Method

All of the components for detection were supplied in a point-of-care kit. This included components for the rapid and simple disinfection and thinning of sputum. No external equipment, reagent or power were required. The point-of-care format was performed and compared to direct smear of the same sputum samples.

Discussion

On this small panel of samples there was complete agreement between the direct microscopy results (by auramine staining) and the point-of-care test. The point-of-care test was able to detect as few as 2-3 mycobacteria per microscopy field (see sample number 9). If sputum thinning is excluded, the point-of-care format takes about 30 minutes.




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Microsens Medtech

Diagnosis of tuberculosis from sputum in a point of care format in 45 minutes by immunodetection of TB antigens

Our aim is to develop a test that is rapid (less than 60 min), simple (can be used by laboratory personnel with minimal training), does not require power, does not require laboratory equipment, is self contained (does not require external reagents) and yet is sensitive for the detection of TB.

In this issue of Consumption we present the first data on our prototype point of care test which satisfies all of these criteria.

Consumption  March 2012/1

Prototype Point-of-Care Test for Mycobacteria

Sample number

Direct smear (numbers of bacilli in 20 microscopy fields)

Point of care result

1

Positive (88)

Positive

2

Positive (279)

Positive

3

Negative

Negative

4

Negative

Negative

5

Positive (813)

Positive

6

Positive (411)

Positive

7

Negative

Negative

8

Negative

Negative

9

Positive (49)

Positive

10

Positive (217)

Positive

11

Negative

Negative

12

Negative

Negative

13

Negative

Negative

14

Negative

Negative

15

Positive (2000)

Positive

16

Positive (611)

Positive

Results


Introduction

In the previous issue of our Newsletter (November 2011/1) we described the results of an ELISA that we had developed in order to detect TB antigens in sputum. Building on the success of this ELISA and using our TB-Beads to extract the TB antigens from sputum, we have developed an immunodetection method that takes 45 minutes (including sputum thinning) and which can be performed without external equipment or reagents by minimally trained technicians.