Bacterial I - Morgan's Qs Flashcards
CA-MRSA virulence factor
panton-valentine leukocidin
If pt is resistant to erythromycin, what other antibiotic should you also check with the D-test
clindamycin
name for superficial bacterial folliculitis and MCC
Bockhart’s impetigo
MCC: staph aureus
T/F: one way to distinguish sycosis vulgaris from tinea barbae is that it affects the upper lip
true: tinea barbae rarely affects upper lip
what are the defects (AD & AR) of Job syndrome? what Ig levels will be elevated and depressed?
AD: STAT3 (regulates osteoclast activity)
AR: DOCK8 (seen w/ viral infections)
IgE increases, IgD decreases
what are the defects (XLR & AR) for chronic granulomatous ds
XLR: gp91-phox
AR: p67-phox
defect in NADPHX oxidase enzyme complex –> inability to produce respiratory burst –> defective killing of catalase positive organisms
causitive agent in chronic pyogenic paronychia
candida
causative agent of abscess formation in pyogenic paronychia? erythema and swelling?
abscess formation: staph aureus
erythema & swelling: strep pyogenes
MCC botryomycosis? sinuses discharge?
staph aureus
sulfur granules
pyomyositis… MC site in children in tropics? MC site in temperate areas in immunosuppressed?
kids in tropics: thigh
immunosuppressed in temperate: deltoid, quad
cause of acute glomerulonephritis in impetigo
strep pyogenes M type 2, 49, 55, 57, 60
bullous impetigo site in kids? in adults? what causes extracellular cleavage of Dsg1?
T/F culture is positive for bullae.
kids: face and hands
adults: axillae and groin
cleavage of Dsg1: staph aureus exfoliative toxins A & B group 2 phage types 55 & 71
true - culture positive
toxin in SSSS? where do you culture? what do you see in adults? T/F: SSSS affects palms/soles, mucous membranes.
toxin: exfoliative toxins A & B group 2 phage types 55 & 71
culture: conjunctiva, nasopharynx, feces, pyogenic foci
adults: immunosuppression, renal ds
false: does not affect palms/soles or mm
cause of staph toxic shock syndrome? acute systemic symptoms?
exotoxin TSST-1 superantigen
acute febrile illness with pharyngitis, scarlatiniform exanthem first on trunk, erythema of palms and soles with desquamation
cause of strep toxic shock syndrome? MC initial symptoms?
M types 1 & 3 produce exotoxins A, B, C
initial sxs: severe local pain in extremity
toxic shock syndrome superantigen binding site? causes release of what cytokines?
binds to V-beta region on T-cells
stimulates T cell release of TNF-alpha, IL-1, IL-6, TLR 2 & 4
T/F: scarlatiniform eruption is more common in strep TSS than staph TSS
False
scarlatiniform eruption more common in staph
cause of ecthyma? initial morphology of the lesion? cause in HIV/IVDA pts?
cause: strep pyogenes
start as vesiculopustule –> crust –> saucer-sharped ulcer with raw base and elevated edges on shins/dorsal feet
cause in HIV/IVDA: staph aureus
cause of scarlet fever? where does blanchable erythema start?
T/F: the palms and soles peel 2 wks after illness for up to 6 wks
cause: strep pyogenes types A, B, & C
neck –> chest & axillae –> trunk –> extremities
true
staph scarlatina refers to?
mimic of scarlet fever except no strawberry tongue
Job syndrome major findings
deficient neutrophil chemotaxis - cold abscesses, cellulitis, carbuncles, eczematous dermatitis, pneumatoceles, bronchitis
major findings of chronic granulomatous disease
recurrent pyoderma, perioral dermatitis, lymphadenopathy, pneumonia with abscesses, empyema, osteomyelitis (serratia marcescens)
Schultz-Carlton phenomenon
blanching erythema secondary to exotoxin
bacteria that causes scarlatiniform exanthem and pharyngitis in young adults
Arcanobacterium haemolyticum
cause of erysipelas? lab abnormalities? predisposing factors?
strep pyogenes
leukocytosis >20,000
venous insufficiency, lymphedema
three types of necrotizing fasciitis
I - polymicrobial
II - strep pyogenes
III - clostridial myonecrosis or gas gangrene
progression of colors in necrotizing fasciitis
red-purple-gray-blue
Meleney’s gangrene is a complication of
surgical trauma
MCC blistering distal dactylitis? can you culture
strep pyogenes (occ staph aureus) blister fluid of volar fat pad can be cultured
cause of perianal dermatitis? in neonates?
strep pyogenes (occ staph aureus) neonates: group b strep
Jones criteria: 2 skin signs and 3 other signs
skin: subcutaneous nodules & erythema marginatum
other: polyarthritis, carditis, chorea
fish pathogen causing cellulitis of hands
strep iniae
cause of erysipeloid of Rosenbach
erysipelothrix rhusiopathiae
erysipeloid purplish swelling of the hands involves the __ but spares the __
involves finger webs, spares phalanges
pediatric presentation of pneumococcal cellulitis? in IVDA/DM pts?
peds: facial and periorbital edema and cellulitis
IVDA/DM: extremity
see fever, leukocytosis, septicemia
in anthrax, what inhibits phagocytosis?
T/F: abx therapy does not alter progression from painless carbuncle –> vesicle –> ulcer –> eschar
polyclutamic acid capsule
true, progression not altered
anthrax exotoxins and affects
edema toxin (edema factor + protective antigen): increases cAMP levels lethal toxin (lethal factor + protective antigen): release of TNF-alpha and IL1-beta
treatment of listeria
ampicillin or bactrim
name of ulcer caused by corynebacterium diptheria? what must be ruled out before giving IM antitoxin
ecthyma dipthericum
must rule out hypersensitivity to horse serum via conjuctival test first
3 infections caused by cornyebacterium
erythrasma = cornyebacterium minutissimum
pitted keratolysis = kytococcus sedentarius
trichomycosis axillaris = cornyebacterium tenuis
what causes coral red fluorescence in erythrasma
coproporphyrin III (woods lamp 365 nm)
kytococcus sedentarius release __ that destroy the stratum corneum
serine proteases K1 and K2 in pitted keratolysis
color produced with woods lamp on trichomycosis axillaris
pale yellow
two membrane toxins produced by clostridium perfringens in gas gangrene? lab abnormalities?
alpha toxin (like sphingomyelinase) and perfringolysin leukocytosis and hemolytic anemia
cause of tropical ulcer/jungle rot
bacteroides vincentii
cause of desert sore in Australia with grouped vesicles –> rupture into ulcers on shins and knees
corynebacterium diphtheriae, staph and strep
MC location of actinomyces israelii
cervicofacial - lumpy jaw caused by sulfur granules
DOC for actinomyces israelii
penicillin G
T/F: norcardia asteroides is most commonly caused by pulm ds that disseminates. cutaneous form caused by what species? DOC?
true
nocardia brasiliensis
bactrim
