The Nature of Infection and Systemic Bacteriology 1-2

Question 1

Cytoplasmic membrane

Answer 1

energy generation in bacteria - positive charge
target of lots of common antimicrobial agents ie ethanol

Question 2

Cell wall

Answer 2

gram positive bacteria: thick layer of peptidoglycan in cell wall retains primary gram stain (purple)
gram negative bacteria thinner peptidoglycan layer, allows crystal violet to wash out and are stained by counterstain (pink)

Question 3

Lipopolysaccharide (LPS)

Answer 3

key component of endotoxin
has a structural role
antigen and bacterial toxin
antibiotic uptake, inflammation

Question 4

five factors for bacterial growth

Answer 4

food
temperature
pH
Osmotic production
oxygen

Question 5

multicellularity

Answer 5

colony development and differentiation

Question 6

biofilm

Answer 6

colonies of bacteria that adhere together and to the environmental surfaces
(much more resistant to antimicrobial agents)

Question 7

four key features of bacteria

Answer 7

shapes
defensive structures
toxin
aerobes and anaerobes

Question 8

five bacteria shapes

Answer 8

coccus/cocci
bacillus/bacilli
vibrio
spirillum
spirochaete

Question 9

coccus/cocci

Answer 9

spheres

Question 10

bacillus/bacilli

Answer 10

rod shaped

Question 11

vibrio

Answer 11

slightly curved rod, gram-negative

Question 12

spirillum

Answer 12

rigid spiral bacterium

Question 13

spirochaete

Answer 13

flexible spiral bacterium

Question 14

two defensive structures

Answer 14

spore
capsule

Question 15

spore

Answer 15

inert structures, resistant to physical and chemical challenge

Question 16

capsule

Answer 16

outermost layer found in many bacteria, usually made of polysaccharides

Question 17

toxin

Answer 17

promotes infection and disease by directly damaging host tissues and disabling the immune system

Question 18

four aerobes and anaerobes

Answer 18

aerobic
obligate aerobe
obligate anerobes
facultative anaerobes

Question 19

aerobic

Answer 19

grow in oxygen

Question 20

obligate aerobes

Answer 20

require oxygen

Question 21

obligate anaerobe

Answer 21

killed by oxygen

Question 22

facultative anaerobe

Answer 22

tolerate oxygen

Question 23

six ways of identifying bacteria

Answer 23

selective media
differential media
metabolic profiling
serological yests
DNA technology (genome sequencing)
MALDI-TOF

Question 24

selective media

Answer 24

presence of specific substances permits the growth of one organism over another

Question 25

differential media

Answer 25

incorporation of chemical produces visible changes in colonies that facilitates identification

Question 26

metabolic profiling

Answer 26

uses biochemical characteristics e.g. utilisation of carbon sources

Question 27

serological tests

Answer 27

use an antibody-antigen interaction to help identify bacteria

Question 28

DNA technology (genome sequencing)

Answer 28

PCR or MLST

Question 29

PCR

Answer 29

amplification of section of genome

Question 30

MLST

Answer 30

entire genome sequencing

Question 31

MALDI-TOF

Answer 31

produces a characteristic signature based on the generation of ions from a sample (dependant on constituent proteins)

Question 32

Virulence

Answer 32

the capacity of a microbe to cause damage to its host

Question 33

pathogen

Answer 33

a harmful organism that produces a pathology

Question 34

commensal

Answer 34

an organism that is part of the normal flora
often has a mutualistic relationship
endogenous

Question 35

opportunistic pathogen

Answer 35

an organism that causes infection when opportunity/change in natural immunity arises

Question 36

Coagulase test

Answer 36

use to differentiate between staph. aureus and coagulase negative staph. (staph epidermis)

Question 37

Haemolysis

Answer 37

used to differentiate between streptococci

Question 38

sepsis