General Bacteriology

Question 1

List properties of prokaryotic cells

Answer 1

No Nucleus, Membrane bound organelles, plasma membrane, cytoskeleton or meiosis. Small diameter
Chemically complex cell wall
Single circular chromosomes
Binary fission

Question 2

What class of cells are bacteria under?

Answer 2

Prokaryotes

Question 3

What are 3 exceptions to bacterial properties?

Answer 3

1. Mollicutes (Mycoplasma) does not have a cell wall
2. Leptospira has two circular chromosomes
3. Borrelia burgdorferi has linear chromosomes

Question 4

What is a unique component about the bacteria cell?

Answer 4

Contains Peptidoglycan

Question 5

What is a unique cell wall component of Gram + bacteria?

Answer 5

Lipteichoic acid (for antigenicity)

Question 6

What is a unique cell wall component of Gram - Bacteria?

Answer 6

Outer membrane containing lipopolysaccharide (LPS) (Virulence factor)

Question 7

What is a unique cell wall component of mycobacteria?

Answer 7

Mycolic acid (Virulence Factor) - Considered gram + bacteria

Question 8

What is unique about LPS?

Answer 8

Contains a lipid A component that can activate immune system and exert harmful effects on host polysaccharide component and contributes to antigenicity

Question 9

What is a gram + stain?

Answer 9

Crystal violet because of thick peptidoglycan layer

Question 10

What is a gram - stain?

Answer 10

Picks up safranin because of think peptidoglycan layer

Question 11

Acid fast staining is due to the presence of what?

Answer 11

Mycolic acid

Question 12

What is an acid fast + organism?

Answer 12

Pink (retains carbol fuschin) because of mycolic acid

Question 13

What is acid fast - organism?

Answer 13

Blue (decolorized) because of lack of mycelia acid

Question 14

What kind of cell wall do acid fast + bacteria have?

Answer 14

Gram + cell wall

Question 15

What 3 things can measure bacterial growth?

Answer 15

1. Colony
2. Turbidimetry
3. Flow Cytometry

Question 16

What kind of bacteria require oxygen for growth?

Answer 16

1. Aerobic
2. Microaerophillic
3. Capnophillic

Question 17

What kind of bacteria not require oxygen for growth?

Answer 17

1. Obligate anaerobe
2. Aerotolerant
3. Anaerobe

Question 18

What kind of bacteria don’t require oxygen but can still utilize it for growth?

Answer 18

Facultative Anaerobe

Question 19

Can bacterial structures enhance the virulence of bacteria?

Answer 19

Yes

Question 20

Do the presence or absence of bacterial structures facilitate the ID of bacteria?

Answer 20

Yes

Question 21

What is the function of flagella?

Answer 21

Locomotion or motility

Question 22

What is the function of Fimbriae or pili?

Answer 22

Adherence

Question 23

What is the importance of a capsule?

Answer 23

Outer covering that helps bacteria evade phagocytosis

Question 24

What contain endoflagella/axial filaments?

Answer 24

Spirochetes

Question 25

What advantage do spores give bacteria?

Answer 25

Help bacteria (Gram +) survive

Question 26

What are two bacterial virulence factors?

Answer 26

1. Exotoxins | 2. Superantigens

Question 27

What are Exotoxins?

Answer 27

Proteins produced by bacteria & released outside to exert action on specific target cell Majority heat labile

Question 28

What are endotoxins?

Answer 28

Released when bacteria are dead or killed Can induce inflammation by stimulating immune system Heat stable

Question 29

What are superantigens?

Answer 29

Produced by pathogenic microbes Binding to MHC class II on APCs and T helper cell receptor Result in polyclonal T cell activation and massive cytokine release

Question 30

How does biofilm form?

Answer 30

Microbes cling to surface and produce EC substances and take in nutrients Slowly grow and cause imbalance

Question 31

How do bacteria use quorum sensing?

Answer 31

When population reaches certain level, changes occur and culminate in infection and overwhelm immune system defenses

Question 32

How do bacteria and fungi cause disease?

Answer 32

Pathogenesis

Question 33

What is pathogenesis?

Answer 33

Mechanism by which pathogen cause disease

Question 34

What is virulence?

Answer 34

Degree of pathogenicity, includes severity

Question 35

Are most bacteria pathogens?

Answer 35

No

Question 36

What two things mediate virulence transfer of Bacteria?

Answer 36

Via Plasmids and Bacteriophages that carry genes for antibiotic resistance, toxins, capsules, and fimbriae

Question 37

How are bacteria virulence factors transferred?

Answer 37

Via conjugation, transformation, and transduction

Question 38

What 5 things increase virulence?

Answer 38

1. Fimbriae 2. Flagella 3. Capsule 4. Quorum sensing 5. Biofilm formatin

Question 39

What are the sequence of events in bacterial or fungal pathogenesis?

Answer 39

1. Host entry 2. Evade host defense 3. Colonize host system 4. Multiply 5. Exert damage in host 6. Transmit to other hosts = INFECTIOUS

Question 40

How do bacteria and fungi cause disease?

Answer 40

1. Deplete host nutrients 2. Toxins 3. As a result of immune response to microbe

Question 41

What are fungi?

Answer 41

1. Eukaryotes 2. Heterotrophs 3. Absorptive nutrition 4. Asexual repro/some sexual repro 5. Plant-like cell wall 6. Unicellular or multicellular 7. Free-living 8. Infections less common than bacterial infections