OBLIGATE INTRACELLULAR ARTHROPOD-BORNE BACTERIA

Question 1

Family
Rickettsiaceae

Answer 1

• Rickettsia sp.
• Orientia sp.

Question 2

Family
Anaplasmataceae

Answer 2

• Ehrlichia sp.
• Anaplasma sp.

Question 3

Family
Coxiellaceae

Answer 3

• Coxiella burnetti

Question 4

Rickettsia and Orientia

Answer 4

• gram negative coccobacilli
• Culture Medium: yolk sac of embryonated eggs, cell cultures
• grouped based of their clinical features, epidemiologic aspects, and
  immunologic characteristics

Question 5

Rickettsia and Orientia Pathogenesis

Answer 5

• multiply in endothelial cells of small blood vessels and produce
  vasculitis characterized by lymphocytes that surround the blood
  vessels
• Cells become swollen and necrotic.
• There is thrombosis of the vessel, leading to rupture and necrosis.
• Vascular lesions are prominent in the skin, but vasculitis occurs in
  many organs.
• Disseminated intravascular coagulation and vascular occlusion may develop.

Question 6

Rickettsia and Orientia Clinical Findings

Answer 6

• fever
• headache
• malaise
• prostration
• skin rash
• hepatosplenomegaly

Question 7

Rickettsia prowazekii

Answer 7

epidemic typhus (louse-borne typhus)
brill-zinsser disease

Question 8

Rickettsia typhi

Answer 8

murinr typhus, endemic typhus, flea borne typhus

Question 9

Orientia tsutsugamushi

Answer 9

scrub typhus

Question 10

rickettsia rickettsii

Answer 10

rocky mountain spotted fever

Question 11

rickettsia conorii

Answer 11

fievre boutonneuse
mediterranean spotted fever
israeli spotted fever
south african tick fever
(kenya) tick typhus
indian tick typhus

Question 12

rickettsia sibirica

Answer 12

siberian tick typhus
north asian tick typhus

Question 13

rickettsia akari

Answer 13

rickettsial pox

Question 14

rickettsia australis

Answer 14

queensland tick typhus

Question 15

Ehrlichia and Anaplasma

Answer 15

• gram-negative bacteria
• Pathogenesis:
• infect leukocytes, erythrocytes, and platelets, where they multiply within
  phagocytic vacuoles, forming clusters with inclusion-like appearance called
  morulae
• resemble Chlamydia in that both are found in intracellular vacuoles but differ in that they are able to synthesize ATP
• Clinical Findings: Ehrlichiosis
• fever, chills, headache, myalgia, nausea or vomiting, anorexia, and weight loss

Question 16

erlichia chaffeensis

Answer 16

human monocyte ehrlichiosis

Question 17

anaplasma phagocytophilum

Answer 17

human granulocyte anaplasmosis

Question 18

ehrlichia ewingii

Answer 18

ewingii ehrlichiosis

Question 19

Coxiella burnetti

Answer 19

• gram-negative cell wall but cannot be stained
• Clinical Findings: Q Fever
• associated with goats, sheep, dairy cattle, or parturient cats
• Acute: resembles influenza, nonbacterial (atypical) pneumonia, and hepatitis
• Chronic: more than 6 months; infective endocarditis