RTI III Flashcards
name 5 criteria that highly suggest strep pharyngitis
- age 3-14
- absence of cough
- swollen and tender anterior and cervical lymph nodes
- temp. >100.4 F (38 C)
- tonsillar exudate or swelling
list 2 pathogens that require specialized growth media that is not standard
- Bordatella pertussis: Bordet-Gengou agar
- C. diphtheriae : Tinsdale agar/Cysteine-Tellurite agar
describe the cell wall of Streptococcus
- polysaccharide capsule
- hyaluronic acid
- Quellung reaction (used specifically for S. pneumoniae, M-protein is used to identify S. pyogenes)
describe Streptococcus pyogenes
clinical syndrome: pharyngitis “strep throat”, skin infections, soft tissue infections, endocarditis
- leukocidin production → inducer of pus formation
the large number of virulence factor in Streptococcus is probably due to _____
the large number of virulence factor in Streptococcus is probably due to transduction-mediated gene transfer and are also capable or transformation
Streptococci lack ____ which make them anaerobies but possess ____ which make them ______
Streptococci lack catalase which make them anaerobes but possess SOD which make them aerotolerant
____ is type specific proteins in the cell wall of S. pyogenes
M protein is type specific proteins in the cell wall of S. pyogenes
____ is group-specific carbohydrate in the cell wall of S. pyogenes
A antigen is group-specific carbohydrate in the cell wall of S. pyogenes
list the factors of S. pyogenes that help them avoid phagocytosis
- avoid phagocytosis:
- capsule, C5a peptidase, M and M-like proteins, lipoteichoic acid, F protein
list the factors of S. pyogenes that help them adhere to and invade cell walls
- adhere to and invade cell wall:
- M protein, lipoteichoic acid, F protein
list the virulence factors and pathogenesis of Group A streptococcus
- 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)
- streptococcal pyrogenic exotoxins (SPE), streptolysin S, streptolysin O, streptokinase, DNAse
name the top 2 suppurative diseases that Streptococcus pyogenes (GAS) causes
name the 2 non-suppurative diseases that Streptococcus pyogenes (GAS) causes
explain the Sketchy for s. pyogenes
Corynebacterium are (G+ve/G-ve) rods and (aerobic/anaerobic)
Corynebacterium are G+ve rods and aerobic
name 2 other medically-important Corynebacterium species
- C. jeikeium: associated with bacteremia, IV catheter colonization
- C. minutissimum: RTI’s wound infxns
describe what is seen in the image
Corynebacterium diphtheriae produces ____ of dub-shaped ____ rods arranged in V or L shapes on Gram stain
Corynebacterium diphtheriae produces gray-to-black colonies of dub-shaped G+ve rods arranged in V or L shapes on Gram stain
Corynebacterium diphtheriae produce ____ and can be seen when grown on _____
Corynebacterium diphtheriae produce granules (volutin) and can be seen when grown on Loeffler coagulated serum
toxin-producing strains of Corynebacterium diphtheriae have ____ carrying genes for the toxin _____
toxin-producing strains of Corynebacterium diphtheriae have B-prophage carrying genes for the toxin lysogeny, B-corynephage
describe the clinical importance of Corynebacterium diphtheriae
describe the pathogenesis Corynebacterium diphtheriae
the main virulence factor for Corynebacterium diphtheriae is _____
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
describe the mechanism of action of diphtheria toxin
