Infection rate and Streptococcus agalactiae serotypes in samples of infected neonates in the city of Campinas (Sao 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, Sao 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 agar plates, Gram stain, catalase test, CAMP test, hippurate hydrolysis or by microbiological automation: Vitek 2 BioMerieux (R). 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.