Micro - Gram Positive Bacteria I

Question 1

streptococci vs. staphylococci

Answer 1

strep - strip

staph - clusters with catalase

Question 2

catalse

Answer 2

present in staphylococci

Question 3

beta-hemolytic

Answer 3

streptococci that completely lyse RBCs

Question 4

alpha-hemolytic

Answer 4

streptococci that partially lyse RBCs

Question 5

gamma-hemolytic

Answer 5

streptococci that cannot lyse RBCs

Question 6

lancefield antigens

Answer 6

streptococci classification with variation of the C-carbohydrate

Question 7

group A beta-hemolytic streptococci

Answer 7

streptococcus pyogenes

-strep throat, scarlet fever, rheumatic fever, post-streptococcal glomerulonephritis

Question 8

M protein

Answer 8

virulence factor for group A streptococcus

-inhibits complement, protects from phagocytosis

Question 9

streptolysin O

Answer 9

enzyme of beta group A streptococcus

• inactivated by oxygen
• destroys RBCs and WBCs

streptolysin S - also beta-hemolytic (oxygen stabile)

Question 10

scarlet fever toxin

Answer 10

pyrogenic exotoxin

-from certain streptococci

Question 11

diseases from group A beta-hemolytic streptococcus

Answer 11

strep pharyngitis
strep skin infection
scarlet fever
strep TSS

also - antibody mediated:
rheumatic fever
glomerulonephritis

Question 12

streptococcal pharyngitis

Answer 12

classic strep throat
-red swollen tonsils and pharynx, purulent exudate, high temp, swollen nodes

-differentiate from virus - use RADT

Question 13

RADT

Answer 13

rapid antigen detection test

• quick and efficient
• specific for streptococcus pyogenes

Question 14

streptococcal skin infections

Answer 14

folliculitis, pyoderma, erysipelas, cellulitis, impetigo

also caused by staph aureus

Question 15

erysipelas

Answer 15

strep infection of dermis only

-raised bright red rash with sharp advancing border

Question 16

pyoderma

Answer 16

pustule - extremity or face

• breaks down after 4-6 days - forms crust
• leaves depigmentated area

Question 17

necrotizing fasciitis

Answer 17

group A beta-hemolytic streptococcal infection

M proteins that block phagocytosis

also caused by staphylococcus, clostridium, gram - enterics, or mixed organisms

Question 18

scarlet fever

Answer 18

rash on trunk and neck spreading to extremities
-spares the face*

caused by pyrogenic toxin

Question 19

rash that spares the face

Answer 19

scarlet fever

Question 20

fourniers gangrene

Answer 20

form of necrotizing fasciitis involving the male genital area and perineum

• mixed organisms often
• also strep pyogenes

Question 21

streptococcal toxic shock syndrome

Answer 21

caused by pyrogenic toxin

Question 22

rheumatic fever

Answer 22

usually children age 5-15

follow group A beta-hemolytic streptococcal pharyngitis
-not after skin infection

antibody mediated - antigens in heart similar to bacteria

Question 23

manifestations of rheumatic fever

Answer 23

fever
myocartidis
joint swelling
chorea
subQ nodules
rash (erythema marginatum)

Question 24

erythema marginatum

Answer 24

rash with red margin that spreads from center

-in rheumatic fever

Question 25

mitral valve damage

Answer 25

often with rheumatic fever

-damages may be apparent many years after initial myocarditis and rheumatic fever**

Question 26

acute post-streptococcal glomerulonephritis

Answer 26

antibody-mediated

-one week after infection of pharynx or skin by nephritogenic strains of beta-hemolytic group A streptococci

Question 27

child with puffy face, dark urine, HTN with sore throat or skin infection recently

Answer 27

acute post-streptococcal glomerulonephritis

-has good prognosis

Question 28

group B streptococci

Answer 28

streptococcus agalactiae

-neonatal meningitis, pneumonia, and sepsis

Question 29

diagnosis of meningitis

Answer 29

made by lumbar puncture

Question 30

3 most common causes of meningitis

Answer 30

listeria monocytogenes
E. coli
group B streptococcus

Question 31

meningitis in babies within first 3 months

Answer 31

listeria monocytogenes
E. coli
group B streptococcus

Question 32

meningitis in babies later in life

Answer 32

neisseria meningitides

haemophilus infulenza

Question 33

pneumonia and sepsis in individuals with co-existant medical conditions (diabetes, cancer, liver or renal failure)

Answer 33

group B strep

older than 65 year old
stroke patients
nursing homes

Question 34

viridans group streptococci

Answer 34

mitis
salivarius
mutans
anginosus

dental plaque, gingival crevices, tongue, saliva

most alpha hemolytic

Question 35

dental infections, endocarditis, abscesses

Answer 35

viridans streptococci

Question 36

Streptococci mutans

Answer 36

dental infections

-binds teeth and ferments sugar

Question 37

dental manipulations

Answer 37

can release viridans group into blood stream
-can lead to endocarditis

subacute bacterial endocarditis

Question 38

subacute bacterial endocarditis

Answer 38

slow growth of bacteria on heart valve
-slow low grade fever, fatigue, anemia, heart murmurs

viridans streptococci after dental manipulation

Question 39

acute infective endocarditis

Answer 39

staphylococcus aureus infection
-shaking chills, high spiking fevers, rapid valve destruction

often in IV drug users

Question 40

abscess

Answer 40

subgroup of viridans - anginosus species group
-normal GI flora

-abscess in brain or abdominal organs

Question 41

streptococcus intermedius in blood

Answer 41

should suspect abscess hiding in an organ

-and investigate with CAT scan with contrast