Typing leptospira from the perspective of a reference laboratory

Area of Science:

• Microbiology
• Bacteriology
• Epidemiology

Background:

• Leptospirosis is caused by diverse Leptospira variants.
• The serovar classification system, defined by cross agglutination absorption tests (CAAT), has recognized approximately 200 serovars for decades.
• The serovar concept faces limitations in defining epidemiologically significant entities and CAAT is cumbersome for routine use.

Purpose of the Study:

• To evaluate the current Leptospira classification system.
• To explore alternative and supplementary methods for Leptospira typing.
• To propose recommendations for Leptospira classification and typing.

Main Methods:

• Cross agglutination absorption tests (CAAT) for serovar definition.
• Analysis of leptospiral DNA fragment length after digestion with restriction enzymes (REA) for typing.
• Review of various experimental antigenic and genetic analysis methods.

Main Results:

• The serovar concept is increasingly recognized as insufficient for defining epidemiologically important Leptospira entities.
• CAAT is time-consuming and cumbersome for routine Leptospira typing.
• Restriction enzyme analysis (REA) has proven useful for Leptospira typing and can supplement existing methods.

Conclusions:

• New genomic analysis methods are expected to become paramount for Leptospira classification.
• Pending the development of superior typing methods, the current serovar system should be maintained.
• Restriction enzyme analysis (REA) should be incorporated into the description of new serovars.