ABSTRACT
Objective: To evaluate the anti-mycobacterial activity of Melia azedarach L. (M. azedarach) and Lobelia chinensis Lour. (L. chinensis) extracts against the growth of Mycobacterium tuberculosis (M. tuberculosis). Methods: The anti-M. tuberculosis activity of M. azedarach and L. chinensis extracts were evaluated using different indicator methods such as resazurin microtiter assay (REMA) and mycobacteria growth indicator tube (MGIT) 960 system assay. The M. tuberculosis was incubated with various concentrations (50–800 mg/mL) of the ex-tracts for 5 days in the REMA, and for 4 weeks in MGIT 960 system assay. Results: M. azedarach and L. chinensis extracts showed their anti-M. tuberculosis ac-tivity by strongly inhibiting the growth of M. tuberculosis in a concentration-dependent manner in the REMA and the MGIT 960 system assay. Particularly, the methanol extract of M. azedarach and n-hexane extract of L. chinensis consistently exhibited their effects by effectively inhibiting the growth of M. tuberculosis in MGIT 960 system for 4 weeks with a single-treatment, indicating higher anti-M. tuberculosis activity than other extracts, and their minimum inhibitory concentrations were measured as 400 mg/mL and 800 mg/mL, respectively. Conclusions: These results demonstrate that M. azedarach and L. chinensis extracts not only have unique anti-M. tuberculosis activity, but also induce the selective anti-M. tuberculosis effects by consistently inhibiting or blocking the growth of M. tuberculosis through a new pharmacological action. Therefore, this study suggests the potential of them as effective candidate agents of next-generation for developing a new anti-tuberculosis drug, as well as the advantage for utilizing traditional medicinal plants as one of effective strategies against tuberculosis.
ABSTRACT
OBJECTIVE@#To evaluate a new pharmacological activity/effect of linolenic acid (α- and γ-form) and conjugated-linoleic acid (CLA) causing antibacterial activity against Mycobacterium tuberculosis (Mtb).@*METHODS@#The anti-Mtb activity/effect of linolenic acid and CLA were determined using different anti-Mtb indicator methods such as resazurin microtiter assay (REMA) and MGIT 960 system assay. The Mtb was incubated with various concentrations (12.5-200 μg/mL) of the compounds and anti-Mtb first-line drugs for 5 d in the REMA, and for 3 wk in MGIT 960 system assay.@*RESULTS@#Linolenic acid and CLA obviously indicated their anti-Mtb activity/effect by strongly inhibiting the growth/proliferation of Mtb in a dose-dependent manner in the REMA and the MGIT 960 system assay. Interestingly, linolenic acid and CLA consistently induced anti-Mtb activity/effect by effectively inhibiting the growth/proliferation of Mtb in MGIT 960 system for 21 d with a single treatment, and their minimum inhibitory concentrations were measured as 200 μg/mL respectively.@*CONCLUSIONS@#These results demonstrate that linolenic acid and CLA not only have effective anti-Mtb activity/properties, but also induce the selective-anti-Mtb effects by strongly inhibiting and blocking the growth/proliferation of Mtb through a new pharmacological activity/action. Therefore, this study provides novel perspectives for the effective use of them and the potential that can be used as potent anti-Mtb candidate drugs, as well as suggests the advantage of reducing the cost and/or time for developing a new/substantive drug by effectively repurposing the existing drugs or compounds as one of new strategies for the global challenge of tuberculosis.
ABSTRACT
Objective: To evaluate a new pharmacological activity/effect of linolenic acid (α- and γ-form) and conjugated-linoleic acid (CLA) causing antibacterial activity against Mycobacterium tuberculosis (Mtb). Methods: The anti-Mtb activity/effect of linolenic acid and CLA were determined using different anti-Mtb indicator methods such as resazurin microtiter assay (REMA) and MGIT 960 system assay. The Mtb was incubated with various concentrations (12.5-200 μg/mL) of the compounds and anti-Mtb first-line drugs for 5 d in the REMA, and for 3 wk in MGIT 960 system assay. Results: Linolenic acid and CLA obviously indicated their anti-Mtb activity/effect by strongly inhibiting the growth/proliferation of Mtb in a dose-dependent manner in the REMA and the MGIT 960 system assay. Interestingly, linolenic acid and CLA consistently induced anti-Mtb activity/effect by effectively inhibiting the growth/proliferation of Mtb in MGIT 960 system for 21 d with a single treatment, and their minimum inhibitory concentrations were measured as 200 μg/mL respectively. Conclusions: These results demonstrate that linolenic acid and CLA not only have effective anti-Mtb activity/properties, but also induce the selective-anti-Mtb effects by strongly inhibiting and blocking the growth/proliferation of Mtb through a new pharmacological activity/action. Therefore, this study provides novel perspectives for the effective use of them and the potential that can be used as potent anti-Mtb candidate drugs, as well as suggests the advantage of reducing the cost and/or time for developing a new/substantive drug by effectively repurposing the existing drugs or compounds as one of new strategies for the global challenge of tuberculosis.
ABSTRACT
Objective To evaluate the anti-mycobacterial activity of Melia azedarach L. (M. azedarach) and Lobelia chinensis Lour. (L. chinensis) extracts against the growth of Mycobacterium tuberculosis (M. tuberculosis). Methods The anti-M. tuberculosis activity of M. azedarach and L. chinensis extracts were evaluated using different indicator methods such as resazurin microtiter assay (REMA) and mycobacteria growth indicator tube (MGIT) 960 system assay. The M. tuberculosis was incubated with various concentrations (50–800 μg/mL) of the extracts for 5 days in the REMA, and for 4 weeks in MGIT 960 system assay. Results M. azedarach and L. chinensis extracts showed their anti-M. tuberculosis activity by strongly inhibiting the growth of M. tuberculosis in a concentration-dependent manner in the REMA and the MGIT 960 system assay. Particularly, the methanol extract of M. azedarach and n-hexane extract of L. chinensis consistently exhibited their effects by effectively inhibiting the growth of M. tuberculosis in MGIT 960 system for 4 weeks with a single-treatment, indicating higher anti-M. tuberculosis activity than other extracts, and their minimum inhibitory concentrations were measured as 400 μg/mL and 800 μg/mL, respectively. Conclusions These results demonstrate that M. azedarach and L. chinensis extracts not only have unique anti-M. tuberculosis activity, but also induce the selective anti-M. tuberculosis effects by consistently inhibiting or blocking the growth of M. tuberculosis through a new pharmacological action. Therefore, this study suggests the potential of them as effective candidate agents of next-generation for developing a new anti-tuberculosis drug, as well as the advantage for utilizing traditional medicinal plants as one of effective strategies against tuberculosis.
ABSTRACT
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 .
ABSTRACT
Tuberculosis (TB) remains a serious health problem in many regions of the world, and the development of resistance to antibiotics by this microbe created the need for new drugs to replace those which have lost effectiveness. This study assesses the medicinal anti-Mycobacterium tuberculosis properties of natural products obtained from plants collected from Eastern Libya. In this study aqueous extracts of nine different plants were assayed for their Mycobacterium tuberculosis inhibitory activity using the BACTEC MGIT960 susceptibility test method. The aqueous extracts of Ceratonia siliqua L, Helichrysum stoechas (L.) Moench and Thymus algeriensis did not show any activity against M.tuberculosis in different concentrations. The aqueous extract of Marrubium vulgare L. from Syria showed high activity against M. tuberculosis. Marrubium alysson L., Marrubium vulgare L., Pistacia lentiscus L, Quercus coccifera L, Thymus capitatus (L.) Hoffm. & Link, showed varying degrees of activity against M. tuberculosis. The results of this study show that aqueous extracts from six different medicinal plants have different effects against M. tuberculosis in vitro.
ABSTRACT
BACKGROUND: The combined use of liquid media and solid media is recommended for mycobacterial culture. We evaluated diagnostic performance of combination of BACTEC Mycobacteria Growth Indicator Tube (MGIT; Becton Dickinson, USA) and 2% Ogawa media (Korean Institute of Tuberculosis, Korea) for recovery of mycobacteria. METHODS: In September 2007, 1,764 specimens from 1,059 patients were cultured with MGIT and Ogawa. Acid fast bacilli (AFB) smear was fluorochrome-stained. The isolates were identified into Mycobacterium tuberculosis (MTB) and nontuberculous mycobacteria (NTM) with PCR using Seeplex TB Detection Kit (Seegene, Korea). Recovery rate, time to detection (TTD), contamination rate, mixed growth rate and species distribution were analyzed. RESULTS: Two hundred thirty-five specimens (13.3%) from 165 patients (15.6%) were positive for mycobacterial culture. Recovery rates of mycobacteria from the group using both media, MGIT only, and Ogawa only were 13.3%, 12.1%, and 7.8%, respectively. While MGIT recovered 98.9% of MTB and 79.7% of NTM, Ogawa recovered 65.9% of MTB and 54.1% of NTM. TTDs of total mycobacteria/MTB/NTM in MGIT and Ogawa were 10.6/11.4/9.7 days and 31/29/33 days, respectively. MGIT TTDs of total mycobacteria/MTB/NTM from AFB-positive specimens were significantly shorter than those of AFB-negative specimens; 8.2/9.5/4.4 days vs 11.6/12.7/10.7 days. Contamination and mixed growth rate of MGIT were 9.6% and 3.7%. Primary culture of Ogawa recovered 1 MTB and 1 NTM among the 170 MGIT-contaminated specimens and 38 mycobacteria among 66 specimens that showed mixed cultures of MGIT. CONCLUSIONS: MGIT warrants sensitive and rapid isolation of mycobacteria. However, the combination of MGIT and Ogawa is more desirable to recover mycobacteria in the case of contaminations or mixed cultures.
Subject(s)
Humans , Culture Media , False Positive Reactions , Mycobacterium/growth & development , Mycobacterium Infections/diagnosis , Mycobacterium tuberculosis/growth & development , Reagent Kits, Diagnostic , Sensitivity and Specificity , Sputum/microbiology , Time FactorsABSTRACT
BACKGROUND: In this study, we evaluated the BACTEC MGIT 960 system (Becton Dickinson Microbiology Systems, Sparks, Md, USA), which is fully automated, noninvasive and nonradiometric fluorescent indicator broth detection system, for the growth and detection of mycobacteria with body fluid specimens. METHODS: Total of 1,891 body fluid specimens were included (pleural fluid 752, ascitic fluid 629, cerebrospinal fluid 214, joint fluid 79, peritozol 54, others 163). Specimens were inoculated into MGIT and solid media (3% ogawa, Japan). Polymerase chain reaction was performed for the discrimination of Mycobacterium tuberculosis from Mycobacterium other than tuberculosis (MOTT). RESULTS: A total of 62 isolates of mycobacteria were recovered from all culture system. With MGIT system, 56 isolates were recovered, compared with solid system recovered 33 isolates. 29 isolates were recovered with MGIT only and 6 isolates recovered with solid media only. Among 62 isolates recovered, 11 isolates were positive in acid fast stain. 10 isolates were recovered with MGIT. One isolate was recovered with solid system. 51 isolates were negative in acid fast stain. Among this, 46 isolates were recovered with MGIT. The mean detection time was 14.2 days with MGIT system, and 38.2 days with solid media. Contamination rate for each system with body fluid specimens were 4.1% for MGIT and 1.7% for solid media. CONCLUSION: In body fluid, the MGIT system has the advantages of improved detection rate and rapid recovery than solid media to recover mycobacteria.
Subject(s)
Ascitic Fluid , Body Fluids , Cerebrospinal Fluid , Discrimination, Psychological , Joints , Mycobacterium , Mycobacterium tuberculosis , Polymerase Chain Reaction , TuberculosisABSTRACT
BACKGROUND: We evaluated the BACTEC MGIT 960 system(Becton Dickinson Microbiology Systems, Sparks, Md, USA), which is a fully automated, noninvasive and nonradiometric fluorescent indicator broth detection system for the growth and detection of mycobacteria with a capacity to incubate and continuously monitor 7 ml MGIT(Mycobacterium growth indicator tube) culture tube. METHODS: We studied 1,690 specimens(1,258 respiratory and 432 non-respiratory specimens). Processed specimens with 2% NaOH-NALC(final NaOH concentration: 1%) were inoculated into MGIT and solid media(3% Ogawa, Japan). Polymerase chain reaction was performed for the discrimination of Mycobacterium tuberculosis complex from Mycobacterium other than tuberculosis(MOTT). RESULTS: From all culture system, a total of 181 isolates of mycobacteria were recovered. The greatest number of isolates of mycobacteria was recovered with MGIT 960 system(174, 96.1%), followed by solid media(73, 40.3%). 108 isolates(59.7%) were recovered with MGIT only and 7(3.9%) recovered with solid media only( P value < 0.0001). From a total of 1,617 AFB smear negative specimens, 101(6.3%) were recovered with MGIT 960 system and 34(2.1%) recovered with solid media. The mean times to detection were average 11.1 days for MGIT 960 system and 31.6 days for solid media(P value < 0.0001). Contamination rates for each system were 14.9% for MGIT 960 and 2.6% for solid media. CONCLUSIONS: The newly introduced MGIT 960 system is easy to use and has advantages of high detection rate and rapid recovery than solid media, but there are some problems such as high contamination rate and high cost in the management of this liquid system.
Subject(s)
Discrimination, Psychological , Mycobacterium , Mycobacterium tuberculosis , Polymerase Chain ReactionABSTRACT
BACKGROUND: BACTEC MGIT 960 system(Becton Dickinson, USA; MGIT 960) is a fully automated, noninvasive culture system for mycobacteria, which has been regarded as a sensitive and least labor-intensive method. This study was purposed to evaluate the performance of MGIT 960 compared to BACTEC 460 TB radiometric system(Becton Dickinson, USA; BACTEC 460) and Ogawa media. METHODS: A total of 1,067 clinical specimens submitted from April to June in 1999 was cultured for acid fast bacilli(AFB). All specimens were digested, decontaminated by the 6% sodium hydroxide(final concentration of 1.5%) and 0.5% N-acetyl-L-cysteine method. All specimens were inoculated into three kinds of media: a MGIT, a BACTEC 12B, and an Ogawa medium. The AFB recovered from cultures were identified to M. tuberculosis complex and MOTT by NAP test. RESULTS: Of 106 isolates of M. tuberculosis recovered from all culture systems, 101(95.3 %) were detected in the MGIT 960, 95(89.6%) in the BACTEC 460 and 76(71.7%) on Ogawa media. MGIT 960 plus Ogawa media detected 104(98.1%) isolates and BACTEC 460 plus Ogawa media recovered 96(90.6%) isolates. The mean time required for detection of M. tuberculosis was 12.7+/-5.8 days with MGIT 960, 16.2+/-7.7 days with BACTEC 460, and 22.8+/-9.5 days with Ogawa media. The contamination rate were 5.1% for MGIT 960, 2.7% for BACTEC 460, and 6.7% for Ogawa media. CONCLUSIONS: MGIT 960 is a sensitive and rapid method to isolate M. tuberculosis.