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Multiplex PCR Assay for Typing of Staphylococcal Cassette Chromosome Mec Types I to V in Methicillin-resistant Staphylococcus aureus
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Assessment of molecular typing methods to determine invasiveness and to differentiate clones of Streptococcus

Caroline A Obert1, Geli Gao, Jack Sublett

  • 1Hartwell Center for Bioinformatics and Biotechnology, St. Jude Children's Research Hospital, 332 North Lauderdale, Memphis, TN 38105, United States. caroline.obert@stjude.org

Infection, Genetics and Evolution : Journal of Molecular Epidemiology and Evolutionary Genetics in Infectious Diseases
|September 5, 2007
PubMed

Insights

Identifying invasive Streptococcus pneumoniae strains is crucial due to rising antimicrobial resistance. Combining multiple typing methods provides the clearest picture of a strain's invasiveness and genetic relatedness for disease prediction.

Area of Science:

  • Microbiology
  • Genetics
  • Epidemiology

Background:

  • Streptococcus pneumoniae is a leading cause of community-acquired pneumonia and invasive bacterial disease in the US.
  • Increasing antimicrobial resistance necessitates accurate identification of invasive pneumococcal disease (IPD) causing strains.
  • Genotypic comparison of isolates to known invasive strains aids in predicting IPD risk.

Purpose of the Study:

  • To compare the efficacy of Pulse-Field Gel Electrophoresis (PFGE), Multilocus Sequence Typing (MLST), Comparative Genomic Hybridization (CGH), and Multi-invasive-locus Sequence Typing (MILST).
  • To evaluate these methods' ability to distinguish between IPD-causing and carrier strains of Streptococcus pneumoniae.
  • To assess the techniques' capacity for differentiating true clones from highly related strains using phylogenetic analyses.

Main Methods:

  • Phylogenetic analyses were employed to interpret the typing data.
  • Comparison of four distinct genotypic typing methods: PFGE, MLST, CGH, and MILST.
  • Evaluation of strain relatedness and invasiveness potential.

Main Results:

  • All typing methods produced phylogenetic trees with similar overall topologies.
  • The collective application of typing methods provided the clearest visualization of strain invasiveness.
  • Combined analysis enhanced the understanding of genetic relatedness between strains.

Conclusions:

  • No single typing method is sufficient for a comprehensive assessment of Streptococcus pneumoniae invasiveness.
  • Utilizing a combination of PFGE, MLST, CGH, and MILST offers superior insights into strain characteristics.
  • Integrated genotypic analysis is essential for accurate prediction of invasive pneumococcal disease potential in clinical and epidemiological settings.

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