Lecture 11 - Rickettsia, Chlamydia & Mycoplasma Flashcards Preview

Medical Microbiology > Lecture 11 - Rickettsia, Chlamydia & Mycoplasma > Flashcards

Flashcards in Lecture 11 - Rickettsia, Chlamydia & Mycoplasma Deck (38):
1

How is Rickettsia spread?

Arthropod-spread, Humans are 'accidental hosts'

2

What circumstances do Rickettsia need to survive?

They are obligate intracellular parasites

3

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

True

4

Why are Rickettsia obligate intracellular parasites?

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

5

How is the bacteria spread and its mode of infection?

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)

6

What are symptoms of Rickettsia infection?

Fever, chills, rash and headache

7

What may occur in severe cases of Rickettsia infection?

Can cause vascular damage in multiple organs and tissues

8

Most of the symptoms of Rickettsia are due to what?

LPS flooding blood stream

9

What is the most common and important disease of Rickettsia

Typhus

10

Name the three different Typhus diseases

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

11

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

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

12

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

Epidemic Typhus. We are reservoir or our clothes are.

13

R. prowazekii is associated with what disease?

Epidemic typhus

14

Which of these do Rickettsia have? LPS, Cell Wall

Both

15

What is the treatment for Epidemic Typhus

Sanitation and antibiotics

16

R. Rickettsii can cause what common disease?

Rocky Mountain spotted fever

17

Where are R. Rickettsii infections common?

SE state of U.S.

18

Is Rickettsia local or systemic?

Systemic

19

What circumstances do Chlamydia need to grow and be successful?

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

20

Which of these does Chlamydia have? LPS, Cell Wall

No Cell Wall!!
2 lipid bilayers and LPS are present

21

What are the 3 major species of Chlamydia

C. trachomatis
C. pneumoniae
C. psittaci

22

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

C. psittaci

23

What two important respiratory infections does C. pneumoniae cause?

Bronchitis and Pneumonia

24

What is the most common cause of infectious blindness?

Trachoma

25

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

Trachoma
STI

26

Is C. trachomatis local or systemic

Local

27

Trachoma is common in what age groups?

Children

28

How is Trachoma transmitted?

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

29

What is the treatment for Trachoma?

No vaccine, Prevention is good hygiene

30

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

C. trachomatis

31

What type of infection is C. pneumoniae?

community-acquired respiratory infection

32

How is C. pneumoniae related to atherosclerosis?

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

33

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

Mycoplasma

34

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

None, No Cell wall or LPS

35

What is significant about the cell membrane on Mycoplasma?

Contains sterols. No LPS or Cell Wall

36

What is the major cause of "walking pneumonia"?

M. pneumonia

37

Does penicillin work for mycoplasma treatment?

No, No cell wall

38

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

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