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Flashcards in Special Culture/features of bacteria Deck (17):
1

Which media does H. influenza grow on?

Chocolate agar with factors NAD+ and hematin

2

Which media does M. tuberculosis grow on?

Lowenstein-Jensen agar

3

Which media does M. pneumonia grow on?

Eaton agar--requires cholesterol

4

Lactose-fermenting enterics media?

Pink colonies on MacConkey agar

5

3 obligate aerobe bacteria
Nagging Pests Must Breathe

1. Nocardia
2. Pseudomonas aeruginosa
3. Mycobacterium tuberculosis--this is why TB is often found in the apices of the lungs where the PO2 is highest

6

3 obligate anaerobe bacteria
Anaerobes *Can't *Breath *Air

1. Clostridium
2. Bacteroides
3. Actinomyces

7

What makes anaerobes obligate?
General clinical characteristics of obligate anaerobes
Which antibiotics are ineffective towards obligate anaerobes?

1. Obligate anaerobes lack catalase and/or superoxide dismutase and are thus susceptible to oxidative damage.
2. Generally foul-smelling, difficult to culture, and produce gas (CO2 and H2) in tissue
3. Aminoglycosides (aminO2glycosides) require oxygen to enter into bacterial cell

8

Two obligate intracellular bugs

Rickettsia and chlamydia --this is why they don't gram stain very well

9

Facultative intracellular bacteria (8)
*Some *Nasty *Bugs *May *Live *Facultative**LY

Salmonella
Neisseria
Brucella
Mycobacterium
Listeria
Francisella
Legionella
Yersina pestis

10

Encapsulated bacteria (7)
***SHiNE SKiS
How does the capsule assist the bacteria?
How can the capsule be used in vaccines?
How are encapsulated bacteria cleared by body?
Who is at risk for infection from encapsulated bacteria?

Streptococcus pneumoniae
Haemophilus influenza type B
Neisseria meningitidis
E. Coli
Salmonella
Klebsiella pneumoniae
Group B Strep

1. Capsule serves as an antiphagocytic virulence factor
2. Capsule + protein conjugate serves as an antigen in vaccines
3. Opsonized and cleared by spleen
4. Asplenic patients are at risk for severe infections from encapsulated organisms

11

Catalase-positive organisms
"you need PLACESS for your *cats"
How does catalase work?
Which patients are at risk for infection from catalase-positive organisms?

Pseudomonas
Listeria
Aspergillus
Candida
E. Coli
Staph aureus
Serratia

Catalase degrades H2O2 before it is converted to microbicidal products by the enzyme myeloperoxidase.
People with CHRONIC GRANULOMATOUS DISEASE (NADPH peroxidase deficiency) have recurrent infections with catalase + organisms

12

Encapsulated bacteria vaccines:
how do they work? for what purpose? why can't a polysaccharide antigen be used alone?
3 examples: "Past Medical History"

1. Some vaccines contain a polysaccharide capsule conjugated to a carrier protein
2. This enhances immunogenicity by promoting T-cell activation and subsequent class switching
3. Polysaccharide antigen alone cannot be presented to T-cells
Examples: Penumococcal vaccine, H. influenza type B vaccine, Meiningococcal vaccine

13

Urease-positive bugs
"CHUNKSS"

Cryptococcus
H. pylori
Ureaplasma
Nocardia
Klebsiella
Staph epidermis
Staph saprophyticus

14

Pigment producing bacteria:
Actinomyces israelii
S. aureus
Pseudomonas aeruginosa
Serratia marcescens

Actinomyces israelli is YELLOW
S. aureus is GOLD
pseudomonas is BLUE-GREEN
Serratia marcescens is RED

15

Protein A virulence factor

Binds Fc region on IgG.
Prevents opsonization and phagocytosis
Expressed by S. aureus

16

IgA protease
Secreted by? (4) SHiNe

Enzyme that cleaves IgA
Secreted by S. pneumoniae, HiB, and Neisseria (SHiN) in order to colonize the respiratory mucosa

17

M protein

Helps prevent phagocytosis.
Expressed by Group A Streptococci