A rapid culture system uninfluenced by an inoculum effect increases reliability and convenience for drug susceptibility testing of Mycobacterium tuberculosis.
Sci Rep
; 8(1): 8651, 2018 06 05.
Article
in En
| MEDLINE
| ID: mdl-29872060
ABSTRACT
The Disc Agarose Channel (DAC) system utilizes microfluidics and imaging technologies and is fully automated and capable of tracking single cell growth to produce Mycobacterium tuberculosis (MTB) drug susceptibility testing (DST) results within 3~7 days. In particular, this system can be easily used to perform DSTs without the fastidious preparation of the inoculum of MTB cells. Inoculum effect is one of the major problems that causes DST errors. The DAC system was not influenced by the inoculum effect and produced reliable DST results. In this system, the minimum inhibitory concentration (MIC) values of the first-line drugs were consistent regardless of inoculum sizes ranging from ~103 to ~108 CFU/mL. The consistent MIC results enabled us to determine the critical concentrations for 12 anti-tuberculosis drugs. Based on the determined critical concentrations, further DSTs were performed with 254 MTB clinical isolates without measuring an inoculum size. There were high agreement rates (96.3%) between the DAC system and the absolute concentration method using Löwenstein-Jensen medium. According to these results, the DAC system is the first DST system that is not affected by the inoculum effect. It can thus increase reliability and convenience for DST of MTB. We expect that this system will be a potential substitute for conventional DST systems.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Microbial Sensitivity Tests
/
Mycobacterium tuberculosis
/
Antitubercular Agents
Type of study:
Evaluation_studies
Language:
En
Journal:
Sci Rep
Year:
2018
Document type:
Article