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Tes​​t​​ Name 

Sen​s​​​​iti​​​tr​​​​​eTM Anti​​mic​robia​l Su​​​sceptibility Testing (AST)

Test ​​​​​M​​​e​th​o​​​d​​​olog​y​​

​B​roth​​ mi​​crodilution-based antimic​robial susceptibility testing (AST) for 18 antibiotics u​​​​​til​izing the Sens​ititreTM Gram Negative GNX2F AST panel. Antibiotics tested include: aztreonam, cefepime, cefotaxime, ceftazidime, colistin, doripenem, ertapenem, imipenem, meropenem, and piperacillin/tazobactam, amikacin, ciprofloxacin, gentamicin, levofloxacin, polymyxin, tigecycline, tobramycin, and trimethoprim/sulfamethoxazole.

Reflex Testing

Isolates submitted for other carbapenemase testing may be reflexed to SensititreTM if certain criteria are met. This test is for surveillance purposes only, no reports will be routinely issued.​

Pre-A​pproval Required​

No.  Test Isolates submitted for mCIM or PCR testing that meet testing criteria may be reflexed to the SensititreTM AST is performed for surveillance purpose only. 

Supp​lemental Information and Required Form(s)​

On the MDL General Submission form, select Form Antimicrobial Susceptibility Testing - AST: MDL General Submission Form (PDF)

​The MDL General Electronic Submission Form should be downloaded and opened using a pdf viewer. To download, right-click the link and select "Save link as." If you are unable to open the Form using a pdf viewer, please contact MDL at 510-412-3700 or MDL.Submissio​ns@CDPH​ 

Instructions on completing the form:​​​​ MDL​ F​orm AST - Antimicrobial Susceptibility Testing

MDL Expanded Carbapenemase Testing Frequently Asked Questions (FAQ) at:  Ex​panded Carbapenemase Testing Services Frequently Asked Questions (FAQ)

Required Specimen Type(s)


Pure culture isolates of:

  • Carbapenem-resistant Enterobacterales (CRE), including  Escherichia coli, Klebsiella oxytoca, Klebsiella pneumoniae, and Enterobacter spp.
  • Carbapenem-resistant Pseudomonas aeruginosa (CRPA)
  • Carbapenem-resistant Acinetobacter baumannii (CRAB)
Minimum Volume Required Not Applicable 

Specimen Stability


Store pure culture isolates at room temperature (15–25 °C) for up to 7 days; or refrigerated (2​–​8 °C) up to 14 days.

If isolates are being stored more than 14 days, preferably freeze in Trypticase Soy Broth (TSB) with 15% glycerol (–​​20 °C or lower) for long-term storage.

​Rejection Criteria


  • Isolate submissions with insufficient or conflicting labelling
  • Broken or leaking samples
  • Samples with insufficient quantities or growth
  • Isolates that are too old or non-viable
  • Specimen/sample types not meeting acceptance criteria (see FAQ), if no prior approval was received
  • Mixed cultures
  • Primary patient samples

Storage/Transport Conditions ​​​

Ship cultures on nonselective nutrient or similar agar in tubes with leak proof screw cap closures.  Ship isolates as soon as possible to ensure viability and to avoid loss of antimicrobial resistance mechanisms.​​
Transport Medium,​
if applicable

Not Applicable
Specimen Labeling Two identifiers, including patient full name, and at least one other identifier (specimen accession number, date of birth, medical record number); date and time of collection as noted for specific tests, if applicable.

Shipping Instructions and Specimen Handling Requirements





Ship isolates grown on agar slants at ambient temperature or refrigerated (cold pack), or ship cultures frozen in trypticase soy broth (TSB) with 15% glycerol on dry ice.

​Follow the appropriate DOT/IATA approved shipping procedures. ​

Ship to:

California Depart​ment of Public Health​
Microbial Diseases Laboratory ​
ATTN:  Bacterial Diseases Section
850 Marina Bay Parkway, Specimen Receiving Room B106
Richmond, CA  94804​
Specimen Collection Instructions, if applicable
Not Applicable
Turnaround Time Not Applicable​

Interferences & Limitations Pure culture isolates must be viable for testing.

Reference Range Not Applicable

Additional Information None

MDL Point of Contact For questions regarding submissions, please email or call the Bacterial Di​seases Section
(510) 412-3903

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