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Identification of Rare Bacterial Pathogens by 16S rRNA Gene Sequencing and MALDI-TOF MS
06:34

Identification of Rare Bacterial Pathogens by 16S rRNA Gene Sequencing and MALDI-TOF MS

Published on: July 11, 2016

Novel molecular method for identification of Streptococcus pneumoniae applicable to clinical microbiology and 16S

Christian F P Scholz1, Knud Poulsen, Mogens Kilian

  • 1Department of Biomedicine, Faculty of Health Sciences, Aarhus University, Aarhus, Denmark.

Journal of Clinical Microbiology
|March 24, 2012
PubMed

Insights

Accurate identification of Streptococcus pneumoniae is challenging due to its similarity to other streptococci. A specific DNA marker in the 16S rRNA gene reliably distinguishes S. pneumoniae from related species, improving diagnostic accuracy.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Genetics

Background:

  • Streptococcus pneumoniae is a significant pathogen with close phylogenetic ties to commensal streptococci like Streptococcus mitis.
  • Gene and phenotypic trait sharing between S. pneumoniae and related species complicates accurate identification.
  • Misidentification of S. pneumoniae in clinical and research settings is a persistent issue.

Purpose of the Study:

  • To identify a reliable molecular marker for the accurate differentiation of Streptococcus pneumoniae from closely related mitis group streptococci.
  • To develop an inexpensive and efficient method for validating the identity of S. pneumoniae clinical isolates.

Main Methods:

  • Sequence analysis of 16S rRNA genes from 634 streptococcal strains, identified using multilocus sequence analysis.
  • Detection of a specific cytosine residue at position 203 in the 16S rRNA gene of S. pneumoniae.
  • Validation of the S. pneumoniae-specific signature using direct sequence analysis and restriction endonuclease digestion of PCR amplicons.

Main Results:

  • A unique cytosine at position 203 in the 16S rRNA gene was identified in all 440 S. pneumoniae strains.
  • This position was occupied by an adenosine in all tested strains of other mitis group streptococci.
  • The identified sequence signature provides a robust method for distinguishing S. pneumoniae.

Conclusions:

  • The S. pneumoniae-specific 16S rRNA gene signature offers an inexpensive and accurate method for identifying this pathogen.
  • This marker should be integrated into molecular identification workflows to prevent misidentification in clinical and research studies.
  • Utilizing this signature can improve the reliability of 16S rRNA-based analyses of human microbiotas.

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