SsTroA presents high topological identity with lipoprotein PsaA in S. pneumoniae, the latter is a surface-exposed multi-functional protein detected on all known serotypes of S. pneumoniae. It is noteworthy that PsaA is immunogenic and being actively evaluated as a candidate vaccine component [53] . Thus far however, no data about SsTroA involvement in adhesion and/or invasion of human host tissues is yet available. There is increasing evidence that surface-related proteins are involved in bacterial pathogenesis, as exemplified by adhesion, invasion, and bacterial defense mechanisms [54] . Surface-displayed SBPs likely present an apparent dual function, metal ions transport and interaction with host cells [25] . Assessment of the potential immunogenicity of SsTroA is currently under way in our laboratory.