. 2008 Dec 22;53(3):1268–1270. doi: 10.1128/AAC.01300-08

TABLE 1.

Distribution of ciprofloxacin and ceftazidime susceptibilities among aac(6′)-Ib-cr⁺ and aac(6′)-Ib-cr E. coli isolates^a

Ciprofloxacin susceptibility	No. of isolates with indicated CAZ susceptibility				Risk ratio	95% CI
	aac(6′)-Ib-cr positive		aac(6′)-Ib-cr deficient
	CAZ-R	CAZ-S	CAZ-R	CAZ-S
S + I/R	18	14	67	619	5.8	3.9-8.4
S	1	2	28	517	6.5	1.2-33.4
I/R	17	12	39	102	2.1	1.4-3.2

S, susceptible; R, resistant; I, intermediate; CI, confidence interval.