DNA probe for beta-hemolytic group B Streptococcus. Diagnostic accuracy in threatened preterm labor.
OBJECTIVE
To determine the diagnostic accuracy of a DNA probe for beta-hemolytic group B Streptococcus (GBS) in women with threatened preterm labor.


METHODS
Two identical vaginal/perianal samples were collected from 75 pregnant women who were being evaluated for threatened preterm labor. One sample was managed in the traditional manner, with direct plating onto blood agar followed by plating after 8 and 24 hours of LIM broth enhancement. The "gold standard" was 24 hours of LIM broth enhancement followed by blood agar plating. The second sample was placed in LIM broth, and DNA probe testing was performed after incubation for 8 and 24 hours.


RESULTS
The prevalence of GBS colonization by the gold standard culture was 32%. After 8 hours of incubation in LIM broth, the DNA probe had poor sensitivity (79%); however, after 24 hours of incubation in LIM broth the DNA probe sensitivity rose to 96%. The DNA probe demonstrated only one false negative result after 24 hours of LIM broth enhancement. All DNA probe results were known 25 hours after sample collection.


CONCLUSIONS
This DNA probe gave results nearly identical to those of standard cultures and allowed a substantial saving of time.
Ryan
K M
KM
Department of Obstetrics and Gynecology, School of Medicine and Statistical Consulting Center, Wright State University, Ohio, USA.
Lencki
S G
SG
Elder
B L
BL
Northern
W I
WI
Khamis
H J
HJ
Bofill
J A
JA
D000328:Adult; D015342:DNA Probes / Q000592:standards*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007235:Infant, Premature, Diseases / Q000517:prevention & control*; D007752:Obstetric Labor, Premature / Q000382:microbiology*; D011237:Predictive Value of Tests; D011247:Pregnancy; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013290:Streptococcal Infections / Q000175:diagnosis* / Q000517:prevention & control; D013292:Streptococcus agalactiae / Q000235:genetics* / Q000302:isolation & purification; D014621:Vagina / Q000382:microbiology
D015342:DNA Probes