Can you explain the process of how a pathologist can tell if a woman has a bacterial infection vaginally?

Swab culture: Any body site that is accessible can be cultured: a gyn physician or nurse using proper sterile technique inserts a culture swab in the vagina and then submits it to the lab where it can be smeared on a slide and examined in a microscope with appropriate stains, and cultured to see what organisms might grow.

Pap smear or culture: We can detect vaginal infections by 2 methods. Your routine pap smear can show cells called "clue cells" which are coated with bacteria indicating bacterial vaginosis. Also, sometimes gynecologists will send culture swabs. We grow the bacteria from these swabs until we can identify what types of bacteria are there. Some types of bacteria are normal in that area while some cause infection.