TABLE 1.

Numbers of isolates studied and rates of resistance to amikacin among Enterobacteriaceae that were collected from a university hospital in South Korea between 1995 and 2006

SpeciesNo. of isolates studied (no. of isolates resistant to amikacin) in:Total no. of isolates (total no. resistant to amikacin)Rate of resistance to amikacin (%)
19951996199719982001 to ∼20022003200420052006
E. coli 132 (0)197 (5)157 (1)6 (2)492 (13)156 (9)418 (14)908 (31)860 (25)3,326 (100)3.0
K. pneumoniae 60 (2)61 (3)141 (3)42 (3)304 (8)83 (5)226 (26)605 (111)537 (108)2,059 (269)13.1
Klebsiella spp.2 (0)9 (0)24 (2)4 (0)39 (0)12 (0)18 (0)36 (2)5 (1)149 (5)3.4
E. cloacae 27 (4)25 (3)29 (9)5 (2)86 (5)13 (2)65 (6)109 (6)125 (5)484 (42)8.7
Enterobacter spp.5 (0)7 (1)29 (0)4 (2)45 (0)5 (0)44 (0)107 (2)108 (5)354 (10)2.8
S. marcescens 16 (0)9 (0)43 (2)7 (0)75 (5)45 (7)23 (2)38 (1)51 (6)307 (23)7.5
Serratia spp.2 (0)2 (0)4 (0)0
C. freundii 4 (0)2 (0)8 (1)1 (1)15 (0)14 (2)17 (0)47 (3)53 (1)161 (8)5.0
Citrobacter spp.3 (0)6 (0)4 (1)13 (1)2.6
Morganella morganii 4 (0)2 (0)4 (0)10 (0)4 (0)25 (1)2 (1)25 (0)76 (2)3.2
P. mirabilis 6 (1)3 (0)6 (0)3 (0)18 (0)10 (0)15 (0)39 (1)40 (1)140 (3)2.1
Proteus spp.2 (0)1 (0)2 (0)5 (0)2 (0)4 (0)11 (0)16 (0)43 (0)0
Providencia spp.3 (0)3 (0)2 (0)3 (0)11 (0)0
Total no. of isolates (total no. resistant to amikacin)261 (7)316 (12)443 (18)72 (10)1,092 (31)344 (25)860 (49)1,913 (158)1,826 (153)7,127 (463)
Rate of resistance to amikacin (%)2.73.84.113.92.87.35.78.38.46.5