Comparative classification of Leptospira serovars of the Pomona group by monoclonal antibodies and restriction-endonuclease analysis.

The serovars of the Pomona group of Leptospira interrogans are antigenically closely related and can be classified only with difficulty by conventional typing methods. Monoclonal antibodies (MCAs) were prepared to serovars of the Pomona group. The MCAs were directed against antigens of polysaccharide nature. A battery of six MCAs was selected for the classification of Pomona group reference strains. These MCAs could be used for the typing of all Pomona group strains and unknown isolates. Alternatively, DNA was extracted from the same strains and isolates and digested with restriction enzymes. The patterns that were obtained after gel separation of the DNA digests were characteristic and also allowed classification. Restriction enzyme analysis was complicated but gave detailed information. Classification with MCAs could be easily and rapidly performed.