Background: The aim of the present study was to monitor the nasopharyngeal presence of Streptococcus pneumoniae in different age groups (especially children) in Banská Bystrica, Slovakia. The purpose of this screening was to determine the prevalence of different serotypes and to follow up the presence of pneumococcus in these children after the vaccination with heptavalent protein-conjugate vaccine. A contribution of molecular biology techniques was the detection of S. pneumoniae DNA by PCR and also the typisation and comparison of pneumococcal strains by pulsed-field gel electrophoresis.
Methods: S. pneumoniae in nasopharyngeal swabs was detected by cultivation on blood agar plates. Serotypisation was performed by standard Quellung reaction. The commercial diagnostic kit was used for PCR detection of S. pneumoniae DNA. Pulsed-field electrophoresis was performed by modified scheme according to literature.
Results: The incidence of pneumococcus is decreasing and less significant with the increasing age. Among youngest children is relatively high prevalence of pneumococci and the relatedness of isolated strains is high as well. After the vaccination, the less invasive serotypes were detected, although the overall incidence of S. pneumoniae was similar.
Conclusions: The monitoring of S. pneumoniae in population is important according to variability of this bacteria with respect to possible changes in pneumococcal types as a consequence of vaccination.