Chapter 12-13 Strept Entero Pneumo

Question 1

describe the microbe streptococcus agalctiae

Answer 1

group B, beta hemolytic, chain like growth, aerobic, polysaccharide capsule

Question 2

where is streptococcus agalactiae found

Answer 2

lower GI tract

Question 3

what diseases does streptococcus agalactiae cause

Answer 3

-pneumonia in neonates
-bacteremia and meningitis
- urinary infections in pregnant women

Question 4

what protects against streptococcus agalactiae

Answer 4

antibodies against group B polysaccharide Ag

Question 5

what causes streptococcal toxic shock syndrome

Answer 5

strains of different S pyogenes or S agalactiae

Question 6

what type of microbe is enterococcus faecalis and where is it found

Answer 6

-gram positive cocci
- alpha and non hemolytic
- facultative anaerobes
- GI flora

Question 7

describe the virulence of enterococcus faecalis

Answer 7

high mutliple antibiotic resistance - plasmid and chromosomal

Question 8

what is the epidemiology for enterococcus faecalis

Answer 8

elderly
- long hospitalization
- high nosocomial risk

Question 9

what is VRSA caused by

Answer 9

vancomycin resistance enterococci

Question 10

what streptococci strain is seen as diplo-cocci

Answer 10

streptococcus pneumoniae

Question 11

what does Beta hemolysis on blood agar plates cause

Answer 11

clearing at and around colonies in streptococcus pyogenes

Question 12

what is alpha hemolysis due to

Answer 12

partial lysis of eythrocytes in S mitis and S pneumoniae

Question 13

what does green color on agar plates mean

Answer 13

pneumolysin degrading hemoglobin

Question 14

what are lancefield groups

Answer 14

a way to classify streptococci. A-W

Question 15

what is group A in lancefield groups

Answer 15

N-Ac glucosamine and rhamnose

Question 16

what is group B in lancefield groups

Answer 16

rhamnose and N-Ac-glucosamine + galactose

Question 17

what is rapid strep throat test based on

Answer 17

group A serological responses

Question 18

what are streptococcal classification methods

Answer 18

-lancefield groups
-biochemical, metabolic classification
- DNA sequencing - phylogenetic analysis

Question 19

describe DNA sequencing - phylogenetic analysis

Answer 19

• sequencing the emm gene for the required virulence factor protein M

Question 20

what is M protein

Answer 20

• cell wall component that is an important virulence factor
• membrane- anchored

Question 21

what do anti- M antibodies do

Answer 21

prevent infection of S.pyogenes but many serotypes

Question 22

what does M protein do

Answer 22

• binds keratinocytes, the main cell type in outer skin layer
• binds fibrinogen, blocking surface from complement system components
• binds complement control proteins and inhibits formation of opsonins by complement cascade

Question 23

what are capsules

Answer 23

virulence factors that prevent phagocytosis

Question 24

what are the capsules of group A strains made of

Answer 24

hyaluronic acid

Question 25

what does F protein do

Answer 25

provides adherence to the fibronectin of throat epithelial cells

Question 26

what does lipoteichoic acid do

Answer 26

adheres to the fibronectin epithelial cell coat

Question 27

what is likely the basis for repeated nature of strep throat and deep tissue infections

Answer 27

adhesion based uptake of cocci into epithelial cells

Question 28

what is the M protein anti complement action through

Answer 28

factor H

Question 29

what does capsulae C3 peptidase do

Answer 29

destroys opsonizing C3b complement opsonization

Question 30

what does G protein do

Answer 30

binds Fc of IgG preventing phagocytosis based on Fc receptors

Question 31

what disease does streptococcus pyogenes cause

Answer 31

pharyngitis

Question 32

what do streptolysins S, O do

Answer 32

lysis of erythrocytes (beta hemolysis) and phagocyte lysosomal membranes

Question 33

what causes scarlet fever and what is the virulence factor

Answer 33

streptococcus pyogenes - a superantigen SPE

Question 34

what do pryogenic SPEs cause

Answer 34

-pyoderma (impetigo) - erysipelas

Question 35

what does flesh eating streptococcus pyogenes cause

Answer 35

-streptococcal gangrene - progression to deep, systemic infection leads to multi organ failure and death - necrotizing fasciitis

Question 36

what is the term for strep throat

Answer 36

acute pharyngitis

Question 37

what type of reaction is glomerulonephritis

Answer 37

type III hypersensitivity

Question 38

what type of reaction if rheumatic fever

Answer 38

type II hypersensitivity

Question 39

what is chorea

Answer 39

brain function impairment

Question 40

what type of reaction is the sequelae of a S. pyogenes infection

Answer 40

immune complex III hypersensitivity

Question 41

what can acute rheumatic fever cause

Answer 41

myocarditis and arthritis

Question 42

describe acute rheumatic fever

Answer 42

-non supprative sequela with some strains - less than 10% of population is susceptible - fever is non responsive to penicillin because disease is autoimmune - high frequency of reoccurence

Question 43

what are the complications of streptococcus pyogenes

Answer 43

glomerulonephritis, rheumatic fever, and chorea

Question 44

what are the complications of staphylococcus aureus

Answer 44

-SSS - impetigo - food poisoning - toxic shock syndrome - boild - abscesses

Question 45

describe streptococcus pneumoniae

Answer 45

-alpha hemolytic - gram positive diplococci

Question 46

how many cases of streptococcus pneumoniae are there per year in the US

Answer 46

500,000

Question 47

what type of streptococcus pneumoniae strains are virulent

Answer 47

only encapsulated strains

Question 48

what is the epidemiology and prevention of pneumococcal pneumonia

Answer 48

- high carrier rates for S pneumoniae - capsular vaccine available

Question 49

what is the causative agent, epidemiology, and prevention for kiebsiella penumonia

Answer 49

- kiebsiella pneumoniae, an enterobacterium - often resistant to antibiotics, fatal nosocomial pneumonias - no vaccine available

Question 50

what is the treatment for mycoplasmal pneumonia

Answer 50

no vaccine available

Question 51

what are the 3 major pneumonia causing agents

Answer 51

- streptococcus pneumoniae - kiebsiella pneumoniae - mycoplasma penumoniae

Question 52

what is the treatment of choice for streptococcal pneumonia

Answer 52

penicillin

Question 53

what are the virulence factors for S pneumoniae

Answer 53

-alpha hemolysis - capsule - secretory IgA protease

Question 54

what causes meningitis

Answer 54

S pneumoniae

Question 55

describe streptococcus pneumoniae

Answer 55

-alpha hemolytic - gram positive diplococci