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Choclate agar with factors V and X
H. Influenzae
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Thayer-Martin media
N. gonorrhea
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Bordet-Gengou agar
B. pertussis
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Tellurite plate, Loffler's media
Corynebacterium diphtheriae
-
Lowenstein-Jensen agar
Mycobacteria tuberculosis
-
MacConkeys agar - pink colonies
Lactose fermenting enterics
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Charcoal yeast extract buffered with cysteine
Legionella
-
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Why are aminoglycosides ineffective against Clostrridium, bacteroides, and actinomyces?
These anaerobes and aminoglycosides require O2 to enter into bacterial cells.
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What are the facultative intracellular bugs?
- Salmonella
- Neisseria
- Brucella
- Mycobacterium
- Listeria
- Francisella
- Legionella
Some Nasty Bugs May Live FacultativeLy
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What are the encapsulated bacteria?
- Strep pneumo
- Klebsiella pneumo
- Haemophilus influenzae type B
- Neisseria meningitidis
- Salmonella
- group B strep
Positive Quellung reaction
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Urease positive bugs
- Proteus
- Klebsiella
- H. pylori
- Ureaplasma
-
Protein A MOA and organism
Binds Fc region of Ig. Prevents opsonization and phagocytosis
Staph aureus
-
IgA protease MOA and organism
Cleaves IgA in order to colonize respiratory mucosa
- Strep pneumo
- H. Influenza type B
- Neisseria
-
M protein MOA and organism
- Prevent phagocytosis
- Group A streptococcus
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What are the ADP ribosylating A-B toxins
- Corynebacterium diphtheriae:
- - inactivates elongation factor
- Vibrio Cholerae:
- - ADP ribosylation of G protein stimulates adenylyl cyclase: increase pumping of Cl- into gut and decrease Na+ absorption.
- E. Coli:
- - Heat labile toxin stimulates Gs protein -> Adenylate cyclase
- Bordetella pertussis:
- - Increases cAMP by inhibiting Ga1
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Toxin of Clostridium perfringens
- Alpha toxin
- - a lecithinase that acts as a phospholipase to cleave cell membranes and causes gas gangrene.
-
Toxin of shigella
- Shiga toxin
- - cleaves host cell rRNA (inactivates 60S ribosome)
- - enhances cytokine release causing hemolytic uremic syndrome
-
Streptococcus agalactiae
- Group B streptococci, B-hemolytic
- Bacitracin resistant
- colonizes vagina
- causes pneumonia, meningitis, and sepsis
- Affects babies
Pregnant women + get intrapartum penicillin prophylaxis
-
Enterococci (Group D strep)
Normal colonic flora that are penicillin G resistant and cause UTI and subacute endocarditis
Grow in 6.5% NaCl and bile
-
Corynebacterium diphtheria
Diphtheria toxin exotoxin encoded by B-prophage - inhibits protein synthesis via ADP ribosylation of EF-2
DX: via tellurite agar -> metachromatic granules
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4 types of Clostridia
1. C. tetani- tetanospasmin causes spastic paralysis
2. C. botulinum- preformed heat-labile toxin that inhibits ACh release at NMJ
3. C. perfringens- a toxin(lecithinase) causes myonecrosis and hemolysis
4. C. difficile- AB toxin destroys cytoskeletal structure of enterocytes, causing pseudomembranous colitis.
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Nocardia
- gram positive rod
- weakly acid fast and aerobic
- causes pulmonary infection in immunocompromised patients
TX: sulfanomides
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What does primary infection with Mycobacterium tuberculosis lead to
- Ghon complex (hilar nodes/ ghon focus)
- healing by fibrosis
- progressive lung disease
- Miliary tuberculosis
- Preallergic lymphatic or hematogenous dissemination -> dormant tubercle bacilli in several organs -> reactivation in adult life (CNS, Pott's, lymphadenitis, renal, GI)
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