MICROEX2 Strep Key Terms Flashcards
(25 cards)
Streptococci may be classified by:
Hemolysis Biochemical Reactions Ability to tolerate NaCl or Bile Salts Sensitivity to Optochin and Vancomysin Lancefield Grouping Immunologically Source of Recovery
Most bacteria which cause ______ hemolysis do not occupy healthy tissue. Prescence almost always indicates a pathogen.
Beta hemolysis
Which antibiotic is Streptococcus pyogenes and Streptococcus pneumoniae sensitive to?
Vancomycin
M-protein
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
Streptolysin S
Streptococcus pyogenes Hemolysin Not produces by all strains Produces hemolysis of RBCs leukocidal and non-antigenic
Streptolysin O
Streptococcus pyogenes Hemolysin Damaged by oxygen Cardiotoxic and leukocidal Antigenic Basis for ASO test to detect rhematic fever
Streptokinase
Streptococcus pyogenes
Fibrinolysin; destruction of fibrin clots
Plasmin deactivator
Medically used as “clot buster”
Erythrogenic toxin
Streptococcal pyrogenic exotoxin (SPE)
Streptococcus pyogenes
Scarlet fever toxin (result of Streptococal pharyngitis)
Causes rash on face and upper trunck
Immunity to toxin (not organism)
Scarlet Fever
Streptococcus pyogenes
Streptococcal pyrogenngitisic toxin (SPE)
pharyngeal involvment with rash on face and upper trunk
Necrotizing fasciitis
Streptococcus pyogenes
“flesh eating” bacteria
Acute pharyngitis
Streptococcus pyogenes
Classic sore throat in children
May spread if not treated
Impetigo
Streptococcus pyogenes
Diffuse maculopapular rash, usually around mouth and nose
Rheumatic Fever
Streptococcus pyogenes
Occures AFTER a S. pyogenes infection
Follows unresolved pharyngitis and/or scarlet fever
Detected by ASO test
Overview of Streptococcus agalactiae
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
Streptococcus agalactiae has a _________ (smaller/larger) zone of beta hemolysis than other beta hemolytic streptococci.
Smaller
Subacute Bacterial Endocarditis (SBE)
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
Streptococcus pneumoniae is normal flora in what region of the body?
nasopharyngeal region
Bacterial (lobular) pneumonia
Streptococcus pneumoniae
Occurs after previous viral infections
More common in alcoholics, smokers, and debilitated
Specimen of choice is transtracheal aspirate
Pneumococcal memingitis
Streptococcus pneumoniae
Bacterial infection in the brain and spinal cord
May initially involve middle ear (otitis media), pharyngitis, sinusitis
Specimen of choice is CSF
Describe the colonies of Streptococcus pneumonia on blood agar.
Alpha hemolytic
Colonies dip down in center (doughnut)
Colonies may be mucoid (capsule)
Auto hemolysis on blood agar resembles volcanos
PCV13 or Prevnar 13
Vaccine against Streptococcus pneumoniae
Recommended for elderly, aspleenic, sickle cell, diabetes, HIV, and immunocompromised)
Quelling Reaction
the swelling of the capsule surrounding a microorganism after a reaction with an antibody.
Positive: Streptococcus pneumoniae and select other capusuled organisms
Group D Strep and Enterococcus are considered normal flora in…
respiratory and alimentary canal
Enterococcus and Group D Strep are resonsible for….
UTI and Subacute Bacterial Endocarditis (SBE)
