Flashcards in weird bacteria Deck (16):
rickettsia rickettsii: clinical presentation, how is it spread, diagnosis, classification, treatment
this causes rocky mountain spotted fever.
presents as a rash that begins on the wrist and ankles, then progresses to the palms and soles, and trunk. this rash is actually due to a vasculitis.
It also presents as fever and headache.
all rickettsia are obligate intracellular ogranizims that need CoA and NAD+ because they can't synthesize ATP. they typically replicate within the cytoplasm. treatment for all rickettsia is doxycycline
may see a positive Weil-Felix test
Erlichiosis: clinical presentation, vector
presents as monocytes with morulae in the cytoplasm
rash is rare
rickettsial disease in which rash is rare.
vector is tick. granulocytes with morulae in the cytoplasm
typhus: types, spread, rash
endemic: spread by fleas and caused by R. typhi
epidemic: spread by human body louse and caused by R. prowazekii.
rash starts centrally and spreads out. spares palms and soles.
Lyme disease: manifestations, transmission, tx
1. erythema chronicum migrans
2. CNS involvement (Bell's palsy- distinguish from stroke by asking pts to raise eyebrows, aseptic meningitis, peripheral neuropathy); CV (carditis or AV block), secondary lesions, migratory myalgias and transient arthritis
3. chronic arthritis, encephalopathy.
carried by mice and spread by the Ixodes tick.
tx: doxycycline for stage 1.
ceftriaxone for later stages, esp. those with cardiac or neuro involvement.
mycoplasma pneumoniae: presentation, dx,
causes atypical pneumonia with insidious onset, non-productive cough, and a diffuse patchy infiltrate. CXR often looks worse than the patient does. May cause transient anemia. most common in pts under 30 and in military recruits and prisons.
Dx: cold hemaglutination with IgM. The cold agglutinins can agglutinate or lyse RBCs. grown on Eaton agar with cholesterol. Bacteria have no cell wall.
tx: macrolide, doxycycline, or fluroquinolone
chlamydia trachomati serotypes; tx, special features of the bug
A-C: chronic conjunctivitis. seen especiallly in africa and causes blindness (ABC = africa, blindness, chronic)
D-K: urehtritis, PID, neonatal pneumonia, neonatal conjunctivitis, reactive arthritis
L1-L3: lymphogranuloma venereum: small, painless genital ulcers that progress to swollen, painful inguinal lymph nodes that
special features: obligate intracellular, cell wall lacks muramic acid. elementary bodies are infectious and enter via endocytosis; reticular bodies do replication. replicates within inclusion bodies.
tx: one time azithromycin; doxycycline for lymphogranuloma venereum.
chlamydia pneumoniae: disease, treatment
causes atypical pneumonia. community acquired. has the elementary body and the reticular body just like C. trachomatis. tx: doxycyline
treponema pallidum: presentation
primary: painless chancer
secondary: condyloma lata (warty stuff on genitals), meningitis, arthritis, maculopapular rash on palms and soles.
tertiary: gummas, aortitis, tabes dorsalis, argylle robertson pupil.
congenital: CN VIII deafness, mulberry molars, saber shins, saddle nose, and hutchinson's incisors. usually transmitted after the 1st trimester.
treponemia diagnosis and false positives; treatment
dark field microscopy, VDRL that detects abs against cardiolipin or RPR, FTA-ABS (specific antibodies against treponema)
VDRL false positives: mono, hepatitis, drugs, rhematic fever, lupus, leprosy
tx: penicillin G
lysis of teponeme due to treatment causes release of endotoxin-like factors and fever, chills, and myalgias.
coxiellar burnetti: disease, spread, dx, tx
causes Q fever: an atypical pneumonia. No rash.
this is a type of rickettsia.
often seen in ppl with contact with cattle, sheep, or goats, esp. cattle placenta. survives as a spore and is inhaled. No arthropod vector (unlike other rickettsia).
Weil-Felix test is negative (unlike other rickettsia).
1. leptospirosis: flu, jaundice, and photophobia
2. weil's syndrome: a vasculitis that causes jaundice and azotemia from liver and kidney dysfunction, fever, hemorrhage, and anemia.
spread by water contaminated with animal urine. often seen in tropics and surfers.
this is a spirochete disorder
treat with penicillin G.
TB virulence factor and TB lung diseases; dx.
cord factor inhibits macrophage maturation and induces release of TNF-alpha.
sulfatides inhibit phaoglysosomal fusion.
may detect Gohn complex (calcified pulmonary tubules + hilar lymph nodes). may stread to other sites by lymphatics and blood.
can also look at IFN-gamma released by lymphocytes exposed to MTB antigens (quantiferon Gold assay)
common extra-pulmonary sites of TB
CNS, vertebral bodies, kidneys, GI, pericarditis, lymph ndues