (one M. tuberculosis, three M. genavense, two M. avium intracellulare complex). The prolonged incubation and the systematic terminal Ziehl—Neelsen increased the recovery of M. genavense from 5% to 14.5%. However, for only three patients did the late microbiological result lead to the introduction of antimycobacterial therapy.Conclusions: Neither a prolonged incubation longer than 6 weeks nor a terminal Ziehl—Neelsen-stained smear of the negative blood cultures at 12 weeks seem to be clinically justified.Neither a prolonged incubation longer than 6 weeks nor a terminal Ziehl—Neelsen-stained smear of the negative blood cultures at 12 weeks seem to be clinically justified.
Use of BACTEC MGIT 960 for recovery of mycobacteria from clinical specimens: multicenter study
Journal of clinical microbiology, 1999
The BACTEC MGIT 960 instrument is a fully automated system that exploits the fluorescence of an oxygen sensor to detect growth of mycobacteria in culture. Its performance was compared to those of the radiometric BACTEC 460 instrument and egg-based Lowenstein-Jensen medium. An identical volume of sample was inoculated in different media, and incubation was carried out for 6 weeks with the automatic systems and for 8 weeks on solid media. A total of 2,567 specimens obtained from 1,631 patients were cultured in parallel. Mycobacteria belonging to nine different taxa were isolated by at least one of the culture systems, with 75% of them being represented by Mycobacterium tuberculosis complex. The best yield was obtained with the BACTEC 460 system, with 201 isolates, in comparison with 190 isolates with the BACTEC MGIT 960 system and 168 isolates with Lowenstein-Jensen medium. A similar but not significant difference was obtained when the most-represented organisms, the M. tuberculosis c...
Scientific Reports, 2021
Extra-pulmonary mycobacterial infections are characterized by a paucibacillary nature and extra-pulmonary samples consist of different matrices; the processing of these samples requires a high level of manual skills and non-standardized procedures. The aim of this study was to compare the performance of MYCO-TB with MycoPrep on extra-pulmonary samples in terms of Mycobacteria detection, culture contamination and suitability for molecular assay. This prospective study was conducted on 201 extra-pulmonary samples from suspected cases of mycobacterial infection. Specimens were divided into two equal aliquots; one was decontaminated with MYCO-TB the other with MycoPrep. The contamination rate of liquid cultures was significantly different: 2.5% (5/201) for MYCO-TB and 7.5% (15/201) for MycoPrep (p = 0.036). At least 1 Mycobacterium tuberculosis complex (MTBc) positive culture was detected in 6 specimens treated with MYCO-TB and 8with MycoPrep, without significant differences in times to...
Memórias do Instituto Oswaldo Cruz, 2011
The objective of the current study was to compare two rapid methods, the BBL Mycobacteria Growth Indicator Tube (MGIT TM ) and Biotec FASTPlaque TB™ (FPTB) assays, with the conventional Löwenstein-Jensen (LJ) media assay to diagnose mycobacterial infections from paucibacillary clinical specimens. For evaluation of the clinical utility of the BBL MGIT TM and FPTB assays, respiratory tract specimens (n = 208), with scanty bacilli or clinically evident, smear negative cases and non-respiratory tract specimens (n = 119) were analyzed and the performance of each assay was compared with LJ media. MGIT and FPTB demonstrated a greater sensitivity (95.92% and 87.68%), specificity (94.59% and 98.78%), positive predictive value (94.91% and 99.16%) and negative predictive value (96.56% and 90.92%), respectively, compared to LJ culture for both respiratory tract and non-respiratory tract specimens. However, the FPTB assay was unable to detect nontuberculous mycobacteria and few Mycobacterium tuberculosis complex cases from paucibacillary clinical specimens. It is likely that the analytical sensitivity of FPTB is moderately low and may not be useful for the direct detection of tuberculosis in paucibacillary specimens. The current study concluded that MGIT was a dependable, highly efficient system for recovery of M. tuberculosis complexes and nontuberculous mycobacteria from both respiratory and non-respiratory tract specimens in combination with LJ media.
Journal of Clinical Microbiology, 1999
The rate of recovery and the mean time to detection of mycobacteria in clinical specimens were evaluated with two nonradiometric broth-based systems, the Mycobacteria Growth Indicator Tube (MGIT) and MB Redox systems. The data obtained for each system were compared with each other and with those obtained with the Löwenstein-Jensen (LJ) and Middlebrook 7H11 reference media. A total of 117 mycobacterial isolates (Mycobacterium tuberculosis, n = 112; nontuberculous mycobacteria, n = 5) were detected in 486 clinical specimens. The recovery rates for M. tuberculosis were 91 of 112 (81.3%) isolates with MGIT and 81 of 112 (72.3%) isolates with MB Redox. The combination of MGIT plus MB Redox recovered 104 of the 112 (92.9%) M. tuberculosisisolates. MGIT plus LJ plus Middlebrook 7H11 recovered 106 of the 112 (94.6%) isolates, MB Redox plus LJ plus Middlebrook 7H11 recovered 99 of the 112 (88.4%) isolates, and LJ plus Middlebrook 7H11 recovered 84 of the 112 (75.0%) isolates. The mean time ...
Isolation and Identification of Mycobacterium from Extrapulmonary Specimen at NTRL, NIDCH
Objective of the study was to see the frequency of isolation of Mycobacterium among different extrapulmonary specimens. The study was carried out at NTRL (National Tuberculosis reference laboratory), NIDCH Bangladesh during January 2008-June 2009.This study was carried out retrospectively by analyzing NTRL laboratory data. A total of 514 extra-pulmonary specimens from different treatment centre of Dhaka was analyzed. Clinical specimens, such as lymph node aspirate, pleural fluid, urine, stool, gastric lavage, pus, ascitic fluid, cerebrospinal fluids, etc was collected. Lowenstein-Jensen media was used for culture and antimicrobial susceptibility testing. Mycobacteria were isolated from 113 extra-pulmonary specimens. Male and female ratio was almost equal among positive cases. The commonest source of isolation was lymph nodes(frequency 55.8%) and lymph node aspirate( frequency 68.4%) pleural fluid (frequency10.6%). Anti-microbial susceptibility of the isolates to the four first line anti-tuberculosis drugs, rifampicin, isoniazid, streptomycin and ethambutol was tested, susceptibility rate was 100%.The results suggest that, emphasis should be placed on laboratory diagnosis and treatment of extra-pulmonary tuberculosis.
European Journal of Clinical Microbiology & Infectious Diseases, 1993
A new biphasic system (MB Check, Roche) for isolation of mycobacteria from clinical specimens was evaluated by eight different microbiological laboratories in comparison with methods routinely used in the respective laboratories. Altogether 1125 clinical specimens were processed; pretrealment, if performed, was by a variety of methods. Mycobacteria were recovered from 167 specimens with the biphasic system and 165 specimens with the other methods. The average time required for isolation of Mycobacterium tuberculosis was 22.6 days with the biphasic system and 24.7 days with egg-based media; for other mycobacterial species it was 23.5 versus 20.8 days. The inclusion of a chocolate agar section in the biphasic system facilitated the early detection of contaminants, while the NAP-containing section appeared unable to differentiate
Diagnostic Microbiology and Infectious Disease, 2002
The BACTEC MGIT system (M960), a fully automated, non radiometric instrument, designed for rapid detection of acid fast bacilli (AFB) from clinical specimens, was compared with the radiometric BACTEC 460 system (B460) and Löwenstein-Jensen (L-J) solid medium. A total of 1,093 respiratory and extrapulmonary specimens were decontaminated by the NALC-NaOH standard method, and randomly inoculated into the media. A total of 122 mycobacteria were recovered, including 47 Mycobacterium tuberculosis complex (MTB) isolates and 75 nontuberculous mycobacteria (NTM) isolates. Overall recovery rates were 59% for M960 system (p Ͻ 0.0001), 58.2% for L-J. medium (p Ͻ 0.0001) and 82% for Bactec 460 system, whereas rates for MTB alone were 91.5, 76.6 (p ϭ 0.007), and 95.7%, respectively. The combination of M960 or B460 systems with L-J medium showed the same recovery rates for MTB strains (97.9%), whereas NTM rates were 68% (p Ͻ 0.0001) and 93.3%, respectively. Mean time to detection of smear-positive MTB, smear-negative MTB, and NTM were 12.2, 13.4, and 23.3 days, respectively, with the M960, 11.7, 21.3, and 24.8 days with the B460 and 20.4, 28.7, and 28.4 days with L-J medium. The M960 system showed a contamination rate of 9.8%, while B460 and L-J medium showed contamination rates of 4.3 and 3.8% respectively. In conclusion, the M960 system appeared to be accurate and rapid for the recovery of MTB, but reduced recovery of NTM and a high number of contaminated cultures deserve further study in order to assess if this system can represent a valuable alternative to the radiometric system.
2010
Tuberculosis (TB) is responsible for about one third of preventable deaths worldwide. Accurate and rapid diagnosis of tuberculosis is essential for controlling the spread of the disease caused by Mycobacterium tuberculosis. The aim of this study was to evaluate the Mycobacteria Growth Indicator Tube {(MGIT 960) (M960)} which is a fully automated, non-invasive, system for growth and detection of mycobacteria and Lowenstein-Jensen (LJ) media for the recovery of Mycobacterium tuberculosis from sputum samples. Out of 67 specimens processed, 60 isolates (89.5%) were recovered by M960 media while, 50 isolates (74.6%) were obtained by LJ. M960 as a single system detected 11 (16.4%) isolates more than L.J media while; L.J media detected 2 (2.9%) isolates (revealed no growth in MGIT 960). In total, Out of these 67 specimens, 48 (71.6%) were positive by all methods (Z-N smear, culture on both LJ and MGIT broth) and 48 (71.6%) isolates also were obtained by the combined use of both culture met...