Gram positive cocci Flashcards
what are the three generally characteristics of gram positive cocci
have a spherical shape, no endospores, and are aerobic
what are the catalase negative cocci
streptococcus, enterococcus
what are the cataplase positive cocci
staphylococcus micrococcus kocuria kytococcus alloiococcus
staphylcocci as opposed to streptococci usually cause what type of infections
pyogenic (only
staphylcocci is _______for catalse
positive
streptococci is ________for catalse
negative
streptcocci appear as
chains or pairs
staphylococci appear s
grape like clusters
type of infections staphylococci cause
pyogenic and pyrogenic both!
what is the significance of how staphylococci grow
they are halophiles
are staphylococci motile
NO
oxygen requirement of staphylococci
facultative anaerobic
common diseases associated with s. aureus
toxin mediated such as food poisoning, scaled skin syndrome, TSS, cutaneous diseases (impetigo), and systemic diseases
___________is associated with bacteremia, endocarditis, UTIS and is opportunistic
s epidermidis
_____________-is associated with UTI’s and is opportunisitc (usaully not older people UTI’s)
s. saprophyticus
S lugdunesis can cause what main clinical concern
endocarditis
S. haemolyticus can cause
bacteremia, bone/joint infections, endocarditis, UTI’s, wound infections, and opportunistic infections
where is staph found
oropharynx, GI tract and urogenital tract
what staph is carried on all persons but only 15-20% is carried on some individuals
s. epidermidis on all
s aureus on some
how is staph transmitted
direct contact or fomites
what are the three virulence factors associated with staph
capsule-inhibits phagocytosis
peptidoglycan-makes cell wall rigid, endotoxin like activity
teichoic acids-bind fibronectin, poor immunogens
____is known as the most important staph species
staph aureus
gram, catalase and coagulase of staph aureus
postive, positive, positive (triple p)
types of agar you culture staph aureus in
manitol salt agars, beta hemolytic on BA gives gold colored colonies
where is staph aureus found
anterior nares
specific virulence factors associated with staph aureus
adhesins
protein A, toxins and enzymes
what staph is associated with impetigo
staph aureus
function of protein A
finds Fc receptor on IgG antibodies and prevents antibody mediated clearance, forms immune complexes, binds compkement and used for specific identification of staph aureus
what are the 5 cytolytic toxins associated with staph aureus
alpha, beta, delta, gamma and panton valentine leukocidin
what are the 2 exfoliative toixins of staph aureus
A and B
what are the 8 enterotoxins associated with staph aureus
A to E, G to I
toxin in staph aureus associated with TSS
exfoliative toin A, enterotxins, TSST-1 are super antigens
all hemolysins lyse
neutrophils
what are the cytolytic toxins of staph aureus that can affect RBC’s
alpha and gamma
is the PV leukocidin of s. aureus associated with lysing RBC’s
no
PVL is linked with
severe pulmonary and cutaneous infections
alpha toxin of s. aureus
produced by most strains
toxic to RBC WBC, hepatocytes, and platelets, pore forming toxins, mediates tissue damage
beta toxin of s. aureus
heat labile, produced by most strains, toxic to RBC,s WBCs, fibroblasts, catalyzes hydrolysis of membrane sphingomyelin, synergizes with alpha toxin
what toxin acts like a surfactant or detergent like action
delta toxin
what toxin lyses macrophages
gamma toxin
what toxin functions in pore formation
panton valentine leukocidin
what toxin is associated with s. aureus MRSA
PVL
_____is heat stable
ETA
________is heat labile
ETB
________split intrercellular bridges in stratum granulosum epidermidis
serine proteases
if there are no bacteria and WBCs in the affected area this means that
ETA or ETB strain of staph aureus
what are two diseases characterizied by strains of staph aureus having ETA or ETB toxins
scalded skin syndrome and bullous impetigo
staph aureus enterotoxin B causes
staphylococcail psudomembranous entercolitis
entertoxin C and D of s. aureus found in
contaminated milk products
what toxins are responsible for causing food poisoning
s. aureus enterotoxins
what cells are responsible for emesis of food poisoning
mast cells
in addition to coagulase and catalse, what other enzyme does staph aureus have
penicillinase beta lactamase
impetgo is caused by what two staph
staph pyogenes and staph aureus
what type of hemolysis does s. aureus have
beta
s aureus turns what in manitol salt sgar
yellow
s epidermidis turns what in manitol salt agar
read
present of antibodies to teichoic acids means you might have a
s. aureus infection
differentiating factor in terms of gram, catalse and coagulase for staph aureus and staph epidermidis/saprophyticus
staph saprophyticius and staph epidermidis are coagulase negative
______-are novobiocin sensitive
staphylociccus epidermidis
________have the ability to adhere to plastic
s. epidermidis
___________are novobiocin resistant
staph. saprophyticus
if your catalse test is negative what type of gram positive cocci do you have
streptococcus species
if your coagulase test is positive, catalase test is positive
staph aureus
if your coagulase test is neg. catalse test is positive
either staph saprophyticus or staph epidermidis
_______________known to cause chronic middle ear infections in children
alloiococcus otitidis
if catalase test is negative on a gram positive cocci then it is
streptoccocus species
if beta hemolytic catalse neg, not sensitive to bacitracin
streptococcus pyogenes
if alpha hemolytici, catalse neg, not sensitive to optochin
streptocuccs pneumoniae
all _______are catalse negative
streptococci
type of oxygen requirement for streptococcus
facultative anaerobes some are capnophilic needing carbon dioxide
ways streptococcus are classified are
serology, hemolytic patterns, and biochemical properties
