Spiral, Curved, and Misc

Question 1

Rickettsia

Answer 1

-Short, nonmotile GNR
-Obligate intracellular
-Two group
–Typhus group
–Spotted fever group

Question 2

Rickettsia Typhus Group

Answer 2

1) R. typhus / R. prowazekii
2) Murine typhus / louse-borne typhus (Brill-zinsser disease)
3) Replicate in cytoplasm of host cell and cause cell lysis (different from other Rickettsia)

Question 3

R. typhus (endemic Murine typhus)

Answer 3

-Oriental rat flea vector / rat
–cat flea can also harbor
-Fever, headache, rash (50%)
–Rash on trunk and extremities
-Weil-Felix rxn antigen: Proteus OX-19
-IFA is gold standard for Ig detection

Question 4

R. prowazekii (epidemic Louse-borne typhus)

Answer 4

-Human louse, squirrel flea, squirrel louse passed via bug feces
-Humans and flying squirrels in eastern US, Africa, Central/South America
-Rash on palms and soles, also face
-Mortality in untreated = 40%
-Brill-Zissner -> recrudescent typhus in previously infected patients.
–Org lies dormant in lymph tissue until infection is reactivated

Question 5

R. rickettsii (RMSF)

Answer 5

-Tick bites (Dermacentor) - passed via tick saliva
-Phagocytized into endothelial cells->replicate->pass back through the plasma membrane w/o harming host cell
-Blood stream
–vasculitis in brain, heart, kidneys
–Pneumonitis, CNS issues, myocarditis
-Flulike symptoms for 1 week then
–headache, myalgia, nausea, vomiting, rash
–Rash on ankles/wrists then palms and soles (NO FACE)
-20% mortality if untreated
-Weil-Felix OX-19 or OX-2

Question 6

R. akari (Rickettsialpox)

Answer 6

-Mouse mite (chigger) / common house mouse
-Similar to RMSF but milder
-Papule->pustule->eschar
-Bloodstream-> fever, rash chills
–Rash on face, trunk, extremities (NO PALMS/SOLES)

Question 7

Orientia (Scrub typhus)

Answer 7

-Chigger / rat
-2 week incubation
-Tache noire (black spots) at site
-Fever, headache, rash
–Trunk->extremities (NO PALMS/SOLES)
-OX-K

Question 8

Coxiella burnetii (Q fever)

Answer 8

-Infects goats, sheep, cattle
-Breathe in dust containing org or eating contaminated food
-< 10 organisms for infectious dose
-50% of people get sick from exposure (2-3 week incubation period)
-flulike symptoms (NO RASH)
–can become chronic
-Treat w/ doxy
-Diagnose w/ Ig test (IFA) after week 2 of illness or
-DFA of tissue
-BIOTHREAT AGENT

Question 9

Bartonella

Answer 9

1) Cat Scratch Fever (B. henselae)
–Culture for 21 days
–Azithromycin
2) Trench Fever (B. quintana)
–Human body louse
–Fever, bone pain, lesions, endocarditis
–tetracyclines, aminoglycosides, and macrolides. More than one antibiotic is often used.

Question 10

Ehrlichia

Answer 10

-E. chaffeenisis
–Human Monocytic Ehrlichiosis
-Fever, headache, malaise, myalgia
-Rash in kids
-Infect WBCs (monocytes)-> make morulae (mulberry-like bodies)
–can see on smear w/ Giemsa/Wright

Question 11

Chlamydia

Answer 11

-Obligate intracellular
-EB (elementary body) INFECTIOUS and RB (reticulate body) NONINFECTIOUS
-Get phagocytized->Reorganize into initial bodies (8 hours)->Multiply and become EB (30 hours)->Release

Question 12

C. trachomatis

Answer 12

1) STI
–serovars D-K
2) TRIC conjunctivitis
–Trachoma (chronic eye infection)
–A, B, Ba, C serovars
–continual abrasion and scarring of cornea -> blindness
3) Lymphogranuloma Venereum
–STD w/ inguinal and anorectal symptoms
–Bubo formation / rupture of lymph nodes
–L1, L2, L2a, L2b serovars

Question 13

C psittaci

Answer 13

-Dust in bird cages
-Respiratory infection in humans

Question 14

C pneumoniae

Answer 14

-Respiratory infection (acute)
-Pharyngitis
-Otitis media

Question 15

Spriochetes

Answer 15

1) Leptospira
2) Borrelia
3) Treponema

Question 16

Leptospira

Answer 16

1) Tightly coiled, thin, flexible -> can look like chain of cocci -> hooks on ends
2) Motile (periplasmic flagella)
3) Stain with silver
–use dark-field, phase-contrast, or immunofluorescent to see unstained
4) Enters through breaks in skin
–flulike symptoms than can lead to hepatic, renal, and CNS issues
–interstitial nephritis
–conjunctival suffusion
–Weil disease -> multiorgan failure
–1-3 weeks
5) Dogs, rats, rodents excrete in urine
–vaccinate
6) Culture on Fletcher’s Stuart, or EMJH
–incubate in dark at RT
7) Doxy / pen

Question 17

Borrelia

Answer 17

-Relapsing fever EXCEPT Lyme
-Arthropod vectors
-less coiled than Leptospira
-Stain easily and can be seen on bright-field microscopy
-periplasmic flagella

Question 18

B. recurrentis

Answer 18

1) Relapsing fever over a period of weeks
–3-7 days then break then recurs days to weeks later
2) Evades complement -> antigenic variation
3) Tick-borne (endemic) or Louse-borne (epidemic)
4) High temps, rigors, headache, muscle pains, weakness
5) See organisms in blood smears during febrile period
6) Tet

Question 19

B. burgdorferi

Answer 19

1) Lyme disease
2) Ixodes ticks (8-12 hours of attachment)
3) Virulence
–Binds plasminogen and plasminogen activator
–Complement evasion
4) Disease
1. Localized Stage (Erythema chronicum migrans)->bulleye rash-> can isolate orgs from rash
2. Early disseminated -> bone/joint pain, neuro signs, cardia, spleen, fatigue
3. Late -> cardiac, musculoskeletal, neuro, ARTHRITIS
4) Diagnose with serology 3-4 weeks after bite
5) Doxy / amoxicillin for early stages -> ceftriaxone for late

Question 20

Treponema pallidum

Answer 20

Syphilis diagnosis
VDRL test (need scope to read)
1) Cardiolipin antigen mixed with patient’s serum or CSF
2) Flocculation if positive

RPR (do not need scope to read)
1) Carbon particles mixed with positive serums
2) Clumping of particles if cardiolipin-antibody complexes

TP-PA
1) Detects antibodies for treponemal antigens
2) Gelatin particles sensitized with T. pallidum antigens
3) More simple than FTA-ABS (no scope or UV needed)

FTA-ABS (Fluorescent Treponemal Antibody Absorption)
1) Absorb patient serum w/ nonpath Reiter treponeme to remove nonspecific antigens
2) Place serum on slide with T. pallidum
3) Remove unbound antibodies
4) Detect anti-T. pallidum antibody w/ labeled anti-human Ig
5) Examine under UV