Rickettsia!!! MICROM442 DECK 13 Flashcards
GM?
GM-
type of organism?
intracellular and obligate
transmission via
arthropod vectors
genera
-spotted fever group -> Rickettsia rickettsii
-typhus group -> R. prowazekii, R. felis, and R. typhi
-ehrlichiacease -> E. chaffeensis, Anaplasma phagocytophilum
Rickettsia rickettsii
(Rocky Mountain Spotted Fever)
transmitted via tick bites, likes to live in dogs and ticks
Rickettsia rickettsii pathogenesis
¤ Enter circulation through tick bite
¤ Attach to and invade vascular endothelial cells
¤ Small genome, but capable of independent metabolism
¤ Intracellular motility and cell to cell spread via actin-based motility
¤ Injury to host cell results in increased vascular permeability
Rickettsia rickettsii Sx
-Fever, muscle pain, severe headache, nausea
and vomiting
-Maculopapular (raised, red) rash usually
appears on day 3-5
Typhus Group: R. prowazekii, R. typhi,
R. felis
transmitted by HUMAN body lice
R. prowazekii =
epidemic typhus
dx latent?
Patients remain latently infected after recovery
and reactivation of disease may occur years later
typhus group sx
Fever, rigors, severe headache, macular rash
R. typhi and R. felis = flea-borne disease
Cat fleas are the most common vector in US but dogs
are likely the primary reservoir
Ehrlichiosis = tick-borne and it infects?
Bacteria infect leukocytes
(monocytes, macrophages,
granulocytes/neutrophils)
Human monocytic
ehrlichiosis
Human granulocytic
anaplasmosis
