Prevalência de sorotipos de Streptococcus grupo B que colonizam gestantes de risco numa maternidade na cidade de São Paulo

• Ano de defesa: 2018
• Autor(a) principal: Kfouri, Renato de Avila [UNIFESP]
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Paulo (UNIFESP)
• Palavras-chave em Português: Streptococcus vaccines; Polymerase chain reaction; Newborn; Infection; Immunization; Vacinas estreptocócicas; Reação em cadeia de polimerase; Recém-nascido; Infecção; Imunização
• Link de acesso: https://sucupira.capes.gov.br/sucupira/public/consultas/coleta/trabalhoConclusao/viewTrabalhoConclusao.jsf?popup=true&id_trabalho=6907623; https://repositorio.unifesp.br/handle/11600/52439

Objectives: Vaccines in development against Group B Streptococcus (GBS) should contain the most prevalent serotypes in the population. The key objective of the study was to investigate the prevalence of different serotypes of GBS that colonize pregnant women at risk in a private maternity hospital in the city of São Paulo. The secondary objectives were to correlate the GBS serotypes with maternal age, parity, and risk factors such as maternal fever, prematurity, prolonged membrane rupture (18 or more hours before delivery), intraamniotic infection and previous history of GBS infection. Methods: The study was developed in a complex of private maternity hospitals of the city of São Paulo, Hospital e Maternidade Santa Joana and ProMatre Paulista, and in the Special Laboratory of Clinical Microbiology (Laboratório Especial de Microbiologia Clínica LEMC) of the Universidade Federal de São Paulo. The strains of GBS isolated in routine maternity procedures, in pregnancy at risk, (20142018) were sent to LEMC for confirmation by mass spectrometry (MALDITOF) with subsequent DNA extraction for identification of serotypes by the polymerase chain reaction (PCR). Demographic and gestational data were analyzed. Results: 820 ToddHewit broths positive for GBS were sent to LEMC by the clinical laboratory of the maternities. Of these, recovery and confirmation of GBS by MALDITOF were possible in 352. The strains were processed for determination of the capsular serotype by PCR. Of the total of 352 GBS isolates, 125 strains (35.5%) were serotyped as Ia; 23 (6.5%) as Ib; 41 (11.6%) as II; 36 (10.2%) as III; 4 (1.1%) as IV; 120 (34.1%) as V and 1 strain (0.3%) as VIII. Two isolates (0.7%) were not serotyped by the methodology used. None of the samples tested were identified as serotypes VI or VII. There was no statistic significant correlation between gestational risk factors, demographic data and distribution of serotypes. Conclusions: GBS serotypes Ia, Ib, II, III, and V were the most prevalent isolates colonizing pregnant women at risk in the present study. Serotypes Ia and V in the composition of future vaccines would cover 69.6% of serotypes that colonize pregnant women in the studied population. No correlation was found between the prevalence of different GBS serotypes and gestational and demographic data and risk factors