Is salmonella and salmonellosis the same thing?
Sort of. Depends on how picky you want to be with the wording. Salmonella is a genus of bacteria. Salmonellosis is the disease caused by various kinds of Salmonella enterica (a particular species of Salmonella). Whenever you want to express the disease name for a certain kind of microbe, you can attach the suffix “osis” to it. In general, “-osis” means “disease.” For example, when you get sick from Listeria monocytogenes (a particular species of bacteria), that’s called “listeriosis.” If you’re sick with some species of Brucella, that’s called brucellosis.