Term
|
Definition
- family: streptococcaceae
- genus
- streptococcus
- abiotrophia (nutrient deficient)
- granulicatela (nutrient deficient)
|
|
|
Term
|
Definition
|
|
Term
| key species in streptococcus and enterocuccus genera |
|
Definition
- S pyogenes (group A)
- S agalactiae (group B)
- S pneumoniae
- Viridans streptococci (green like)
- E faecalis
- E faecium
|
|
|
Term
| Strept physiololgy: morphology |
|
Definition
- gram positive
- multiplication in one dimension, with incomplete separation of daughter cells resulting in formation of pairs and chains
|
|
|
Term
| Strept physiol: growth (mode of metabolism) |
|
Definition
- rapid growth of sharply defined, smooth, translucent colonies on routine, nonselective media
- oxygen tolerant anerobic mode of met.
|
|
|
Term
| Characteristics to ID streptococci or enterococci |
|
Definition
- gram positive cocci usually in pairs or chains
- catalase test- negative
|
|
|
Term
| Options for IDing strept. pyogenes |
|
Definition
- wide zone of beta hemolysis on 5% sheep blood agar (slow)
- bacitracin (A disk) susceptible, trimethoprim-sulfamethoxazole (SXT disk) resistant
- zone of inhibiton around bacitracin or SXT disk (SLOW TEST)
- pyroglutamyl aminopeptidases (PYRase) positive (popular and cheap)
- detection of lancefield group A Ag in colonies (popular)
- agglutination test to detect group A Ag
|
|
|
Term
| Options for IDing Strept. agalactiae |
|
Definition
- narrow zone of beta hemolysis on 5% sheep blood agar
- bacitracin resistant and SXT disk resistant
- PYRase negative
- cAMP test positive
- see narrow zone hemolysis
- increase in hemolysis caused by S aureus cAMP interacting with strept agalactiae hemolysis
- detection of Lancefield group B Ag in colonies
|
|
|
Term
| Options for IDing Strept. pneumoniae |
|
Definition
- alpha hemolysis on 5% sheep blood agar
- green discoloration around colonies
- optochin (P disk) susceptible
- quellung reaction positive
- bile solubility positive
|
|
|
Term
| Options for IDing Viridans Strept. |
|
Definition
- alpha hemolysis on 5% sheep blood agar
- P disk resistant
- Quellung reaction negative
- overlay serum with omniserum (costs too much, so rare test)
- Ab bind to organism and gives "halo" around the organism
- bile solubility negative
|
|
|
Term
| IDing Enterococcus species |
|
Definition
- alpha, beta, or gamma hemolysis on 5% sheep blood agar
- esculin (glucose + esculitin) hydrolysis in presence of bile salts
- growth in 6.5% NaCl broth
- Pytroglutamyl aminopeptidases (PYRase) test positive
|
|
|
Term
| S pyogenes somatic (cell associated) VF's and their functions |
|
Definition
- capsule (hyaluronic acid)
- M protein (inh. phagocytosis)
- protein F (fibronectin-BP)
- lipoteichoic acid (adherence)
|
|
|
Term
| S pyogenes VF's (enzymes and toxins) |
|
Definition
-
enzymes
-
streptolysisn O and S- leuckocyte lysis
-
sterptodornase B- DNA dig.
-
streptokinase- fibrin clot lysis
-
hyaluronidases- CT dig.
-
toxins
|
|
|
Term
| VF's of S. agalactiae and function |
|
Definition
- polysaccharide capsule- inhibit phagocytosis
- hemolysin- leukocyte lysis
|
|
|
Term
| VF's of Enterococcus species and function |
|
Definition
- lipoteichoic acid- adherence
|
|
|
Term
| VF's of Viradins streptococci |
|
Definition
- adhesins of unknown composition and specificity
|
|
|
Term
| S pneumonia VF's and function |
|
Definition
- polysaccharide capsule- evade phagocytosis (90 different serotypes)
- lipoteichoic acid- adherence
- peptidoglycan- inflammation via activation of alternative complement cascade pathway
- neuraminidases- exposure of receptors to host cell
- pneumolysin- leukocidin and induction of cytokine production
- IgA protease- digestion of IgA
- altered penicillin binding proteins- resistance to beta lactam antibiotics
|
|
|
Term
| Epidemiology of S pyogenes: where live |
|
Definition
- live on mucous membranes
- preferentially colonize upper resp. tract
|
|
|
Term
| epidemiology of S agalactiae |
|
Definition
- live on mucous membrane
- preferentially colonizes vagina and upper respiratory tract
|
|
|
Term
| epidemiology of S pneumoniae |
|
Definition
- live on mucous membrane
- colonize upper resp. tract
|
|
|
Term
| Epidemiology of Viridans strept |
|
Definition
| live on mucous membrane
colonize upper resp. tract |
|
|
Term
| epidemiology of enterococcus species |
|
Definition
- lives on mucus membrane, skin
- colonize GI tract
|
|
|
Term
| Infections caused by S pyogenes |
|
Definition
- resp. tract infections
- pharyngitis
- scarlete fever
- sequelae
- suppurative sequelae
- tonsilar abscess
- retropharyngeal abscess
- nonsuppurative sequelae
- acute rheumatic fever (treat to prevent this)
- acute glomerulonephritis
- impetigo
- pyoderma (aggressive folliculitis)
- ecthyma
- erysipelas (reddening of tissue)
- cellulitis
- TSS
|
|
|
Term
|
Definition
- erythema (redness in throat)
- uvulitis
- tonsilar exudates (white surface)
|
|
|
Term
| Symptoms of scarlett fever |
|
Definition
|
|
Term
| Infections caused by S agalactiae |
|
Definition
- neonatal sepsis/meningitis (if born vaginally are at risk for this)
- early onset (init. during birth)
- late onset (postnatal infection)
- postpartum sepsis (after child birth)
|
|
|
Term
| Infections of S pneumoniae |
|
Definition
- pneumonia
- bacteremia
- meningitis (the number one cause of meningitis is S pneumoniae)
- otitis media
- sinusitis
|
|
|
Term
| Infection caused by Viridans Streptococci |
|
Definition
- dental caries
- endocarditis
|
|
|
Term
| Infection by Enterococcus species |
|
Definition
- endocarditis
- catheter related sepsis
- UTI's
|
|
|
Term
| lab diagnosis of strept. infections |
|
Definition
- gram stain
- Ag detection via immunochromatography for:
- S pyogenes
- S agalactiae
- S pneumoniae
- molecular diagnositics
- S pyogenes (direct detect via rRNA)
- S agalactiae (realtime PCR for detection of amplified DNA)
- culture
- nonselective media (chocolate agar, 5% sheep blood agar)
- selective media
- strep selective for S pyogenes and S agalactiae
- Ab detection
- antistreptolysin O
- anti DNAse B for S pyogenes
|
|
|
Term
| Antimicrobial resistance seen in streptococci |
|
Definition
- penicillin/cephalosporin resistance
- inducible clindamycin R
|
|
|
Term
| Antimicrobial resistance seen in Enterococci |
|
Definition
- ampicillin R
- vancomycin R
|
|
|
Term
| Mechanism of discovering penicillin/cephalosporin and ampicillin resistance |
|
Definition
| in vitro antimicrobial susceptibility testing |
|
|
Term
| Mechanism of inducible clindamycin resistance |
|
Definition
|
|
Term
| Mechanism of discovering vancomycin resistance |
|
Definition
- growth on vancomycin agar
- in vitro antimicrobial susceptibility testing
|
|
|
