Antibiotic Resistance Transfer- Lecture 11/2/21

Question 1

2 ways to acquire resistance

Answer 1

• Mutation

- Horizontal transfer

Question 2

Enterococcus Faecalis

Answer 2

Usually commensal, but can acquire virulence by picking up vancomycin resistance and pathogenicity island

Question 3

Examples of mobile genetic elements (3)

Answer 3

• Plasmid
• Transposons
• Phages

Question 4

Plasmid

Answer 4

Self-replicating circular DNA that can move between bacterial cells

Question 5

Transposons

Answer 5

Linear DNA that can move within a bacterial cell

Question 6

Phages

Answer 6

Viruses that attack bacteria

Question 7

Transformation

Answer 7

When a bacterial cell takes up free DNA and incorporates it

Question 8

Conjugation

Answer 8

The transfer of a plasmid through a sex pilus

Question 9

Transduction

Answer 9

Incorporation of DNA brought to bacterium through a bacteriophage

Question 10

Two types of transduction

Answer 10

• Specialized transduction

- Generalized transduction

Question 11

Lysogenic viruses

Answer 11

Can insert DNA into host bacteria

Question 12

Lytic pathway

Answer 12

Phages enter, replicate DNA and exit

Question 13

Specialized transduction

Answer 13

Done by lysogenic Phages, when part of host DNA is aberrently packaged into phage and brought to another bacteria

Question 14

Generalized transduction

Answer 14

Lytic Phages, host DNA is randomly taken up into phage and brought to new host

Question 15

Bacterial defense mechanisms to prevent foreign DNA (2)

Answer 15

• restriction modification (cut unmethylated DNA)

- CRISPR CAS9

Question 16

RecA

Answer 16

DNA that has homologous regions are incorporated by RecA into the genome

Question 17

Replicons

Answer 17

DNA elements that are capable of self replication (Bacterial chromosomes and plasmids)

Question 18

Rep proteins

Answer 18

Binds to Ori and recruits host DNA poly to initiate DNA replication

Question 19

OriV or OriR

Answer 19

Origin of replication on plasmid

Question 20

Tra operon

Answer 20

A set of genes that encode transfer apparatus and other proteins required for conjugation, doesn’t need to be on plasmid, just in cell

Question 21

OriT

Answer 21

Origin of transfer, needs to be on plasmid

Question 22

Conjugative pilus

Answer 22

Reaches out from donor and grabs the recipient, forms channel for plasmid to pass through

Question 23

Relaxase

Answer 23

Encoded by the tra genes, knicks the DNA at oriT site generates single stranded DNA substrate for transfer

Question 24

Transposase

Answer 24

Encoded within Transposons, needed to jump

Question 25

Inverted repeats

Answer 25

Where transposases recognize DNA

Question 26

R factors

Answer 26

Drug resistance genes

Question 27

Two modes of transposition

Answer 27

• Cut and paste

- Copy and paste