Antibiogram – MTB (Rifabutin)

Tuberculosis or TB, caused by Mycobacterium tuberculosis (MTB) is one of the diseases with a high fatality rate that mostly affects the lungs (Pulmonary TB) and sometimes affects other components like pleura, joints, abdomen, skin, etc. (Non-pulmonary TB). The disease spreads when the bacteria are dispersed in the air when an infected person spits, coughs, or sneezes. Patients/individuals suffering from tuberculosis develop symptoms like – cough for more than three weeks, chills, fever, night sweats, loss of appetite, weakness, weight loss. Due to slow growth patterns and drug resistance, the disease presents a major challenge in terms of treatment and quick diagnostic techniques.

Antibiogram test or Antimicrobial Susceptibility testing is performed to measure the susceptibility of microbes to certain antibiotics. Antibiogram MTb (Rifabutin) test checks for the sensitivity or resistance of MTB to Rifabutin drug. Rifabutin is a first-line antibiotic used to treat tuberculosis and prevent and treat Mycobacterium avium complex. It is typically only used in those who are intolerant to rifampin such as people with HIV/AIDS on antiretrovirals. For active tuberculosis, it is used with other antimycobacterial drugs. For latent tuberculosis, it may be used by itself when the exposure is with drug-resistant TB.

https://www.newtbdrugs.org/pipeline/compound/rifabutin

Why and When to get Tested with Antibiogram MTb Rifabutin?
Antibiogram MTb (Rifabutin) test checks for the sensitivity or resistance of Mycobacterium tuberculosis to Rifabutin drug. This test is needed if an infection has shown to have antibiotic resistance or is otherwise hard to treat or if there’s a bacterial or fungal infection that is not responding to standard treatments.

https://medlineplus.gov/lab-tests/antibiotic-sensitivity-test/

What is an Antibiogram test?

Antibiogram test or Antibiotic susceptibility testing (AST), is a widely-used technique for evaluating antibiotic resistance and determining the treatment of the patient. This is can be measured by observing the effect of the antibiotic on the growth of the microbe. Thereby the  therapy can be directed based on the knowledge of the microbe and its sensitivities to the drug

https://www.synbiosis.com/application-notes/antibiotic-susceptibility-test-ast/

What sample is used and what preparation is required in the Antibiogram MTb Rifabutin test?
A pure culture obtained from body fluids, sputum, bronchial alveolar lavage, cerebrospinal fluid (CSF), pus, tissue, biopsies, lymph nodes, abscess, urine is used for performing this test. There is no special preparation required before getting this test.

What are the types of drug-resistant TB?
Drug-resistant tuberculosis infection, caused by drug-resistant Mycobacterium tuberculosis (MTB) bacterium is divided into the following categories

• Multidrug-resistant or MDR TB: MDR TB is the TB infection caused by MTB that is resistant to the most potent drugs used in TB treatment – isoniazid and rifampin.
• Extensively drug-resistant or XDR TB: TB infection caused by MTB that is resistant to most commonly used drugs used in TB treatment like isoniazid and rifampin, plus any fluoroquinolone as well as at least one of the three injectable second-line drugs (amikacin, kanamycin, and capreomycin).

https://www.cdc.gov/tb/topic/drtb/default.htm

What is the role of Rifabutin in Tuberculosis treatment?
Rifabutin is also known as Mycobutin. It is most commonly used as a replacement for Rifampicin, which is one of the strongest first-line drugs. Rifabutin has been demonstrated to be as effective as rifampicin for TB treatment.

https://www.tbonline.info/posts/2011/9/10/rifabutin/