TABLE 2.

In vitro susceptibilities of the 4 E. coli isolates, 12 K. pneumoniae isolates, and their transconjugants determined by the agar dilution method

Antibiotica	MIC (μg/ml)b			% Susceptible strains
	Range	50%	90%
ATM	2–64	16	64	25
CAZ	4–≥256	128	≥256	25
CAZ+CLA	0.06–4	0.5	4
CTX	2–32	16	32	43.8
CTX+CLA	≤0.03–2	0.5	2
FEP	0.12–2	1	2	100
AMP	16–≥256	≥256	≥256	0
AMX+CLA	2–32	8	32	62.5
CFZ	16–≥256	64	128	0
CMZ	0.5–16	2	16	100
AMK	0.5–16	4	16	100
IPM	0.06–0.5	0.12	0.25	100
CIP	≤0.03–1	≤0.03	0.5	100
PIP+TZB	1–128	2	16	93.8

^aATM, aztreonam; CAZ, ceftazidime; CTX, cefotaxime; FEP, cefepime; AMP, ampicillin; AMX, amoxicillin; CFZ, cefazolin; CMZ, cefmetazole; AMK, amikacin; IPM, imipenem; CIP, ciprofloxacin; PIP, piperacillin; CLA, clavulanic acid (which was used at a fixed concentration of 4 μg/ml when tested with ceftazidime, cefotaxime, aztreonam, and cefepime and at a ratio of 2:1 when it was tested with amoxicillin); TZB, tazobactam (fixed concentration of 4 μg/ml). 

^b50% and 90%, MICs at which 50 and 90%, respectively, are inhibited.