A neutral sugar is responsible for serovar specificity of the antigenic determinant of Leptospira interrogans serovar canicola.

To provide information on the chemical structures of antigenic determinants of leptospira, glycolipids of Leptospira interrogans serovar canicola strain Hond Utrecht IV (Ut-IV) and its antigenic variant selected in the presence of a serovar-specific monoclonal antibody were compared physicochemically. Gas-liquid chromatography-mass spectrometry analysis revealed that the glycolipid of Ut-IV contained 6 neutral sugar species; rhamnose, mannose, galactose, glucose, and unknown sugars III and IV, in addition to unknown sugars I and II that had been previously reported. On the other hand, the glycolipid of the variant lacked unknown sugar III, suggesting that this sugar is responsible for the serovar-specific antigenic determinant.