Serotypes and clinical manifestations of group B streptococcal infections in western Sweden
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Updated: Aug 5, 2026

Capsular Serotyping of Streptococcus pneumoniae Using the Quellung Reaction
Published on: February 24, 2014
S Berg1, B Trollfors, T Lagergård
1Department of Paediatrics, Sahlgrenska University Hospital (East), Göteborg, Sweden. stefan.berg@pediat.gu.se
Objectives:
To study the serotype distributions of group B streptococci (GBS) isolated from blood and cerebrospinal fluid and from the genital tract of pregnant women and to investigate any possible relation between serotype, age and clinical manifestation.
Methods:
Invasive strains were collected from 1988 to 1997 and genital strains from 1995 to 1996. Strains of GBS were serotyped with coagglutination. Clinical data were obtained from hospital notes.
Results:
A total of 144 invasive strains, 78 from neonates and infants and 66 from adults, were serotyped. The most common isolates from neonates and infants were types III (62%), Ia (18%), and V (9%). The most common isolates from adults were types III (29%), Ib (23%), V (21%) and II (15%). A majority of the adults (94%) had an underlying medical condition. The most common serotypes of the 114 strains isolated from the genital tract of pregnant women were types III (32%), V (22%), Ia (13%), Ib (13%) and II (11%).
Conclusions:
Serotype III was the single most frequent GBS isolate from infants and adults. Serotype V, which appeared first in 1992, was the third most frequent isolate. A vaccine containing five GBS capsular polysaccharides appears to be appropriate for the Swedish population.
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