Anti-tubercular drug susceptibility can be done by all of the following methods, except ?
**Core Concept**
Anti-tubercular drug susceptibility testing (DST) is a crucial step in managing tuberculosis (TB) patients, especially those with multidrug-resistant TB (MDR-TB). It involves determining the minimum inhibitory concentration (MIC) of first-line anti-tubercular drugs against Mycobacterium tuberculosis (M. tuberculosis) isolates.
**Why the Correct Answer is Right**
The correct answer is **B.** because the BACTEC MGIT 960 system is a widely used automated liquid culture system for DST, which detects the growth of M. tuberculosis in the presence of anti-tubercular drugs.
**Why Each Wrong Option is Incorrect**
* **Option A:** The Löwenstein-Jensen medium is a solid culture medium used for isolating M. tuberculosis, but it is not the recommended method for DST due to its slow growth rate and difficulty in interpreting results.
* **Option C:** The proportion method involves inoculating M. tuberculosis onto a solid medium and observing the growth of colonies in the presence of anti-tubercular drugs. While it is a traditional method, it is less sensitive and more time-consuming compared to other methods.
**Clinical Pearl / High-Yield Fact**
The most commonly used methods for DST are the BACTEC MGIT 960 system, the automated liquid culture system (e.g., BACTEC 460 TB), and the MGIT 960 system with a fluorescence-based detection method. These methods provide accurate and timely results, enabling healthcare providers to make informed treatment decisions.
**Correct Answer:** A. Löwenstein-Jensen medium is not the recommended method for anti-tubercular drug susceptibility testing.