Chronic bacterial infection models for BRM screening

Models of chronic infections have been established to test the therapeutic and prophylactic potency of biological response modifiers (BRM). As an example for a BRM the immunostimulating drug Bestatin was tested. It is of dipeptide nature and was purified from culture supernatants of Streptomyces olivoreticuli. In two chronic bacterial infection models, induced by the inoculation of NRMI mice with Salmonella typhimurium or with a nephropathogenic strain of Escherichia coli, Bestatin acted prophylactically as well as therapeutically. This could be seen from the reduction of bacterial organ colonization and the inhibition of organ lesion formation. Bestatin could be shown to stimulate macrophage activity and to potentiate delayed type hypersensitivity, but not be effective on the humoral immune response.