Which of the following is an airborne pathogen?

Mycobacterium tuberculosis is identified as an airborne pathogen due to its mode of transmission. This bacterium spreads through respiratory droplets when an infected person talks, coughs, or sneezes. These droplets can remain suspended in the air for extended periods, allowing others to inhale them and become infected. The disease it causes, tuberculosis (TB), is primarily a respiratory illness, emphasizing the importance of recognizing airborne pathogens for infection control in healthcare settings.

In contrast, Escherichia coli is primarily transmitted through contaminated food or water, Staphylococcus epidermidis is a skin flora that can cause infection through direct contact, and Clostridium difficile typically spreads via spores in environments contaminated with feces. Therefore, these organisms do not classify as airborne pathogens, which underscores why Mycobacterium tuberculosis is the correct answer in this context.