Microbiology 11 (antibacterials and resistance)

Question 1

Enzymatic cleavage

Answer 1

method of most B-lactam and aminoglycoside resistance

Question 2

Altered receptors

Answer 2

mechanism of Strep. pneumo. resistance to penicillin

mechanism of MRSA resistance to methicillin

Question 3

Altered permeability

Answer 3

mechanism of Pseudomonas resistance to aminoglycosides

Question 4

Bypass of metabolic block

Answer 4

mechanism of enterococcus resistance to TMP/SMX

Question 5

McFarland standard

Answer 5

10^8 CFU/mL

Question 6

B-lactamase disk test

Answer 6

Nitrocefin (a chromogenic cephalosporin)

red = a Beta-lactamase is present in the organism

Question 7

Percentage of Haemophilus producing B-lactamase

Answer 7

20-40%

Question 8

Primary mechanism of resistances of Bacteroides fragilis

Answer 8

B-lactamase production

Question 9

MRSA resistance to oxacillis is via

Answer 9

Penicillin binding proteins (PBPs)

Question 10

PBPs are produced by

Answer 10

mecA gene

Question 11

If oxacillin or cefoxitin resistance, then

Answer 11

resistant to all cephalosporins and penicillins

Question 12

D-test

Answer 12

= clinaadmycin induction test

if zone of inhibition blunted, then organism can be induced to become resistant to clindamycin by erythromycin

Question 13

All enterococcus resistant to

Answer 13

Cephalosporins
Clindamycin
TMP-SMX

Question 14

Synergistic treatment for enterococcus

Answer 14

Ampicillin and Gentamycin

Question 15

Enterococcus faecium resistance to vancomycin is by

Answer 15

vanA gene

Question 16

E. faecalis resistance to vancymycin is by

Answer 16

vanB gene

Question 17

Drugs for treating VRE

Answer 17

Linezolid

Synercid

Question 18

ESBL found in

Answer 18

enteric G- rods (E. coli, Klebsiella, Proteus)

Question 19

ESBL transmitted by

Answer 19

Tem1 B-lactamase plasmid

Question 20

If ESBL found, report

Answer 20

all penicillins and cephalosporins resistant

Question 21

Drugs to treat ESBL

Answer 21

Imipenem

Pip/Tazo

Question 22

What is a B-lactamase blocker

Answer 22

Clavulanic acid

Question 23

Carbapenemase producers (KPCs) are resistant to

Answer 23

all penicillins, cephalosporins, and carbapenems

Question 24

Treat KPCs with

Answer 24

Colistin

Question 25

Most sensitive screen for KPC

Answer 25

Ertapenem

Question 26

Modified Hodge test

Answer 26

for KPC

Lawn of E. coli with streaks of test organism

Question 27

testing fro Strep. pneumo resistance to penicillin

Answer 27

Test against Oxacillin first

if resistnant, confirm with penicillin MIC testing

Question 28

If strep. pneumo resistant to penicillin, treat with

Answer 28

Cefoxatime, Vancomycin, or Quinolone

Question 29

Hypervirulent strain of C. diff

Answer 29

NAP1 strain