Antimicrobial Chemotherapy - Mechanisms of bacterial resistance

Question 1

What is a resistant organism?

Answer 1

an organism which is unlikely to respond to attainable levels of drug in tissue

Question 2

what is inherent / intrinsic resistance?

Answer 2

all strains of the bacteria are naturally resistant

Question 3

give an example of inherent resistance.

Answer 3

streptococci is always resistant to ahminoglycosides

Question 4

what is acquired resistance?

Answer 4

there is resistance in some strains - lab testing required

Question 5

how many acquired resistance of drug be acquired and how may it spread?

Answer 5

acquired by a spotanaeous mutation.

spread by plasmids or transposons

Question 6

what are are two ways that bacteria can become resistant to b - lactams?

Answer 6

by producing b - lactamase

by altering the penicillin binding sight

Question 7

How does b - lactamase work?

Answer 7

its cleaves the b - lactam ring to make it inactive

Question 8

is b - lactamase common in gram positive or gram negative organisms?

Answer 8

gram negative

Question 9

what bacteria tends to produce b- lactamase?

Answer 9

staph. aureas

Question 10

how can bacteria get around being faced with a b - lactamase?

Answer 10

• add b - lactamase inhibitor

- modify antibiotic side chain to get resistant to b- lactamase

Question 11

give an example of a drug that has an added b - lactamase inhibitor, and name the original drug?

Answer 11

co - amoxiclav
antibiotic - amoxicillin
inhibitor - clavulanic acid

Question 12

give an example of a drug that is modified to be resistant to b - lactamase

Answer 12

flucoxacillin

Question 13

what is an ESBL?

Answer 13

extended spectrum b- lactamases

Question 14

what type of bacteria may produce ESBL?

Answer 14

negative

Question 15

what generation of cephalosporin can ESBL break down?

Answer 15

third

Question 16

are ESBLS resistant to all B - lactams?

Answer 16

Yes

Question 17

What are CPE and CRE?

Answer 17

carbapenemase producing enterobacteriacaea

carbapenem resistant enterobacteriacaea

Question 18

what are CPE and CRE extremely resistant too?

Answer 18

Gram negative bacteria.

No antimicrobial options

Question 19

what are carbopenams.

Answer 19

antibiotics that cover a broad range of illnesses that CPE and CRES are resistant too.

Question 20

How do bacteria develop a resistance to glycoproteins?

Answer 20

by altering their peptidoglycan precursor target site

Question 21

name two vancomycin resistant bacteria.

Answer 21

enterococcus faecium

enterococcus faecalis

Question 22

what are some other methods of antibiotic resistance?

Answer 22

blocking transport of drug into cell

stimulating active transport of drug out of cell