Microfluidic-chip-based multiple-locus variable-number tandem-repeat fingerprinting with new primer sets for...

Area of Science:

• Medical Microbiology
• Infectious Disease Epidemiology
• Molecular Typing

Background:

• Rapid detection and source identification of methicillin-resistant Staphylococcus aureus (MRSA) outbreaks are critical in hospital settings.
• Traditional methods for MRSA strain typing can be time-consuming and may lack sufficient discriminatory power for real-time outbreak investigations.

Purpose of the Study:

• To evaluate the application potential of multiple-locus variable-number tandem-repeat fingerprinting (MLVF) combined with microfluidics technology for rapid MRSA lineage discrimination.
• To compare the discriminatory power and efficiency of MLVF against established methods like spa typing and multiple-locus variable-number tandem-repeat analysis (MLVA).

Main Methods:

• Analysis of 206 MRSA isolates from the University Medical Center Groningen (2000-2010) using MLVF with microcapillary electrophoresis and newly designed primers.
• Comparison of MLVF results with those obtained from spa typing and MLVA.
• Calculation of discriminatory power and concordance using the adjusted Rand's coefficient method.

Main Results:

• MLVF demonstrated the highest discriminatory power (0.980, 107 patterns) compared to MLVA (0.969, 85 allelic profiles) and spa typing (0.959, 66 types).
• All methods showed good concordance, supporting their reliability.
• An 88% similarity cutoff for MLVF patterns was proposed for epidemiological studies, including outbreak and transmission analyses.

Conclusions:

• MLVF, particularly when applied to microfluidic chips, is a rapid, cost-effective, reproducible, and highly discriminating tool for determining MRSA isolate clonality.
• MLVF excels at tracing the spread of MRSA strains over extended periods, offering significant advantages over existing methods.
• While spa typing offers data portability, MLVF provides superior discrimination, making it a valuable addition for MRSA epidemiological surveillance and outbreak management.