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allied
academies
September 20-21, 2017 | Philadelphia, USA
Global summit on
TUBERCULOSIS AND LUNG DISEASE
Int J Respir Med 2017 Volume 2 Issue 2
S
ince 2006, nanodiagnostics for tuberculosis (TB) have witnessed considerable
development. Around thirty-five TB nanoassays have been partially or fully
characterized. Accuracy, low-cost, and short time-to-result represent the common
properties of proposed platforms. Among variable metals, gold NPs are the most
used in the proposed platforms. Despite several advantages and high potential,
translation into clinical use has not been reached. Most of the published reports do
not proceed beyond proof of concept. This study aims to evaluate clinical performance
of TB nanodiagnostic in clinical sputum samples using anionic unmodified gold
nanoparticles. The study follows diagnostic case-control design where 60 participants
are involved. Briefly, TB DNA was extracted from sputum samples and unmodified
anionic gold nanoparticles were directly added to TB amplicon after amplification of
TB IS6100 loci using conventional PCR. Colorimetric result was obtained after 15 min
by direct visualization. Sputum culture (BACTEC™ MGIT™) was used as the reference
test. Results of nano-gold assay were compared with those obtained by sputum
smear microscopy and chest X-ray. Our assay prototype shows concordance with
culture results, and higher clinical performance than sputum smear and chest X-ray.
Obtained sensitivity was 95% and specificity 100%.The total turnaround time was
3 hours, and the obtained lower limit of detection was 11.2 ng/ µl TB DNA. Future
studies are needed to lower assay cost through optimizing DNA extraction protocol
using simple reagents. DNA amplification could be performed using Loop mediated
isothermal amplification (LAMP) or rolling circle amplification (RCA) to minimize cost.
Future studies could adopt diagnostic test accuracy study (DTA) design for accurate
assessment of assay performance. To the best of our knowledge, this is the first study
to assess performance of TB nanodiagnostic by using unmodified gold nanoparticles in
real clinical settings. Our prototype shows potential for point-of-care use in developing
countries where TB burden prevails.
e:
helsamadony@umaryland.eduColorimetric detection of active pulmonary tuberculosis using gold nanoparticles
Hesham EL-Samadony
Ministry of Health, Egypt