MICROEX2 Strep Key Terms

Question 1

Streptococci may be classified by:

Answer 1

Hemolysis
Biochemical Reactions
Ability to tolerate NaCl or Bile Salts
Sensitivity to Optochin and Vancomysin
Lancefield Grouping
Immunologically
Source of Recovery

Question 2

Most bacteria which cause ______ hemolysis do not occupy healthy tissue. Prescence almost always indicates a pathogen.

Answer 2

Beta hemolysis

Question 3

Which antibiotic is Streptococcus pyogenes and Streptococcus pneumoniae sensitive to?

Answer 3

Vancomycin

Question 4

M-protein

Answer 4

Streptococcus pyogenes
Major virulence factor
Has anti-phagocytic properties via hya;uronidase in capsule
Facilitates attachement to tissue
May be lost if repeatedly cultured in lab

Question 5

Streptolysin S

Answer 5

Streptococcus pyogenes
Hemolysin
Not produces by all strains
Produces hemolysis of RBCs
leukocidal and non-antigenic

Question 6

Streptolysin O

Answer 6

Streptococcus pyogenes
Hemolysin
Damaged by oxygen
Cardiotoxic and leukocidal
Antigenic
Basis for ASO test to detect rhematic fever

Question 7

Streptokinase

Answer 7

Streptococcus pyogenes
Fibrinolysin; destruction of fibrin clots
Plasmin deactivator
Medically used as “clot buster”

Question 8

Erythrogenic toxin

Streptococcal pyrogenic exotoxin (SPE)

Answer 8

Streptococcus pyogenes
Scarlet fever toxin (result of Streptococal pharyngitis)
Causes rash on face and upper trunck
Immunity to toxin (not organism)

Question 9

Scarlet Fever

Answer 9

Streptococcus pyogenes
Streptococcal pyrogenngitisic toxin (SPE)
pharyngeal involvment with rash on face and upper trunk

Question 10

Necrotizing fasciitis

Answer 10

Streptococcus pyogenes

“flesh eating” bacteria

Question 11

Acute pharyngitis

Answer 11

Streptococcus pyogenes
Classic sore throat in children
May spread if not treated

Question 12

Impetigo

Answer 12

Streptococcus pyogenes

Diffuse maculopapular rash, usually around mouth and nose

Question 13

Rheumatic Fever

Answer 13

Streptococcus pyogenes
Occures AFTER a S. pyogenes infection
Follows unresolved pharyngitis and/or scarlet fever
Detected by ASO test

Question 14

Overview of Streptococcus agalactiae

Answer 14

Beta hemolytic (Lancefield group B)
Neonatal sepsis (normal flora of vagina)
Neonatal meningitis
Rare: UTI, osteomyelitis
Capsule interfers with phagocytic activity and complement cascade activation

Question 15

Streptococcus agalactiae has a _________ (smaller/larger) zone of beta hemolysis than other beta hemolytic streptococci.

Answer 15

Smaller

Question 16

Subacute Bacterial Endocarditis (SBE)

Answer 16

Streptococcus pneumoniae
Enterococcus
Group D Strep
Inflammation of the inner layer of the heart
Common flowwing rheumatic fever (damages valves) or in abnormal hearts
Speciman of choice is blood

Question 17

Streptococcus pneumoniae is normal flora in what region of the body?

Answer 17

nasopharyngeal region

Question 18

Bacterial (lobular) pneumonia

Answer 18

Streptococcus pneumoniae
Occurs after previous viral infections
More common in alcoholics, smokers, and debilitated
Specimen of choice is transtracheal aspirate

Question 19

Pneumococcal memingitis

Answer 19

Streptococcus pneumoniae
Bacterial infection in the brain and spinal cord
May initially involve middle ear (otitis media), pharyngitis, sinusitis
Specimen of choice is CSF

Question 20

Describe the colonies of Streptococcus pneumonia on blood agar.

Answer 20

Alpha hemolytic
Colonies dip down in center (doughnut)
Colonies may be mucoid (capsule)
Auto hemolysis on blood agar resembles volcanos

Question 21

PCV13 or Prevnar 13

Answer 21

Vaccine against Streptococcus pneumoniae

Recommended for elderly, aspleenic, sickle cell, diabetes, HIV, and immunocompromised)

Question 22

Quelling Reaction

Answer 22

the swelling of the capsule surrounding a microorganism after a reaction with an antibody.
Positive: Streptococcus pneumoniae and select other capusuled organisms

Question 23

Group D Strep and Enterococcus are considered normal flora in…

Answer 23

respiratory and alimentary canal

Question 24

Enterococcus and Group D Strep are resonsible for….

Answer 24

UTI and Subacute Bacterial Endocarditis (SBE)

Question 25

VRE

Answer 25

Vancomycin Resistant Enterococcus