Test ID CGBS Group B Streptococcus (Streptococcus agalactiae) Culture
Useful For
Screening for maternal colonization with Streptococcus agalactiae at 35 to 37 weeks gestation as a guide for intrapartum antibiotic prophylaxis to decrease the risk of infection by Streptococcus agalactiae in the infant
Reflex Tests
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
RMALD | Ident by MALDI-TOF mass spec | No, (Bill Only) | No |
GID | Bacteria Identification | No, (Bill Only) | No |
STRP | Identification Streptococcus | No, (Bill Only) | No |
ISAE | Aerobe Ident by Sequencing | No, (Bill Only) | No |
Testing Algorithm
When this test is ordered, the reflex tests may be performed and charged.
Method Name
Conventional Culture Technique
Reporting Name
Grp B Strep (S. agalactiae) CultureSpecimen Type
VariesSpecimen Type: Swab
Sources: Vaginal/rectal combination swab
Container/Tube: Culture transport swab
Specimen Volume: Swab
Additional Information:
1. Specimen source is required.
2. Vaginal/rectal combination swab is the only acceptable specimen according to Centers for Disease Control and Prevention (CDC) guidelines. Vaginal only, rectal only, or other sources are not acceptable.
3. This assay is used for assessment of carriage of Streptococcus agalactiae (group B streptococcus) in pregnant women.
Specimen Stability Information
Specimen Type | Temperature | Time |
---|---|---|
Varies | Ambient (preferred) | 24 hours |
Refrigerated | 24 hours |
Clinical Information
Streptococcus agalactiae (group B streptococcus) is a cause of morbidity and mortality among infants. Infections occurring within the first week of life are considered early-onset; those occurring in infants >1 week of age are considered late-onset. Maternal vaginal or rectal colonization with Streptococcus agalactiae is a risk factor for early-onset disease in infants. Ten to 30% of pregnant women are vaginally or rectally colonized with Streptococcus agalactiae and may transmit the organism to their infant during labor and delivery. The Centers for Disease Control and Prevention recommends screening for colonization with Streptococcus agalactiae at 35 to 37 weeks gestation as a guide for intrapartum antibiotic prophylaxis to decrease the risk of infection with Streptococcus agalactiae in the infant.
Reference Values
Negative
Cautions
No significant cautionary statements
Day(s) Performed
Monday through Sunday; Continuously
Report Available
3 daysPerforming Laboratory

Test Classification
This test uses a standard method. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
87081-Strep Grp B (S. agalactiae) culture
87077-Ident by MALDI-TOF mass spec (if appropriate)
87077-Bacteria identification (if appropriate)
87077-Identification Streptococcus (if appropriate)
87153-Aerobe ident by sequencing (if appropriate)