Antibiotics

Front 1

Extended Spectrum Beta-Lactamases (ESBL's) are found in what organisms?

Back 1

exclusively in Gram negative organisms, primarily in Klebsiella pneumoniae, Klebsiella oxytoca, and Escherichia coli but also in Salmonella, Proteus, Enterobacter, Citrobacter, Serratia, and Pseudomonas spp.

Front 2

Spectrum of Extended Spectrum Beta-Lactamas (ESBL) antibiotic resistance

Back 2

Typically confer resistance to penicillins, first-generation and some third-generation cephalosporins (eg, cefotaxime, ceftazidime, and ceftriaxone).

Front 3

First generation cephalosporin

Back 3

Cefazolin

Front 4

Antibiotic class of cefuroxime, cefoxitin, and cefotetan

Back 4

2nd generation cephalosporins. Cefoxitin and cefotetan belong to the Cephamycin subgroup.

Front 5

Antibiotic class of cefotaxime, ceftriaxone, ceftizoxime, cefoperazone and ceftazidime

Back 5

Third generation cephalosporins

Front 6

Third generation cephalosporins

Back 6

cefotaxime, ceftriaxone, ceftizoxime (poor acticity against Pseudomonas aeruginosa); cefoperazone and ceftazidime (good acticity against Pseudomonas aeruginosa)

Front 7

Antibiotic class of Cefepime

Back 7

Fourth generation cephalosporin

Front 8

Antibiotic class - Cefazolin

Back 8

First generation cephalosporin

Front 9

Beta-lactam antibiotics: bactericidal or bacteriostatic?

Back 9

bactericidal

Front 10

Distinguishing feature between plasmid-mediated and chromosomal AmpC beta lactamases.

Back 10

chromosomal: inducible; plasmid-mediated: not inducible

Front 11

Which Enterococcus species is most commonly associated with Vancomycin resistance?

Back 11

E. faecium

Front 12

Two species of Enterococcus with intrinsic Vancomycin resistance. What genotype is responsible?

Back 12

Enterococcus gallinarum and E. casseliflavus. Low-level Vanc resistance (MIC’s < 32 mcg/ml) is conferred by the chromosomal, non-transferrable vanC genotype (a cluster of genes). The vanC genotype results in peptidoglycans with a terminal D-alanyl-D-serine (wild type is D-alanyl-D-alanine) with reduced vancomycin affinity.

Front 13

Vancomycin-resistant S. aureus is now being treated with what drug

Back 13

Quinupristin-dalfopristin

Front 14

What does MRSA look like on chromagar

Back 14

MRSA colonies are pink. Methicillin-sensitive S. aureus will not grow, and other bacteria are blue.

Front 15

Antobiotic for elimination of nasal carriage of Staph aureus

Back 15

Mupirocin, topically

Front 16

Nitrocefin is a colorimetric reagent used for detecting

Back 16

beta lactamase

Front 17

Glycopeptide inetrmediate staph aureus refers to:

Back 17

SA with intermediate resistance to glycopeptide antibiotics, i.e. vancomycin. The bug is sensitive to vanc at doses of 8-16mcg/ml

Front 18

E-test for ESBL detection

Back 18

The E test ESBL strip carries two gradients, on the one end, ceftazidime and on the opposite end ceftazidime plus clavulanic acid. MIC is interpreted as the point of intersection of the inhibition ellipse with the E test strip edge. Ratio of ceftazidime MIC and ceftazidime clavulanic acid MIC equal to or greater than 8 indicates the presence of ESBL.

Front 19

Spectrum of activity of TEM-1 and TEM-2 beta-lactamases

Back 19

Confer resistance to penicillins and narrow spectrum cephalosporins (eg cephalothin or cefazolin)

Front 20

Name two mechanisms for resistance to carbapentems (imipenem, meropenem). How do you tell which it is by a micro test?

Back 20

Porin mutation (no entry) and/or efflux, metallo beta-lactamse (antibiotic breakdown). Larger zone of inhibition to imipenem than meropenem suggestive of entry inhibition (mira can enter via a different route, impenem requires a specific porin that can be mutated). E-test with imipenem +/- EDTA will demonstrate presence of metallo (zinc-containing) beta-lactamase. (EDTA should make the drug more active on the plate).