Previous Article | Next Article ![]()
Journal of Clinical Microbiology, November 1999, p. 3705-3706, Vol. 37, No. 11
Henry Ford Health System, Detroit, Michigan
48202
Received 19 March 1999/Returned for modification 11 May
1999/Accepted 23 July 1999
The combination of neomycin-nalidixic acid (NNA) agar and a
selective broth medium (SBM) has recently been shown to improve the
sensitivity of screening cultures for group B streptococcal (GBS)
carriage in women. Because of the relatively high cost of NNA agar, a
study was initiated to determine whether Columbia colistin-nalidixic
acid (CNA) agar would be an equally sensitive, more economical
alternative. A total of 580 cervical-vaginal and/or rectal specimens
submitted for detection of GBS were included in the study. Each was
plated onto NNA and CNA agar and then inoculated into SBM. GBS were
recovered from 95 of 580 (16.4%) specimens, including 61 isolates from
CNA, 74 from NNA, 73 from the CNA-SMB combination, and 86 from the
NNA-SMB tandem. Of those, 22 isolates were recovered on NNA but not
CNA, 9 were cultured on CNA but not NNA, 52 were isolated on both
media, and 12 were recovered from subcultures of SBM only. The overall
sensitivity of CNA alone (64.2%) was statistically significantly less
than that of NNA agar (77.9%), as was the sensitivity of combination
of CNA plus SBM (76.8%) compared to that of NNA plus SBM (90.5%).
Based on these findings, CNA should not be considered an acceptable
alternative to NNA for the detection of GBS colonization in women
despite potential cost savings.
0095-1137/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.
Comparison of Selective Broth Medium Plus
Neomycin-Nalidixic Acid Agar and Selective Broth Medium Plus Columbia
Colistin-Nalidixic Acid Agar for Detection of Group B Streptococcal
Colonization in Women
*
Mailing address: Henry Ford Health System, 2799 W. Grand Blvd., Detroit, MI 48202. Phone: (313) 916-2341. Fax: (313)
916-8309. E-mail: mdunne1{at}hfhs.org.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»