Rapid plasmid replicon typing by real time PCR melting curve analysis

Area of Science:

• Microbiology
• Molecular Biology
• Genetics

Background:

• Extended Spectrum Beta Lactamase (ESBL) genes are typically found on transferable plasmids, each with a unique replication mechanism.
• Plasmid incompatibility group identification is crucial for understanding bacterial resistance.
• Previous PCR-based replicon typing (PBRT) methods exist but can be laborious.

Purpose of the Study:

• To develop a rapid, sensitive, and labor-efficient method for plasmid replicon typing.
• To adapt existing PBRT methods for routine laboratory use.
• To improve the detection of genes encoding Extended Spectrum Beta Lactamases.

Main Methods:

• Designed a rapid approach based on Carattoli et al.'s PCR-based replicon typing.
• Utilized real-time melting curve analysis for amplicon detection.
• Integrated post-PCR analysis into a closed system using crude lysates and SYBR-green.

Main Results:

• Achieved a 10-fold increase in sensitivity compared to agarose gel visualization.
• Demonstrated high sensitivity and specificity using crude lysates and SYBR-green.
• The method proved to be fast, sensitive, less laborious, and less prone to contamination.

Conclusions:

• The real-time melting curve replicon typing method is a valuable tool for identifying plasmid replicons.
• This method is suitable for routine laboratory application in clinical microbiology.
• It offers a significant improvement in speed and efficiency for ESBL gene detection.