Streptococcus agalactiae em gestantes: prevalência de colonização e avaliação da suscetibilidade aos antimicrobianos

Abstract

PURPOSE: to verify the occurrence of colonization by Streptococcus agalactiae in pregnant women attended at the prenatal outpatient clinic of the Teaching Maternity Hospital of Rio de Janeiro University (UFRJ) and to evaluate the susceptibility of the isolates to antimicrobial agents. METHODS: a total of 167 pregnant women between the 32nd and 41st week of gestation, regardless of risk factors, attended at the antenatal clinic between February 2003 and February 2004, were evaluated. The vaginal/anal material, collected by the same swab, was inoculated in Todd-Hewitt broth to which nalidixic acid (15 µg/mL) and gentamicin (8 µg/mL) were added, with following subcultures onto sheep blood-agar. Identification was carried out observing colony morphology and beta-hemolysis type on blood-agar, catalase, cAMP, and serological tests. The antimicrobial susceptibility testing used agar diffusion and agar dilution methods. Statistical analysis was performed by the c2 test with the level of significance set at p 0.05). All 32 isolated strains were susceptible to penicillin, cefotaxime, ofloxacin, chloramphenicol, vancomycin and meropenem. Resistance to erythromycin and clindamycin was detected in 9.4 and 6.2% of the isolates, respectively. CONCLUSIONS: the relatively high incidence (19.2%) of colonization by S. agalactiae among the evaluated pregnant women and the recovery of antimicrobial resistant strains, especially those recommended in cases of penicillin allergy, emphasize the importance, for a correct prevention of neonatal infections, of detecting colonization at the end of pregnancy and evaluating antimicrobial susceptibility.