Early detection of the growth of Mycobacterium tuberculosis using magnetophoretic immunoassay in liquid culture

Biosens Bioelectron. 2017 Oct 15:96:68-76. doi: 10.1016/j.bios.2017.04.025. Epub 2017 Apr 20.

Abstract

Tuberculosis (TB) is an often neglected, epidemic disease that remains to be controlled by contemporary techniques of medicine and biotechnology. In this study, a nanoscale sensing system, referred to as magnetophoretic immunoassay (MPI) was designed to capture culture filtrate protein (CFP)-10 antigens effectively using two different types of nanoparticles (NPs). Two specific monoclonal antibodies against CFP-10 antigen were used, including gold NPs for signaling and magnetic particles for separation. These results were carefully compared with those obtained using the commercial mycobacteria growth indicator tube (MGIT) test via 2 sequential clinical tests (with ca. 260 clinical samples). The sensing linearity of MPI was shown in the range of pico- to micromoles and the detection limit was 0.3pM. MPI using clinical samples shows robust and reliable sensing while monitoring Mycobacterium tuberculosis (MTB) growth with monitoring time 3-10 days) comparable to that with the MGIT test. Furthermore, MPI distinguished false-positive samples from MGIT-positive samples, probably containing non-tuberculous mycobacteria. Thus, MPI shows promise in early TB diagnosis.

Keywords: CFP-10 antigen; Gold nanoparticle; Magnetic particle; Magnetophoretic immunoassay; Magplas probes; Tuberculosis.

MeSH terms

  • Antibodies, Monoclonal / chemistry
  • Antigens, Bacterial / immunology
  • Bacterial Proteins / immunology
  • Bacteriological Techniques / methods
  • Biosensing Techniques / methods
  • Ferrosoferric Oxide / chemistry
  • Gold / chemistry
  • Humans
  • Immunoassay / methods*
  • Limit of Detection
  • Magnetics
  • Metal Nanoparticles / chemistry*
  • Mycobacterium tuberculosis / growth & development
  • Mycobacterium tuberculosis / isolation & purification*
  • Nontuberculous Mycobacteria / growth & development
  • Nontuberculous Mycobacteria / isolation & purification
  • Particle Size
  • Surface Properties

Substances

  • Antibodies, Monoclonal
  • Antigens, Bacterial
  • Bacterial Proteins
  • CFP-10 protein, Mycobacterium tuberculosis
  • Gold
  • Ferrosoferric Oxide