SM SM Antimicrobial Resistance & Stewardship 3

Question 1

Which international surveillance network monitors global antimicrobial resistance trends in clinically important bacteria?

Accepted Answer

GLASS (Global Antimicrobial Resistance and Use Surveillance System) by WHO

Answer

WHO's GLASS is the primary global surveillance system for standardized AMR monitoring across countries, providing data to guide global health policy.

Question 2

Colistin resistance in Gram-negative bacteria has emerged globally via a plasmid-mediated gene. What is this gene called?

Accepted Answer

mcr-1

Answer

The mcr-1 gene (mobile colistin resistance) encodes a phosphoethanolamine transferase that modifies lipid A, reducing colistin binding and conferring transferable resistance.

Question 3

In the context of antibiotic stewardship, 'de-escalation' refers to:

Accepted Answer

Narrowing antibiotic spectrum based on culture and susceptibility results

Answer

De-escalation means transitioning from broad-spectrum empiric therapy to a narrower agent once culture results identify the pathogen and its susceptibilities.

Question 4

Which of the following beta-lactamase classes, per the Ambler classification, includes the metallo-beta-lactamases (MBLs)?

Accepted Answer

Class B

Answer

Ambler Class B beta-lactamases are metallo-enzymes that require zinc ions for catalysis and can hydrolyze carbapenems; they include NDM, VIM, and IMP enzymes.

Question 5

A specimen shows Pseudomonas aeruginosa resistant to all beta-lactams, fluoroquinolones, and aminoglycosides. This is classified as:

Accepted Answer

Extensively drug-resistant (XDR)

Answer

XDR is defined as non-susceptibility to at least one agent in all but two or fewer antimicrobial categories, leaving only one or two categories potentially active.

(SM) Specialist in Microbiology Practice Test

(SM) Specialist in Microbiology Practice Test

SM SM Antimicrobial Resistance & Stewardship 3