Which of the following tests can be used to differentiate mycobacterial species?

The differentiation of mycobacterial species is often accomplished through specific biochemical tests, and the catalase test is particularly relevant in this context. Mycobacteria can produce the enzyme catalase, which breaks down hydrogen peroxide into water and oxygen. The presence or absence of this enzymatic activity is helpful in identifying various mycobacterial species.

For instance, Mycobacterium tuberculosis is known to produce catalase, but some other non-tuberculous mycobacteria exhibit different catalase activity levels. Therefore, measuring the catalase reaction can help in distinguishing among mycobacterial species by observing how they interact with hydrogen peroxide.

The other tests listed are more suitable for identifying different types of bacteria or have limited application in differentiating mycobacterial species. The urease test is primarily used for identifying urease-producing bacteria, the coagulase test is designed to detect Staphylococcus aureus, and the triple sugar iron agar test is used to differentiate enteric gram-negative bacteria. These tests do not provide the necessary specificity for mycobacterial differentiation, which underscores why the catalase test is the appropriate choice in this scenario.