In vitro activity of sulbactam plus ampicillin against hospital isolates of coagulase-negative staphylococci and Acinetobacter species.
The antimicrobial susceptibility of 54 recent clinical isolates of coagulase-negative slime- and non-slime-producing staphylococci and 52 Acinetobacter spp. to sulbactam, ampicillin and the combination of both drugs with a 1:1 ratio was studied by means of an agar dilution test. The coagulase-negative staphylococci showed resistance against sulbactam alone, whereas ampicillin as a single agent was nearly as active as sulbactam plus ampicillin (mode of MIC and MBC 0.03 and 4 mg/l vs. 1 mg/l; geometric mean of MIC and MBC 0.38 and 0.56 vs. 0.26 and 0.38 mg/l, respectively). Among slime-producing or non-slime-producing strains, there was no difference in the susceptibility against ampicillin alone compared to the sulbactam/ampicillin combination, with the exception of the higher MBC (mode: 4 mg/l) for slime-producing strains. Both ampicillin and the sulbactam/ampicillin combination were more active against non-slime-producing than slime-producing strains with modes of MIC and MBC of 0.03 vs. 1 or 4 mg/l. Acinetobacter spp. were susceptible to sulbactam alone (mode of MIC and MBC 1 mg/l; geometric mean of MIC and MBC 1.51 and 2.98, respectively), but resistant to ampicillin. However, the sulbactam/ampicillin combination was highly active against Acinetobacter spp. (mode of MIC and MBC 0.5 and 2 mg/l; geometric mean of MIC and MBC 0.74 and 2.08 mg/l, respectively).
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D000150:Acinetobacter / Q000187:drug effects*; D000667:Ampicillin / Q000008:administration & dosage / Q000494:pharmacology*; D003030:Coagulase; D003428:Cross Infection / Q000382:microbiology; D004338:Drug Combinations; D006801:Humans; D013210:Staphylococcus / Q000187:drug effects* / Q000201:enzymology; D013407:Sulbactam / Q000008:administration & dosage / Q000494:pharmacology*
D003030:Coagulase; D004338:Drug Combinations; D000667:Ampicillin; D013407:Sulbactam