Serotype determination for Streptococcus agalactiae (Group B Streptococcus)

The determination of serotype for Streptococcus agalactiae (Group B Streptococcus).

Pure culture, presumptively identified as S. agalactiae, isolated from a normally sterile site (such as blood or CSF).

Specimens may be subject to rejection if they are not the appropriate sample type, a duplicate sample**, have insufficient volume, are not accompanied by relevant patient information, not on the correct requisition, or requisition is absent.

Isolate provided on culture medium.

Send as growth on culture medium (preferred) or on a swab in transport medium.  Chocolate or charcoal media are recommended.  Cultures can be also shipped frozen on dry ice. 

Shipping of specimens shall be done by a TDG certified individual in accordance with TDG regulations. For additional information regarding classification of specimens for the purposes of shipping, consult either Part 2 Appendix 3 of the TDG Regulations or section 3.6.2 of the IATA Dangerous Goods Regulations as applicable.

Isolates from infants less than 1 month of age with invasive disease due to Streptococcus agalactiae may be submitted.

Completed Isolate Submission Requisition for Streptococcus form including sender lab name, address, telephone number and email address. Patient age or date of birth, sex, culture reference number, clinical source, date collected, and test requested. Outbreak or specimens requiring expedited testing or phylogenetic analysis must be indicated as such on the requisition. The above information must be sent as a hardcopy with the shipment, and an excel file may be sent to nml.strepsti-lnm.strepits@phac-aspc.gc.ca.

Isolates of Streptococcus agalactiae isolated from contacts of infected infants may also be submitted for testing.

**Duplicate samples should not be submitted without prior consent as they may not be processed. Isolates collected from the same patient within 3 weeks are considered duplicates.

* Serotyping using whole genome sequencing (primary) (2)

Serotyping using qPCR Assay (secondary) (1)

30 calendar days

Outbreak associated or urgent isolates will be granted priority status and completed as soon as possible. Please contact Streptococcus and STI Section to notify of these requests.

**Turnaround times may not be guaranteed when isolates are submitted in large batches.

1. Breeding KM, Ragipani B, Lee KD, Malik M, Randis TM, Ratner AJ. Real-time PCR-based serotyping of Streptococcus agalactiae. Sci Rep. 2016 Dec 2;6:38523. doi: 10.1038/srep38523.
2. Kapatai, G.; Patel, D.; Efstratiou, A.; Chalker, V. J. Comparison of Molecular Serotyping Approaches of Streptococcus Agalactiae from Genomic Sequences. BMC Genomics 2017, 18 (1), 429. https://doi.org/10.1186/s12864-017-3820-5.