What feature does Modified Thayer Martin (MTM) provide?

Modified Thayer Martin (MTM) agar is specifically designed to isolate Neisseria gonorrhoeae, the causative agent of gonorrhea, and it includes a range of features that make it effective for this purpose. One of its key characteristics is the inclusion of antibiotics that suppress the growth of competing flora. This selective pressure is crucial because Neisseria gonorrhoeae is a fastidious organism that often resides in environments populated by many other bacteria that could outcompete it for nutrients.

The antibiotics in MTM agar typically include substances like vancomycin, which targets Gram-positive bacteria, colistin, which targets Gram-negative bacteria (other than Neisseria), and nystatin, which inhibits yeast. By suppressing these other microorganisms, MTM allows for the enhanced detection and isolation of Neisseria gonorrhoeae in clinical samples, making it an essential tool in laboratories focused on diagnosing sexually transmitted infections.

This highlights the specificity of MTM's composition, which is tailored to support the growth of the target organism while limiting interference from non-target organisms.