Gram +ve streptococci Flashcards
what is a way of identifying the type streptococci a bacteria is?
its interaction with red blood cells on agar plate
partial haemolysis of blood on agar plate indicates what type of streptococci?
a-haemolysis
oral streptococci
complete haemolysis of blood on agar plate indicates what type of streptococci?
b-haemolysis
group A streptococci -> S.pyogenes
no haemolysis of blood on agar plate indicates what type of streptococci?
y-haemolysis
enterococcus faecalis
what does GAS stand for?
group A streptococci
where does GAS -> S.pyogenes colonise
back of the throat (oropharynx)
what allows GAS -> S.pyogenes colonise the oropharynx?
M protein for binding
hyaluronic acid capsule that is similar to humans
how is GAS -> S.pyogenes identified?
presence of M protein
name three general things that GAS -> S.pyogenes causes
skin infections
upper respiratory tract infections
autoimmune diseases
what skin infections does GAS-S.pyogenes cause? 4
impetigo
celullitis
necrotising fasciitis
acute streptococcal gingivitis
what is impetigo?
highly contagious skin condition that causes sores and blister. very common in children
what is celullitis?
deeper infection of the dermis
what is necrotizing fasciitis?
destruction of connective tissue “flesh eating bug”
what is acute streptococcal gingivitis?
when Coughing causes the bacteria to spread to the gingiva
name an upper respiratory tract infection caused by GAS -> S.pyogenes
strep sore throat
what are the 3 symptoms of strep throat?
sudden, pain, fever
what is scarlet fever?
severe form of strep throat with associated rash
what can strep throat lead to?
pharyngitis
how can you tell the difference between bacterial and viral strep throat?
viral has a cough present
no fever
and coryza (inflammation of nasal mucous membrane)
name 2 autoimmune diseases caused the GAS - S.pyogenes
rheumatic fever
glomerularnephritis
what does rheumatic fever effect?
the heart
what does glomerularnephritis effect?
the kidneys
GAS - S.pyogenes Have many virulence factors and super antigenic toxins what do these do?
overstimulate the immune system
name 3 antibiotics used to treat GAS - S.pyogenes
penicillin V, amoxicillin, erythromycin
what type of streptococci is this?
a- haemolysis
most oral streptococci
what type of streptococci is this?
b-haemolysis
group A streptococci GAS -> S.pyogenes
what type of streptococci is this?
y-haemolysis
enterococcus faecalis
