Pathogen

Percentage of Isolates

1986-1989

(N = 16,727)

Percentage of Isolates

1990-1996

(N = 17,671)

Staphylococcus aureus

17

20

Coagulase-negative Staphylococci

12

14

Enterococcus spp.

13

12

Escherichia coli

10

8

Pseudomonas aeruginosa

8

8

Enterobacter spp.

8

7

Proteus mirabilis

4

3

Klebsiella pneumoniae

3

3

Other Streptococcus spp.

3

3

Candida albicans

2

3

Group D streptococci (non-enterococci)

-

2

Other gram-positive aerobes

-

2

Bacteroides fragilis

-

2