Introduction to Bacteria and Bacterial Diseases

Question 1

what are the three bacterial shapes?

Answer 1

spheres/cocci
rods/bacilli
spirals

Question 2

what is a diplococci?

Answer 2

Streptococcus pneumoniae

Question 3

what does the bacterial capsule do?

Answer 3

protects from desiccation and immune response

Question 4

what makes up the bacterial capsule?

Answer 4

polysaccharides

Question 5

is the bacterial capsule intra- or extracellular?

Answer 5

extracellular

Question 6

what does the cell wall contain?

Answer 6

peptidoglycan

Question 7

what does the cell wall protect from?

Answer 7

mechanical damage
osmotic lysis

Question 8

what makes something gram positive?

Answer 8

thick peptidoglycan layer

Question 9

what makes something gram negative?

Answer 9

thin peptidoglycan layer covered by lipopolysaccharide

Question 10

true/false: there are bacteria that show variable gram staining

Answer 10

true
Mycobacteria

Question 11

what makes up the plasma membrane?

Answer 11

phospholipids and proteins

Question 12

what is the function of the plasma membrane?

Answer 12

flexible barrier
transport

Question 13

what are plasmids?

Answer 13

small, circular DNA
replicate autonomously
physically distinct from chromosome

Question 14

why do we care about plasmids?

Answer 14

encode virulence factors and resistance genes
transmissible

Question 15

pili are for _____________. also known as ______________

Answer 15

adhesion
fimbriae

Question 16

flagella are for ___________

Answer 16

motility

Question 17

in what are flagella more common?

Answer 17

gram negative

Question 18

what is the important protein in flagella?

Answer 18

flagellin

Question 19

what is genetic variation in bacteria induced by?

Answer 19

mutation: spontaneous or induced

Question 20

where do spores divide?

Answer 20

within cell walls

Question 21

what is conjugation via F-pilus?

Answer 21

F-pilus transfers DNA from donor to recipient

Question 22

what is transduction?

Answer 22

DNA transfer by (bacterio)phages

Question 23

in conjugation via F-pilus, proteins involved are encoded on a __________

Answer 23

plasmid

Question 24

where is transformation (uptake DNA directly) usually seen?

Answer 24

laboratory experiment
has been documented in natural

Question 25

what are bacterial virulence factors?

Answer 25

bacteria-associated molecules that are required for a bacterium to cause disease while infecting eukaryotic hosts

Question 26

what are the classes of virulence factors in bacteria?

Answer 26

adhesins toxins and enzymes capsule secretion systems super-antigens

Question 27

how do adhesins binding to host cell receptors alter the host cell?

Answer 27

trigger intracellular signaling induce endo- or phagocytosis promote transport change gene expression

Question 28

what is an E. coli adhesin?

Answer 28

FimH

Question 29

define endotoxins

Answer 29

components of bacterial cell wall released when bacteria are lysed

Question 30

define exotoxins

Answer 30

produced and secreted by live bacteria many types

Question 31

what are some properties of endotoxin (LPS)?

Answer 31

heat stable antigenic activates host cells

Question 32

what do high levels of endotoxins lead to?

Answer 32

endotoxemia: fever, shock, disseminated intravascular coagulation

Question 33

what is activation by endotoxin?

Answer 33

ligand-receptor interactions that cause intracellular signaling then release of pre-formed products, gene transcription and/or synthesis/release of new products

Question 34

what are some exotoxins that cause disease?

Answer 34

botulinum toxin tetanus toxin Clostridium perfringens toxins shiga toxin

Question 35

in which bacteria are secretion systems best known?

Answer 35

gram negatives

Question 36

what is a streptococci?

Answer 36

Streptococcus pyogenes

Question 37

what is a species that presents as chains of rods?

Answer 37

Bacillus anthracis

Question 38

what is a species that presents as flagellate rods?

Answer 38

Salmonella typhi

Question 39

what is a species that is a spiral/vibrios?

Answer 39

Vibrio cholerae

Question 40

what is a species that is a spirilla?

Answer 40

Helicobacter pylori

Question 41

what is a species that is spirochaetes?

Answer 41

Treponema pallidum

Question 42

what is a bacteria with a capsule?

Answer 42

Bacillus anthracis

Question 43

what are some important features of spores?

Answer 43

dormant highly resistant dehydrated divides within cell walls

Question 44

what are two species that are spore-forming?

Answer 44

Bacillus spp Clostridium spp

Question 45

what is the structure of LPS?

Answer 45

O-antigen core lipid A: most toxic

Question 46

what do superantigens do?

Answer 46

cross-link the T cell receptors to major histocompatibility molecules: non-specific activation of immune system, massive proinflammatory cytokine release

Question 47

are endotoxins or exotoxins heat stable?

Answer 47

endotoxins (released from cell wall when lysed)

Question 48

what is an example of an endotoxin?

Answer 48

lipopolysaccharide from gram positive bacteria

Question 49

what are some bacteria that have superantigens?

Answer 49

Staphylococcus aureus Staphylococcus pyogenes Histophilus spp