Open Access Research article

The usefulness of biotyping in the determination of selected pathogenicity determinants in Streptococcus mutans

Wirginia Krzyściak1, Katarzyna K Pluskwa1, Jakub Piątkowski2, Paweł Krzyściak3, Anna Jurczak4, Dorota Kościelniak4 and Anna Skalniak2*

Author Affiliations

1 Department of Medical Diagnostics, Jagiellonian University, Medical College, Pharmacy Faculty, Medyczna 9, 30-688 Krakow, Poland

2 Genetics Laboratory, Department of Endocrinology, Jagiellonian University, Medical College, Kopernika 17, 31-501 Krakow, Poland

3 Department of Mycology, Microbiology, Jagiellonian University, Medical College, Czysta 18, 31-121 Krakow, Poland

4 Department of Pediatric Dentistry, Institute of Dentistry, Jagiellonian University, Medical College, Montelupich 4, 31-155 Krakow, Poland

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BMC Microbiology 2014, 14:194  doi:10.1186/1471-2180-14-194

Published: 5 August 2014



Streptococcus mutans is known to be a primary etiological factor of dental caries, a widespread and growing disease in Polish children. Recognition of novel features determining the pathogenicity of this pathogen may contribute to understanding the mechanisms of bacterial infections.

The goal of the study was to determine the activity of prephenate dehydrogenase (PHD) and to illuminate the role of the enzyme in S. mutans pathogenicity. The strains were biotyped based on STREPTOtest 24 biochemical identification tests and the usefulness of biotyping in the determination of S. mutans pathogenicity determinants was examined.


Out of ninety strains isolated from children with deciduous teeth fifty three were classified as S. mutans species. PDH activity was higher (21.69 U/mg on average) in the experimental group compared to the control group (5.74 U/mg on average) (P <0.001). Moreover, it was demonstrated that biotype I, established basing on the biochemical characterization of the strain, was predominant (58.5%) in oral cavity streptococcosis. Its dominance was determined by higher PDH activity compared to biotypes II and III (P = 0.0019).


The usefulness of biotyping in the determination of Streptococcus mutans pathogenicity determinants was demonstrated. The obtained results allow for better differentiation of S. mutans species and thus may contribute to recognition of pathogenic bacteria transmission mechanisms and facilitate treatment.

Prephenate dehydrogenase (PDH); Biotyping; Childhood caries (CC); Streptococcus mutans