Exam 2: Rickettsia, Chlamydia, and Coxiella Flashcards
What are the 2 genera in the family Rickettsiaceae
- Rickettsia
2. Orientia
_____ are arthropod transmitted parasites of blood cells or endothelial cells and may cause persistent infections
Rickettsia
Small, obligate intracelluular bacteria that reside freely within the cytoplasm of the infected host cell
Rickettsia
T/F rickettsia are Gram positive coccobacilli
F. gram neg.
What are reservoirs for Rickettsia
rodents and sm. mammals
How do animals become infected with rickettsia?
arthropod bite
What are the 2 groups of Rickettsia
- Typhus group (TG)
2. Spotted fever group (SFG)
What are the two spp of ricketsia in the typhus group?
- R. prowazekii
2. R. typhi
Which Spp of rickettsia is isn the Spotted fever group?
R. rickettsii
Rickettsial isolation is performed in BSL __ laboratories
3
Dx of rickettsia
Direct detection
PCR
Serology Culture
Tx of rickettsia
Tetracycline
Doxycycline
Chloramphenicol
Enrofloxacin
Cause of rocky mtn. spotted fever in humans and dogs
R. rickettsia
What is the pathogenecis of R. rickettesia
invades and repicates in endothelial cells of blood vessels, initiating platelet activation
C/S of R. rickettsia
Fever Depression Anorexia SQ Edema Stiff gait
Tx of R. rickettsia
Tetracycline
Type of Rickettsia causing Epidemic typhus, spread by human and flying squirrel luse
R. prowazekii
Type of rickettsia causing murine typhus
R. typhi
What is the cycle of importance for R. typhi spread?
opossum flea cycle
Rikettsia transmitted by the cat flea and causes inapparent infection in the cat
R. felis
What does Rickettsia felis cause in humans?
Flea-borne spotted fever
Rickettsia that is transmitted by chigger mites and causes scrub typhys
orientia tsutsugamshi
Type of rickettsia that infects Farmed fish
Piscirickettsia salmonis
which species of tick transmitts Anaplasma phagocytophilum
Ixodes
What does Anaplasma phagocytophilum cause in dogs
canine granulocytic ehrlichiosis
Anaplasma that causes infectious cyclic thromboytopenia
A. platys
What cells become infected with Anaplasma playts
Platlets
How do you Dx Anaplasma playts
Blood smear
FA
PCR
Tx for Anaplasma playts
Doxycycline
What are the target cells for Anaplasma marginale
Erythrocytes
What ssp of Anaplasma causes anaplasmosis in ruminants?
A. marginale
T/F. Calves are much more resistant to Anaplasma marginale than adults
T
Tx of Anaplasma marginale
Tetracycline and imidocarb
Ehrlichia canis causes what disease in dogs?
Canine monocyclic ehrlichiosis (CME)
What cells does Ehrlichia canis infect?
Forms a cluster of bacteria within the cytoplasm of the monocyte
Ehrlichia canis is transmitted by _____
Rhipichephalus sanguineus (brown dog tick)
What are the two phases of the pathogenesis of CME?
acute and chronic
T/F CME is associated with lymphadenopathy and splenomegaly
T
______ on CBC typifies the severe chronic form of ehrlichiosis due to hypoplasia of alll bone marrow cells
Pancytopenia