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Updated: Feb 19, 2026
Capsular Serotyping of Streptococcus pneumoniae by Latex Agglutination
Published on: September 25, 2014
Serotype distribution and clinical correlation of Streptococcus agalactiae causing invasive disease in infants and
Chiao-Wei Lo1, Hao-Chuan Liu2, Chien-Chung Lee2
1Department of Pediatrics, Cathay General Hospital, Taipei, Taiwan; Institute of Emergency and Critical Care Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
Background:
Streptococcus agalactiae, or group B Streptococcus (GBS), remains to be one of the leading pathogens causing invasive infections in infants.
Methods:
The clinical GBS isolates from sterile sites of patients younger than 18 years old were collected from October 1998 to December 2014 in two hospitals in Taiwan. Medical records were retrospectively reviewed. Every isolate was serotyped with a multiplex PCR assay. Multilocus sequence typing (MLST) was performed in representative isolates of different serotypes. A total of 205 GBS isolates were collected from 181 patients with 182 infection episodes.
Results:
Serotype Ia was the most common in patients less than 72 h old, whereas III the most common in patients older than 72 h. In early-onset disease (0-6 days), Ia and III each caused 27.5% of the infection, followed by Ib (14.5%). In late-onset disease (7-89 days), serotype III predominated (75.3%), followed by Ia (10.1%) and Ib (6.8%). Thirty-one episodes (17%) were complicated with culture-confirmed meningitis. We compared serotype Ia and III patients, and found that serotype Ia patients were significantly younger (median age, 3 days), had more perinatal maternal fever and higher mortality. ST17 and ST19 were exclusively found in serotype III, while ST23 and ST24 comprised of 85% of serotype Ia.
Conclusion:
In Taiwan, serotypes Ia and III are the most common cause for early-onset and late-onset neonatal GBS infections, respectively. Some differences in the clinical features of invasive GBS infections caused by serotype Ia and III were observed.
Insights
Group B Streptococcus (GBS) serotypes Ia and III are the primary causes of neonatal infections in Taiwan. Serotype Ia is linked to early-onset disease, while serotype III dominates late-onset GBS infections.
Area of Science:
- Microbiology
- Neonatal Infectious Diseases
- Epidemiology
Background:
- Streptococcus agalactiae, or group B Streptococcus (GBS), is a major cause of invasive infections in infants.
- Understanding GBS epidemiology is crucial for effective infant healthcare strategies.
Purpose of the Study:
- To investigate the serotype distribution and clinical characteristics of invasive GBS infections in Taiwanese children.
- To compare clinical features between GBS serotypes Ia and III infections.
Main Methods:
- Retrospective review of medical records for GBS isolates from sterile sites in patients under 18 years old (October 1998-December 2014).
- Serotyping using multiplex PCR and multilocus sequence typing (MLST) for representative isolates.
- Analysis of 205 GBS isolates from 181 patients with 182 infection episodes.
Main Results:
- Serotype Ia was most common in infants <72 hours old; serotype III was most common in those >72 hours old.
- In early-onset disease, Ia and III each caused 27.5% of infections. Serotype III predominated in late-onset disease (75.3%).
- Serotype Ia infections were associated with younger patient age, maternal fever, and higher mortality compared to serotype III.
Conclusions:
- Serotypes Ia and III are the predominant GBS serotypes causing neonatal infections in Taiwan, for early-onset and late-onset disease, respectively.
- Distinct clinical features differentiate invasive GBS infections caused by serotype Ia and III.
