Sialic acid Mimicry
A number of human pathogens mimic sialic acids, using several distinct mechanisms to suppress or misdirect host immune responses. For example, high density expression of sialic acid residues allows several bacterial pediatric pathogens to survive and multiply in the bloodstream. Our recent work suggests that expression of sialic acids and related nonulosonic acids (NulOs) among bacteria is much more common than previously realized.
Sialic Acids, Legnionaminic Acids, Pseudaminic Acids
 We here use the abbreviation NulO for Non-2-ulosonic acids, which assumes Nul for Non-2-uloses and maintains the discrimination between aldonic acids and uronic acids such as Glucuronic acid (GlcA). We suggest that the use of the term “sialic acid" (Sia) continue to be limited to their original use in describing Neu, Kdn and their derivatives in deuterostomes and their pathogens, and that “NulO” be used to encompass the entire group of nine carbon alpha-keto acids.