Listeria monocytogenes – Confirmation and Whole Genome Sequencing

Specimen Collection and Handling

Specimen Requirements

Test Requested Required Requisition(s) Specimen Type Minimum Volume Collection Kit

Listeria monocytogenes

Pure viable subculture of organism (eg Blood Agar)

Listeria monocytogenes

A swab of the pure subculture in Amies transport medium

Submission and Collection Notes

1

Submit subculture of an organism on an appropriate medium that supports the growth (e.g. Blood Agar). Swab of pure culture in bacterial transport medium is an acceptable alternative.

2

If a swab is received the turn-around time will be delayed by at least 24 hours.

3

Primary cultures are unacceptable as they should be processed in the originating laboratory. The submitter will be contacted by telephone. A report will be issued to indicate that the test has been rejected.

4

Complete all fields of the Reference Bacteriology Requisition, including:

  • test(s) requested
  • culture information
  • clinical/epidemiology
  • contact information

Preparation Prior to Transport

Place specimen into a biohazard bag and seal. Label the specimen with 2 unique identifiers prior to shipment. Specimen should be transferred to the laboratory within 48 hours of collection.

Requisitions and Kit Ordering

Test Frequency and Turnaround Time (TAT)

Listeria monocytogenes cultures are tested daily, Monday to Friday.

Turnaround time for test results is up to 4 days from receipt by PHO laboratory for identification/confirmation.

Reporting

Results are reported to the ordering physician or health care provider as indicated on the requisition.

Specimens that are positive for Listeria monocytogenes are to be reported to the Medical Officer of Health as per Health Protection and Promotion Act.

Test Methods

Listeria monocytogenes isolates are identified by conventional biochemicals. Isolates from all sites are forwarded to the Molecular Surveillance section at the PHO Laboratory Toronto for Whole Genome Sequencing for provincial surveillance and outbreak testing support.

Mis à jour le 25 sept. 2019