Infection rate and Streptococcus agalactiae serotypes in samples of infected neonates in the city of Campinas (São Paulo), Brazil

PURPOSE: To describe the epidemiological cases and microbiological profile of Streptococcus agalactiae serotypes isolated from infected newborns of a Women's Health Reference Centre of Campinas, São Paulo, Brazil. METHODS: Cross-sectional laboratory survey conducted from January 2007 to December 2011. The newborns' strains, isolated from blood and cerebrospinal fluid samples, were screened by hemolysis on blood ágar plates, Gram stain, catalase test, CAMP test, hippurate hydrolysis or by microbiological automation: Vitek 2 BioMerieux®. They were typed by PCR, successively using specific primers for species and nine serotypes of S. agalactiae. RESULTS: Seven blood samples, one cerebrospinal fluid sample and an ocular sample, were isolated from nine newborns with infections caused by S. agalactiae, including seven cases of early onset and two of late onset. Only one of these cases was positive for paired mother-child samples. Considering that 13,749 deliveries were performed during the study period, the incidence was 0.5 cases of GBS infections of early onset per 1 thousand live births (or 0.6 per 1 thousand, including two cases of late onset) with 1, 3, 2, zero and 3 cases (one early and two late onset cases), respectively, for the years from 2007 to 2011. It was possible to apply PCR to seven of nine samples, two each of serotypes Ia and V and three of serotype III, one from a newborn and the other two from a paired mother-child sample. CONCLUSIONS: Although the sample was limited, the serotypes found are the most prevalent in the literature, but different from the other few Brazilian studies available, except for type Ia.OBJETIVO: Descrever os casos e o perfil microbiológico dos sorotipos de Streptococcus agalactiae provenientes de recém-nascidos em um Centro de Referência da Saúde da Mulher na cidade de Campinas, São Paulo, Brasil. MÉTODOS: Estudo transversal clínico-laboratorial realizado de janeiro de 2007 a dezembro de 2011. As cepas suspeitas, isoladas em amostras de sangue e líquor, foram identificadas a partir da hemólise em ágar sangue, coloração de Gram, provas de catalase, teste de CAMP, hidrólise do hipurato ou por automação microbiológica Vitek 2 BioMerieux®. A seguir, estas cepas foram tipadas por PCR utilizando sucessivamente primers específicos para espécie e para nove sorotipos de S. agalactiae. RESULTADOS: Foram isoladas sete amostras de sangue, uma de líquor e uma de secreção ocular provenientes de nove recém-nascidos com infecções causadas pelo S. agalactiae, sendo sete casos de infecção de início precoce e duas de início tardio. Apenas um destes casos foi positivo para amostras pareadas mãe-filho. Para um total de 13.749 partos no período, os 7 casos correspondem a 0,5 caso de infecção precoce por Streptococcus do Grupo B a cada 1 mil nascidos vivos (ou 0,6 casos por 1 mil, incluindo os 2 de infecção tardia), tendo ocorrido 1, 3, 2, nenhum e 3 casos (um precoce e dois tardios), respectivamente, nos anos de 2007 a 2011. Foi possível realizar o PCR para sete amostras, sendo duas de cada um dos sorotipos Ia e V e o sorotipo III em três amostras, uma delas em um recém-nascido e outras duas em amostra pareada mãe-filho. CONCLUSÕES: Embora com casuística limitada, os sorotipos encontrados coincidem com os mais prevalentes na literatura mundial, mas diferem dos estudos brasileiros, exceto para o sorotipo Ia.54454

[infection Rate And Streptococcus Agalactiae Serotypes In Samples Of Infected Neonates In The City Of Campinas (são Paulo), Brazil].

To describe the epidemiological cases and microbiological profile of Streptococcus agalactiae serotypes isolated from infected newborns of a Women's Health Reference Centre of Campinas, São Paulo, Brazil. Cross-sectional laboratory survey conducted from January 2007 to December 2011. The newborns' strains, isolated from blood and cerebrospinal fluid samples, were screened by hemolysis on blood ágar plates, Gram stain, catalase test, CAMP test, hippurate hydrolysis or by microbiological automation: Vitek 2 BioMerieux®. They were typed by PCR, successively using specific primers for species and nine serotypes of S. agalactiae. Seven blood samples, one cerebrospinal fluid sample and an ocular sample, were isolated from nine newborns with infections caused by S. agalactiae, including seven cases of early onset and two of late onset. Only one of these cases was positive for paired mother-child samples. Considering that 13,749 deliveries were performed during the study period, the incidence was 0.5 cases of GBS infections of early onset per 1 thousand live births (or 0.6 per 1 thousand, including two cases of late onset) with 1, 3, 2, zero and 3 cases (one early and two late onset cases), respectively, for the years from 2007 to 2011. It was possible to apply PCR to seven of nine samples, two each of serotypes Ia and V and three of serotype III, one from a newborn and the other two from a paired mother-child sample. Although the sample was limited, the serotypes found are the most prevalent in the literature, but different from the other few Brazilian studies available, except for type Ia.34544-