Prevalencia e fatores associados a colonização retal e vaginal pelo Estreptococo do grupo B em parturientes e suas caracteristicas fenotipicas

by Neder Alves, Valeria Moraes

Abstract (Summary)
Introduction - Genital colonization with Group B Streptococcus(GBS) occurs in 4% to 30% of pregnant women. GBS can be vertically transmitted and cause significant morbidity and mortality in newborns. Strategies for prevention and treatment to reduce the incidence of the newborn infection have not been established yet in Brazil. In order to be effective, these strategies must be made based on the knowledge on prevalence, risk factors for GBS colonization and on GBS phenotypic characteristics. Objectives: To establish the prevalence of GBS genital colonization, to identify the factors associated with this colonization and the GBS phenotypic characteristics (antibiotic susceptibility and serotypes). Methodology: The study was carried out from November 11, 2003 to May 14, 2004. A total of 316 pregnant women of the University Hospital of Jundiaí was sampled for GBS cultures at the admission for delivery. Samples were collected using sterile swab from the vagina and rectum, which were immediately inoculated onto Todd Hewitt?s selective medium. Data regarding to the factors associated with the colonization were obtained from patient?s clinical record files. GBS antibiotic susceptibilities were determined using disk diffusion to seven antibiotics (penicillin, ampicillin, erythromycin, clindamycin, cefalotin, gentamycin and nitrofurantoin) according to the guidelines of the National Committee for Clinical Laboratory Standards (NCCLS). Serotypes were determined using specific anti-serum Ia, Ib, II, III, IV and V. Results: GBS colonization rate was 14.6%. The only factor significantly associated with GBS colonization was to have a job out of home. None isolate was resistant to penicillin, ampicillin, erythromycin or nitrofurantoin. The highest resistance rate was to gentamycin (76.1%), followed by clindamycin (17.4%). The most frequent serotype was Ib (23.9%) followed by serotypes II and Ia (19.6% and 17.4%, respectively). No correlations were found between serotype and antibiotic resistance. Conclusion: GBS colonization rate was high in pregnant women attending the University Hospital of Jundiaí for delivery. No risk factors were associated with the colonization except to have a job out of home. Penicillin continues to be the drug of choice for intrapartum antibiotic prophylaxis. However, clindamycin as an alternative in women allergic to penicillin should be better evaluated using antibiotic sensitivity tests. The most frequent serotype found in this study (Ib) was not the same found in most of studies from another countries. This result highlights the importance of the knowledge of the most prevalent serotypes in each region to further development of an appropriate vaccine for GBS
This document abstract is also available in Portuguese.
Bibliographical Information:

Advisor:Jose Antonio Simões; Jose Antonio Simões [Orientador]; Jose Roberto E. Gabiatti; Arlete M. dos S. Fernandes

School:Universidade Estadual de Campinas

School Location:Brazil

Source Type:Master's Thesis



Date of Publication:04/13/2005

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