Blood culture test - can antibiotics cause a false positive?

Question

Or will they just possibly limit the growth of bacteria in the petri dish?

If a person has been taking antibiotics will that cause any false positives for any bacteria in a blood culture test? Sounds unlikely to me but just wanted to know for sure.

Answer 1

you would obviously kill bacteria with antibiotics so you wouldnt get a false positive as youd have less bacteria not more.. unless i didnt understand your question properly..?

Answer 2

How could it? Blood is normally sterile, and putting antibiotics into the blood can't put bacteria in it. The sources of contamination that cause false positives in blood cultures (and they are fairly common) lie elsewhere.

Answer 3

Probably not. Antibiotics can cause certain false readings, but for bacteria, not usually.  Besides, the reason to take them is for killing bacteria, usually, so there would be some bacteria somewhere in the body.