Replication And Lifestyle

Question 1

Heterotrophic

Answer 1

Req organic substrates for e production and a wide substrate variety are used

Question 2

Metabolism of most pathogenic bact

Answer 2

Take up and catabolise sugars
Peptides/aas
And nucleic acids to gen basic building blocks of anabolic process

Question 3

Strict aerobes

Answer 3

Grow at atm O2 tensions

Question 4

Strict anaerobes

Answer 4

Req O2 abscence for growth

Question 5

Facuktative anaerobes

Answer 5

Can handle both presence and absence

Question 6

Factors influencing bacterial griwth

Answer 6

Nutrients
Temp pH
Ion concs
Atm
Hydration

Question 7

What may cause commensal bact pop alteration

Answer 7

Nutritional status
Stress
Age
Antiobiotics
(Pops are stable but not static)

Question 8

Lag phase of growth

Answer 8

Bact adjust to enviro conditions

Question 9

Log phase

Answer 9

Bact prolif exponentially by binary fission

Question 10

Stationary phase

Answer 10

Nutrients become exhausted so growth arrest

Question 11

Decline or death phasr

Answer 11

Bact number falls as incr hostility of enviro

Question 12

What occurs during binary fission

Answer 12

A new CM and CW are formed
Chromosome duplicates and segregates
Septum spilts bact cell into 2 compartments
Separate into 2 cells

Question 13

Growth phases

Answer 13

Lag
Log
Stationary
Decline/death

Question 14

When sporulation Occurs

Answer 14

Stationary phase usually

In response to stress or nutrient limitation

Question 15

Spore producing bacteria

Answer 15

Clostridium

Bacillus

Question 16

What are spores

Answer 16

Dormant struct res to adverse cond of heat dehydration freezing and many chem that would kill most vegetative bact

Question 17

Conditions to kill vegetative bact v spores

Answer 17

V: 50-70 degree C
S: most resist boiling but not autoclave (121 degree C 15min)

Question 18

Changes during sporulation

Answer 18

Many components of vegetative cell disappear and thick wall formed to protect genetic material and transcription translation machinery

Question 19

Spore germination

Answer 19

Under appropriate conditions

Can persist for 50+ yrs in poor enviro so source of infection fir long time periods

Question 20

Septicaemia growth eg

Answer 20

Can have Rapid multiplication in blood and host resp to high bact product (LPS and peptidoglycan) level lead to septic shock and organ failure

Question 21

Mycobacterium growth rate eg

Answer 21

Take long time to manifest, can be harder for host ti tackle

Question 22

Other factors affecting growth rate

Answer 22

Site of infection

Question 23

Niche specialisation IC eg

Answer 23

Diff IC bact use diff C source in infected cell, may alter cell metabolism in favour of these products

Question 24

Niche specialisation skin eg

Answer 24

Can survive lower temp and can take advantage if sebaceous gland secretion (cont TG) or may degrade skin and pro with enz and proteases to give substrates for growth

Question 25

Mech to obtain Fe if conc is low

Answer 25

EC hydrolytic enz Transferrin and lactoferrin bind pros Siderophores and spec recs

Question 26

Niche specialisation GIT eg

Answer 26

Can kill related bact with colicins and bacteriophages (compete for nutrients) Invasion Community formation to BD complex substrates

Question 27

Eg of niche bact

Answer 27

``` Mycobact leprae (schwann cell) E coli (end of bovine GIT) Salmonella (gall bladder persistance) Strep (horse guttyral pouch) Staph (bone joint infections) ```

Question 28

Technique to ID bact not easily cultured

Answer 28

PCR amplification and immunodiagnostic tachniques (same as virus diagnostics)