title: Early detection of mycobacteria using a novel hydrogel culture method.
abstract: BACKGROUND
  Early laboratory detection of Mycobacterium tuberculosis is crucial for controlling 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 liquid media (Becton-Dickinson and Company, USA) and mixed with 75 µL of 9-fluorenylmethoxycarbonyl (Fmoc)-Phe-Phe-OH hydrogel stock solution in an Eppendorf tube just before culture incubation. The mixtures were cultured at 37℃ 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 conventional 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.
authors.affiliation: Department of Laboratory Medicine, Pusan National University School of Medicine, Yangsan, Korea.
authors.forename: Mi Hee
authors.initials: MH
authors.lastname: Jang
authors.affiliation: Department of Laboratory Medicine, Pusan National University School of Medicine, Yangsan, Korea.
authors.forename: Shine Young
authors.initials: SY
authors.lastname: Kim
authors.affiliation: Department of Laboratory Medicine, Korean Institute of Tuberculosis, Osong, Korea.
authors.forename: Chang-Ki
authors.initials: CK
authors.lastname: Kim
authors.affiliation: Department of Laboratory Medicine, Center for Diagnostic Oncology, National Cancer Center Hospital, Goyang, Korea.
authors.forename: Sang-Hyun
authors.initials: SH
authors.lastname: Hwang
authors.affiliation: Department of Physical Medicine & Rehabilitation, Korea University College of Medicine, Seoul, Korea.
authors.forename: Byung Kyu
authors.initials: BK
authors.lastname: Park
authors.affiliation: Department of Social Studies of Medicine, Pusan National University School of Medicine, Yangsan, Korea.
authors.forename: Sung Soo
authors.initials: SS
authors.lastname: Kim
authors.affiliation: Department of Laboratory Medicine, Pusan National University School of Medicine, Yangsan, Korea.
authors.forename: Eun Yup
authors.initials: EY
authors.lastname: Lee
authors.affiliation: Department of Laboratory Medicine, Pusan National University School of Medicine, Yangsan, Korea. ; Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea.
authors.forename: Chulhun L
authors.initials: CL
authors.lastname: Chang
mesh_terms: D001431:Bacteriological Techniques / Q000379:methods*; D003470:Culture Media / Q000737:chemistry; D042241:Early Diagnosis; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D014376:Tuberculosis / Q000175:diagnosis / Q000382:microbiology*
chemical_list: D003470:Culture Media; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate
keywords: Hydrogel scaffold; Mycobacterial culture; Mycobacterium tuberculosis