Antibiogram – MTB (Moxifloxacin Higher Dose)

Tuberculosis or TB, caused by the bacterium Mycobacterium tuberculosis (MTB) is one of the diseases with a high fatality rate that mostly affects the lungs (Pulmonary TB) and sometimes infects other parts of the body like pleura, joints, abdomen, skin, etc (Non-pulmonary TB). The disease spreads mainly when the bacteria are dispersed in the air when an infected person spits, coughs, or sneezes. Due to the slow growth pattern 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 (Moxifloxacin higher dose) test checks for the sensitivity or resistance of MTB to the antibiotic – Moxifloxacin at higher doses (2.0 µg/ml). Moxifloxacin, a second-line drug belongs to the fluoroquinolone class of antibiotics and is used in treating multidrug-resistant TB. It is bactericidal in nature that interferes with the replication of bacterial DNA. As per research, Mycobacteria resistant to the critical concentration of a drug can be susceptible at higher concentrations, thus making the drug available for treatment.

Cough for more than three weeks, chills, fever, night sweats, loss of appetite, weakness, and weight loss are some of the symptoms observed in individuals suffering from TB infection.

Why and when get tested with Antibiogram – MTB (Moxifloxacin Higher Dose) test?
Antibiogram – MTB (Moxifloxacin higher dose) test is used for determining and monitoring drug susceptibility pattern of Mycobacterium tuberculosis, the bacterium that is responsible for Tuberculosis against the antibiotic – Moxifloxacin at higher doses (2.0 µg/ml). This test is needed if an infection has shown to have antibiotic resistance, is otherwise hard to treat or if there’s a bacterial or fungal infection that is not responding to standard treatments.

What is an Antibiogram test?
Antibiogram test or Antibiotic susceptibility testing (AST) is a widely-used technique for evaluating antibiotic resistance and determining the most effective antibiotic for treatment. This is achieved by observing the effect of a particular antibiotic on microbial growth. The treatment can be directed as per the knowledge of the microbe and its sensitivity to the drug.

What sample is required and what preparation is needed for this 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: XDR-TB is the 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).

What is the role of Moxifloxacin in Tuberculosis treatment?
Moxifloxacin is used as a second-line drug in treating multidrug-resistant TB infections. It is bactericidal in nature, that is it works by killing the organisms that cause TB.