On the list of pathogens (from left): Staphylococcus aureus (causes skin infections, pneumonia, bloodstream infections), Pseudomonas aeruginosa (causes blood infections, pneumonia, infections after surgery) and Neisseria gonorrhoeae (causes the sexually-transmitted disease gonorrhea). (NIAID; Scott Chimileski and Roberto Kolter, NIH Image Gallery/Flickr; NIAID)
