"So, naturalists observe, a flea has smaller fleas that on him prey; and these have smaller still to bite ’em; and so proceed ad infinitum."
- Jonathan Swift
April 10, 2010
April 9 - Pneumocystis jirovecii
Pneumocystis jirovecii is a fungus that can be an opportunistic pathogen and produce pneumonia in humans. This species was previously known as Pneumocystis carinii, thus these pneumonias are still usually called "PCP." These infections principally infect immunocompromised people and have become associated with AIDS. These fungi are geographically widespread and most people are exposed to them by a young age. In addition to the change in the species name, these pathogens were also previously classified as protozoa since they are single-celled, however genetic and biochemical evidence all places them in with fungi.