Table 3.

MICs of cephalosporins and aztreonam conferred by TEM-1 β-lactamase and various types of mutant derivatives forE. coli JM83

β-Lactamase or mutant derivative MIC (μg/ml)
CephalothinCephaloridineCeftazidimeCeftriaxoneAztreonam
a 420.1250.030.06
TEM-1321280.250.030.06
1420.1250.030.06
3420.1250.030.06
4420.1250.030.06
5420.1250.030.06
6420.1250.030.06
7420.1250.030.06
8420.1250.030.06
9420.1250.030.06
10420.1250.030.06
11161280.50.030.06
  • a −, E. coli JM83 without a plasmid.