Bacterial Vaginosis and Yeast

Question 1

Vaginitis?

Answer 1

Inflammation of the vaginal epithelium

Question 2

Chlamydia and gonorrhea usually present how?

Answer 2

Cervicitis - inflammation of the endocervix with mucopurulent discharge

This is the case unless the female is pre-pubescent or post menopausal.

Question 3

Besides cervicitis, how can chlamydia and gonorrhea present?

Answer 3

Urethritis with mucopurulent discharge. We see this in men and women.

Question 4

Vaginosis?

Answer 4

Distinct syndrome of vaginal irritation, pruritis, and odor generally without a PMN response (this is key)

Question 5

Candidiasis?

Answer 5

Inflammation associated with overgrowth of the yeast Candida Albicans

Question 6

Trichomoniaisis??

Answer 6

Vaginal inflammation associated with infection by Trichomonas vaginalis

Question 7

What sign and symptoms do we associate with Bacterial Vaginosis?

Answer 7

• Lower abdominal pain
• Pruritis
• Red vaginal wall and labia
• Thin grayish/white discharge
• Odor

Question 8

There is significant impact on reproductive health with Bacterial Vaginosis. What are they?

Answer 8

• Preterm delivery
• Increased fetal mortality
• Postpartum infection
• Post surgical infection
• Increased risk of STDS

Question 9

Bacterial vaginosis is significant in effect due to the imbalance of normal flora. What causes this imbalance?

Answer 9

• Change in hormone status (high estrogen favors lactobacillus colonization)
• Change in sexual activity
• Antibiotic therapy/douching that alters normal flora

Question 10

What microbiology do we see with bacterial vaginosis, secondary to these imbalances?

Answer 10

• Lots of lactobacilli, proliferation of other anaerobes
• Increased Mobiluncus species (anaerobe)
• Increased gardnerella vaginalis (facultative anaerobe)

Question 11

Describe these numerous lactobacilli we see under histology

Answer 11

Large or pleomorphic gram POSITIVE rods

• Produce acid by fermentation
• Produce H2O2

Question 12

Discuss the diagnostic findings for BV

Answer 12

• Elevated vaginal pH (normally 4-4.5)
• Clue cells (epithelial cells coated with small gram + rods accompanied by infrequent inflammatory cells)
• Amine odor (Whiff test with 10% KOH)
• Culture positive for Gardnerella vaginalis (beta hemolytic susceptible to metronidazole disk)

Question 13

Symptoms of yeast infection and how we distinguish it from BV

Answer 13

• Vulvo-vaginal itching
• Discharge (thick, white)
• Burning on urination

Difficult ti distinguish. Yeast are not pH sensitive (they like the acid) and will have hyphae on staining.

Question 14

What is the structure of trichomonas vaginalis? How does it replicate? How do we describe it?

Answer 14

• Flagellated protozoan that is an aerotolerant anaerobe

- Replicates by binary fission (no cyst stage)

Question 15

BV and Trichomoniasis have many similarities. However, they have one important difference. What is it?

Answer 15

They both increase vaginal pH, disturb the normal flora, give similar symptoms of abdominal pain and itching and discharge, and both cause similar reproductive risks of premature birth, post partum complications and increased risk of other STDs.

HOWEVER, Trichomoniasis gives us an inflammatory response.

Question 16

Link HIV to the inflammatory response in Trichomoniasis:

Answer 16

• Intense cell mediated response causes recruitment of CD4+ lymphocytes susceptible to HIV.
• Presence of pinpoint hemorrhaging in vaginal mucosa increases access of virus to host
• T. vag degrade secretory leukocyte protease inhibitor (a product known to block HIV cell attachment)
• Trichomonas infection increases shedding of HIV in women and men

Question 17

We have this T-cell mediated response to Trichomonas! Yay! That means we can develop protective immunity right?!

Answer 17

Nope.

Reinfection with other strains occurs due to phase variation among T. vaginalis surface molecules (cysteine proteases and adhesins).

Phase variation in surface antigens is augmented by T. vaginalis infection with dsRNA viruses.

Proteinases are produced that digest antibodies.

Question 18

How do we diagnose Trichomoniasis?

Answer 18

• Visualize motile protozoans on wet mount
• Dip stick
• PCR
• Cx - 48-72 hours

Question 19

Treating Trichomonas

Answer 19

You guessed it, metronidazole.

Question 20

Alright so we seem to keep using this metronidazole thing. Describe its structure and how it works

Answer 20

Imidazole ring is a prodrug activated by reduction reactions, then attacking DNA. Due to the need for reduction, it works best where redox potential is really low, like with anaerobic bacteria and anaerobic protozoans like Trichomonas which have an organelle “hydrogenosome,” where anaerobic respiration occurs.