This invention relates generally to molecules that specifically bind bacterial V-tip proteins of the type III secretion system of Gram negative bacteria such as PcrV from Pseudomonas aeruginosa. More specifically, this invention relates to molecules that block the injection of effector molecules into target cells. This invention also relates to molecules that specifically bind to bacterial lipoproteins, such as OprI. The molecules of the present invention are monospecific or multispecific and can bind their target antigen in a monovalent or multivalent manner. The invention also relates generally to molecules that specifically bind bacterial cell surface proteins such as OprI, and to methods of use these molecules in a variety of therapeutic, diagnostic, and/or prophylactic indications.
