title: The activity of polymyxins against Escherichia coli in an in-vitro model of the urinary bladder.
abstract: The activities against a strain of Escherichia coli of polymyxin B, colistin (polymyxin E) and their sulphomethyl derivatives sulphomyxin and colistin sulphomethate have been examined in an in-vitro model of the urinary bladder under conditions similar to those that may operate in the therapeutic situation. In the dynamic conditions of the model, polymyxins exhibited a reduced activity against E. coli in comparison with activity against exponentially growing cultures in a static system. Nevertheless, long-term suppression of bacterial growth was achieved with levels of polymyxin B and colistin that can be attained during therapy, whereas sulphomethylpolymyxins had little effect on bacterial growth even on prolonged exposure.
mesh_terms: D001433:Bacteriolysis / Q000187:drug effects; D003091:Colistin / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects*; D008954:Models, Biological; D011113:Polymyxins / Q000031:analogs & derivatives / Q000494:pharmacology*; D001743:Urinary Bladder / Q000382:microbiology*
chemical_list: D011113:Polymyxins; D003091:Colistin