The broth microdilution plate method represents a promising solution for comprehensive and quality-assured phenotypic drug susceptibility testing in tuberculosis (TB). Using this method up to 12 anti-TB agents can be tested simultaneously providing quantitative levels of resistance and aid individualized patient treatment decisions. The document provides an optimized plate design and standardized methodology to facilitate the improvement of the method for clinical use. The WHO calls on manufacturers to take forward this optimized method and make it available for programmatic use in resource-limited settings.
Diagnosis of TB and drug-resistant TB remains a challenge with a third of people with TB and more than a half of people with drug-resistant TB not receiving quality diagnosis and care globally. Rapid molecular methods represent the most appropriate option to close the diagnostic gap for drug-resistant TB due to shorter time to diagnosis, ease of use, and lower biohazard risk. However, phenotypic methods are still needed when the molecular mechanisms of resistance are not fully known, or where determining the level of resistance is clinically important. Quantitative phenotypic methodologies, such as the broth microdilution plate method, have the added value to advance individualized TB treatment decisions.
