What kindof STD is this?

i have a girlfriend,she went to a doctor for a papsmear the result is this,tiny grams variable coccobacilli-abundant,negative gram pleomorphic, gram negative bacilli-abundant, clue cells found,suggestive of bacterial vaginosis,my questions are:
a.is this an infection or STD?
b.if ever this is an STD,how many months a bacteria could stay in a body of a person from the time he/she had sex?
c.we had sex before but that was 3 months ago and after that we didin't do have sex,how could it possibly she is positive to that kind of bacteria and im not?

[empathy60]

This is a question better suited for the STD community, they'll be able to explain this in depth there.

[Emma_08]

Bacterial vaginosis is not considered to be an STD.  It is an overgrowth of the "bad" bacteria in the normal vaginal flora.  It is possible to have sex and not transmit BV.
Good luck,
Em

[empathy60]

Coccobacilli is an STD though, so it is best to take this question over to the STD board.