Open AccessIn vitro activities of various beta-lactam antimicrobial agents against clinical isolates of Escherichia coli and Klebsiella spp. resistant to oxyimino cephalosporins
Author(s) -
Bradley D. Jett,
David J. Ritchie,
Richard M. Reichley,
Thomas C. Bailey,
Daniel F. Sahm
Publication year - 1995
Publication title -
antimicrobial agents and chemotherapy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.07
H-Index - 259
eISSN - 1070-6283
pISSN - 0066-4804
DOI - 10.1128/aac.39.5.1187
Subject(s) - cefepime , aztreonam , cefotetan , imipenem , cephalosporin , microbiology and biotechnology , piperacillin , cefotaxime , ceftazidime , tazobactam , piperacillin/tazobactam , klebsiella pneumoniae , broth microdilution , biology , antimicrobial , escherichia coli , antibiotics , antibiotic resistance , bacteria , minimum inhibitory concentration , genetics , pseudomonas aeruginosa , gene
Broth microdilution testing was used to study the activity of several beta-lactam antimicrobial agents, including piperacillin-tazobactam and cefepime, against 108 clinically derived Escherichia coli and Klebsiella sp. strains resistant to oxyimino cephalosporins (i.e., putative extended-spectrum beta-lactamase producers). On the basis of the percentage of susceptible strains, imipenem (100%), cefotetan (> or = 92%), and piperacillin-tazobactam (> or = 86%) were the most active agents. Cefepime activity (52 to 64% susceptible) was comparable to that of cefotaxime (40 to 63% susceptible) and aztreonam (20 to 63% susceptible). Among all beta-lactams tested, imipenem and cefotetan demonstrated the highest and most consistent level of activity and were the least affected by challenges with increased sizes of inocula of these resistant organisms.