Molecular genotyping of Streptococcus agalactiae isolates with non-typeable serotype, Czech Republic, 2008–2020

Abstract

The NRL for Streptococcal Infections performed serotyping of 1038 isolates of Streptococcus agalactiae from 972 patients by the latex agglutination method in 2008–2020. Forty-three isolates (4.4%) whose serotyping failed were classified as non-typeable. The aim of the present study was to determine the genotype of these non-typeable isolates using multiplex polymerase chain reaction (mPCR). Genotyping was successful in the entire set of 43 non-typeable isolates. The most common genotype was V (41.9%), followed by Ia (20.9%). The isolates serotyped by latex agglutination were predominantly assigned to serotype III (29.2%) and V (26.2%). Complete data were obtained on the prevalence of S. agalactiae serotypes/genotypes in the Czech Republic in 2008–2020. Monitoring the serotype and genotype distribution of the pathogen is a prerequisite for the introduction of a potential vaccine against S. agalactiae into clinical practice.