strep infections Flashcards
which bacteria have the IgA protease s a virulence factor ?
SHiN
strep pneumonia
Haemophilus influenza
Neisseria
what are the lab features of strep pyogens ?
group A streptococci
gram positive in chains
on;ybeta hemolytic strep that is PYR positive
what is the virulence factor of strep pyogens ?
M protein
what are the toxin mediated diseases in association with strep pyogens ?
scarlet fever
necrotizing fascitis
toxic shock syndromew
what are the immune diseases associated with strep pyogens ?
rheumatic fever
post strep GN
what are the 2 important skin infections in association with strep pyogens ?
cellulitis
impetigo
what are the strep pharyngitis complication ?
scarlet fever
what is the toxin associated with nscarlet fever that happens as a complication of strep pharyngitis ?
erythrogenic toxin
the skin reacts to this toxin
where is the gene for the eryhtrogenic encoded ?
in the lysogenic phase
what is distinctive about scarlet fever ?
strawberry tongue
sandpaper skin
can be differentiated from kawasaki by the presence of a sore throat before the appearance of the strawberry tongue
what toxin is associated with necrotizing fasciitis ?
strep pyogenic exotoxin
what are the two types of necrotizing fasciitis ?
type 1 - caused by anaerobes and usually in diabetics and in the immunocompromised
type 2 - associated with group A strep and occurs in healthy people after skin injury
what is the classic case associated with necrotizing fasciitis ?
pain that is out of proportion
can be commonly mistaken for cellulitis
may be further associated with hypotension and shock
what type of autoimmune reaction is rheumatic fever ?
type 2
what are the pathognomonic features of rheumatic fever ?
aschoff bodies - nodues in the heart , granuloma
antisckow cell- has an owl eye appearance
what are the lab findings associated with rheumatic fever ?
elevated ASO titre
what are the clinical clues asociated with rheumatic fever ?
patient with a sore throat
which then presented with a new heart murmur and joint pain is most likley rheumatic
what is the treatment for rheumatic fever ?
penicillin for life
what valvular abnormality is associated with late RF ?
mitral stenosis
what are the features of strep agalactai ?
its a group b strep which releases CAMP that interacts with beta hemolysin in staph aureus
what is the normal flora of the vagina ?
group b strep 3amatan
what is the shape of strep pneumoniae ?
lancet shaped gram positive cocci
what is the most important virulence factor in strep pneumonia ?
IgA protease polysaccharide capsule
which is used for vaccinations
what is the function of the polysacchride capsule in strep pneumonia ?
prevents phagocytosis
