Listeria monocytogenes – Confirmation and Serotyping

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


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.


If a swab or broth is received the turnaround time will be delayed by at least 24 hours.


Primary cultures are not acceptable; and must be processed by the originating lab. The submitter will be contacted by telephone prior to rejection of the primary sample followed by a written report to indicate that the test has been rejected.


Complete all fields of the Reference Bacteriology Requisition, including:

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

Preparation Prior to Transport

Label the specimen with the patient’s full name, date of collection and one other unique identifier such as the patient’s date of birth or Health Card Number. Failure to provide this information may result in rejection or testing delay.

Special Instructions

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. 

Turnaround time for test results is up to 21 days from receipt by PHO laboratory TAT for Serotyping.


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 systemic infections as well as outbreak specimens are forwarded to the Public Health Agency of Canada, Winnipeg for Typing.

PFGE is performed on outbreak specimens as well as isolates from systemic infections.

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Updated 25 Sep 2019