Introduction to Medical Microbiology

Question 1

Which is the smallest microbe?

Answer 1

viruses

Question 2

Viruses

Answer 2

require host cell for replication

difficult to treat

Question 3

Bacteria

Answer 3

simple unicellular organisms

prokaryotes

Question 4

Ways to test for bacteria clinically

Answer 4

microscopy
detection of bacterial antigens
detection of bacterial nucleic acids
Culture
Detection of antibody response to bacteria

Question 5

Ways to test for bacteria microscopy

Answer 5

morphology

gram stain

Question 6

Ways to test for bacterial antigens

Answer 6

flagella
capsule
LPS

Question 7

Ways to culture for bacteria

Answer 7

metabolic properties

biochemical tests

Question 8

Ways to test bacterial nucleic acids

Answer 8

PCR

sequencing

Question 9

Ways to test for antibody response to bacteria

Answer 9

ELISA
Western Blot
Immuno staining

Question 10

Bacterial cytoplasm

Answer 10

made of chromosome, mRNA, ribosomes, proteins, and metabolites

Question 11

Cell wall of bacteria is made of

Answer 11

peptoglycan

Question 12

Proinflammatory effects of bacterial cell wall

Answer 12

fixes complement
binds pattern recognition receptors
triggers TNF production

Question 13

Gram negative cell wall contains

Answer 13

outer membrane
peptidoglycan (thin)
perplasmic space
plasma membrane

Question 14

Which is more complex, gram neg or positive?

Answer 14

negative

Question 15

What color does gram positive and negative stain?

Answer 15

negative - red

positive - purple

Question 16

Gram negative enveliope

Answer 16

made of peptidoglycan
acts like a stiff canvas sack around bacteria
has asymmetric phospholipid bilayer

Question 17

Where is LPS found?

Answer 17

outer leaflet of phospholipid bilayer in gram NEGATIVE bacteria only

Question 18

What is LPS made of?

Answer 18

Lipid A
Core polysaccharide
O antigen

Question 19

Lipid A

Answer 19

responsible for endotoxin activity

fatty acids anchor it into OM

Question 20

Core polysaccharide

Answer 20

branches polysaccharide

required to bacterial structure and viability

Question 21

O antigen

Answer 21

lots of species variation

helps classify different bacteria

Question 22

What does LPS/endotoxin do?

Answer 22

causes inflammation, septic shock
activates immune system
binds to CD14 and TLR4 on phagocytes/antigen presenting cells

Question 23

What does gram positive bacteria cell wall contain?

Answer 23

thick peptidoglycan

plasma membrane

Question 24

components of gram positive envelope

Answer 24

peptidoglycan

teichoic acid

Question 25

Teichoic acid

Answer 25

only associated with gram positive

Question 26

LTA and teichoic acid promote what

Answer 26

attachment to other bacteria and to host cells

Question 27

Acid fast bacteria

Answer 27

have complex cell envelop structurally similar to gram positive contains LAM and arabinogalactins

Question 28

Fungi

Answer 28

more complex eukaryotes can be unicellular or filamentous

Question 29

Parasites

Answer 29

most complex eukaryotes unicellular to multicellular

Question 30

Prokaryotes

Answer 30

no nucleus circular DNA smaller ribosome mesh-like peptidoglycan cell wall

Question 31

What are pili/fimbrae made of?

Answer 31

protein subunits called pilin which forms a tube with a small hollow core

Question 32

Two types of pili

Answer 32

common, somatic

Question 33

Sex pili

Answer 33

only one per cell involved in gene transfer bind to other bacteria and a tube for transfer of genetic material, usually a plasmid

Question 34

Flagella

Answer 34

locomotion | has H-antigen

Question 35

Capsule

Answer 35

``` loose polysaccharide (or protein) layer surrounding some gram positive or negative bacteria hydrophilic ```

Question 36

Biofilm

Answer 36

organized community of bacteria that has capsule/slime

Question 37

What can capsule be detected by

Answer 37

quelling reaction

Question 38

Where do endospores happen

Answer 38

only in gram negative bacteria

Question 39

Endospores

Answer 39

bacteria convert from a vegetative state to a dormant state. give rise to a single bacteria when environmental conditions are favorable

Question 40

Structure of endospores

Answer 40

dehydrated multishelled structure

Question 41

contents of endospores

Answer 41

complete copy of chromosome proteins and ribosomes high concentration of calcium bound to dipicolinic acid

Question 42

Why are endospores important?

Answer 42

Can be aerosolized Can be found in a lot of environments Can withstand extreme environments Can exist for centuries