TABLE 1.

Numbers of nonduplicated isolates of members of the family Enterobacteriaceae that produced ESBLa

SpeciesNo. of isolatesESBL-producing isolates
No. (%)% ESBL positive
E. coli 4,60455 (1.2)10.8
K. pneumoniae 946189 (20.0)37.1
K. oxytoca 16625 (15.1)4.9
P. mirabilis 805131 (16.3)25.7
P. vulgaris b 521 (1.9)0.2
P. stuartii 9627 (28.1)5.3
M. morganii 1919 (4.7)1.8
E. aerogenes 15131 (20.5)6.0
E. cloacae 41812 (2.9)2.4
S. marcescens 22411 (4.9)2.2
C. freundii 25612 (4.7)2.4
C. koseri 496 (12.2)1.2
Other speciesc570 (0.0)0.0
    Total8,0155096.3
  • a Isolates shown to produce ESBL by double-disk synergy test.

  • b Proteus vulgaris.

  • c Other species include Hafnia alvei, Salmonella spp., Proteus penneri, Providencia rettgeri, Enterobacter agglomerans, Enterobacter gergoviae, Enterobacter sakazakii, and Serratia liquefaciens.