BACTERIAL GROWTH AND REPRODUCTION

Question 1

Bacteria reproduce by asexual reproduction via _________.

Answer 1

transverse binary fission

Question 2

Growth cycle

Little or no multiplication but enzymes are very active. A period of adjustment and adaption.

Answer 2

Lag phase

Question 3

Growth cycle

Organisms grow at maximum rate (exponential rate). Most sensitive to antimicrobials.

Answer 3

Logarithmic/ exponential phase

Question 3

Growth cycle

Plateau; growth ceases because nutrients are exhausted or toxic metabolic products have accumulated

Answer 3

Stationary phase

Question 4

Growth cycle

Direct microscopic count may retain constant but variable count slowly decreases.

Answer 4

Decline or death

Question 5

Direct uptake DNA from surrounding environment; Allows for evaluation of DNA over time; Very useful in micro labs; introduces genes to bacteria for replication

Answer 5

Transformation

Question 6

Transfer from one cell to another via pilus; requires physical contact of two organisms; DNA transferred via plasmids

Answer 6

Conjugation

Question 7

Are small DNA molecule within a cell:

Answer 7

Plasmids

Question 8

Transfer of DNA via a bacteriophage (virus that infects bacteria); virus picks up DNA, transfers to another bacteria

Answer 8

Transduction

Question 9

Nuclear material enters bacteria; Multiplies, lyses cell; Releases progeny viruses

Answer 9

Lytic cycle

Question 10

Nuclear material enters cell; Incorporates in host DNA; May later become excised then enter lytic phase’ Genes for some bacterial toxins are transferred to non-toxic strains via lysogeny

Answer 10

Lysogenic cycle

Question 11

Also known as “Jumping genes”. DNA segment within bacterial DNA;

Answer 11

Transposons

Question 12

A mechanism of transfer of resistance to antibiotics; can even transfer antibiotic resistance genes between two different bacterial species

Answer 12

Transposition

Question 13

Requires preformed organic compounds (e.g. sugar, amino acids) for growth. Includes most medical important bacteria

Answer 13

Heterotrophs/Organotrophs

Question 14

Do not require preformed organic compounds for growth because they can synthesize the from inorganic compounds and carbon dioxide

Answer 14

Autotrophs/Lithotrophs

Question 15

Use light as energy source

Answer 15

Phototrophs

Question 16

Use redox potential generated by various chemical reactions

Answer 16

Chemotrophs

Question 17

Grows in the presence of atmospheric (free) oxygen

Answer 17

Aerobe

Question 18

Cannot grow in absence of free oxygen, which serves as final electron acceptor.

Answer 18

Obligate Aerobe

Question 19

Obligate aerobes contain ____________, which protects from the toxic oxygen

Answer 19

superoxide dismutase

Question 20

Requires reduced amount of free oxygen.

Answer 20

Microaerophile

Question 21

Grows in the absence of atmospheric (free) oxygen

Answer 21

Anaerobe

Question 22

Cannot grow in the presence of atmospheric (free) oxygen; lack superoxide dismutase, catalase, and cytochromic-C oxidase

Answer 22

Obligate anaerobe

Question 23

obligate anaerobe uses _____, _____ and _____ as final electron acceptor

Answer 23

Nitrates, sulfates, and carbonates

Question 24

Fundamentally an aerobe but can grow in the absence of atmospheric (free) oxygen

Answer 24

Facultative anaerobe

Question 25

Does not grow well, but survives in the presence of atmospheric (free) oxygen

Answer 25

Aerotolerant

Question 26

Mention Obligate Aerobes:

Answer 26

• Pseudomonas aeruginosa
• Nocardia
• Bacillus
• Mycobacterium
• Corynebacterium

Remember: “May Cash sa PNB” / MC PNB

Question 27

Mention Obligate Anaerobes:

Answer 27

• Actinomyces
• Bacteroides
• Clostridium
• Fusobacterium
• Eubacterium
• Prevotella

Remember: ABC FEP

Question 28

Mention Aerotolerant microorganisms:

Answer 28

• Lactobacillus
• Propionibacterium

Question 29

Mention Microaerophiles:

Answer 29

• Campylobacter
• Helicobacter

Remember: both ends with “-bacter”

Campylobacter requires 5% O2 for incubation

Question 30

Difference and similarity of Bacillus and Clostridium:”

Answer 30

Difference:
Bacillus - Obligate aerobe
Clostridium - Obligate anaerobe

Similarity: Both are spore forming

Question 31

Difference and similarity of Nocardia and Actinomyces

Answer 31

Difference:
Nocardia - Obligate aerobe, ACID-FAST (+)
Actinomyces - Obligate anaerobe, NON ACID-FAST

Similarity: both are fungi-like/filamentous/branching bacteria

Question 32

Growth is enhanced by the increased CO2; independent from oxygen requirement.

Answer 32

Capnophile

Question 33

Capnophilic incubation:

Answer 33

5-10% CO2

Question 34

Mention Capnophilic organisms:

Answer 34

• Streptococcus
• Campylobacter
• Haemophilus
• Helicobacter
• Moraxella catarrhalis
• Mycobacterium
• Pathogenic Neisseria

remember: “SCHHMMP”

Question 35

grow below 10C:

Answer 35

Psychrophilic

Question 36

examples of psychrophilic organisms:

Answer 36

Listeria monocytogenes
Yersinia enterocolitica (blood bank contaminant [pRBC])

Question 37

grow at 20 - 40C (best at 30-37C). Most pathogens

Answer 37

Mesophilic

Question 38

grow at 50-55C (basis of test for effective autoclaving)

Answer 38

Thermophilic

Question 39

example of an acidophile organism:

Answer 39

Lactobacillus

Question 40

example of an Alkalophiles/basophile microogranism:

Answer 40

Vibrio

Question 41

Enrichment medium for vibrio:

Answer 41

Alkaline peptone water