Abstract:

Objective To evaluate the in vitro bacteriostasis effect of cephalosporin/sulbactam compound preparations on Gram negative bacilli that cause bloodstream infections. Methods Thirty isolates of each of following bacteria that can cause bloodstream infections were collected, i.e. ESBLs producing Escherichia coli，nonESBLs producing Escherichia coli, ESBLs producing Klebsiella pneumoniae, non-ESBLs producing Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii. The minimum inhibitory concentrations (MIC) of CTX/SBT, ceftriaxone/sulbactam (CRO/SBT), cefoperazone/sulbactam (CPZ/SBT), CTX, CRO, and CPZ were determined by the agar dilution method and 50% minimun inhibitory concentrations (MIC50) were calculated. Results The antibacterial activity of three third-generation cephalosporin/sulbactam compound preparations was better than that of single prescription preparations. MIC50 decreased 4-8 times. The antibacterial activity of CTX/SBT was better than that of CRO/SBT and CPZ/SBT. MIC50 of CTX/SBT against ESBLs producing Escherichia coli and Klebsiella pneumoniae decreased to 32-64 μg/mL, which was 8 times lower than that of CTX preparation. Conclusion For Gram negative bacilli that can cause bloodstream infections, the antibacterial activity of three third-generation cephalosporin/sulbactam compound preparations is better than that of single prescription preparations. The antibacterial activity of CTX/SBT is the best, especially for ESBLs producing isolates.

Key words: cephalosporin/sulbactam compound preparations, bloodstream infections, Gram negative bacilli, bacteriostasis effect, in vitro