Detection of Mycobacterium in fine-needle aspiration biopsy specimens from children with tuberculous lymphadenitis / 中华微生物学和免疫学杂志

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 .

Antibacterial Activity of Medicinal Aqueous Plant Extracts against Mycobacterium tuberculosis

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.

Evaluation of Combination of BACTEC Mycobacteria Growth Indicator Tube 960 System and Ogawa Media for Mycobacterial Culture / 대한진단검사의학회지

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.

Detection of Mycobacterium tuberculosis using BACTEC Mycobacteria Growth Indicator Tube(MGIT) 960 system: Comparison with BACTEC 460 TB system and Ogawa Media / 대한임상병리학회지

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.