Why don't people seem to die from salmonella in bites?
Salmonella infect via the fecal-oral route. They have proteins on their surface that match our gut cell surfaces, allowing them to attach and invade the gut. Those cell markers aren't present when you are bitten. it's the same reason that plant virus dont make us sick. 

https://www.ncbi.nlm.nih.gov/pubmed/17593246

this is a bit heavy if you dont usually read primary papers, but looking for "Salmonella route of infection" or similar will yield the same kind of information