Neu5Ac is also important in the biology of a number of pathogenic and symbiotic bacteria[1][2] as it can used either as a nutrient, providing both carbon and nitrogen to the bacteria, or in some pathogens, can be activated and placed on the cell surface.[1] Bacteria have evolved transporters for Neu5Ac to enable them to capture it from their environment and a number of these have been characterized including the NanT protein from Escherichia coli,[3] the SiaPQM TRAP transporter from Haemophilus influenzae[4] and the SatABCD ABC transporter from Haemophilus ducreyi.[5]