While it is true that salmon can get infected with salmonella, it is a much more common type of bacteria with poultry and other types of meat. Listeria is more of a concern with salmon than anything else because it is fairly common in raw fish. In order to avoid ingesting listeria and getting sick, it will be important to cook your fish all the way through before eating it.
Both salmonella and listeria can be harmful and sometimes even deadly, especially for small children and elderly people. In order to avoid ingesting any type of harmful bacteria from this type of fish, you will need to make sure to store it well and cook it before eating.