Modified Granada Agar Medium for the detection of group B streptococcus carriage in pregnant women
Document Type
Article
Department
Obstetrics and Gynaecology (East Africa)
Abstract
Objectives
To improve the detection rate of group B streptococci (GBS) in pregnant women, aiming at the prevention of early-onset septicemia in the newborn.
Methods
The yield from culturing two sites, vaginal and anorectal, on a Modified Granada Medium (MGM) was compared with our standard approach of culturing a vaginal swab on blood agar (BA).
Results
Samples were processed from 430 consecutive pregnant women. GBS was isolated from the vagina in 11.6% with BA, and in 13.7% with MGM. In 17.0% of anorectal samples, GBSwas identified with MGM. The combination of both sites and media had a yield of 20.0%. MGM identified all but six (2%) of 310 GBS strains after aerobic incubation, with use of a cover slide, and missed only three strains (1%) after anaerobic incubation.
Conclusions
Separate culture of vaginal and anorectal samples using the same MGM agar plate resulted in an increase in detection rate for GBS of 76% as compared to BA alone. The technique is simple and results are available after overnight incubation. MGM was confirmed as a specific medium for the identification of GBS, with a sensitivity of 98–99%.
Publication (Name of Journal)
Clinical Microbiology and Infection
Recommended Citation
Claeys, G.,
Verschraegen, G.,
Temmerman, M.
(2001). Modified Granada Agar Medium for the detection of group B streptococcus carriage in pregnant women. Clinical Microbiology and Infection, 7(1), 22-24.
Available at:
https://ecommons.aku.edu/eastafrica_fhs_mc_obstet_gynaecol/571
Comments
This work was published before the author joined Aga Khan University.