Lactobacillus in the vagina contributes to an acidic environment by producing lactic acid. Which statement is true?

Lactobacillus in the vagina contributes to an acidic environment by producing lactic acid. Which statement is true?

• A. It is Gram-negative bacilli.
• B. It is not part of the normal vaginal flora.
• C. It is Gram-positive bacilli and part of normal vaginal flora.
• D. It causes bacterial vaginosis.

Answer: (C)

Lactobacillus in the vagina helps keep things acidic by producing lactic acid, which creates an environment that inhibits many pathogens. These bacteria are Gram-positive rods and normally colonize the vaginal tract in reproductive-age women. Their presence and acid production, sometimes along with hydrogen peroxide and bacteriocins, form a protective, microbiota-balanced state. The correct statement reflects both features: they are Gram-positive bacilli and they are part of the normal vaginal flora. Why the other ideas don’t fit: lactobacilli aren’t Gram-negative, so that label wouldn’t be accurate. They are indeed part of the normal vaginal flora, not a nonresident. And they don’t cause bacterial vaginosis; BV is associated with overgrowth of anaerobes when lactobacilli are depleted and the pH rises, rather than caused by lactobacilli themselves.

Lactobacillus in the vagina helps keep things acidic by producing lactic acid, which creates an environment that inhibits many pathogens. These bacteria are Gram-positive rods and normally colonize the vaginal tract in reproductive-age women. Their presence and acid production, sometimes along with hydrogen peroxide and bacteriocins, form a protective, microbiota-balanced state. The correct statement reflects both features: they are Gram-positive bacilli and they are part of the normal vaginal flora.

Why the other ideas don’t fit: lactobacilli aren’t Gram-negative, so that label wouldn’t be accurate. They are indeed part of the normal vaginal flora, not a nonresident. And they don’t cause bacterial vaginosis; BV is associated with overgrowth of anaerobes when lactobacilli are depleted and the pH rises, rather than caused by lactobacilli themselves.