[Prevalence of the colonization by Streptococcus agalactiae in pregnant women from a maternity in Ceará, Brazil, correlating with perinatal outcomes].

PURPOSE

To assess the prevalence of Streptococcus agalactiae, a Group B streptococcus, in pregnant women, and their possible risk factors, as well as the impact of perinatal colonization and antimicrobial susceptibility.

METHODS

We evaluated 213 pregnant women from 20 weeks of gestation, regardless of risk factors, attending a tertiary teaching hospital. The technique used was a single sterile swab to collect secretions from the vaginal and perianal regions. The newly obtained samples were stored in Stuart transport medium and taken to the laboratory, where they were inoculated in Todd-Hewitt selective medium supplemented with Gentamicin (8 ug/mL) and nalidixic acid (15 ug/mL), with subsequent cultivation on blood agar plates. The materials were tested with Gram, catalase with hydrogen peroxide and CAMP (Christie, Atkins, Munch-Petersen), and results were serologically confirmed with the Streptococcal Grouping Kit, Oxoid®. The positive samples were tested for antimicrobial susceptibility. We also assessed socioeconomic, reproductive, clinical, and obstetric variables, and newborn care. Statistical analysis was performed with Epi-Info 6.04.

RESULTS

The prevalence of colonization obtained by field tests was 9.8% by CAMP test, but only 4.2% by serology. The only protective factor was white skin color (p=0.01, 0.45>OR>0.94, 95%CI). There was no difference in prevalence of Group B streptococcus regarding other reproductive and obstetric variables. Infection occurred in only one of the newborns from colonized mothers; although it was revealed infection with Pseudomonas spp. High resistance to ampicillin (4/9), cephalothin (4/9), penicillin (4/9), erythromycin (3/9), clindamycin (7/9), and cloramphenicol (1/9) was detected.

CONCLUSIONS

The infection rate was lower than that found in other studies, although a high rate of resistance to antibiotics commonly used for treatment was detected. Since there are no studies on the prevalence of Group B streptococcus in Ceará, we cannot perform a comparative analysis of the population, and further studies are needed with geographically similar groups to validate these results.