Susceptibility testing of Mycobacterium tuberculosis by broth microdilution method: a rapid alternative method

Area of Science:

• Microbiology
• Infectious Diseases
• Antimicrobial Resistance

Background:

• Tuberculosis (TB) remains a significant global health threat, caused by Mycobacterium tuberculosis.
• Accurate and timely drug susceptibility testing is crucial for effective TB treatment and control.
• Traditional methods for determining drug susceptibility can be time-consuming and labor-intensive.

Purpose of the Study:

• To evaluate the broth microdilution method (BMM) as a rapid and reliable alternative for determining the minimum inhibitory concentration (MIC) of primary antitubercular drugs.
• To compare the performance of BMM against a standard method for drug susceptibility testing of Mycobacterium tuberculosis clinical isolates.

Main Methods:

• Fifty clinical isolates of Mycobacterium tuberculosis were tested.
• Antitubercular drug susceptibility was assessed using both the proportion method and the broth microdilution method (BMM).
• Results were analyzed after a 14-day incubation period.

Main Results:

• The broth microdilution method (BMM) demonstrated high agreement with the proportion method for most primary antitubercular drugs.
• A 100% agreement was observed for all drugs except streptomycin, which showed a 96% agreement.
• The BMM proved to be a rapid, reliable, and less labor-intensive method.

Conclusions:

• The broth microdilution method (BMM) is a viable and efficient tool for determining minimum inhibitory concentrations (MIC) of antitubercular drugs.
• BMM offers a promising alternative for routine drug susceptibility testing of Mycobacterium tuberculosis, potentially improving patient management.
• This method facilitates faster identification of effective treatment regimens for tuberculosis.