Skildum

Question 1

What is the environment of the vagina normally?

Answer 1

Anaerobic

Question 2

In 80% of healthy women, what microorganism dominates the vaginal flora?

Answer 2

Lactobacilli

Question 3

What is the gram staining and morphology of lactobacilli?

Answer 3

Gram positive rods; facultative anaerobes

Question 4

What are the products of lactobacilli?

Answer 4

Lactic acid (decreases pH), hydrogen peroxide, bacteriocins

Question 5

What organism produces lactocin 160?

Answer 5

L rhamnosus

Question 6

The vaginal microbial community depends on what hormone?

Answer 6

Estrogen

Question 7

How is lactate transported into cells?

Answer 7

MCTs

Question 8

What sterioisomer of lactate is taken up by MCTs?

Answer 8

L-lactate

Question 9

What is transported with lactate through the MCT?

Answer 9

H+

Question 10

What is the function of lactate racemase?

Answer 10

Interconverts L and D lactate

Question 11

What is the function of the enzyme pyruvate oxidase in lactobacilli?

Answer 11

Makes H2O2 from pyruvate; detoxifies of O2; helps maintain anaerobic environment

Question 12

What is produced by the enzyme glucose oxidase in lactobacilli?

Answer 12

Takes glucose and makes D-gluconolactone; a by product from this reaction is H2O2 (again another detoxification process)

Question 13

What enzymes are used by lactobacilli for detoxification of O2?

Answer 13

Pyruvate oxidase and glucose oxidase

Question 14

What is the most abundant bacteria in healthy women?

Answer 14

L. Iners

Question 15

What is the function of bacteriocins produced by lactobacilli?

Answer 15

For pores in target cell membranes

Question 16

What bacteroicin disrupts the cell wall in gram positive bacteria?

Answer 16

Lysostaphin

Question 17

What bacteriocin forms pores in cell membrane and disrupts the peptidoglycan transfer to the cell wall?

Answer 17

Nisin (class I)

Question 18

In 20% of healthy women, lactobacilli are not present. What bacteria are predominant in these women? What is different about their vagina?

Answer 18

Atopobium, corynebacterium, anaerococcus, gardnerella; pH is slightly higher 5.3-5.5

Question 19

What organism is responsible for bacterial vaginosis?

Answer 19

Gardnerella vaginalis

Question 20

Bacterial vaginosis is associated with increasing concentration of what organisms?

Answer 20

Gardnerella vaginalis, mycoplasma hominis, mobiluncus sp. atopobium vaginae

Question 21

What is Amsel criteria?

Answer 21

Used to diagnose BV; 3/4 = BV

Question 22

What are the criteria of Amsel criteria?

Answer 22

Increased homogenous thin vaginal discharge; pH of the secretion greater than 4.5; amine odor when KOH is added; presence of clue cells in wet preparations

Question 23

If small gram variable rods are in abundance in the vaginal secretions, according to Nugent score what does this mean?

Answer 23

G. Vaginalis

Question 24

How does BV stick to epithelial cells?

Answer 24

Forms biofilms on the epithelial surface

Question 25

What is used to treat BV?

Answer 25

Metronidazole

Question 26

Metronidazole requires what type of environment for treatment?

Answer 26

Anaerobic; metronidazole can only be reduced to its active form in anaerobic organisms

Question 27

What is the MOA of metronidazole?

Answer 27

Metronidazole is reduced by pyruvate:feredoxin oxidoreductase - interferes with bacterias fuel metabolism and generates reactive nitrogen

Question 28

What effect does PID have on the epithelium of fallopian tubes?

Answer 28

Loss of ciliated epithelial cells; can result in infertility or ectopic pregnancy

Question 29

What organism causes PID and is tiny, lacks a cell wall and requires cholesterol in growth media?

Answer 29

M genitalium

Question 30

What gram negative coccobacilli can cause PID?

Answer 30

Hemophilus influenza

Question 31

What two organisms may accompany neisseria of chlamydia in PID?

Answer 31

H influ; S pyogenes

Question 32

What is the MOA of doxycycline?

Answer 32

Binds 30s ribosome and prevents tRNA binding; prevents protein synthesis

Question 33

What is the gram stain and morphology of S aureus?

Answer 33

Gram positive cocci that grow in clusters; catalase positive coagulase positive, non-motile; facultative anaerobe

Question 34

What is the importance of coagulase in S aureus?

Answer 34

Promotes fibrin activation and therefore wall that protects bacteria

Question 35

What pathogenicity island is associated with TSST-1 production?

Answer 35

SaPI1

Question 36

How is SapI1 spread?

Answer 36

Phage transduction

Question 37

What organism is the penile flora predominated by?

Answer 37

Lactobacillus

Question 38

Where is the most common site of viral entry?

Answer 38

The urethra and inner foreskin

Question 39

What is part of the issue with having a foreskin and the increased susceptibility to STI infection?

Answer 39

The inner foreskin is non-keratinized, making it easier for pathogens to penetrate

Question 40

What benefits does circumcision have?

Answer 40

Removes non-keratinized epithelium; shifts microbial community to aerobic bacteria which reduced inflammation and reduces the number of CD4+/CCR5+ macrophages in the urethra