Radiomimetric BACTEC detect growth of M tuberculosis in how much time ?
**Core Concept**
The Radiomimetric BACTEC is a rapid automated culture system used for the detection of Mycobacterium tuberculosis (M. tuberculosis) growth. This system employs a radiometric technique to detect the growth of M. tuberculosis by measuring the radioactive carbon dioxide (14CO2) produced during the bacterial metabolism of a radiolabeled substrate.
**Why the Correct Answer is Right**
The Radiomimetric BACTEC system typically detects the growth of M. tuberculosis within 2-3 weeks. This rapid detection is due to the high sensitivity of the system in detecting even small amounts of 14CO2 produced by the growing bacteria. The system's ability to detect growth within this timeframe is crucial for early diagnosis and treatment of tuberculosis (TB). The growth of M. tuberculosis is detected by the system's ability to measure the increase in radioactivity, which is directly proportional to the bacterial growth.
**Why Each Wrong Option is Incorrect**
**Option A:** 1 week - This is too short a timeframe for the Radiomimetric BACTEC system to detect the growth of M. tuberculosis, as the system requires a minimum of 2-3 weeks to accurately detect growth.
**Option C:** 4-8 week - This is an excessively long timeframe for the Radiomimetric BACTEC system to detect the growth of M. tuberculosis, as the system is designed to detect growth within a shorter period.
**Option D:** > 10 weeks - This is an even longer timeframe than option C and is not a valid option for the detection of M. tuberculosis growth using the Radiomimetric BACTEC system.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that the Radiomimetric BACTEC system is a rapid diagnostic tool that can detect the growth of M. tuberculosis within 2-3 weeks. This rapid detection allows for early initiation of treatment, which is critical for preventing the spread of TB and improving patient outcomes.
**✓ Correct Answer: B. 2-3 week**