Microbiology of Vagina and Penis

Question 1

What is the oxygen makeup of the vagina?

Answer 1

Usually anaerobic. Oxygen concentrations can increase transiently with tampon use, sexual activity, damage.

Question 2

What are the dominant microorganisms in about 80 percent of healthy women?

Answer 2

Lactobacilli

Question 3

What are the traits of Lactobacilli?

Answer 3

Gram positive rods/bacilli, facultative anaerobes.

Question 4

What are the most common Lactobacilli?

Answer 4

Lactobacilli iners, L. gasseri, L. cripsatus and L. jensenii are the most common.

Question 5

What are three Lactobacilli products?

Answer 5

Lactic acid (decreases pH), Hydrogen peroxide (hydroxyl radicals), Bacteriocins (proteins that depolarize pathogenic bacteria)

Question 6

What are Lactobacilli under study for?

Answer 6

Lactobacilli are currently under study as probiotics, orally or vaginally, for prevention and treatment of bacterial vaginosis.

Question 7

What is different about pre-pubertal and post-menopausal women?

Answer 7

They have different microbial communities with less robust pathogen defense activity.

Question 8

What is the pathway from 17beta-estradiol to lactate?

Answer 8

Ovaries secrete 17beta-estradiol. Vaginal epithelial expansion and glucose combine. Vaginal epithelial glycogen production. Epithelial cell sloughing. Extracellular glycogen. Extracellular glucose. Glucose becomes 2 pyruvate and then 2 lactate (high energy substrate for immune cells).

Question 9

What does the vaginal microbial community depend on?

Answer 9

Estrogen

Question 10

What are MCTs?

Answer 10

Monocarboxylate transporters (MCTs) act as symporters transporting one proton with each molecule of lactate. When cells take up lactate, they increase extracellular pH.