RTI III

Question 1

name 5 criteria that highly suggest strep pharyngitis

Answer 1

• age 3-14
• absence of cough
• swollen and tender anterior and cervical lymph nodes
• temp. >100.4 F (38 C)
• tonsillar exudate or swelling

Question 2

list 2 pathogens that require specialized growth media that is not standard

Answer 2

• Bordatella pertussis: Bordet-Gengou agar
• C. diphtheriae : Tinsdale agar/Cysteine-Tellurite agar

Question 3

describe the cell wall of Streptococcus

Answer 3

• polysaccharide capsule
  
  • hyaluronic acid
  • Quellung reaction (used specifically for S. pneumoniae, M-protein is used to identify S. pyogenes)

Question 4

describe Streptococcus pyogenes

Answer 4

clinical syndrome: pharyngitis “strep throat”, skin infections, soft tissue infections, endocarditis

• leukocidin production → inducer of pus formation

Question 5

the large number of virulence factor in Streptococcus is probably due to _____

Answer 5

the large number of virulence factor in Streptococcus is probably due to transduction-mediated gene transfer and are also capable or transformation

Question 6

Streptococci lack ____ which make them anaerobies but possess ____ which make them ______

Answer 6

Streptococci lack catalase which make them anaerobes but possess SOD which make them aerotolerant

Question 7

____ is type specific proteins in the cell wall of S. pyogenes

Answer 7

M protein is type specific proteins in the cell wall of S. pyogenes

Question 8

____ is group-specific carbohydrate in the cell wall of S. pyogenes

Answer 8

A antigen is group-specific carbohydrate in the cell wall of S. pyogenes

Question 9

list the factors of S. pyogenes that help them avoid phagocytosis

Answer 9

• avoid phagocytosis:
  
  • capsule, C5a peptidase, M and M-like proteins, lipoteichoic acid, F protein

Question 10

list the factors of S. pyogenes that help them adhere to and invade cell walls

Answer 10

• adhere to and invade cell wall:
  
  • M protein, lipoteichoic acid, F protein

Question 11

list the virulence factors and pathogenesis of Group A streptococcus

Answer 11

• avoid phagocytosis
  
  • capsule, C5a peptidase, M and M-like proteins, lipoteichoic acid, F protein
• adhere to and invade cell wall
  
  • M protein, lipoteichoic acid, F protein
• toxins
  
  • streptococcal pyrogenic exotoxins (SPE), streptolysin S, streptolysin O, streptokinase, DNAse
    
    • streptolysins = lysis of blood cells (specifically WBCs)

Question 12

name the top 2 suppurative diseases that Streptococcus pyogenes (GAS) causes

Answer 12

Question 13

name the 2 non-suppurative diseases that Streptococcus pyogenes (GAS) causes

Answer 13

Question 14

explain the Sketchy for s. pyogenes

Answer 14

Question 15

Corynebacterium are (G+ve/G-ve) rods and (aerobic/anaerobic)

Answer 15

Corynebacterium are G+ve rods and aerobic

Question 16

name 2 other medically-important Corynebacterium species

Answer 16

• C. jeikeium: associated with bacteremia, IV catheter colonization
• C. minutissimum: RTI’s wound infxns

Question 17

describe what is seen in the image

Answer 17

Question 18

Corynebacterium diphtheriae produces ____ of dub-shaped ____ rods arranged in V or L shapes on Gram stain

Answer 18

Corynebacterium diphtheriae produces gray-to-black colonies of dub-shaped G+ve rods arranged in V or L shapes on Gram stain

Question 19

Corynebacterium diphtheriae produce ____ and can be seen when grown on _____

Answer 19

Corynebacterium diphtheriae produce granules (volutin) and can be seen when grown on Loeffler coagulated serum

Question 20

toxin-producing strains of Corynebacterium diphtheriae have ____ carrying genes for the toxin _____

Answer 20

toxin-producing strains of Corynebacterium diphtheriae have B-prophage carrying genes for the toxin lysogeny, B-corynephage

Question 21

describe the clinical importance of Corynebacterium diphtheriae

Answer 21

Question 22

describe the pathogenesis Corynebacterium diphtheriae

Answer 22

Question 23

the main virulence factor for Corynebacterium diphtheriae is _____

Answer 23

the main virulence factor for Corynebacterium diphtheriae is diphtheria exotoxin (genes for toxin acquired via lysogenic conversion → bacteriophage)

• responsible for:
  
  • inflammation and formation of pseudomembrane
  • damage to organs

Question 24

describe the mechanism of action of diphtheria toxin

Answer 24

Question 25

describe the screening test for pathogenic *Corynebacterium diphtheriae*

Answer 25

Question 26

describe the Elek test

Answer 26

Question 27

list the most common pathogens involved in sinusitis and acute otitis media (AOM)

Answer 27

Question 28

explain the Sketchy for *Corynebacterium diphtheriae*

Answer 28

Question 29

name the signs and symptoms of sinusitis and acute otits media

Answer 29