Table 1.

Number and Proportion of Fluoroquinolone-susceptible Gram-negative bacilli Infections Among Hospitalized Children at Alfred I. duPont Hospital for Children, 2001-2009

Organism	All Isolates N = 2112 (%)	Fluoroquinolone Susceptible Isolates
		Ciprofloxacin N = 1997 (%)	Levofloxacin N = 2012 (%)
E. coli	729 (34.5)			672 (92)	672 (92)
P. aeruginosa	559 (26.5)	533 (95)	534 (95.5)
K. pneumoniae	290 (13.7)	287 (99)	287 (99)
E. cloacae	223 (10.6)	222 (99.5)	222 (99.5)
Serratia marcescens	119 (5.6)	118 (99)	118 (99)
Proteus mirabilis	84 (4)	83 (99)	83 (99)
S. maltophilia*	57 (2.7)	32 (56)	55 (97)
Acinetobacter spp.	51 (2.4)	50 (98)	50 (98)

^*S. maltophilia is intrinsically more resistant to ciprofloxacin than levofloxacin.