Group B Streptococcus Colonization Detection, NAA
Use
Antepartum detection of group B β-hemolytic streptococci.
Special Instructions
The CDC and ACOG guidelines recommend the collection of both a vaginal and rectal swab to maximize sensitivity of GBS detection. Swabbing both the lower vagina and rectum substantially increases yield compared to sampling the vagina alone. This test includes a nucleic acid amplification (NAA) test following incubation in a selective enrichment broth medium to enhance detection.
Limitations
A positive result does not necessarily indicate the presence of viable organisms. The test should not be used for patients who have used systemic or topical (vaginal) antibiotics in the week prior or for those diagnosed with placenta previa. Susceptibility testing is generally not performed due to universal susceptibility of the organism to penicillin, and resistance surveillance is not routinely recommended.
Methodology
PCR-based (RT-PCR)
Biomarkers
LOINC Codes
- 48683-7
- 48683-7
- 11502-2
Result Turnaround Time
1-2 days
Related Documents
For more information, please review the documents below
Specimen
Other
Volume
Single or double bacterial swab
Minimum Volume
Single bacterial swab
Container
Bacterial Cult Trans Swab with Media or ESwab®
Collection Instructions
Collection of both a vaginal and rectal swab specimen is strongly recommended. Swab the lower vagina (vaginal introitus), followed by the rectum using the same swab. Move swab from side to side, or rotate the swab at the collection site, allowing several seconds for absorption. Cervical or perianal specimens are not acceptable; a speculum should not be used for culture collection.
Storage Instructions
Specimen is stable for 24 hours at room temperature. If arrival at lab will extend beyond 24 hours, refrigerate.
Causes for Rejection
Inappropriate specimen transport; inappropriate transport conditions; improper labeling; specimen received after delay over 48 hours; cervical/endocervical, perianal, perirectal or perineal specimen or any source other than vagina and rectum
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 24 hours |