Antimicrobial Susceptibility - Expanded AST Panel | Minnesota Department of Health

Aliases

Aztreonam, Aztreonam/avibactam, Ceftazidime/avibactam, Synergy testing

Test Name

Antimicrobial Susceptibility - Expanded AST Panel

Test Code

ASTEXP

Methodology

Broth microdilution

Overview/Supplementary

This test determines antimicrobial susceptibility to ceftazidime/avibactam, aztreonam, and aztreonam/avibactam for Enterobacterales that either:

1. Tested non-susceptible to all beta-lactams, including ceftazidime-avibactam or meropenem-vaborbactam, if tested OR,

2. Tested positive for NDM, VIM, or IMP genes by a molecular test AND were highly resistant to all or the majority of antimicrobials already tested.

Testing is done as part of the Antimicrobial Resistance Laboratory Network (AR Lab Network).

Turn Around Time

3-5 days

Specimen Requirements

Isolates: 18-24 hour culture of Enterobacterales on non-selective media that support the growth of bacteria.

Isolates should be subcultured as few times as possible prior to sending for testing to limit the potential for loss of resistance mechanisms during passage.

Special Considerations

Please email arlnmn@state.mn.us before submitting isolate.

Transport/Stability

Store and ship at ambient (8°C to 25°C) or refrigerated (2°C to 8°C) temperature.

Interface/Codes

LOINC: 50545-3