Term
| How do you differentiate between streptococci and staphylococci? |
|
Definition
staphylococci: catalase +
streptococci: catalase - |
|
|
Term
| Divide streptococci into three groups depending on hemolytic ability |
|
Definition
* beta-hemolytic: completely lyse RBC
* alpha-hemolytic: incomplete/partial, green-colored hemoglobin metabolite
* gamma-hemolytic: non-hemolytic |
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|
Term
| What are "Lancefield antigens"? |
|
Definition
| Antigenic C carbohydrate found on the cell wall. A ~ S |
|
|
Term
| What are 5 most significant human pathogenic streptococci species? |
|
Definition
Lancefield group A, B, and D.
Streptococcus pneumoniae
Viridans group streptococci. |
|
|
Term
| Which streptococcus species has Lancefield group A, and is beta-hemolytic? |
|
Definition
Streptococcus pyogenes
(pus-producing) |
|
|
Term
| 4 diseases that streptococci pyogenes cause |
|
Definition
| strep throat, scarlet fever, rheumatic fever, post-streptococcal glomerulonephritis |
|
|
Term
|
Definition
| Antigenic cell wall component of group A streptococcus. Inhibits activation of complements, but is a target of antibodies of the host. |
|
|
Term
| Enzymes in streptococcus pyogenes (group A, beta-hemolytic) |
|
Definition
* streptolysin O: lyses RBC, WBC; antigenic. INactivated by oxygen
* streptolysin S: Oxygen stable. Hemolytic but not antigenic
* Pyrogenic exotoxin (erythrogenic toxin): in a few strains; cause scarlet fever; some are superantigens that lead to toxic shock syndrome
* streptokinase, hyaluronidase, DNAses, anti-C5a peptidase |
|
|
Term
| 4 diseases by local invasion and/or exotoxin release of streptococcus pyogenes? |
|
Definition
1. streptococcal pharyngitis
2. streptococcal skin infections
3. scarlet fever
4. streptococcal toxic shock syndrome |
|
|
Term
| 2 delayed antibody mediated diseases by streptococcus pyogenes: |
|
Definition
1. rheumatic fever
2. glomerulonephritis |
|
|
Term
| How to diagnose streptococcal pharyngitis? |
|
Definition
1. Rapid Antigen Detection Test (for antigenic C carbohydrate)
2. throat culture |
|
|
Term
| How do you treat streptococcal skin infection? |
|
Definition
| With dicloxacillin (penicillinase resistant penicillin), which covers both Streptococcus pyogenes and Staphylococcus aureus |
|
|
Term
|
Definition
| Streptococcal pyogenes infection of the superficial skin (dermis). Unlike cellulitis, rarely caused by Staph. aureus |
|
|
Term
| Virulent factor of Strep. pyogenes that causes necrotizing fasciitis? |
|
Definition
| M protein--block phagocytosis, allowing the bacteria to move rapidly through tissue, along the fascia. |
|
|
Term
|
Definition
A form of necrotizing fasciitis involving the male genital area and perineum.
Can be caused by Strep. pyogenes |
|
|
Term
| Scarlet fever's rash spares which part of the body? |
|
Definition
|
|
Term
| How to treat Streptococcus pyogenes infection? |
|
Definition
* penicillin G
* clindamycin, which inhibits bacterial ribosome ---> blocks pyrogenic toxin and M protein syntheses |
|
|
Term
|
Definition
| beta-hemolytic group A streptococcal pharyngitis (not skin infection) |
|
|
Term
| Clinical features of acute post-streptococcal glomerulonephritis |
|
Definition
* fluid retention
* dark urine (hematuria) |
|
|
Term
| Group B streptococci (also beta-hemolytic) are called: |
|
Definition
|
|
Term
| Streptococcus agalactiae can cause what diseases in neonates (< 3 mo. old) |
|
Definition
| meningitis, pneumonia, sepsis |
|
|
Term
| Clinical features of neonatal meningitis |
|
Definition
| nonspecific: fever, vomiting, poor feeding, irritability |
|
|
Term
| Three most common bacteria that cause neonatal meningitis: |
|
Definition
* Listeria monocytogenes
* Escherichia coli
* Streptococcus agalactiae (group B) |
|
|
Term
| two most common bacteria that cause meningitis between maternal Ab and synthesis of new Ab? |
|
Definition
* Neisseria meningitides
* Haemophilus influenzae |
|
|
Term
| Where are Viridans group streptococci found? |
|
Definition
| GI tract, esp. in the mouth |
|
|
Term
| 3 infections caused by Viridans group streptococci: |
|
Definition
* dental infections
* endocarditis
* abscesses |
|
|
Term
| subacute and acute endocarditis are caused by: |
|
Definition
subacute: viridans streptococci
acute: staphylococcal infection |
|
|
Term
| Streptococcus intermedius and anginosus |
|
Definition
| immediately assess for abscess (CAT scan with contrast). viridans group |
|
|
Term
| Group D streptococci: hemolysis type and divisions |
|
Definition
* alpha-hemolytic
* enterococci (faecalis and faecium) and non-enterococci (S. bovis and S. equinus) |
|
|
Term
|
Definition
| urinary tract infections, biliary tract infections, bacteremia, subacute bacterial endocarditis, target hospitalized patients. |
|
|
Term
| Enterococci are not resistant to: |
|
Definition
| ampicillin and vancomycin |
|
|
Term
| How do you grow Streptococcus bovis (group D, non-enterococci)? |
|
Definition
| In 40% bile (but not in 6.5% NaCl)--enterococci grow in either 40% bile or 6.5% NaCl |
|
|
Term
| Which bacterial infection is associated with colon cancer? |
|
Definition
|
|
Term
| Streptococcus pneumoniae (pneumococcus) cause which diseases? |
|
Definition
| bacterial pneumonia and meningitis in adults; otitis media in children |
|
|
Term
|
Definition
1. Quellung reaction (capsule)
2. Optochin sensitivity (Strep. viridans is also alpha-hemolytic) |
|
|
Term
| 3 most common bacteria that cause otitis media: |
|
Definition
1. Streptococcus pneumoniae
2. Haemophilus influenzae
3. Moraxella catarrhalis |
|
|
Term
| Who should get pneumovax (pneumococcal vacine)? |
|
Definition
| immunocompromised (HIV), elderly, no spleen |
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