Multisystem Infections Flashcards
virulence attributes required to cause multisystem infections
antigenic variation serum resistance cloaking (with host proteins to avoid immune system) cell invasion tissue invasion
How is Lyme disease Borrelia virulent?
recombinatines VIs locus-antigenic variation
Which species binds to, enters, and replicates in the cytoplasm of endothelial cells?
Rickettsia
Which species binds to, enters, and repicates in late endosomes of netorphils
Anaplasma phagocytophilum
Which species binds to , enters and replicates in early endosomes of monocytic cells?
Ehrlichia chaffeensis
Define transstadial transmission
pathogen is transmitted/maintained in the different life stages of the same individual vector
Transovarial transmission
pathogen is transmitted from one vector generation to next generation
Anaplasmosis and Ehrlichiosis vector, stain, location, shape, site of replication
tick gram negative bacilli intracellular replicates in vacuoles
Rocky Mountain spotted fever (Rickettsiosis) vector, stain, location, shape, site of replication
tick gram negative bacilli intracellular replicates in cytoplasm
Lyme disease vector, stain, location, shape, site of replication
tick gram negative spirochete extracellular replicates outside of host cell
Zoonotic infection
I scapularis (lyme disease, anaplasmosis)
Lyme disease occurs most often in what season
summer
I scapularis infections are transmitted usually by what form of the species?
nymph
Ehrlichiosis stain, shape, replication site, special features, invades what type cells
gram negative coccobacilli vacuoles NO LPS OR PEPTIDOGLYCAN type IV secretion invades monocytes, neutrophils
Symptoms of Anaplasmosis and Ehrlichiosis infections
fever, chills headache, myalgia anorexia leukopenia, thrombocytopenia, anemia increased liver aminotransferases
Unique feature of Rickettsia rickettsii
transovarial AND transstadial transmission in ticks
Where are cases of Rocky Mountain spotted fever mostly found?
in the eastern belt Missouri area horizontally
Rickettsia rickettsii stain, shape, site of replication, type of cell invaded
Gram negative
coccobacilli
replicates in the cytoplasm
invades endothelial cells–moves within and to new cells by actin polymerization
Symptoms of Rickettsiosis
fever malaise headache myalgia anorexia abdominal pain nausea RASH 3-5 DAYS AFTER ONSET (begins at ankles, wrists, forehead)
Where is LYme disease frequently seen?
WI, MN, Northeastern US
Borrelia burgdorferi tick infects humans in what form?
Nymph
Borrelia burgdorferi stain, shape, any LPS/toxins/special secretion systems?
gram negative
spirochete
NO LPS, TOXINS, OR SPECIAL SECRETION SYSTEMS
what is special about lyme disease transmission?
it takes more than 36 hours for it to move up gut of tick and into human
Lyme disease symptoms
Early localized: Erythema migrans (bulls eye sometimes ) greater than 5 cm
Early, disseminated: fever, malaise, arthralgia, facial palsy on one side, AV block, polyradiculopathy
Late, in months to years: arthritis, encephalopathy, polyradiculopathy
Diagnosis of Lyme disease
if see EM lesion and tick encounter, enough to start the therapy
if no EM lesion, then can do ELISA and then immunoblot
Why do these vector borne bacterial pathogens have few virulence factors identified?
b/c difficult to grow on culture
How are diagnoses made for these vector borne bacterial infections?
througouh history and clinical suspician, don’t rely on culture, gram stain hard to see
Enzootic cycle of Treponema pallidum
none, no vector, just in humans
Describe primary syphilis
lesion that is painless
Secondary syphilis symptoms
6 weeks to 6 months after primary syphilis
diffuse rash all over, even palms and soles
myalgias, arthralgias
fever
condyloma latum (wart like lesions)
Tertiary syphilis symptoms
tabes dorsalis: sensory and motor neuron fxn loss dementia blindness urinary incontinence joint degeneration aortic aneurysm, valve insufficiency tissue destruction DAMAGE DUE TO HOST'S RESPONSE
These Multisystem infections can cause disease in what hosts?
immunocompetent
These multisystem infections are characterized by what kind of diagnositics?
no culture reliance because difficult to grow
