Complete Blood Count (CBC)
This test detects genetic mutations in the rpsL gene of bacteria that indicate resistance to certain antibiotics, helping doctors choose the most effective treatment for infections.
{"The test looks for specific genetic changes (mutations) in bacteria that make antibiotics less effective","It is commonly used to detect drug-resistant tuberculosis and other bacterial infections","Results help doctors select the right antibiotic treatment for your infection","The test uses a sample of your blood (serum) to analyze bacterial DNA","Results are typically available within a few days to a week"}
Key facts at a glance
- LOINC
- 94063-5
- Short code
- rpsL
- Synonyms
- Bacterial rpsL drug res mut Islt/Spm
- Category
- chemistry
- Sample
- serum
- Container
- Sterile, leak-proof container for bacterial isolate or clinical specimen; appropriate transport media for clinical samples
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- molgen
- CPT
- 87153 (Identification of bacteria by molecular methods); related codes may include 87150 for culture-based identification
- SNOMED
- 43491000 | 398535006
- Specimen volume
- Pure bacterial isolate from culture or 1-5 mL of clinical specimen (blood, tissue, body fluid) depending on source
- Stability
- Bacterial isolates stable at 2-8°C for up to 7 days; clinical specimens should be processed within 24-48 hours at room temperature or refrigerated
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 24–168 hours
- Order
- routine
What is this test? A complete blood count (CBC) is a common blood test that measures the different cells in your blood, including red blood cells, white blood cells, and platelets. It gives your doctor a broad picture of your overall health and helps screen for many conditions.
The bacterial rpsL gene drug resistance test is a molecular test that detects specific genetic mutations in bacteria. The rpsL gene is found in bacteria like tuberculosis (TB), and certain changes in this gene can make the bacteria resistant to antibiotics, particularly streptomycin and other related drugs. This test identifies these genetic changes by analyzing the bacterial DNA in your sample.
Why do I need this test? Your doctor may order a CBC as part of a routine checkup or to look into symptoms such as fatigue, weakness, fever, unusual bruising, or signs of infection. It can help detect anemia, infections, inflammation, and certain blood disorders before they cause serious problems.
Your doctor may order this test if you have a bacterial infection that is not responding to standard antibiotic treatment, or if you are at risk for a drug-resistant infection. The test helps determine whether the bacteria causing your infection have developed resistance to certain antibiotics, allowing your doctor to choose a more effective treatment plan. It is especially important for treating tuberculosis, as drug-resistant TB requires specific medications.
How is the test performed? A healthcare professional will draw a small sample of blood from a vein in your arm, usually on the inside of your elbow. The procedure takes only a few minutes, and you can return to your normal activities right away with no recovery time needed.
A healthcare professional will collect a blood sample from your arm using a small needle. This sample is then sent to a laboratory where scientists extract the bacterial DNA and analyze it for mutations in the rpsL gene. The test uses molecular techniques to identify specific genetic changes associated with antibiotic resistance.
What do the results mean? Your results show the levels of each blood cell type compared with normal reference ranges. Values that are too high or too low may point to conditions such as anemia, infection, inflammation, or clotting problems, and your doctor will explain what your specific numbers mean for you.
If the test detects mutations in the rpsL gene, it indicates that the bacteria causing your infection are likely resistant to certain antibiotics (such as streptomycin). Your doctor will use this information to prescribe alternative antibiotics that will be effective against the infection. If no mutations are found, the bacteria are likely still sensitive to standard antibiotic treatments.
Reference range
No mutations detected in the rpsL gene (wild-type sequence); Result reported as 'Detected' or 'Not Detected' for specific resistance-conferring mutationsN/A
No special patient preparation required. Specimen should be collected prior to initiation of antimicrobial therapy when possible to avoid false-negative results
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
The rpsL gene mutation test is clinically significant because it enables personalized antibiotic therapy for bacterial infections, particularly tuberculosis. Drug-resistant infections are a growing concern worldwide, and early detection of resistance mutations allows doctors to avoid ineffective treatments and start appropriate therapy sooner. This can improve treatment outcomes, reduce the spread of drug-resistant bacteria, and help conserve the effectiveness of existing antibiotics. The test is especially valuable in cases of treatment failure, recurrent infection, or when TB exposure to someone with drug-resistant disease is suspected.
Frequently asked questions
Is the test painful?
How long does it take to get results?
Do I need to prepare for the test?
What happens if my test shows drug resistance?
Can this test detect all types of antibiotic resistance?
Sources
- 1
- 2
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy