Streptococci GBS

Question 1

characteristics of GBS

Answer 1

non motile, faculative anerobe, most b hemolytic, catalase neg, + cAMP and hip hydrous.

Question 2

3 serological markers in GBS

Answer 2

1. B antigen - group specific cell wall poly saccaride
2. multiple type specific capsular poly sacc
3. surface protein C (note: early onset in babies)

Question 3

Epidemiology of GBS

Answer 3

asympt colonization of GU and URI and lower GI

no seasonal incidence

postpartum sepsis

certain neonates at risk

non prey people with DM cancer low complement and low ab or ETOH

Question 4

neonatal early onset GBS

Answer 4

early onset, in utero or on delivery, abrupt onset, pneumonia, bacteremia, meningitis, low mortality

Question 5

neonatal late onset GBS

Answer 5

insidious. poor feeding at first…. at 4-8 wks of life. organism must be at birth. meningitis (pus in CSF) and bacteremia, high survival

Question 6

pregnant women GBS

Answer 6

UTI during or after delivery, NOOOOO bacteremia, endocarditis, meningitis, osteomylitis

Question 7

characteristics of streptococcus pneumonia (SP)

Answer 7

slimy capsule. fac anerobe. oval or lancet shaped diplococci. pneumolysins, harder to grow bc needs special nutrients

Question 8

how is SP alpha or beta hemolytic?

Answer 8

alpha if grown with O2, beta if not

Question 9

pneumolyssin

Answer 9

in SP. necessary for alpha hemolysis

Question 10

epidemiology of SP

Answer 10

common in nose and through of healthy people. children are colonized by 6 mo. more common in cooler season. caused by a distant place from colonized site in lungs sinus ears and meninges.

Question 11

SP spread?

Answer 11

P2P droplet

Question 12

SP increase risk?

Answer 12

inc risk if no cilia or impairment of anything that promotes bacterial clearance. other: COPD, URI, DM, CHF, ETOH

elderly and old at risk for meningitis

no spleen or sickle cell at risk for sepsis

Question 13

clinical dz in SP and what is each preceding event for all of them?

Answer 13

aspiration pneumonia s/p viral

sinusitis and OM s/p URI with PMN infection

meningitis - mostly peds

bacteremia with endocarditis

Question 14

what is the virulence of SP dependent on?

Answer 14

the competency of the hosts immune system

Question 15

where does SP colonize? and spread?

Answer 15

oropharynx to lung and tissue (local v. distal via blood)

CAPSULE IS ESSENTIAL FOR VIRULENCE

Question 16

SP - 2 types of adhesins

Answer 16

F antigen and C polypeptide - both techoic

Question 17

what is required for autolysis in SP?

Answer 17

cholin and techoic acid (required by autolysin)

Question 18

what is secretory IgA protease?

Answer 18

prevents enveloping of bacteria by mucous so it can spread in SP

Question 19

pneumolysin

Answer 19

binds to cholesterol in host membrane forms pores. destroys ciliated epithelium and phagocytes. so it can spread — -then autolysin released. #1 VIRULENCE FACTOR

SP

Question 20

phiosphoryl choline

Answer 20

helps colonization in SP - binds plt activating factor, internalize and sequester bacteria and protects from opson

Question 21

what protects SP from oxidative burst?

Answer 21

capsule and pneumolysin - capsule poly sac can be soluble - and free - and bind opsin

Question 22

how is C5a produced and what activates the alternative compliment pathway and classic thereby increasing tissue destruction in SP?

Answer 22

techoic acid - alt (C5a)

pneumolysin - classic (releases C5 and C3a)

Question 23

E. facium and E. fecalis (EF)

Answer 23

also gram + cocci. faculative anerobe, non motile, nonspecific and nonhemolytic.

Question 24

EF AND EF epidemiology

Answer 24

not a threat unless in the hospital and/or you lack all normal flora. similar to staph epi.

colonize GI of human and animals.

spread P2P

NOOOOOO toxins

Question 25

EF and EF causes what dz.’s?

Answer 25

nosocomial UTI, wound infection, bacteremia, endocarditis

Question 26

cytolisin in EF

Answer 26

ruptures cells. bacteriocidin. inhibits other gram + from colonizing. local tissue damage. virulence similar to staph epi.

Question 27

gelatinase in EF

Answer 27

Gel-E. hydrolysis gelatin, collegin, and small molecules. mediates and binds aggregative factors. vanc resistent (VRE!!!!!!!!) and pheromones which attract neutrophils.