TABLE 1

Isolate susceptibilities and genotypes

Genus and speciesnNo. (%) of isolates witha:No. (%) of isolates in which ampC was detectedb
Cefoxitin MIC ≥ 16 μg/mlCefepime MIC ≥ 16 μg/mlMeropenem MIC ≥ 4 μg/mlTZP MIC ≥ 128 μg/ml
Enterobacter species10397/100 (97)4/102 (4)0/103 (0)15/102 (15)88/96 (92)
    E. aerogenes1515/15 (100)0/15 (0)0/15 (0)3/15 (20)13/14 (93)
    E. asburiae22/2 (100)0/2 (0)0/2 (0)0/2 (0)2/2 (100)
    E. cancerogenus11/1 (100)0/1 (0)0/1 (0)1/1 (100)0/1 (0)
    E. cloacae8579/82 (96)4/84 (5)0/85 (0)11/84 (13)73/79 (92)
Serratia species4536/44 (82)0/45 (0)0/45 (0)0/29 (0)38/40 (95)
    S. marcescens4335/42 (83)0/43 (0)0/43 (0)0/28 (0)38/38 (100)
    S. liquefaciens21/2 (50)0/2 (0)0/2 (0)0/1 (0)0/2 (0)
Citrobacter species177/16 (44)0/16 (0)0/16 (0)2/14 (14)3/16 (19)
    C. braakii22/2 (100)0/2 (0)0/2 (0)1/2 (50)0/2 (0)
    C. freundii33/3 (100)0/3 (0)0/3 (0)1/1 (100)2/3 (67)
    C. koseri111/10 (10)0/10 (0)0/10 (0)0/10 (0)0/10 (0)
    C. youngae11/1 (100)0/1 (0)0/1 (0)0/1 (0)1/1 (100)
  • a Percentages were calculated based on the number of isolates for which MIC data were available (n = 160).

  • b Percentages were calculated based on the number of isolates available for genotyping (n = 152), including nontypeable isolates (for Enterobacter spp., n = 1; Serratia spp., n = 3; Citrobacter spp., n = 0).