Salt effectively displaces water, and is bacteriostatic. Packing meat in salt dessicates the meat. Sodium nitrite, or sodium nitrate is added to almost all commercially cured meats. These salts inhibit anaerobic bacteria such as botulinum.(which can kill you in a matter of minutes) To get to the point, all foodborne pathogens need an ample supply of moisture to thrive. Some salt-cured meats such as prosciutto ham are "cured" by a natural acidifying process that salts and cultures the meat with live lactobacilli which both "cure" the meat and give it its distinctive salami-like flavor.