From Sanford Robbins III, MD, Chief Pathologist, and Jacqui Kozireski, Microbiology Lab Manager
We are pleased to announce that the Cepheid Xpert GBS LB (Group B Strep LIM broth enriched) is a qualitative real-time PCR test used to detect GBS DNA from LIM broth culture of vaginal/rectal swabs after 18 to 24 hours of incubation. This test is for antepartum testing (35-37 weeks).
Conventional methods of culturing are less sensitive and can take up to 72 hours from collection to reporting. The combination of LIM broth enrichment and PCR provides reduced turnaround time with an extremely sensitive and specific method to detect GBS colonization in antepartum women, which fulfills the CDC (November, 2010) recommendations for testing. Results will be reported in 20 to 24 hours as compared to the three-day turnaround of current culture methods.
Routine susceptibility testing will only be performed on those patients who are penicillin-allergic at the request of the physician, and can be requested up to three days post collection or indicated when the test is ordered. Susceptibility testing will require an additional two to three days when requested.
Specimen collection: Use Remel BactiSwab (double swab) provided by the lab as long as testing is sent to us. PAR levels will be monitored periodically. We will no longer accept gel swabs as this is incompatible with PCR testing.
Store specimens refrigerated and transport to the lab within 24 hours of collection. Patients who have used systemic or topical (vaginal antibiotics in the week prior or patients with placenta previa should not be tested.)
On written/printed orders, please specify:
- Group B Strep, Lim Broth PCR (Antepartum Only)
- Group B Strep Lim Broth, PCR w/Sens (Antepartum Only) for Penicillin Allergy
Contact the Microbiology Laboratory at 443-481-4232 with questions or if further testing is needed.