Clostridium difficile infections cause serious disease with increasing incidence worldwide. The infections occur primarily in hospitals and long term care facilities in patients receiving prolonged antibiotic treatments. The disease symptoms may result from production and release by C. difficile organisms of two toxins, TcdA and TcdB in the colon.
A need exists for generating high affinity binding agents that treat both routine incidents of disease and pandemics, and efforts to discover and produce these agents are underway. The production of antibodies and their storage is a costly and lengthy process. In fact, development of a single antibody therapeutic agent often requires years of clinical study. Yet multiple, different therapeutic antibodies are necessary for the effective treatment of patients exposed to a disease agent, an infection outbreak or a bio-terrorist assault. Developing and producing multiple antibodies that can bind to different targets (e.g. microbial pathogens, viral pathogens, toxins, and cancer cells) is often a difficult task because it involves separately producing, storing and transporting multiple antibodies for each pathogen or toxin. Production and stockpiling a sufficient amount of antibodies to protect large populations is a challenge and currently has not been achieved. The shelf life of antibodies is often relatively short (e.g., weeks or months), and accordingly freshly prepared batches of antibodies have to be produced to replace the expiring antibodies.
Accordingly, there is a need for a cost effective and efficient way to provide alternatives to current therapeutic agents. Further a need exists for alternative therapeutics that are easier to develop and produce, have a longer shelf life, and bind as a single agent to multiple targets on the same disease agent, as well as to different disease agents.