Molecular Typing Techniques in Clinical Microbiology

Molecular typing techniques are central to the identification, surveillance and control of infectious agents within clinical settings. Traditional approaches such as pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST) remain in use for their reproducibility and well-established nomenclature, but they are increasingly complemented by high-resolution methods. Whole-genome sequencing (WGS) and core-genome MLST (cgMLST) enable fine-scale discrimination of strains, tracking transmission chains in real time and uncovering genetic determinants of resistance or virulence. Other emerging platforms include Fourier-transform infrared (FTIR) spectroscopy and matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS), which offer rapid, low-cost profiles of cellular components for routine outbreak investigation. Gene-by-gene approaches, single nucleotide polymorphism (SNP) analysis and variable-number tandem repeat (VNTR) schemes further diversify the toolbox. Together, these methods underpin global efforts in infection prevention, support one-health initiatives and facilitate the deployment of targeted interventions against multidrug-resistant pathogens.

Research from Nature Portfolio

A foundational study demonstrated the application of FTIR spectroscopy with attenuated total reflectance (FTIR-ATR) coupled to chemometric algorithms to discriminate major high-risk Escherichia coli clones. By analysing spectral fingerprints, researchers achieved accurate separation of prevalent phylogroups and sequence types using both unsupervised cluster analysis and supervised classification models. This work highlighted the potential of infrared-based typing to deliver near-real-time, high-throughput surveillance of key pathogens without extensive genomic processing, suggesting a pathway to routine implementation in clinical laboratories.

Molecular Typing Techniques in Clinical Microbiology publication trend

The graph below shows the total number of articles in molecular typing techniques in clinical microbiology across all publications each year (not limited to Nature Index journals).

Technical terms

Pulsed-field gel electrophoresis (PFGE): A DNA separation technique that resolves large fragments after restriction enzyme digestion for strain differentiation.

Multi-locus sequence typing (MLST): A method assigning a sequence type based on allelic profiles at several housekeeping genes.

Whole-genome sequencing (WGS): High-throughput determination of an organism’s complete DNA sequence for comprehensive analysis.

Core-genome MLST (cgMLST): Gene-by-gene approach focusing on conserved loci across strains to enhance resolution over standard MLST.

Fourier-transform infrared spectroscopy (FTIR): A technique measuring molecular vibrations in cellular components to generate biochemical fingerprints.

Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS): An ionisation method that profiles protein spectra for rapid microbial identification and potential subtyping.

Single nucleotide polymorphism (SNP): A variation at a single base position in the genome, used for high-resolution phylogenetic and epidemiological analyses.

References

1. ReporType: A Flexible Bioinformatics Tool for Targeted Loci Screening and Typing of Infectious Agents. International Journal of Molecular Sciences (2024).
2. Evaluation of IR Biotyper for carbapenem-resistant Pseudomonas aeruginosa typing and its application potential for the investigation of nosocomial infection. Frontiers in Microbiology (2023).
3. Fourier-transform infrared spectroscopy for typing of vancomycin-resistant Enterococcus faecium: performance analysis and outbreak investigation. Microbiology Spectrum (2023).
4. Diverse high-risk B2 and D Escherichia coli clones depicted by Fourier Transform Infrared Spectroscopy. Scientific Reports (2013).