Eligible Submitters
|
Isolates will be accepted from California Local Public Health Laboratories
only. Isolates
will not be accepted directly from hospitals or other healthcare facilities unless approved by the MDL and
CDPH HAI Program, and applicable Local Public Health Laboratories.
|
Test Methodology
|
The MBT STAR®-Carb assay is a MALDI-TOF based phenotypic method to rapidly detect carbapenemase-producing organisms (CPOs), including CRE, CRPA, and CRAB. Timely detection of CPO is essential for effective infection prevention and control.
|
Reflex Testing
Criteria |
Isolates detected positive for carbapenemase production by MBT STAR®-Carba assay may be reflexed to molecular testing to identify potential carbapenemase genes, if not already performed. Isolates may also be reflexed for other surveillance (non-reportable) testing purposes.
|
|
Pre-Approval Required |
Carbapenem resistant
Escherichia coli,
Klebsiella oxytoca, Klebsiella pneumoniae,
Klebsiella aerogenes,
Enterobacter species,
Pseudomonas aeruginosa, and
Acinetobacter baumannii that meet the criteria listed in the Expanded Carbapenemase Testing Services Frequently Asked Questions (FAQs) and ‘Acceptable Sample/Specimen Type for Testing’ can be routinely submitted (pre-approval not required).
Please routinely submit pan-non susceptible
Pseudomonas aeruginosa,
Acinetobacter baumannii, and
Enterobacterales isolates for surveillance testing (pre-approval not required). Testing is available for carbapenem resistant
Enterobacterales other than those listed above; please refer to the criteria listed in the FAQs.
|
|
Supplemental Information and Required Form(s) |
Preferred method:
MDL Lab Web Portal (LWP).
For submitters who do not have access to the MDL LWP; please contact
MDL.Submissions@CDPH.ca.gov for additional information.
Please attach a copy of AST results, and other available molecular or phenotypic test results, to the requisitions when submitting isolates for carbapenemase testing.
|
|
Required Specimen Type(s)
|
Pure culture isolates.
Isolate must be identified to at least the genus level for
Enterobacterales and the species level for Pseudomonas aeruginosa and
Acinetobacter baumannii by the submitter.
Mixed cultures received by MDL will not be tested.
Isolates
must meet one of the following criteria:
Carbapenem resistant Enterobacterales (CRE)
Enterobacterales must be resistant to at least one relevant carbapenem, i.e., imipenem, ertapenem, or meropenem (i.e., minimum inhibitory concentrations (MIC) of ≥4 µg/mL for imipenem or meropenem, or ≥2 µg/mL for ertapenem).
Carbapenem-resistant
Pseudomonas aeruginosa (CRPA)
Submit carbapenem-resistant
P. aeruginosa isolates that are resistant to imipenem or meropenem by standard AST methods (i.e., MIC of ≥ 8 µg/mL)
and non-susceptible (i.e., intermediate or resistant MIC ≥ 16µg/ml) to cefepime, ceftazidime, or ceftolozane-tazobactam.
Carbapenem resistant
Acinetobacter baumannii (CRAB)
Submit carbapenem-resistant
A. baumannii isolates that are resistant to imipenem or meropenem by standard AST methods (i.e., MIC of ≥8 μg/mL).
Please Note: If the species is intrinsically resistant to a carbapenem antibiotic (for example Proteus and Morganella morganii and imipenem) they must also be resistant to another relevant carbapenem. Please refer to the FAQs and contact MDL at MDL.Submissions@CDPH.ca.gov to request a review of the available AST results prior to submission as needed.
|
|
Minimum Volume Required |
Not Applicable
|
|
Specimen Stability
|
It is recommended to store pure culture isolates at room temperature (15 to 25 °C) for up to 7 days; or refrigerated (2 to 8 °C) up to 14 days. Limit subpassages as this may lead to plasmid loss.
If isolates are being stored more than 14 days prior to shipping, it is recommended to freeze it in Trypticase Soy Broth (TSB) with 15% glycerol (–20 °C or lower) for long-term storage.
|
|
Rejection Criteria
|
|
|
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 first and last 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 (up to 35°C), or ship cultures frozen in trypticase soy broth (TSB) with 15% glycerol on dry ice. Isolates that are improperly frozen or shipped at high temperatures (>35°C) may lose viability.
Follow the appropriate DOT/IATA approved shipping procedures.
Ship to: California Department 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 |
7–10 business days
|
|
Interferences & Limitations |
Some OXA- type carbapenemases might not be detected using the MBT STAR®-Carba IVD Kit due to weak carbapenemase activity.
The MBT STAR®-Carba assay can only detect present carbapenemase activity, requiring an expressed and functional carbapenemase in sufficient quantity and availability. A negative MBT STAR®-Carba assay result may be caused by low cell numbers or low expression of carbapenemase, which may lead to “false negative” (non- hydrolyzing) results. Caution should be taken in interpretation and negative results should not be used to conclude a diagnostic or therapeutic decision.
False positive results can also be observed from the possible presence of alternative or additional resistance mechanisms.
|
|
Reference Range |
Not Applicable
|
|
Additional Information |
Expanded Carbapenemase Testing Services Frequently Asked Questions (FAQs) - February 2025
|
|
MDL Point of Contact |
For questions regarding submissions, please email MDL.Submissions@CDPH.ca.gov or call Bacterial Diseases Section at (510) 412-3903
|