A 31-year-old woman has had vulvar pruritus along with a thick, whitish, odorless, globular vaginal discharge for the past week. On pelvic examination, the cervix appears erythematous, but there are no erosions or masses. A Pap smear shows budding cells and pseudo hyphae. No dysplastic cells are present. Which of the following infectious agents is most likely to produce these findings?

The presence of the budding cells with pseudo hyphae indicates a fungal infection with Candida. Candidal (monilial) vaginitis is common; this organism is present in about 5% to 10% of women. Recurrent episodes of vaginal candidiasis may be associated with non-albicans species. The inflammation tends to be superficial, and there is typically no invasion of underlying tissues. Urea plasma is a bacterial agent, as is Chlamydia, and both can produce cervicitis. Neisseria gonorrhoeae, a gram-negative diplococcus, is the causative agent of gonorrhea. Infection with Trichomonas vaginalis can produce a purulent vaginal discharge, but the organisms are protozoa and do not produce hyphae.