Public Health Division

Test Menu Details

Carbapenem-Resistant Organisms (CRO) Testing
Updated	8/4/2025
Search Terms	Carbapenem-Resistant Enterobacterales (CRE) PCR; KPC and NDM; CRE Screen; Carba NP; IMP; Carba-R; VIM; OXA-48 in Enterobacterales; Formerly Enterobacteriaceae; Pseudomonas aeruginosa (CRPA); Acinetobacter species (CRA); Pan-resistant resistant (Pan-R) organisms; Multidrug resistant organisms (MDRO); pan-non-susceptible organisms
How to Order	On the General Microbiology Test Request Form (OHA0060): For CRE and CRPA: In the “Miscellaneous Testing” section, check the “CRE” or "CRPA" box. Include the organism name. For CRA or pan-resistant organisms, or MDRO, in the "Referral Testing" section, select or write in the organism submission. Attach your laboratory's susceptibility testing results. If a laboratory suspects verified, dual colony morphology, please inform the lab on the test order or by calling the lab at 503-693-4100 to prevent rejection or delays.
Availability	All clients
Performed	Tuesday through Friday on regular business days
Time to Reporting	Preliminary report will be released within 2 working days after receipt of specimen. Final report will be released within 5 working days after receipt of specimen
Public Health Data	De-identified data from antimicrobial surveillance testing are shared with the Centers for Disease Control and Prevention as part of the Antimicrobial Resistance Laboratory Network.
CPT Code	87798 x 2, 87185

Specimen Collection Details
Collection	Actively growing isolates of the Enterobacterales family, Pseudomonas aeruginosa or Acinetobacter spp. resistant to carbapenems. Submit pure isolates on an agar slant or non-selective plate media. Avoid multiple subcultures of the originally recovered organism.
Optimal Volume	N/A
Minimum Volume	N/A
Handling	Seal plate or tube, place in biohazard transport bag. Store specimens at ambient temperatures (20-25°C) pending transport. Do not freeze, avoid extreme heat.
Transport	Package specimens to maintain ambient temperatures during transport.
Rejection Criteria	Mixed culture; Subsequent samples of the same organism from the same source submitted from the same patient and facility within 30 days Specimens are subject to the requirements of the OSPHL Specimen Submission Policy.
Comments	If a laboratory suspects verified, dual colony morphology, please inform the lab on the test order or by calling the lab at 503-693-4100 to prevent rejection or delays. CRE and CRPA are testing at the OSPHL and referred out to the Washington State Public Health Laboratory (WSPHL) Antibiotic Resistance Laboratory Network Regional Laboratory (ARLN) for additional testing if indicated. CRA and pan-resistant MDRO are not testing at the OSPHL and are forwarded to WSPHL ARLN for testing. To understand OSPHL's CRO testing, please visit our CRO Testing Algorithm (pdf). Original material submitted for testing is retained for 5 calendar days after receipt at the laboratory. For additional information or assistance, please contact the OSPHL at 503-693-4100.

Method Details
Methodology	Xpert^® Carba-R, Carba NP Test, Multiplex Real-Time PCR, Susceptibility testing by broth microdilution
Performance Specifications	Carba NP: Percent accuracy - 92.18% Xpert® Carba-R: Method performance specifications are available from the manufacturer, Cephied. Broth microdilution: Percent accuracy - >90% Precision/Reproducibility - >95% Additional method performance specifications may be available. Contact the OSPHL if needed.

Change Log
8/4/2025	Updated Search Terms; How to Order; Time to Reporting; Comments; Methodology; Performance Specifications
4/1/2025	Updated How to Order; Public Health Data; Performed; Collection; Rejection Criteria
3/13/2024	New test menu page, replaces CRE test menu page