Salmonella in stool sample

[pregnantandsick]

Hello, would be grateful for any advice. I'm 27 weeks pregnant and had very bad vomiting and diarrhoea last week, which was originally ascribed to the norovirus. Just got the results of my stool sample and they have found:

Salmonella
E. Coli
Shigella

Midwife couldn't give any advice on phone about likelihood that any of these bacteria were harmful to baby, but am becoming anxious after internet searching. Can anyone advise? Do I need antibiotics? Can the bacteria be transmitted through the placenta or would it be at birth?

I am still feeling somewhat ill but acute symptoms have gone, so not worried on my own account.

No advice about shigella, but my pregnancy bible (expecting better by Emily Oster) says salmonella and E. coli aren't bad for the foetus (apart from one strain that isn't that common in the uk)

Have you spoken to the midwife?

Thank you for replying! Midwife said she would ask obstetrician to review the results and call me back. It does seem as if many of these bacteria can cause maternal illness without being transmitted to the fetus, but internet not entirely reassuring.

God knows what I ate that managed to have all three in it!