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Flashcards in Micro Basic Deck (71)
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1

Peptidoglycans
Composition
Function

Sugar backbone with peptide side chains cross linked by transpeptidase
Support. Protects against osmotic pressure

2

Lipoteichoic acid
Where is it?
What does it do?

Cell wall of Gram+
Induces TNF and IL1

3

LPS
AKA
Location
What is it?
Components

Endotoxin
Outer membrane of Gram-
Major Surface Ag
Lipid A (induces TNF and IL1)
O polysaccharide is the antigen

4

Periplasm
What is it?
What kind of organisms
What does it contain

Space between cytoplasmic membrane outer membrane
Gram-
Hydrolytic enzymes include β lactamase

5

Capsule
Made from...
Function

Polysaccharides (except in Bacillus anthracis which contains D-glutamate)
Protects against phagocytosis

6

Pilus/Fimbria
Composition
Function

Glycoprotein
Mediates adherence of bacteria to cell surface. Sex pilus for conjugation

7

Flagellum
Composition
Function

Protein
Motility

8

Spore
Composition
Function

Keratin-like coat, Dipicolinic acid, Peptidoglycan
Resistance to heat, chemicals, dehydration

9

Glycocalyx
Composition
Function

Polysaccharide
Mediates adherence to surfaces (especially foreign surfaces)

10

Outer layer composition in Gram+ vs Gram- bacteria

+
Inside to outside:
Cytoplasmic membrane, Peptidoglycan (cell wall), Capsule
Pilus, Flagellum, Lipoteichoic acid (lipids + teichoic acids)
-:
Cytoplasmic membrane, Perplasm, Peptidoglycan, Endotoxin (LPS), Capsule
Pilus, Flagellum

11

Outer layers of Mycoplasma

Membrane contains sterols and have no cell walls

12

Cell wall of Mycobacteria

Contains mycolic acid with high lipid content

13

Bugs that do not gram stain?

"These Rascals May Microscopically Lack Color"
Treponema (too thin), Rickettsia (intracellular), Mycobacteria (high lipid content in cell wall), Mycoplasma (no cell wall), Legionella pneumophila (intracellular), Chlamydia (intracellular and lacks muramic acid in cell wall)

14

Giemsa Stains for what organisms

"Certain Bugs Really Try my Patience"
Chlamydia, Borrelia, Rickettsiae, Trypanosomes, Plasmodium

15

PAS
Name
What does it stain?
Use

Periodic Acid Schiff Base
"PASs the sugar"
Glycogen, Mucopolysaccharides
Diagnoses Whipple's Disease (Tropheryma Whipplei)

16

Ziehl-Neelsen Stain
Name
Organisms

Carbol Fuchsin
Acid Fast organisms (Nocardia, Mycobacterium)

17

India Ink

Cryptococcus neoformans
Mucicarmine can also be used to stain thick polysaccharide capsule red

18

Silver Stain

Fungi, Legionella, Helicobacter pylori

19

Culture Requirements for H. influenzae

Chocolate agar with factor V (NAD) and X (hematin)

20

Culture Requirements for N gonorrhoeae and N meningitidis

Thayer-Martin (or VPN) media
Vancomycin (inhibits Gram+ organisms), Polymyxin (inhibit Gram- organisms except Neisseria), Nystatin (inhibits fungi)

21

Culture Requirements for B pertussis

"Bordet for Bordetella)
Bordet-Gengou (potato) agar

22

Culture Requirements for C diphtheriae

Tellurite plate, Loffler's media

23

Culture Requirements for M tuberculosis

Lowenstein Jensen agar

24

Culture Requirements for M pneumoniae

Eton's agar

25

Culture Requirements for lactose fermenting enterics

Pink colonies on MacConkey's agar (fermentation produces acid, turning colonies pink)
E coli is also grown on eosin-methylene blue (EMB) agar as colonies with green metallic sheen

26

Culture Requirements for Legionella

Charcoal yeast extract on agar buffered with cysteine and iron

27

Culture Requirements for Fungi

"Sab's a Fun Guy"
Sabouraud's agar

28

Obligate Aerobes

"Nagging Pests Must Breathe"
Nocardia, Pseudomonas aeruginosa (can use nitrates in anaerobic environment), Mycobacterium tuberculosis, and Bacillus

29

Obligate Anaerobes
Name
Weakness
Gross
Culture?
What doe they produce?
Where are they normally?
What antibiotics don't work on them?

"Anaerobes Can't Breathe Air"
Clostridium, Bacteroides, Actinomyces
Lack Catalase and/or SOD and are thus susceptible to oxidative damage
Foul smelling because of short chain fatty acids
Difficult to culture
Produce gas (CO2, H2) in tissue
Normal GI flora
Aminoglycosides ineffective because they need O2 to enter cell

30

Obligate intracellular bugs

"Stay inside when its Really Cold"
Rickettsia, Chlamydia
Can't make their own ATP