Lecture 11 - Rickettsia, Chlamydia & Mycoplasma

Question 1

How is Rickettsia spread?

Answer 1

Arthropod-spread, Humans are ‘accidental hosts’

Question 2

What circumstances do Rickettsia need to survive?

Answer 2

They are obligate intracellular parasites

Question 3

T or F, Rickettsia are small, stain poorly with gram stain and are gram negative coccobacilli

Answer 3

True

Question 4

Why are Rickettsia obligate intracellular parasites?

Answer 4

They lack many of the enzymes required to produce amino acids and thus depend on host derived AA.

Question 5

How is the bacteria spread and its mode of infection?

Answer 5

Infected tick, mite, louse or flea defecates as it eats its blood meal
Person itches the site which brings feces and bacteria in contact with wound
Bacteria enter blood stream and infects endothelial cells
Replicate slowly, affect adjacent endothelial cells, kil them and cause local blockage of blood flow (Rash)

Question 6

What are symptoms of Rickettsia infection?

Answer 6

Fever, chills, rash and headache

Question 7

What may occur in severe cases of Rickettsia infection?

Answer 7

Can cause vascular damage in multiple organs and tissues

Question 8

Most of the symptoms of Rickettsia are due to what?

Answer 8

LPS flooding blood stream

Question 9

What is the most common and important disease of Rickettsia

Answer 9

Typhus

Question 10

Name the three different Typhus diseases

Answer 10

1. Epidemic Typhus
2. Endemic Typhus
3. Scrub Typhus

Question 11

What vectors are associated with each of the three typhus diseases?

Answer 11

Epidemic Typhus - Louse
Endemic Typhus - Flea
Scrub Typhus - Mite

Question 12

Which of the three typhus diseases is unique and have humans as the reservoir?

Answer 12

Epidemic Typhus. We are reservoir or our clothes are.

Question 13

R. prowazekii is associated with what disease?

Answer 13

Epidemic typhus

Question 14

Which of these do Rickettsia have? LPS, Cell Wall

Answer 14

Both

Question 15

What is the treatment for Epidemic Typhus

Answer 15

Sanitation and antibiotics

Question 16

R. Rickettsii can cause what common disease?

Answer 16

Rocky Mountain spotted fever

Question 17

Where are R. Rickettsii infections common?

Answer 17

SE state of U.S.

Question 18

Is Rickettsia local or systemic?

Answer 18

Systemic

Question 19

What circumstances do Chlamydia need to grow and be successful?

Answer 19

They are obligate intracellular parasites. They are energy parasites and steal ATP from host cell.

Question 20

Which of these does Chlamydia have? LPS, Cell Wall

Answer 20

No Cell Wall!!

2 lipid bilayers and LPS are present

Question 21

What are the 3 major species of Chlamydia

Answer 21

C. trachomatis
C. pneumoniae
C. psittaci

Question 22

Which of the three major species of chlamydia is a bird pathogen?

Answer 22

C. psittaci

Question 23

What two important respiratory infections does C. pneumoniae cause?

Answer 23

Bronchitis and Pneumonia

Question 24

What is the most common cause of infectious blindness?

Answer 24

Trachoma

Question 25

C. trachomatis has two important and serious disease. What are they?

Answer 25

Trachoma | STI

Question 26

Is C. trachomatis local or systemic

Answer 26

Local

Question 27

Trachoma is common in what age groups?

Answer 27

Children

Question 28

How is Trachoma transmitted?

Answer 28

Transmitted eye-to-eye by tears, hands and flies

Question 29

What is the treatment for Trachoma?

Answer 29

No vaccine, Prevention is good hygiene

Question 30

What is the most common bacterial STI in the U.S.

Answer 30

C. trachomatis

Question 31

What type of infection is C. pneumoniae?

Answer 31

community-acquired respiratory infection

Question 32

How is C. pneumoniae related to atherosclerosis?

Answer 32

Clear association but role is unclear. Thought that chlamydia directs cells to produce lipids at 5x the normal rate

Question 33

What bacteria is the smallest self-replicating organisms with smallest genomes?

Answer 33

Mycoplasma

Question 34

Which of these does Mycoplasma have? LPS, Cell Wall?

Answer 34

None, No Cell wall or LPS

Question 35

What is significant about the cell membrane on Mycoplasma?

Answer 35

Contains sterols. No LPS or Cell Wall

Question 36

What is the major cause of "walking pneumonia"?

Answer 36

M. pneumonia

Question 37

Does penicillin work for mycoplasma treatment?

Answer 37

No, No cell wall

Question 38

What sets M. pneumonia a part from Chlamydia and Rickettsia?

Answer 38

M. pneumonia is an Extracellular pathogen whereas the other two are obligate intracellular parasites