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Test Order

Corynebacterium diphtheriae Isolate 
Identification or Confirmation Referral for Toxin Testing

Pre-Approval Required


Supplemental Information or Form

1.    Pure, viable subculture

2.    Completed submittal form with 2 patient identifiers (e.g. name and date of birth), collection date and source, a brief but complete patient history, cultural history and submitting laboratory’s findings

3.    Documentation that indicates the role of this isolate in clinical disease

4.   LAB 446 (11/07) (MDL-N-11)

Performed on Specimens from

Nasopharynx or pharyngeal membrane, wound swab or aspiration

Acceptable Sample Type for Testing

Confirmed or suspected Corynebacterium diphtheriae isolate

Minimum Volume Required


Storage & Preservation of Sample Prior to Shipping


Transport Medium

Tubed agar medium with a secured screw cap, labeled with patient’s name, date subcultured, and organism suspected

Sample Labeling


Shipping Instructions which Include Specimen Handling Requirements

1.    Grow isolate under appropriate conditions prior to shipping and verify purity

2.    Ship at ambient temperature using appropriate DOT/IATA approved shipping procedures.

Test Methodology

As needed - Biochemical testing, Gene Sequencing by PCR, and/ or MALDI-TOF mass spectrometry, and subculture for referral to CDC if the isolate is confirmed as C. diphtheriae. Please note that referral to the CDC for diphtheria toxin testing will only be performed if the isolate is confirmed as C. diphtheriae

Turnaround Time

1 month and additional time if sent to CDC for toxin testing.

Interferences & Limitations

Mixed or nonviable culture

Additional Information

Please contact the MDL Bacterial Diseases Section (Reference Bacteriology Unit) for special consideration if any of the above criteria cannot be met.

MDL Points of Contact

Reference Bacteriology Unit (510) 412-3903

Monday-Friday 8 AM to 5 PM PT

Emails: margot.graves@cdph.ca.gov or robin.hogue@cdph.ca.gov

Last modified on: 1/15/2015 11:46 AM