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Borrelia
Gram-P/N?
Shape?
Gram-N spirochetes
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Rickettsia, Ehrlichia, Orientia, Anaplasma, and Coxiella are all
obligate intracellular parasites
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Name 5 obligate intracellular parasites
Rickettsia, Ehrlichia, Orientia, Anaplasma, and Coxiella
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What organism causes Lyme disease?
Borrelia burgdorferi (Gram-N spirochete)
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What organism causes Rocky Mountain Spotted Fever?
Rickettsia rickettsii
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What two organisms are transmitted by body lice, and thus have a solely human reservoir?
Borrelia recurrentis, R. prowazekki(epidemic typhus), R. quintana (trench fever)
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What drug/class works very well on these diseases?
Doxycycline (tetracycline)
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Name 3 spirochete disease agents
- Borrelia
- Leptospira
- Treponema
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Borrelia causes Lyme disease which is characterized by
relapsing fevers
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Spirochetes:
Aerobic/Anaerobic?
Motility?
Not usually visible with conventional light microscopy
- Anaerobic
- Corkscrew motility
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Most common tickborne illness in N. America and Europe
Lyme Disease, caused by Borrelia burgdorferi
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Borrelia burgdorferi:
Difficul to grow in vitro
Aerobic/Anaerobic?
Outer sheath?
- Microaerophilic
- Few proteins in outer sheath, most of those are lipoproteins which are potent activators of innate immunity via TLRs
- Phase variation
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When is lyme disease most commonly diagnosed? Which forms of tick are most commonly the transmitters of lyme disease?
Most commonly diagnosed in june/july (summer). Nymph and larva are most likely to cause disease because they are smaller and thus harder to feel on you. They must be on you 36-48 hours before you get lyme disease.
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Characteristic expanding (bulls-eye) rash at site of tick bite in 60-80% of patients is called _____ and is diagnostic of?
Erythema migrans, Lyme disease
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Early Localized Lyme Disease presents with?
Cure rate at this stage?
- Erythema migrans
- Flu-like symptoms- fever, headache, malaise, fatigue, myalgia, arthralgia, regional lymphadenopathy
99% cure rate at this stage
HOWEVER mostly misdiagnosed at this stage if there is no erythema migrans
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Disseminated multiple erythema migrans is characteristic of what lyme disease stage?
Early Disseminated Lyme Disease
Can present with Bell's palsy and arthritis in large joints
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Stages of Lyme Disease and characteristic symptoms:
- 1) Early Localized Lyme Disease: Erythema migrans at site of tick bite, flu-like symptoms
- 2) Early Disseminated Lyme Disease: Disseminated multiple erythema migrans, arthritis in large joints, Bell's palsy
- 3) Late Disseminated (Chronic) Lyme Disease: Chronic arthritis w/ pain and swelling, neurologicl disorders (numbness, tingling, shooting pains), cognitive defects (short-term memory loss), sleep disturbances, fatigue
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In Late Disseminated Lyme Disease: Are spirochetes found in affected tissue? What is hypothesized? Why?
No spirochetes in affected tissue, autoimmune involvement is thought to be involved because it is associated with certain haplotypes.
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What is the only stage of Lyme disease that does NOT respond well to antibiotics?
Late Disseminated (Chronic) Lyme Disease
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Lyme Arthritis occurs in what stage of Lyme Disease? What joints does it primarily effect?
- Late Disseminated (Chronic) Lyme Disease
- Affects larger joints (knee or elbow), usually affects a SINGLE joint, bone/cartilage destructin are RARE
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Lyme Disease Tx:
Erythema migrans/ facial palsies, mild cardiac disease
Doxycycline, amoxicillin, or cefuroxime axetil
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Lyme Disease Tx:
Neurologic disease /cardiac disease/ arthritis
- Ceftriaxone IV
- (or doxycycline, amoxicillin, or cefuroxime axetil for up to 1 month)
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Post-Tx Lyme Disease: (PTLDS)
Occurs in what percent of patients?
Symptoms?
Cause?
- 10% (last for months to years)
- Arthralgias, myalgias, cognitive defects, sleep disturbances, fatigue
- Possibly an autoimmune response
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Relapsing Fever caused by
Epidemic:
Endemic:
- Epidemic: Borrelia recurrentis
- Endeic: B. hermsii, B. turicatae
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Relapsing Fever caused by Borrelia recurrentis (Epidemic) is transmitted by
Body lice (via skin abrasions by hemolymph of crushed lice)
More severe disease, only imported cases in USA
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Relapsing Fever caused by B. hermsii and B. turicatae (Endemic ) transmitted by
- soft ticks
- 30 cases/yr in USA
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Relapsing Fever:
Epidemic --> B. recurrentis --> Lice (single relapse)
Endemic --> B. hermsii, B. turicatae --> soft ticks (3-10 episodes)
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Spirochetes in blood that undergo antigenic variation are seen in
Relapsing Fever
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Relapsing fever can cause
- Flu-like symptoms
- Hepatosplenomegaly, Jaundice
- Spontaneous abortion, premature birth
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What stain do you use to stain spirochetes in Relapsing Fever?
Giemsa/Wright
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Tx for Relapsing Fever
Doxycycline (tetracycline), Erythromycin (macrolide)- in pregnant women or children since can't use tetracycline
If Neurologic involvement: Ceftriaxone
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Monitor patients being treated for Relapsing Fever for ____
Jarish-Herxheimer rxn (50%)
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Jarish-Herxheimer reaction can be seen in patients being treated for
Relapsing Fever
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Rickettsia, Orientia, Coxiella, Ehrlichia, and Anaplasma:
Aerobic or anaerobic?
AERObiC
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Of the obligate intracellular bacteria, which ones escape the endocytic vacuole? Where do they infect?
- They escape vacuole and ROVe the cell.
- 1) Rickettsia- endothelial cells of small blood vessels
- 2) Orientia- blood vessel epithelium, macrophages
- 3) Vasicuitis/rash for Rickettsia and Orientia
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Of the obligate intracellular bacteria, which ones remain in the endocytic vacuole of the host cell (morulae)
- Coxiella and Ehrlichia- monocytes and macrophages
- Anaplasma- neutrophils
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Two forms of Rickettsioses
Both are sensitive to _____
- 1) Spotted Fever Group
- 2) Typhus Group
Sensitive to doxycycline
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Rickettsioses: Spotted Fever Group
Vectors?
Type of rash?
Rocky Mountain Spotted fever caused by?
- Ticks
- Centripetal (spreads from extremities to trunk)
- R. rickettsii
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Which type of Rickettsia infection causes spotted fever with eschar?
R. parkeri
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4 Types of Recketssia in Spotted Fever Group
- R. rickettsii - Rocky Mountain Spotted Fever
- R. parkeri - Spotted fever w/ eschar
- R. akari - Rickettsialpox
- R. coronii - Mediterranean Spotted Fever (MSF)
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2 Types of Reckettsia in Typhus group
- R. typhi (fleas)
- R. prowazekii (lice)
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Types of Rash
Spotted Fever Rickettsias:
Typhus Rickettsias:
- SFR: Centripetal (extremities to trunk)
- TR: Centrifugal (trunk to extremities)
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Classic triad of RMSF
- Fever
- Headache
- Rash (ankles/wrists --> palms, soles, trunk, face)
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Rickettsialpox causative agent?
Found in?
Presenting symptom.
Treat with?
- Rickettsia akari (transmitted by mouse bite)
- Urban areas
- Eschar forms at bite site
- Treat with doxycycline, quinolones
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Eschar + mousebite =
Ricketssialpox (Rickettsia akari)
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Causative agent of Endemic or Murine Typhus (NOT typhoid)
Causesd by Rickettsia typhi
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Epidemic Typhus
Transmission, causative agent.
Louse borne, R. prowazekki
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Causative agent of Scrub Typhus
Spread by?
Found in?
Symptoms?
Tx?
- Orientia tsutsugamushi
- Chiggers
- Asia, Western Pacific
- Rash with eschars spreads from trunk to extremities, CNS complications
- Doxycycline
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Ehrlichhia:
Human Monocytic Erlichiosis (HME): Morulae in cytoplasem of ______
Human Granulocytic Anaplasmosis (HGE): Morulae in cytoplasm of _____
Both are transmitted by hard ticks
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Two cell types of Coxiella burnetti
- Small cell variant (SCV)- small like spore, can survive for months
- Large cell variant (LCV)- found in body, can survive at low pH's (allows phagolysosome fusion)
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Q fever causative agent
Most common in
- Coxiella burnetti
- Most prevalent in active men, 25-40 year
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Primary reservoir of Coxiella burnetti
Cattle, sheep, goats
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30 year old male sheep/goat farmer probably has
Q fever (Coxiella burnetti)
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Disease that's almost exclusively in patients with heart disease or valve defects--> subacute endocarditis
Chronic Q fever
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Disease that can cause spontaneous abortion or premature labor in pregnant women.
Ab to Phase I and Phase II antigen (LPS)
Chronic Q fever
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Category B-Bioterorrism Agen because it is highly infections an dcan be airborne
Coxiella burnetii
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