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Quiz 1 > Bacteriology > Flashcards

Flashcards in Bacteriology Deck (26):
0

prokaryotic cells characterics

0.2-2 micron
-no nucleus has nucleoid area
-simple flagella
-70s ribosomes
-single circular ribosomes
-binary fission replication

1

eukaryotic cells characteristics

10-100 micron
-true nucleus and membrane bound organelles
-80 s ribosomes in mitochondria
-flagella and cytoskeleton
-multiple linear chromosomes
-mitosis and meiosis

2

prion

only present in bacteria

3

bacterial shapes

cocci- spherical
strepo-long chain, diplo ( pairs), entero ( intestine)

bacilli- rod shaped
cocco ( egg shaped)

spiral bacteria ( corkscrew)
-vibrio ( comma)
- spirillum ( spiral, wavy)
- spirochaete ( old telephone, coiled)


4

different types of stains

simple- one color only, white background
differential- gram stain and acid fast
capsule- colors background and bacteria, shows capsule that exclude stain from around organism ( HALO effect)

5

gram stain

based on cell wall structure- amount of peptiologlycan ( mesh/lattice structure)
-useful for antibiotics and tissue damage
-rapid and allows us to see if there is bacteria

6

gram stain procedure

1. fix specimen on slide and flood with methanol or pass slide through a flame
2. Add primary stain- crystal violet ( gentian)
3. Add mordant to keep stain stay in cells-iodine
4. Add acetone-alcohol wash (decolorizer) to wash away purple brown color
differentiation step: + retain statin and is purple, - lose all stain and is colorless (leaky cell wall)
5. add safranin (counter stain) to allow visibility in microscope
+ doesn't effect
- we can see it now!


7

gram negative

thin layer peptidoglycan
-no teichoic acid
- lipolysaccharide
-outer membrane and periplasm ( space in inner cell wall)
-less susceptible to penicillin
pink/red

8

gram positive

remains purple
-thick layer peptidoglycan
-teichoic acid present allowing stick to surface charge
-no lipopolysaccharide
-no outer membrane or periplasm
-more susceptible to penicillin

9

Ziehl-Neelsen/acid fast stain

tests for TB
- have wax in cell wall
-carbon fuchsin is added to smear and heated to enhance penetration of dye
-colorization: acid-alcohol removes RED, methytone BLUE colors background
Ex: cryptosporidium- parasite that causes diarrhea

10

glycocalyx

capsule or slime layer ( outer most layer)

11

axial filament

internal flagella in spirochaetes

12

fimbriae and pill

hair-like appendages on gram - bacteria

13

sex pilus

transfer of genes ( DNA from cell to cell)- conjugation

14

peptidoglycan

lattice structure, provides structure for gram +

15

lipopolysaccharide

outer membrane in gram -
-lipid A: endotoxin ( inflammation)
-polysaccharide: O antigen ( typing)

16

teichoic and lipoteichoic acids

attach to peptidoglycan layer, projects outwards and cause cells to have negative charge, easier attachment to host cells and tissues

17

inclusions

reserve deposits of nutrients for bacteria

18

Endospores

genetic material in thick coat, no metabolic activity, resistant to heat and drying chemicals. Clostridium and bacillus produce endospores

19

metabolism

sum total of all chemical reactions within an organism.
-Catabolic: release energy
-Anabolic: produce store energy

20

physical factors for microbial growth

1. temperature: pyschrophiles: cold loving
-thermophiles: heat loving
- hyperthermophiles: hot spring
2. pH
- 5 to 8 for human pathogens
-acidophiles down, alkalophile up
3. Osmotic pressure
- obligate halophiles is INCREASE salt
-falculative halophiles is TOLERATE salt


21

growth requirements for microbacteria

strict aerobe- needs O2
facultative anaerobe- both
Strict anaerobe- minimal O2
Aerotolerant anaerobe- some O2
microaeroble- needs a little of both

22

bacterial growth curve

lag-infection
log- growth of bacteria
stationary-stops growth
death-dies!

23

biofilms

lives in communities like the plaque on our teeth, WBC can't penetrate, antibiotics are ineffective

24

Agar

complex polysaccharide from algae for culture matrix, add animal blood

25

differential vs. selective media

differential- blood agar, hemolytic reactions ( breakdown of RBC that are mixed with agar) A-partial, B-total, G-none
selective- prevents species from growing and induce others to grow