Leptospira interrogans genome strain expresses sialic acid (Neu5Ac). HPLC analysis demonstrates peaks consistent with Kdo and Neu5Ac in Leptospira interrogans str. L1-130. Confirmation of the L1-130 Neu5Ac peak assignment was performed by parallel derivatization and LCMS analysis of Neu5Ac (Sigma). The structure of DMB-derivatized Neu5Ac has a protonated exact mass (m+H) of 426.1. The dehydrated and sodium adduct have expected m+H values of 408.1 and 448.1 respectively. This experiment was performed twice with similar results.