mummyboo no worries - I'm sure it was a MNer who first told me all of this so it's nice to pass it along! I think that our immune systems are lowered in pregnancy so we do have a generally higher risk if we are exposed to these bacteria, but even a weakened immune system can't create salmonella out of nothing 
I tried those Vertbaudet jeans last week actually! They looked good but in the end I sent them back as the Seraphina ones seemed to fit me better and I was given 5 pairs of mat jeans/trousers by a friend. Hope they suit you 