Early Detection of Mycobacteria Using a Novel Hydrogel Culture Method

다국어 초록 (Multilingual Abstract)

Background: Early laboratory detection of Mycobacterium tuberculosis is crucial for con- trolling tuberculosis. We developed a hydrogel mycobacterial culture method that retains the advantages of both solid and liquid methods in terms of speed, cost, and efficiency.
Methods: Mycobacterium bovis bacillus Calmette-Guérin (BCG) suspensions and 200 acid-fast bacilli (AFB)-positive clinical specimens were inoculated in Middlebrook 7H9 liq- uid media (Becton-Dickinson and Company, USA) and mixed with 75 μL of 9-fluorenyl- methoxycarbonyl (Fmoc)-Phe-Phe-OH hydrogel stock solution in an Eppendorf tube just before culture incubation. The mixtures were cultured at 37°C for as long as 14 days to monitor culture status.
Results: The number of M. bovis BCG increased with time. For 200 AFB smear-positive specimens, 155 of 158 conventional culture-positive specimens and 4 culture-negative or contaminated specimens yielded positive cultures within 14 days. For 128 specimens positive with the liquid culture method, the time to positive culture using the hydrogel method (mean, 12.6 days; range, 7 to 14 days) was significantly shorter than that for con- ventional liquid culture (mean, 16.2 days; range, 6 to 31 days; P <0.0001).
Conclusions: The hydrogel scaffold culture system is useful for timely, economical, and efficient detection of mycobacteria in clinical specimens.

참고문헌 (Reference)

1 Viera AJ, "Understanding interobserver agreement: the kappa statistic" 37 : 360-363, 2005

2 Jayawarna V, "Three-dimensional cell culture of chondrocytes on modified di-phenylalanine scaffolds" 35 (35): 535-537, 2007

3 Chang CL, "Survey on changes in mycobacterial testing practices in Korean Laboratories" 4 : 108-114, 2001

4 고원중, "Rapid Diagnosis of Tuberculosis and Multidrug Resistance Using a MGIT 960 System" 대한진단검사의학회 32 (32): 264-269, 2012

5 Miyamoto J, "New drug susceptibility test for Mycobacterium tuberculosis using the hybridization protection assay" 34 : 1323-1326, 1996

6 Jayawarna V, "Nanostructured hydrogels for three-dimensional cell culture through self-assembly of fluorenylmethoxycarbonyl-dipeptides" 18 : 611-614, 2006

7 Bollela VR, "McFarland nephelometer as a simple method to estimate the sensitivity of the polymerase chain reaction using Mycobacterium tuberculosis as a research tool" 32 : 1073-1076, 1999

8 Tibbitt MW, "Hydrogels as extracellular matrix mimics for 3D cell culture" 103 : 655-663, 2009

9 World Health Organization, "Guidelines for the programmatic management of drug-resistant tuberculosis-emergency update 2008" World Health Organization 2008

10 World Health Organization, "Global tuberculosis report 2012" WHO 2012

11 Semino CE, "Functional differentiation of hepatocyte-like spheroid structures from putative liver progenitor cells in three-dimensional peptide scaffolds" 71 : 262-270, 2003

12 Levenberg S, "Differentiation of human embryonic stem cells on three-dimensional polymer scaffolds" 100 : 12741-12746, 2003