MTB Susceptibility – Cycloserine Test: Booking, Price, and Results
About MTB Susceptibility – Cycloserine Test: Booking, Price, and Results
| Field | Value |
|---|---|
| Also Known As | Cycloserine Susceptibility Test, AFB Susceptibility – Cycloserine, MTB-Cycloserine Antibiotic Sensitivity, D-Cycloserine DST |
| Sample Type | Ascitic fluid, aspirate, BAL, bile, bone marrow, bronchial fluid, catheter tip, corneal scraping, CSF, endotracheal secretion, gastric fluid, hair clipping, liver abscess fluid, nail, pericardial fluid, peritoneal fluid, pleural fluid, pus, swab, reproductive tract secretions, semen, skin scraping, sputum, synovial fluid, throat swab, tissue, urine, vaginal fluid, vaginal swab, pure culture |
| Fasting Required | No |
| Report Time | 29 days |
| Recommended For | Adults and children with confirmed or suspected drug-resistant tuberculosis (MDR-TB or XDR-TB) |
| Price | Starting at ₹2,200 |
What Is an MTB Susceptibility – Cycloserine Test?
The MTB Susceptibility – Cycloserine test checks whether the tuberculosis (TB) bacteria in a patient's sample can be treated with cycloserine, a second-line antibiotic used in drug-resistant TB cases. It is also known as the Cycloserine Susceptibility Test or AFB Susceptibility – Cycloserine. Doctors order this test when a patient has confirmed or suspected multidrug-resistant TB (MDR-TB) or when first-line TB treatment has not worked. The sample used can vary widely, from sputum and respiratory fluids to tissue and other body fluids.
What Does an MTB Susceptibility – Cycloserine Test Measure?
This test examines how the TB bacteria in your sample respond to cycloserine. The following are the key things it assesses:
| Parameter | What It Tells You |
|---|---|
| Cycloserine susceptibility | Whether the TB bacteria can be effectively controlled by cycloserine |
| Minimum Inhibitory Concentration (MIC) | The lowest cycloserine concentration that stops bacterial growth, measured using systems such as the MGIT (Mycobacteria Growth Indicator Tube), MIC of 25 µg/mL or below, indicates susceptibility |
| Resistance mutations | Genetic changes in the TB bacteria (in genes such as alr, ddl, ald, and cycA) that may cause resistance to cycloserine |
Why Is an MTB Susceptibility – Cycloserine Test Done?
This test is ordered when there is concern about drug-resistant TB or when treatment is not producing the expected improvement. The sections below explain the common reasons it may be requested.
Common Symptoms That May Require This Test
Patients are typically referred for an MTB Susceptibility – Cycloserine test procedure when they present with symptoms suggestive of active or treatment-resistant TB. The following symptoms are the most common triggers:
- Persistent cough lasting more than two weeks
- Unexplained weight loss
- Night sweats
- Fever without a clear cause
- Coughing up blood (haemoptysis)
- Fatigue and weakness
- Chest pain
Conditions This Test Can Help Detect
This test is used to identify or evaluate the following conditions:
- Cycloserine resistance in drug-resistant TB cases
- Multidrug-resistant TB (MDR-TB), resistant to both isoniazid and rifampicin
- Extensively drug-resistant TB (XDR-TB)
- Treatment failure on existing TB medications caused by drug-resistant Mycobacterium tuberculosis
MTB Susceptibility – Cycloserine Test for Chronic Disease Monitoring
Cycloserine is included in treatment regimens for MDR-TB under Indian national guidelines. Because MDR-TB treatment can last 12 to 24 months, this test may be repeated if a patient's response to treatment is poor. Monitoring cycloserine susceptibility over time helps doctors detect emerging resistance and adjust the treatment plan accordingly.
How to Prepare and What to Expect
No special preparation is needed for the MTB Susceptibility – Cycloserine test, but a few practical steps will help ensure a reliable result.
Do You Need to Fast?
No fasting is required before this test. You may eat and drink normally before your sample is collected.
Practical Tips Before Your Test
The following steps will help make the process straightforward:
- Bring a detailed clinical history including your symptoms, previous test results and any past TB treatment, as this is required for the test.
- Provide your complete address and mobile number at the time of booking or registration.
- Inform your doctor about all current medications, including any antibiotics or anti-TB drugs.
- Also, mention if you have previously been treated for TB or if you have been exposed to someone with drug-resistant TB.
- For sputum collection, early morning specimens typically yield better results.
- Ensure the sample is delivered to the laboratory within 24 hours of collection; refrigerate it if transport is delayed.
Step-by-Step Procedure
The collection process depends on the sample type your doctor has requested. The steps below describe the most common approach (sputum), though the same principles of sterile collection and prompt transport apply to all sample types:
- You will be asked to produce a deep, productive cough to bring up sputum from your lungs, not just saliva from your mouth.
- The sputum is collected into a sterile, sealed container provided by the lab or collection team.
- The sample is labelled with your details and stored at 2 to 8 degrees Celsius until it reaches the laboratory.
- At the laboratory, the sample is processed to separate and concentrate the TB bacteria.
- The bacteria are then tested against cycloserine using an automated method to determine their sensitivity or resistance.
- Results are reviewed and reported within 29 days, given the time required for mycobacterial culture.
For other specimen types (such as urine, pus, tissue, body fluids or swabs), a trained healthcare professional at the centre will collect the appropriate sample using a sterile technique.
Factors That Can Affect Accuracy
The following factors may affect the reliability of your MTB Susceptibility – Cycloserine test result:
- Collecting saliva instead of true sputum (incorrect technique)
- Starting TB treatment before sample collection
- Delayed or improper sample transport without refrigeration
- Insufficient sample volume
- Contamination of the sample
- Natural degradation of cycloserine in culture medium, which can affect MIC readings and reduce test reliability in some methods
Understanding Your MTB Susceptibility – Cycloserine Test Results
Your results will indicate whether the TB bacteria are susceptible or resistant to cycloserine. The table below shows general reference values used in laboratory interpretation.
| Parameter | Interpretation | Value |
|---|---|---|
| Cycloserine MIC | Susceptible | 25 µg/mL or below |
| WHO critical concentration (MGIT system) | Susceptibility threshold | 16 µg/mL |
A susceptible result means cycloserine can be considered for inclusion in your TB treatment plan. A resistant result means the bacteria are unlikely to respond to cycloserine, and your doctor will explore other second-line treatment options.
These ranges are general guidelines. Your doctor will interpret your results based on your age, health history and other factors. Always consult a qualified healthcare professional for personalised medical advice.
Results During Special Conditions
Cycloserine degrades naturally in culture medium over time. This degradation can alter MIC values and reduce the reliability of the result. Historically, cycloserine susceptibility testing was not endorsed by CLSI guidelines due to concerns about reproducibility. The WHO has since established a critical concentration to improve consistency, but your doctor will consider these technical limitations when interpreting your result.
How to Maintain Healthy Levels
These general wellness tips support TB treatment outcomes:
- Complete the full course of prescribed TB medications without interruption, even if symptoms improve.
- Maintain adequate nutrition and rest throughout the treatment period to support recovery.
- Attend all scheduled follow-up appointments so your doctor can monitor your response to treatment.
Lupin Diagnostics MTB Susceptibility – Cycloserine Test Price
The MTB Susceptibility – Cycloserine test price at Lupin Diagnostics starts at ₹2,200. This test requires a visit to a Lupin Diagnostics centre; home collection is not available for this test.
| City | Approximate Price (₹) |
|---|---|
| BHOPAL | 2200 |
| CHENNAI | 2200 |
| HYDERABAD | 2200 |
| KOLKATA | 2200 |
| NAVI MUMBAI | 2200 |
| PUNE | 2200 |
Prices are indicative and may vary by location. Please confirm the current price at the time of booking.
How to Book
Follow these steps for your MTB Susceptibility – Cycloserine test online booking through the Lupin Diagnostics website:
- Select the test on the Lupin Diagnostics website.
- Choose your city and preferred centre location.
- Visit the centre at your scheduled time for sample collection.
- Receive your report via email or WhatsApp within the stipulated turnaround time.
Frequently Asked Questions
This test checks whether the TB bacteria in your body are sensitive or resistant to cycloserine, a second-line antibiotic. It is ordered for patients with MDR-TB or those who have not responded to first-line TB treatment. The result helps your doctor choose the most effective treatment regimen.
This test is typically needed when an MTB isolate is found to be resistant to rifampicin or two or more primary TB drugs. It is ordered for patients with multidrug-resistant TB (MDR-TB), extensively drug-resistant TB (XDR-TB) or confirmed treatment failure on existing medications.
Results are available within 29 days. This extended turnaround time is due to the need for mycobacterial culture, which requires the bacteria to grow under controlled laboratory conditions before testing can be performed.
No fasting or special preparation is required. You should bring a detailed clinical history along with your address and mobile number. Ideally, samples should be collected before starting or changing TB treatment, as medication can affect bacterial growth.
No, the MTB Susceptibility – Cycloserine test home collection is not available. Samples must be collected under proper conditions and transported promptly to a laboratory equipped for mycobacterial culture.
Cycloserine degrades naturally in culture medium, which can alter MIC readings. Earlier international guidelines did not endorse this test due to concerns about reproducibility. The WHO has since provided updated guidance with a recommended critical concentration to improve the accuracy of results.
A resistant result means cycloserine may not be effective against the TB strain in your body. Your doctor will review your full drug susceptibility profile and adjust your treatment regimen to include alternative second-line anti-TB drugs. You should not stop or change your medications without medical guidance.
MTB Susceptibility – Cycloserine Test: Booking, Price, and Results
