Unit 3- Rickettsiales

Question 1

Anaplasma and Ehrlichia Outer Membrane

Answer 1

Lacks LPS

Question 2

Anaplasma and Ehrlichia Peptidoglycan

Answer 2

Minimal

Question 3

Rickettsia Cell Wall

Answer 3

Classical gram negative LPS on outer membrane and peptidoglycan wall

Question 4

Anaplasma and Ehrlichia Life Forms

Answer 4

Morula within vacuoles in host cell, dense-cored cells extracellularly

Question 5

Rickettsia Intracellular

Answer 5

Only one life form, does not hide in vacuoles

Question 6

Why obligate intracellular?

Answer 6

Highly permeable cytoplasmic membrane, cannot produce sufficient ATP, anaplasma and ehrlichia dependent on cholesterol

Question 7

Host Ranges

Answer 7

Vertebrate hosts but arthropod transmission

Question 8

Anaplasma and Ehrlichia Transmission

Answer 8

Ticks

Question 9

Spotted Fever Group

Answer 9

Rickettsia transmitted by Dermacentor ticks

Question 10

Ancestral Group

Answer 10

Rickettsia transmitted by tick

Question 11

Typhus Group

Answer 11

Rickettsia transmitted by body lice and fleas

Question 12

Transitional Group

Answer 12

Rickettsia transmitted by ticks, mites, and fleas

Question 13

Arthropod Transmission

Answer 13

Injected by arhtropods into or near blood stream

Question 14

Tick Life Cycle

Answer 14

Larvae, nymphs, and adults all take blood meal on different hosts, risk of transovarian or transstadial transmission of pathogen

Question 15

Medically Important Ticks

Answer 15

Brown dog tick, lone star tick, American dog tick, eastern black legged tick

Question 16

Anaplasma Cell Predilecition

Answer 16

RBC, platelets, WBC

Question 17

Ehrlichia Cell Predilection

Answer 17

WBC, endothelial

Question 18

Rickettsia Cell Predilection

Answer 18

Endothelial cells

Question 19

Cell Predilection in Arthropods

Answer 19

Midgut cells and salivary glands

Question 20

Anaplasma Destroying RBC

Answer 20

A. marginale, centrale, and ovis

Question 21

Anaplasma in RBC and WBC

Answer 21

A. bovis

Question 22

Anaplasma Destroying Neutrophils

Answer 22

A. phagocytophilum

Question 23

Anaplasma Destroying Platelets

Answer 23

A. platys

Question 24

Ehrlichia Destroying Phagocytes

Answer 24

E. chaffeensis, ewingii, and canis

Question 25

Zoonotic Ehrlichia

Answer 25

E. chaffeensis and ewingii

Question 26

Ehrlichia Destroying Endothelium

Answer 26

E. ruminatum

Question 27

Human and Rodent Rickettsia

Answer 27

R. prowazekii, typhi, akari, and Orentia tsutsugamushi

Question 28

Human and Pet Rickettsia

Answer 28

R. ricketsii and felis

Question 29

Rocky mountain spotted fever

Answer 29

R. ricketsii and felis

Question 30

Anaplasma and Ehrlichia Virulence Factors

Answer 30

Adhesion, internalization, morula formation, replication and lysis of blood cells

Question 31

Rickettsia Virulence Factors

Answer 31

Adhesion, internalization, replication and lysis of endothelial cells

Question 32

Anaplasma Clincial Signs

Answer 32

Fever, weakness, muscle pain, anemia, jaundice, leukopenia, thrombocytopenia

Question 33

Ehrlichia Clincial Signs

Answer 33

Fever, weakness, muscle pain, anemia, leukopenia, thrombocytopenia, vasculitis

Question 34

Rickettsia Clinical Signs

Answer 34

Disseminated endothelial infection of all organs, fever, vasculitis, skin bleeding, nose bleeding, hemorrhage, organ failure

Question 35

Gold Standard Test

Answer 35

Indirect immunofluorescent IgG antibody assay

Question 36

Culture

Answer 36

Requires live cell lines, tick cell lines, mammalian endothelial cell, or human leukemia cell line

Question 37

Rickettsia Serology

Answer 37

Similar LPS to Proteus

Question 38

Well-Felix Test

Answer 38

Mix patient seerum with Proteus antigens for cross reaction

Question 39

Control

Answer 39

Prophylactic antibiotics, break transmission cycle, kill arthropods, reduce stress

Question 40

Treatment

Answer 40

Doxycycline