Abstract: The present invention relates to compositions comprising analogues of purine nucleosides containing a ring-expanded (“fat”) heterocyclic ring, in place of purine, and an unmodified or modified sugar residue, pharmaceutically acceptable derivatives of such compositions, as well as methods of use thereof. In particular, these compositions may be utilized in the treatment of certain cancers, bacterial, fungal, parasitic, and viral infections, including, but not limited to, Acquired Immunodeficiency Syndrome (AIDS), hepatitis, Epstein-Barr and cytomegalovirus.

Abstract: A majority of E. faecalis and E. faecium clinical isolates fall into two groups and three groups, respectively. Distinct antigens are associate with each of the five groups. The Enterococcus antigens are readily obtained from strains of E. faecalis and E. faecium, and can elicit production of protective antibodies. Accordingly, the antigens are useful for vaccines which protect against infection by clinically significant (pathogenic) Enterococcus isolates. The antigens and antibodies generated to the antigens are also useful in diagnostic assays.