Abstract
Basic studies were carried out on the antibacterial activity of sultamicillin tosilate. It was revealed that sodiurr p-toluenesulfonate did not influence on both antibacterial activity of ampicillin (ABPC) and β-lactamase in activation activity of sulbactam (SBT). Since sultamicillin was rather unstable and split into ABPC and SBT ir solutions with pH higher than 7.0, its antibacterial activity could be measured without treatment by esterase.
Sultamicillin manifested higher antibacterial activity against ABPC resistant Staphylococcus aureus includinf MRSA, ABPC-resistent Haemophilus influenzae, and Bacteroides fragilis than ABPC, cefaclor (CCL), and cepha lexin (CEX), although it was inferior to CCL and CEX against Escherichia coli carrying R (bla) plasmids and Klebsiella spp. The antibacterial spectrum of sultamicillin was confirmed to expand to Proteus vulgaris, P morganii, Enterobacter cloacae, Citrobacter freundii and Serratia marcescensto which ABPC, CCL, and CEX could not work, the MICs of sultamicillin to those bacteria, however, were rather high.
Sultamicillin induced morphological changes of cells of β-lactamase producing P. vulgaris and E. coli at lom concentrations because SBT in the drug could inactivate the β-lactamases. No evidences were obtained showinf that sultamicillin possessed higher binding affinities to bacterial penicillin-binding proteins (PBPs) than ABPC.
