Bacterial cultures – Anaerobic – Reference Identification/Confirmation
|Test Requested||Required Requisition(s)||Specimen Type||Minimum Volume||Collection Kit|
Bacterial Cultures – Anaerobic – Reference ID/Confirmation
Pure viable subculture of 24 – 48 hours growth of organism on appropriate pre-reduced medium submitted in an anaerobic transport kit or anaerobic swab2,3
Submission and Collection Notes
If a swab or broth is received the turnaround time will be delayed by at least 24 hours.
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.
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
- specimen source (e.g. brain abscess)
- antibiotic treatment
- gGram stain description, aerotolerance test results and catalase reaction
- presumptive identification
- if isolate is part of a polymicrobic infection
- the number of consecutive blood cultures positive for the submitted isolate when isolates are from blood cultures
- Mixed or non-viable cultures will not be tested. The submitter will be contacted by telephone. A written report will be issued to indicate that the test has been rejected.
- The submitting laboratory will be contacted regarding isolates or specimens from critical sites (e.g. brain abscess) that are submitted inappropriately (e.g. improper transport conditions or mis-labelled/un-labelled).
- Do not submit multiple isolates from the same specimen/site of infection - for polymicrobic infections, only submit the two most predominant isolates. Laboratories should perform preliminary identification tests including catalase (15% hydrogen peroxide) and Gram stain. Note growth characteristics on all isolates on the Reference Bacteriology Requisition.
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.
Transport a fresh subculture in anaerobic conditions to ensure viability on receipt.
Place specimen in biohazard bag and seal. Specimen should be transferred at room temperature to the laboratory within 48 hours of collection in anaerobic conditions.
Test Frequency and Turnaround Time (TAT)
Anaerobic bacteria cultures are tested daily, Monday to Friday.
Turnaround time for test results is up to 8 days from receipt by PHO laboratory.
Results are reported to the ordering physician or health care provider as indicated on the requisition.
All anaerobe isolates are identified/confirmed by MALDI –TOF and/or 16S rRNA Gene Sequencing.
- Speciation and/or susceptibility testing will be attempted for Lactobacillus spp. isolated from systemic infections only (e.g. blood, pleural fluid etc).
- Lactobacillus spp. from urine cultures will not be processed.
- Pleomorphic Gram positive bacilli that are catalase-positive and spot indole-positive are reported as P. acnes. These do not require further testing at PHO laboratory.
- Indole or catalase negative strains may be forwarded to the PHO laboratory for confirmation.
- Susceptibility testing will only be performed on isolates from sterile sites (excluding urines).
- For treatment failure cases, please include the clinical information and antimicrobial therapy.
- Requests for susceptibility testing may require consultation with the Medical Microbiologist