"Candida species can adhere to and invade host cells, form biofilms, secrete hydrolases such as proteases, phospholipases, and lipases that assist in their spread through tissues, and change their phenotypes to protect themselves from the immune system. However, they typically only cause disease in the female reproductive tract under conditions that compromise the host’s defenses. While there are at least 20 Candida species of clinical importance, C. albicans is the species most commonly responsible for fungal vaginitis. Lactobacilli in the vagina inhibit the growth of other organisms, including bacteria and Candida, but disruptions can allow Candida to increase in numbers. Typical disruptions include antibiotic therapy, illness, especially diabetes, pregnancy, and the presence of transient microbes. Immunosuppression can also play a role, and the severe immunosuppression associated with HIV infection often allows Candida to thrive. This can cause genital or vaginal candidiasis, a condition characterized by vaginitis and commonly known as a yeast infection. When a yeast infection develops, inflammation occurs along with symptoms of pruritus, or itching, a thick white or yellow discharge, and odor. Other forms of candidiasis include cutaneous candidiasis and oral thrush. Although Candida species are found in the normal microbiota, they may also be transmitted between individuals. Sexual contact is a common mode of transmission, although candidiasis is not considered an STI. Diagnosis of vaginal candidiasis can be made using microscopic evaluation of vaginal secretions to determine whether there is an excess of Candida. Culturing approaches are less useful because Candida is part of the normal microbiota and will regularly appear. It is also easy to contaminate samples with Candida because it is so common, so care must be taken to handle clinical material appropriately. Samples can be refrigerated if there is a delay in handling. Candida is a dimorphic fungus, so it does not only exist in a yeast form; cultivation can be used to identify chlamydospores and pseudohyphae, which develop from germ tubes. The presence of the germ tube can be used in a diagnostic test in which cultured yeast cells are combined with rabbit serum and observed after a few hours for the presence of germ tubes. Molecular tests are also available if needed. The Affirm VPII Microbial Identification Test tests simultaneously for the vaginal microbes C. albicans, G. vaginalis, and Trichomonas vaginalis. Topical antifungal medications for vaginal candidiasis include butoconazole, miconazole, clotrimazole, tioconazole, and nystatin. Oral treatment with fluconazole can be used. There are often no clear precipitating factors for infection, so prevention is difficult. Lactobacilli are visible as gram-positive rods on and around a squamous epithelial cell. A wet mount prepared with KOH shows Candida albicans pseudohyphae and squamous epithelial cells in a vaginal sample from a patient with candidiasis."