Detection of Streptococcus agalactiae colonization in pregnant women by using combined swab cultures: cross-sectional prevalence study.
OBJECTIVE
Maternal Streptococcus agalactiae colonization and early-onset neonatal sepsis have aroused interest in the worldwide literature. Streptococcal neonatal disease is associated with significant morbidity and mortality in the perinatal period, especially among premature neonates. The aim of this study was to assess the prevalence of maternal streptococcal colonization by using combined swab cultures, compared with swab collection from a single site.


METHODS
Cross-sectional study at Faculdade de Medicina de Botucatu, Universidade Estadual Paulista.


METHODS
Samples were obtained from 405 patients at gestational ages of 35 to 37 weeks. Swabs from the perianal (rectal) region, vaginal introitus and upper lateral vaginal vault were cultured in Todd-Hewitt selective broth. Colonies suggestive of Streptococcus agalactiae were subjected to the catalase and CAMP (Christie, Atkins, Munch-Petersen) tests. To evaluate the positivity of combined swab cultures, Tukey's test was used for comparison of proportions.


RESULTS
The prevalence of streptococcal colonization was 25.4%. Among the patients with positive cultures, 28.1% had this at only one collection site, 24.2% simultaneously at two sites and 47.5% at all three sites. Associating the swabs from two collection sites significantly increased streptococcal isolation, compared with a single swab (P < 0.05), except for perianal (rectal) collection. Use of combined swabs from three collection sites showed statistically higher isolation rates.


CONCLUSIONS
In combined swab cultures collected from three collection sites, the prevalence of maternal Streptococcus agalactiae colonization was higher than in swabs collected from a single site.
Marconi
Camila
C
Department of Pathology, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil.
Rocchetti
Talita Trevizani
TT
Rall
Vera Lúcia Mores
VL
Carvalho
Lidia Raquel de
LR
Borges
Vera Terezinha Medeiros
VT
Silva
Márcia Guimarães da
MG
D001938:Brazil; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D011247:Pregnancy; D015995:Prevalence; D012007:Rectum / Q000382:microbiology*; D013048:Specimen Handling / Q000379:methods; D013292:Streptococcus agalactiae / Q000302:isolation & purification*; D014621:Vagina / Q000382:microbiology*