Medical Laboratory Scientist (MLS) ASCP Exam 2025 – 400 Free Practice Questions to Pass the Exam

Mycobacterium fortuitum is a rapid-growing mycobacterium that has distinct characteristics useful for identification in a clinical laboratory setting. One of the key distinguishing features is its ability to uptake iron. This property is associated with its metabolism and growth patterns, which help differentiate it from other mycobacterial species that do not exhibit similar iron uptake capabilities.

While other choices might seem plausible, they do not accurately characterize M. fortuitum. For instance, M. fortuitum does grow on blood agar, but this characteristic is not unique to this organism, as many other bacteria can grow on this medium as well. It also has a positive reaction in nitrate reduction tests, indicating that it can reduce nitrate to nitrite or further products, which is contrary to what option C suggests. Lastly, Mycobacterium fortuitum does not exhibit fermentative metabolism; instead, it is more aligned with aerobic respiration. Thus, the unique ability of M. fortuitum for iron uptake is the correct distinguishing characteristic for this organism.