Micro 11 - Nonstaining Bacteria

Question 1

What is the treatment for Bacterial vaginosis?

Answer 1

Metronidazole cream or oral.

Question 2

What bacterias cause bacterial vaginosis?

Answer 2

Gardnerella vaginalis, mobiluncus, Bacteroides, Mycoplasma.

Question 3

Why are Ricjettsiae organisms hard to stain?

Answer 3

Because they are obligate intracellular organisms.

Question 4

What is the Rickettsial triad that all Rickettsial spp. Cause?

Answer 4

Headache, fever, rash. Except Ehrlichiosis and Q fever (no rash).

Question 5

What is the treatment for Rickettsiae spp.?

Answer 5

Doxycycline.

Question 6

Which bacteria causes Endemic typhus and which one causes Epidemic typhus?

Answer 6

Endemic typhus is caused by Rickettsia typhi by rat fleas. Epidemic typhus is caused by Rickettsia prowazekii by human body lice.

Question 7

What is the difference between endemic an epidemic?

Answer 7

Endemic: Exists in the population. Epidemic: Very sudden onset in the population.

Question 8

What is the difference of the rash seen in R.rickettsii and R.typhi and R.prowazekii?

Answer 8

The rash from R.rickettsii starts on hands and feet and moves inward. R.typhi and R.prowazekii start centrally and spread outward and do not affect soles and palms.

Question 9

What are the symptoms of Q fever and how is it spread?

Answer 9

Caused by Coxiella burnetii. It causes fever and interstitial pneumonia. It is spread by inhaled aerosols, tick feces and cow placenta spores (it is a spore-former).

Question 10

What is the Weil-Feliz reaction?

Answer 10

Rickettsial infections have antibodies against Rickettsia. Anti-rickettsial antibodies cross-react and agglutinate, causing a positive Weil-Felix reaction.

Question 11

What is would the Weil-Felix reaction be in a Coxiella infection?

Answer 11

Negative.

Question 12

What does Chlamydophila pneumoniae cause?

Answer 12

Atypical pneumonia. It is transmitted by aerosols.

Question 13

What are the three organisms that cause atypical pneumonia?

Answer 13

Legionella pneumophila, Chlamydophila pneumoniae, Mycoplasma pneumoniae.

Question 14

What is the treatment for Chlamydophila pneumoniae?

Answer 14

Doxycycline as first treatment. If not sure, then use azithromycin.

Question 15

What does Chlamydia trachomatis cause?

Answer 15

Reactive arthritis, conjunctivitis, urethritis, PID.

Question 16

What are the serotypes of Chlamydia trachomatis and what do they cause?

Answer 16

Types A,B,C cause chronic eye infection called Trachoma which can lead to blindness (prevalent only in Africa). Types D to K, causing urethritis, PID, Ectopic pregnancy (from scarring of the fallopian tubes), neonatal penumonia and conjunctivitis (from passage of the birth canal). Often subclinical. Types L1, L2, L3 cause lymphogranuloma venereum; acute lymphadenitis, starts with ulcer and inguinal lymphadenitis fro 2-6 weeks. Can cause rectal disease, (may be mistaken for IBD).

Question 17

Why can we not stain Mycoplasma pneumoniae?

Answer 17

Because it does not have cell wall.

Question 18

Which is the only bacteria that contains cholesterol?

Answer 18

Mycoplasma pneumoniae.

Question 19

What does mycoplasma pneumoniae cause?

Answer 19

Causes Atypical (interstitial) pneumonia AKA walking pneumonia (insidious onset: headache, nonproductive cough, diffuse interstitial infiltrate). It is subclinical. CXR looks worse than the patient. Causes High titer of cold agglutinins (IgM antibodies that agglutinate or lyse RBCs only in cold environments).

Question 20

What is the treatment for mycoplasma pneumoniae?

Answer 20

Macrolides (like azithromycin).

Question 21

Who are more likely to be infected by mycoplasma pneumoniae?

Answer 21

Patients younger than 30, frequent outbreaks in military recruits and prisons.

Question 22

A young adult patient w/ Mycoplasma atypical pneumonia exhibits anemia due to cryoagglutinins. What type of immunoglobulins are responsible for the anemia?

Answer 22

IgM antibodies.

Question 23

A homeless, alcoholic patient vomited while intoxicated and subsequently developed foul-smelling sputum. What organism is most likely causing his infection?

Answer 23

Klebsiella pneumoniae.

Question 24

Which antibiotic should be used for Mycoplasma pneumoniae?

Answer 24

Tetracycline or macrolides (azithromycin).

Question 25

Which antibiotic should be used for Rocky Mountain Spotted fever?

Answer 25

Doxycycline.

Question 26

Which antibiotic should be used for bacterial vaginosis?

Answer 26

Metronidazole.

Question 27

What does Gardnerella vaginalis cause?

Answer 27

Causes Bacterial vaginosis: gray vaginal discharge with a fishy smell. Causes Clue cells (vaginal squamous epithelium covered in bacteria.)