Rickettsia, chlamydia, and mycoplasma pneumoniae

Question 1

What is the treatment for all Rickettsial diseases and vector-borne illnesses?

Answer 1

Doxycycline

Question 2

Causative agent for Rocky Mountain Spotted Fever?
Vector for agent?
Geographical location for RMSF?

Answer 2

Rickettsia rickettsii
Tick
Occurs mostly in Southern Atlantic states, especially North Carolina

Question 3

RMSF rash progression

Answer 3

starts at wrist and ankles and then spreads to trunk, palms, and soles

Question 4

Rickettsiae are what kind of organisms?

Require which cofactors (2)? Why?

Answer 4

Rickettsiae are obligate intracellular organisms
Require CoA and NAD+
Cannot synthesize their own ATP

Question 5

Classic triad associated with RMSF?

Answer 5

Headache
Fever
Rash (caused by vasculitis)

Question 6

“Palms and soles rash” are usually seen in which in which disease states?
“you drive CARS with your PALMS and SOLES”

Answer 6

Coxsackievirus A
RMSF
Secondary Syphilis

Question 7

Causative agent of endemic typhus? Vector?

Causative agent of epidemic typhus? Vector?

Answer 7

R. typhi causes ENDEMIC typhus. Fleas.

R. prowazekii causes EPIDEMIC typhus. Human body louse

Question 8

Where does the rash occur for Rickettsi and Typhus?

Answer 8

“Rickettsii on the wRists…Typhus on the Trunk”

Question 9

Causative agent for Ehrlichiosis?
Vector?
What to look for on microscopy?

Answer 9

Ehrlichia
Vector is the tick
Look for monocytes with morulae (berry-like inclusions) in the cytoplasm

Question 10

Causative agent for Anaplasmosis?
Vector?
What to look for on microscopy?

Answer 10

Anaplasma
Vector is the tick
Granulocytes with morulae in cytoplasm

Question 11

Causative agent for Q fever?
Vector? (this is a trick question)
How is one exposed to the disease?

Answer 11

Coxiella burnetii
No arthropod vector
Tick feces and cattle placenta release spores that are inhaled as aerosols

Question 12

How does Q fever present?

Answer 12

As pneumonia

Question 13

What is queer about Q fever?

Answer 13

It has no rash or vector and its causative organism can survive outside in its endospore form

Question 14

Is chlamydia intracellular or extracellular organism? Why?

Answer 14

Obligate intracellular organism because they cannot make their own ATP

Question 15

What are the two forms of chlamydia?

Answer 15

Elementary bodies

Reticular bodies

Question 16

What is an elementary body? What does it look like? And what does it do?

Answer 16

Elementary chlamydia bodies are small, dense, and INFECTIOUS. Enter the cell via Endocytosis.
Transformers into reticular bodies

Question 17

What is a reticular body? And what does it do?

Answer 17

Replicates in the cell by FISSION. Reorganizes into elementary bodies

Question 18

Chlamydia trachomatis causes what? (4)

Answer 18

1. Reactive arthritis (Reiter syndrome)
2. Follicular conjunctivitis
3. Nongonococcal urethritis
4. PID

Question 19

C. pneumoniae and C. psittaci cause what? How are they transmitted?

Answer 19

They cause aytpical pneumonia.

Transmitted via aerosols

Question 20

How to treat chlamydia? 2

Answer 20

Azithromycin–1 time treatment

Doxycycline

Question 21

What do chlamydia serotypes A, B, and C cause?

Answer 21

Chronic infection &
Blindness due to follicular conjunctivitis
in Africa
ABCs: Africa/Blindness/Chronic infection

Question 22

What do chlamydia serotypes D-K cause? 4

Answer 22

1. Urethitis/PID
2. Ectopic pregnancy
3. Neonatal pneumonia (staccato cough)
4. Neonatal conjunctivitis

Question 23

Best way to remember chlamydia serotypes D-K?

Answer 23

D-K cause everything else

Question 24

How is the neonatal disease transmitted?

Answer 24

Passage through infected birth canal

Question 25

What do chlamydia serotypes L1, L2, and L2 cause?

Answer 25

Lymphogranuloma venereum

Question 26

What in the hell are Lymphogranuloma venereum? What do they lead to

Answer 26

Small, painless ulcers on the genitals that cause swollen painful lymph nodes that eventually ulcerate.
The ulcerated LNs are known as “buboes”

Question 27

What does mycoplasma pneumonia cause? How does it present

Answer 27

1. Classic cause of atypical “walking pneumonia”

2. Insidious onset with HA, non-productive cough, and patchy or diffuse interstitial infiltrate

Question 28

How does the x-ray of mycoplasma pneumonia compare to the patient?
On which agar is m. pneumoniae cultured?

Answer 28

1. The xray looks worse than the patient does

2. Eaton agar

Question 29

How does mycoplasma pneumoniae predispose to lysed or aggultinated RBCs?

Answer 29

M. pneumoniae creates a high titer of cold agglutinins (IgM) which can agglutinate or lyse RBCs

Question 30

What can treat m. pneumoniae? (3) What can’t…and why not? (1)

Answer 30

Macrolide, doxycycline, or flurorquinolone.

PCN ineffective because mycoplasma does not have a cell wall

Question 31

1. Best way to stain m. pneumoniae?

2. What gives the membrane of m. pneumoniae stability

Answer 31

1. No cell wall so it doesn’t Gram stain. Use acid fast

2. Membrane contains sterols for stability

Question 32

M. pneumoniae is common in which patient age?

Frequent outbreaks in what kind of populations? (2)

Answer 32

1. Patients