Intro To Bacteria

Question 1

Prokaryote

Answer 1

No cytoplasmic organelle other than ribosomes, genetic info stored in circular chromosome, can have plasmids (plasmids)

Question 2

Gram positive

Answer 2

Thick (20-80nm) cell wall external to cell membrane (purple is positive)

Question 3

Gram negative

Answer 3

Thin cell wall, between inner/out membrane

Question 4

Aerobic bacteria

Answer 4

Grows in the presence of oxygen

Question 5

Facultative

Answer 5

Can grow in the presence or absence of oxygen

Question 6

Anaerobic bacteria

Answer 6

Grows in the absence of oxygen

Question 7

Fastidious bacteria

Answer 7

Special growth requirements

Question 8

Non-fastidious bacteria

Answer 8

Simple growth requirements

Question 9

Capnophilic bacteria

Answer 9

Requires CO2

Question 10

Halophilic baccteria

Answer 10

Salt loving

Question 11

Gram positive cell wall characteristics

Answer 11

Thick peptidoglycan wall with teichoic (TA) and lipoteichoic acids (LTA). Are important for viability, virulence, and serotyping. Promote attachment to mammalian cells, low endotoxin activity

Question 12

Protein synthesis inhibitor MOA

Answer 12

Better in toxigenic diseases than cell wall inhibitors.

Question 13

Encapsulated bacteria

Answer 13

Looks polysaccharide layer (or protein layer). Unnecessary for growth but important for virulence. Promotes adherence, anti-phagocytic, poor antigen

Question 14

Endospores

Answer 14

Produced under unfavorable conditions. Non-replicating entity with thick coat. Contain DNA/essential substances. Toughest life form, can germinate back to vegetative cells

Question 15

Flagella

Answer 15

Are H-antigens. Motility towards food and away from poisons. Assist in bacteria attachment to human cells (virulence factor)

Question 16

Types of flagella

Answer 16

Mono-
Lopho-
Amphi-
Peri-
(-trichous)

Question 17

Fimbriae

Answer 17

Fimbriae are F-antigens. Hair-like projections (thinner/shorter than flagella). Originate in plasma membrane and protrude thru cell wall. Can act as adhesins and are major virulence factors

Question 18

Outer membrane of gram negative bacteria

Answer 18

Permeable barrier for large molecules. Protects from adverse conditions. Asymmetric bilayer (normal inner, outer is primarily LPS)

Question 19

Bacterial Lipopolysaccharide (LPS)

Answer 19

Gram negative bacteria. Integral part of outer membrane, released after cell death! When host senses LPS, turns on defense at its disposal

Question 20

Acid-fast/Partially acid-fast bacteria

Answer 20

PG layer is surrounded by wax-like lipid coat. Lipid coat contains mycolic acid, cord factor, wax D, sulfolipids. Lipid coat responsible for virulence and antiphagocytic.

Question 21

What determines acid fastness?

Answer 21

C-chain length of mycolic acids

Question 22

Lag phase

Answer 22

Bacteria has very little growth

Question 23

Exponential phase

Answer 23

Populations double every 20 minutes

Question 24

Stationary phase

Answer 24

Growth phase

Question 25

Death phase

Answer 25

Bacteria die faster than they multiply

Question 26

What part of the intestine has the most bacterial cells?

Answer 26

Small intestine

Question 27

Low number of bacteria sites

Answer 27

Bladder, uterus, parts of GI/Respiratory tracts

Question 28

Normally sterile sites (no bacteria)

Answer 28

Blood, lymph, CSF, synovial fluid, sub-epidermal tissue

Question 29

Step(s) of infection: epidemiology

Answer 29

Acquisition/colonization

Question 30

Step(s) of infections: virulence

Answer 30

Immune evasion/infection —> replication/proliferation—>Dissemination and disease

Question 31

Step(s) of infection: identification

Answer 31

Treatment

Question 32

Transmission of bacterial pathogens

Answer 32

Bacterial shedding, talking (f, p, t, s sounds spread more), stability of pathogens in environment, living conditions, age group and immune-status

Question 33

Factors that affect outcome of bacterial infections

Answer 33

Strain and inoculum. Length of presence, host factors.

Question 34

Virulence factors

Answer 34

Used for survival and disease

Question 35

Toxins from bacteria

Answer 35

When are in the blood, can harm the body