Micro of Vagina/Penis

Question 1

Vagina microbiome

Answer 1

normally anaerobic –> O2 [ ] increase with tampon use, sex, and damage

• Lactobacilli are dominant microorganisms (gram + bacilli, facultative anaerobes
• they produce lactic acid (decrease pH), hydrogen peroxide (hydroxyl radicals), and bacteriocins (lethal to other bacteria)

Question 2

Estrogen effects on microbiome

Answer 2

Estrogen promotes the menstrual cycle which results in sloughing of epithelial cells –> cells have glycogen which is converted to glucose –> utilized to make lactate from pyruvate –> production of H+ decreases the pH and lactate is used for energy by immune cells

Question 3

Pre-pubertal and postmenopausal women microbiome

Answer 3

is different from reproductive women because they lack estrogen, so they have less robust immune activity

Question 4

Monocarboxylate Transporters

Answer 4

MCTs –> symport lactate and H+

- take up lactate –> increase extracellular pH

Question 5

Lactobacillus

Answer 5

gram (+) bacilli –> facultative anaerobe

• can make both L-lactate and D-lactate
• L-lactate is taken up by immune cells through MCTs to make ATP
• D-lactate is not
• Lactate racemase = interconverts 2 forms
• Pyruvate oxidase/glucose oxidase = makes hydrogen peroxide
• Bacteriocins = makes pore in target cell membrane –> depolarization and outflow of cytoplasmic contents

Question 6

Lactobacillus

Answer 6

gram (+) bacilli –> facultative anaerobe

• can make both L-lactate and D-lactate
• L-lactate is taken up by immune cells through MCTs to make ATP
• D-lactate is not
• Lactate racemase = interconverts 2 forms
• Pyruvate oxidase/glucose oxidase = makes hydrogen peroxide
• Bacteriocins = makes pore in target cell membrane –> depolarization and outflow of cytoplasmic contents

Question 7

Bacterial Vaginosis

Answer 7

not caused by single pathogen –> disruption of normal vaginal flora (decrease in lactobacilli, increase in other anaerobes)

• Gardnerella is most abundant in BV
• can progress to ascending infection
• tx = metronidazole

Question 8

Pelvic Inflammatory Disease

Answer 8

infection/inflammation of upper genital tract
- ab pain, discharge
- clue cells, hyphae, trichomoniasis (not really a single agent every identified)
Tx = ceftriaxone (Gonorrhea), doxycycline (chlamydia)

Question 9

Toxic Shock Syndrome

Answer 9

fever, diffuse rash, hypotension, organ dysfunction
Staph aureus (tampon use) - gram (+) cocci --> clusters of grapes --> catalase (+) -> coagulase (+)
SUPERANTIGEN - bind both TCR and MHC II --> create immunological synapse without specificity --> activation of all T cells regardless of specificity --> immune response against everything

Question 10

TSST-1

Answer 10

toxin from staph aureus responsible for toxic shock syndrome

• occurs because of pathogenicity island (SaPI1) –> encoded by non-essential gene so it is present in some staph but not others
• spread but phage transduction –> benign community can become pathologic very quickly

Question 11

Penis microbiome

Answer 11

similar to vaginal –> dominated by lactobacilli

• infection with STI depletes lactobacilli
• most common is neisseria

Question 12

Circumcision effect on microbiome

Answer 12

documented effect on HIV transmission

• also reduces incidence of bacterial vaginosis in partners
• it alters microbial community and increases protection
• the foreskin is not keratinized and is a common site of entry
• other penile skin is keratinized and is protective
• circumcision associated with reduced inflammation and reduced # of macrophages in urethra

Question 13

Epididymitis

Answer 13

usually bacterial infection -> pain, swelling, fever, dysuria
Young boys = E. Coli
Sexually Active = chlamydia, gonorrhea
>35 years = E. Coli and Pseudomonas

Question 14

Prostatitis

Answer 14

not known if prostate has its own microbiome
bacterial prostatitis = infection of prostate
- UTI or STI organisms