Streptococci and Enterococci

Question 1

A-hemolys

Answer 1

Optochin-sens = pneumococcus

Optochin-res = viridans group

Question 2

B-hemolys

Answer 2

Lancefield grpings of A-G

Question 3

Grp A strep

Answer 3

strep pyogenes

Question 4

grp B strep

Answer 4

strep agalactiae

Question 5

grp A strep vir factors

Answer 5

M proteins; erythrogenic tox; streptolysin; hyaluronidase

Question 6

two types of grp A BHS inf are?

Answer 6

Suppurative; nonsuppurative

Question 7

nonsuppurative grp A BHS inf due to bac itself?

Answer 7

no, abnorm body immune response

Question 8

famous grp A BHS inf complics

Answer 8

pneumonia; scarlet fever; ARF; SSTIs; necrotizing fasciitis; Strepto TSS; AGN

Question 9

Circumoral pallor evident in?

Answer 9

scarlet fever

Question 10

Scarlet fever mediated by?

Answer 10

strep pyrogenic exotox (specifically SPE A and C), ie erythogenic tox

Question 11

necrotizing fasciitis caused by?

Answer 11

strep pyogenes

Question 12

necrotizing fasciitis spreads along ______

Answer 12

the fascial plane

Question 13

nonsupp inf of strep pyogenes incl?

Answer 13

AGN and ARF

Question 14

what happen if ARF progresses?

Answer 14

RHD (rhem heart disease) – predispose to inf endocard; kiv Revised Jones’ Criteria

Question 15

how Dx strep pyogenes?

Answer 15

ASOT (serology); can Gram stain; can culture

Question 16

strep TSS Tx?

Answer 16

toxin-mediated hence; IVIG – neutralize tox; clindamycin – reduce tox prod

Question 17

grp B BHS

Answer 17

strep agalactiae

Question 18

common carriages?

Answer 18

GIT; vaginal in 20-30% of ppl; 30% of the time

Question 19

Tx (not rly but…) for grp B BHS neonatal sepsis?

Answer 19

prophylactic penicillin to select pregnant mothers b4 birth

Question 20

grp B BHS can cause?

Answer 20

neonatal sepsis (EOD within 7d; LOD aft 7d); in adults, assoc w/ ppl w/ comorbs and raw freshwater fish (Sg outbreak in 2015). endemic in SEA for decades

Question 21

grp D BHS?

Answer 21

Enterococci (now a new species) and strep bovis

Question 22

strep bovis describe?

Answer 22

assoc w/ endocard and bowel cancer; hepatobiliary infs most common focus; split into 3 – gallolyticus, pasteurianus, infantarius

Question 23

desc enterococci?

Answer 23

endocard; UTI; biliary tract inf

nosocomial

some VRE

Question 24

strep pneumoniae desc?

Answer 24

optochin-sens AHS; capsulated; cause pneumonia, meningitis, bacteremia, URTIs

Question 25

desc viridans strep?

Answer 25

optochin-res; oropharyngeal carr and some nonhemoly

Question 26

huge huge risk factor for strep pneumoniae?

Answer 26

asplenic pts!! who r also prone to meningococcus + capsulated Haemophilus influenzae

Question 27

pneumococcal vacc

Answer 27

polysacch – PPSV23 but dont work too well on young

conjugate vacc – PCV7/10/13 – polysacch linked to some carrier protein

all babies get PCV; adults >65 get both; 2-65yo – vacc only those at risk (incl smokers)

Question 28

a large % of pneumococci ___?

Answer 28

less S to penicillin; some less S to ceftriaxone

Question 29

why penicillin-R/ ceftriaxone-R pneumococci problem when meningitis?

Answer 29

B-lactams dont penetrate into the meninges/ CSF well

Question 30

Empirical Tx for pneumococcal meningitis

Answer 30

Incl vancomycin

Question 31

viridans strep; disease?

Answer 31

common cause of native valve endocard, when heart valves alr have prev dmg

heart dmg can be congenital (bicuspid aorta) or acq (RHD or prev IE)

Question 32

penicillin

Answer 32

Grp ABCFG BHS = S; strep bovis = S; viridans and nonhemoly = range from S to R

Enterococci = reduced S, some R; severe inf req combi therapy; endocard – ampicillin and gentamicin

Cephalosporins – strep = S; enterococci = R

Question 33

strep and enterococci desc

Answer 33

GPC in pairs (diplococci) or chains, catalase neg