Necrotizing fasciitis causal organism
strep pyogenes
initial diffuse redness, swelling and extreme tenderness
followed by crepitus, purple skin discoloration, bullae and loss of sensation to the area
Necrotizing fasciitis
erysylpela causal organism
strep pyogenes
causal organisms of cellulitis
S. areus
strep pyogenes
clostridium perfringens
pseudomonas
virulence enzyme of clostridium perfringens and its mechanism
alpha toxin: lecitihinase
hydrolyzes cell membranes causing cell death
causal organism of gas gangrene
clostridium perfringens
causes of impetigo
Bullous: s. aureus
Nonbullous: strep pyogenes
causal agent of furuncles and carbuncles
s. areus
causes of folliculitis
s. aureus
pseudomonas
treatments of clostridium infections
penicillin
clindamycin
treatment for strep pyogenes
penicillin
macrolides
cephalosporins
what causes scarlet fever in strep pyogenes infections
phag encoded toxin: pyogenic/ erythrogenic toxin
virulence factors of Strep pyogenes that induce adherence
lipoteichoic acid
M protein
role of M protein in strep pyogenes
adherence
molecular mimicry: avoiding apoptosis
antigen of Rheumatic fever and post strep glomerulonephritis
which streptolysin is antigenic in strep pyogenes and what does it do
streptolysin O
Beta hemolytic- degrades cell membranes
rol of streptokinase in strep pyogenes
converts plasmin into plasminogin
role of hyaluronidase and where can it be found
breaks down connective tissues (hyaluronic acid)
S. areus and strep pyogenes
virulence factor of strep pyogenes responsible for toxic shock like syndrome
erythrogenic toxin A
which S. aureus proteins cleave desmoglein-1 protein and what happens thereafter
exfoliatoxin- separates epidermis to cause scalded skin syndrome
serine protease caises loss of adhesion of superficial dermis causing bullous impitigo
what causes food poisoning in S. areus
enterotoxin
what prevents opsinization and phagocytosis in S. aureus
Protein A
how does S. aureus prevent the body from isolating infections
staphylokinase lyses thrombi
treatments for S. aureus
vancomycin
linezolid
clindamycin
what causes disruption of blood vessels in pseudamonas infections
elastase: serine protease cleaves desmoglein
how does pseudomonas cause folliculitis
exotoxin A blocks EF-2, inhibiting protein synthesis
no protein synthesis contributes to cell necrosis
Necrosis at the site of follicle promotes inflammation at the follicle
what causes sepsis in pseudomonas infections
exotoxin/ Lipid A
what causes membrane degradation in pseudomonas infections
phospholipase c
pseudomonas treatment
penicillin/ ticarcillin
cephalosporins
carbapenems
shellfish/ marine environment
vibro vulnificus
virulence factor of vibrio vulnificus
oxidase positive
treatment for vibrio vulnificus
tetracyclines
ceftriaxone
fluoroquinolones
animal bites
pasteurella
pasteurella description
gram negative coccobacilli
encapsulated
facultative anaerobe with bipolar staining
virulence factor of pasturella
endotoxin
treatment for pasteurella
amoxicillin
what forms of HPV cause verruca vulgaris
HPV types 1-4
verruca vulgaris
common cutaneous warts
morphology of HPV 1-4
hyperplasia of prickle cells
hyperkeratosis
description of molluscum contagiosum
enveloped dsDNA Pxvirus
largest DNA virus
Poxvirus
how do you catch molluscum contagiosum
fomites
direct contact
scratched skin
humid climates
morphology of molluscum contagiosum
nontender fleshy colored pearly dome shaped papules with central umbilication
hyperpigmentation
scarring
Gram positive aerobic spore forming cocci
Bacillus anthracis
describe cutaneous anthrax
painless papules that evolve into ulcers with surrounding erythema, then eventually a black necrotic eschar
When healed, it appears as hyperpigmented or scarred skin
cutaneous anthrax treatment
fluoroquinolones or doxycycline
diagnostics of anthrax
leukocytosis
increased transaminases
mediastinal widenind
ELISA immunohistochemistry
Gram positive filamentous aerobic branching rod
Nocardia
Nocardia diagnostics
acid fast
urease positive
cutaneous nocardia clinical presentation
cellulitis
LAD
Lymphangitis
Nocardia treatment
Bactrim
Carbapenems
Cephalosporins
Amikacin