Variable genetic element typing: a quick method for epidemiological subtyping of Legionella pneumophila

Area of Science:

• Microbiology
• Genetics

Background:

• Legionella pneumophila is a significant human pathogen.
• Accurate strain typing is crucial for epidemiological investigations of Legionella outbreaks.

Purpose of the Study:

• To develop and evaluate a novel Variable Element Typing (VET) system for L. pneumophila.
• To assess the utility of VET for epidemiological characterization.

Main Methods:

• Monoclonal antibody subgrouping, seven-gene locus sequence-based typing (SBT), and the new VET system were used.
• VET utilized gel-based polymerase chain reaction (PCR) assays targeting ten variable genetic elements.
• PCR amplification of the mip gene served as a control.

Main Results:

• The VET system demonstrated an index of discrimination of 0.87.
• This is comparable, though slightly lower than, the SBT scheme (0.97).
• The VET assay proved to be simple and quick.

Conclusions:

• The Variable Element Typing (VET) system is a viable 'proof of principle' method.
• VET may be a useful tool for the epidemiological characterization of L. pneumophila strains.