Gram Negative Infections

Question 1

pseudomonas greenish-blue, yellow-green, and black pigment causes

Answer 1

greenish-blue: pyocyanin
yellow-green: fluorescein
brown-black: pyomelanin

Question 2

recurrent infections with n. meningitidis caused by?

Answer 2

late complement deficiency (C5-C9)

Question 3

glanders: 1. bug, 2. vector, 3. presentation, 4. txt

Answer 3

burkholderia mallei
contact with horses
ulcerated nodule at inoculation site, LAD, farcy buds
sulfonaminde

Question 4

Tularemia: 1. aka, 2. bug, 3. vector, 4. presentation, 5. txt

Answer 4

• francisella tularensis
• rabbits (ticks, deer flies) - hunters
• hands- HSM, violaceous papulonodular eruption
• doxy w/ rifampin

Question 5

vibrio infection 1. bug, 2. vector, 3. presentation, 4. txt

Answer 5

• vibrio vulnificus
• raw seafood, wound in seawater
• fever, chills, abd pain, red-violaceous macules –> painful hemorrhagic bullae with cellulitis
  TCN PO

Question 6

plague 1. bug, 2. vector, 3. presentation, 4. txt

Answer 6

• yersinia pestis
• flea
• fever, small papule/pustule at site of flea bite w/ swollen painful fluctuant lymph nodes (buboes)
• streptomycin IM

Question 7

malakoplakia 1. bug, 2. presentation, 3. histo, 4. txt

Answer 7

• e. coli (also pseudomonas, proteus, klebsiella)
• uti, weeping perianal plaque or polypoid mass
• michaelis-gutmann bodies
• cipro, surgery

Question 8

rhinoscleroma 1. bug, 2. transmission, 3. presentation, 4. histo, 5. txt

Answer 8

• klebsiella rhinoscleromatis
• inhalation droplets, fomites
• infectious granulomas in nasal mucosa, resp tract, epistaxis, Hebra nose (destruction cartilage)
• mikulicz cell, russell bodies
• cipro

Question 9

rat-bite fever: 1. aka, 2. bug, 3. vector, 4. presentation, 5. txt

Answer 9

• haverhill fever
• streptobacillus moniliformis
• rodents, contaminated food
• fever, arthritis, ulceration at site of bite, generalized morbilliform eruption with acral invoment
• PCN

Question 10

cat bite: 1. bug, 2. txt

Answer 10

pasteurella multocida

augmentin +/- tetanus ppx

Question 11

dog bite bug/txt

Answer 11

pasturella canis and multocida, capnocytophaga canimorsus

augmentin +/- tetanus

Question 12

human bite bug/txt

Answer 12

eikenella corrodens

augmenting +/- tetanus

Question 13

bartonella bug, vector, pathogenesis

Answer 13

gram neg intracelluar
ticks, fleas, sand flies, mosquitos
bacilliformis adheres to and invades RBCs
all 3 types produce endothelial-stimulating factor –> proliferation endothelial cells and blood vessels

Question 14

oroya fever aka, bug, vector, 2 stages, txt

Answer 14

• carrion’s ds, verruga peruana, Peruvian wart
• bartonella bacilliformis
• sanfly lutzomyia verrucarum
• acute stage (oroya) = fever + hemolytic anemia
• chronic stage (verruga) = erythematous papules/nodules for years
• acute txt chloramphenicol (covers salmonella coinfection)
• chronic txt TCN or PCN

Question 15

cat-scratch disease bug, vector, presentation, txt

Answer 15

• bartonella henselae
• cat flea ctenocephalides felis (comb)
• u/l tender LAD 2-4 wks after scratch in axilla/epitrochlear node
• spontaneous resolution, doxy/erythro

Question 16

parinaud oculoglandular syndrome: 1. bug, 2. presentation

Answer 16

bartonella henselae (cat-scratch ds)
u/l conjunctivitis and regional LAD

Question 17

trench fever aka, bug, vector, presentation, txt

Answer 17

• shinbone fever
• bartonella quintana
• body louse pediculus humanus corporis
• relapsing fever, tender shins, back pain, transient macular eruption
• doxy/erythro

Question 18

pediculus humanus corporis carries causes what 3 diseases

Answer 18

trench fever (bartonella quintana)
epidemic typhus (rickettsiae prowazekii)
louse-born relapsing fever (borrelia recurrentis)

Question 19

rocky mountain spotted fever bug, vector, presentation, txt

Answer 19

• rickettsiae rickettsii
• dermacentor andersoni, dermacentor variabilis
• fever, HA, myalgias –>purpuric or hemorrhagic macules & papules on wrists & ankles –> trunk, hands, feet
• doxy (15-25% mortality w/o txt)

Question 20

mediterranean spotted fever aka, bug, vector, 2 forms, txt

Answer 20

• boutonneuse fever
• rickettsiae conorii
• brown dog tick rhipicephalus sanguineus
• 1. tache noir = indurated papule at site of tick bite –> necrotic ulcer
• 2. exanthem = erythematous papules over lower limbs
• doxy or chloramphenicol

Question 21

rickettsialpox bug, vector, presentation, txt

Answer 21

• rickettsiae akari
• mouse mite liponyssoides sanguineus
• papule or vesicle at site of bit –> eschar & LAD –> fever, chills, HA, diffuse vesicular rash
• doxy, chloramphenicol

Question 22

epidemic typhus bug, vector, reservoir, presentation, txt

Answer 22

• rickettsiae prowazekii
• body louse pediculosis humanus corporis
• flying squirrel
• fever, chills, HA –> pale red macules on trunk –> diffuse petechial papules (spares face, palms, soles)
• vascular inflammation of skin, CNS, heart, kidneys, muscle
• doxy or chloramphenicol

Question 23

endemic typhus aka, bug, vector, presentation, txt

Answer 23

• murine typhus
• rickettsiae typhi
• rat flea xenopsylla cheopis (no comb)
• fever, HA, myalgias, transient truncal maculopapular exanthem
• doxy, chloramphenicol

Question 24

scrub typhus bug, vector, presentation, txt

Answer 24

• rickettsiae tsutsugamushi
• chigger mites (trombiculid - larval stage)
• HA, chills, eschar at inoculation w/ LAD –> maculopapular rash on trunk +/- cardiac and pulm ds
• doxy, chloramphenicol

Question 25

ehrlichiosis, 2 bugs and types, 2 vectors and types, txt

Answer 25

ehrlichiosis chaffeenis - ambyloma americanum = monocytic
e. phagocytophilia - ixodes scapularis & pacificus = granulocytic
tetra or doxy

Question 26

Q fever bug, presentation, txt

Answer 26

• coxiella burnetii
• no skin findings, limited febrile illness +/- organ involvement
• doxy

Question 27

lyme disease bug, vector, 3 presentations, dx, txt

Answer 27

• borrelia burgdorferi
• eastern US: ixodes dammini/scapularis; western: ixodes pacificus; europe: ixodes ricinus
• early localized: flu + erythema migrans 1-2 wks post bite, disappears in 4 wks w/o txt
• early disseminate: satellite erythema migrans, bell’s palsy, arthralgias, carditis
• chronic: acrodermatitis chronic atrophicans (loss of subcu fat w/atrophic skin)
• PCR, tissue cx
• doxy or amox x 14-21 days

Question 28

borrelial lymphocytoma aka, 2 bugs, presentation, txt

Answer 28

• lymphocytoma cutis
• borrelia afzellia, borrelia garinii
• firm bluish-red tumor or plaque on ear lobes of children or areolae of adults
• doxy

Question 29

louse-borne relapsing fever: 1. bug, 2. vector, 3. presentation, 4. txt

Answer 29

1. borrelia recurrentis
2. body louse pediculus humanus corporis
3. paroxysmal fevers, myalgias, no specific cutaneous findings
4. doxy

Question 30

tick-born relapsing fever: 1. bugs, 2. vector, 3. presentation, 4. txt

Answer 30

1. borrelia parkeri & hermsii
2. soft ticks ornithodoros
3. paroxysmal fevers, no specific cutaneous findings; risk of Jarisch-Herxheimer rxn
4. doxy

Question 31

leptospirosis: 1. aka’s, 2. bug, 3. transmission, 4. presenation, 5. txt

Answer 31

1. fort bragg fever, pretibial fever, weil ds
2. leptospira interrogans
3. direct skin contact w/ animal urine in water
4. fever, HA, painful pretibial plaques, conjunctivitis, jaundice, diffuse exanthem
5. PCN or macrolide or doxy

Question 32

yaws: 1. aka, 2. bug, 3. transmission, 4. primary, secondary, tertiary presentation

Answer 32

1. frambesia
2. treponema pallidum (pertenue)
3. direct contact
4. primary: erythematous papules at inoculation (“mother yaw) –> enlarges, ulcerates, disappears with scar
   secondary: daughter yaws symmetrically over body
5. tertiary: gummata, keratoderma, midfacial destruction, bony inflammation/damage

Question 33

pinta: bug, transmission, primary, secondary tertiary presentation

Answer 33

treponema carateum
direct contact
primary: smooth papule at inoculation
secondary: psoriaform yellowish-brown papules & plaques (pintids)
tertiary: depigmented vitiligo-like lesions over face, wrists, trochanteric areas

Question 34

endemic syphilis: 1. aka, 2. bug, 3. transmission, 4. primary, secondary presentation

Answer 34

1. bejel
2. treponema pallidum endemicum
3. direct skin contact
4. primary: skin lesions rare
   secondary: mucosal patches, condylomata lata, LAD +/- osteitis, periostitis, bony damage, gummata

Question 35

chancroid 1. bug, 2. presentation, 3. gram stain findings, 4. txt

Answer 35

1. haemophilus ducreyi
2. soft painful ulcer w/purulent base & ragged borders, buboes w/ suppuration. no healing w/o txt.
3. school of fish pattern
4. azithro 1g x 1 or ceftriaxone IM x1 or cipro 500 mg bid x3d

Question 36

granuloma inguinale: 1. aka, 2. bug, 3. presentation, 4. histo finding, 5. txt

Answer 36

1. donovanosis
2. klebsiella (calymmatobacterium) granulomatis
3. painless subcu nodule –> ulcerates to painful beefy red granulation tissue. does not heal w/o txt
4. donovan bodies
5. 3 wks with: azithro 1g qwk or bactrim ds bid or cipro 750 mg bid or doxy 100 my bid

Question 37

lymphogranuloma venereum 1. aka, 2. bug, 3. presentation, 4. txt

Answer 37

1. tropical buob
2. chlamydia trachomatis L1-L3 serotypes
3. stage I w/ papule –> painless ulcer w/ gray base. stage II w/ u/l suppurative bubo & groove sign
4. gamma-favre bodies
5. 3 wks with: azithro 1g qwk or erythro qid or levo 500mg qd, or doxy 100mg bid

Question 38

gonorrhea: 1. bug, 2. presentations (4), 3. txt

Answer 38

1. neisseria gonorrhoeae
2. men: urethritis w/ dysuria and pus
   women: urethritis & purulent cervicitis
   ascending: salpingitis or PID
   disseminated: fever, arthralgias, pustualr hemorrhagic lesions
3. azithro 1g x1 or ceftriaxone IM x1 or doxy 100 mg bid x 1wk