Pseudomonas is most often spread by direct contact. Although it is possible to catch pseudomonas by inhaling the germ from the air coughed out by an infected person, this is unusual. A person infected with pseudomonas may infect another person at any time. However they are more likely to infect another person when they have a flare up. Another key element for someone to become infected with pseudomonas is that their immune system be weakened in some way, such as overwhelming stress or illness.
Contracting Pseudomonas is like getting the common cold. If someone coughs in your face, if you shake hands, and them wipe your nose, open wounds, etc. It can infect anywhere in your body. Predominantly the lungs. But again, your immune system needs to be very weak for it to make you symptomatic. Otherwise, you have nothing to worry about really.
Andy, RRT, CPFT