UCSF Adult Inpatient Susceptibility Data (Gram-Negatives)1 

R-testing not applicable to organism and should be considered resistant, CFPM-cefepime, CIP-ciprofloxacin, CTAZ-ceftazidime, CTRX-ceftriaxone, ERTA-ertapenem, IMI-imipenem-cilastatin, MER-meropenem, P/T-piperacillin-tazobactam, TOB-tobramycin

Total isolates include floor isolates and ICU isolates from Parnassus, MB Adult, and MZ 
Reported as % susceptible, tested from all sites except as indicated 

Organism 
Total Isolates 
CFPM 
CIP 
CTAZ 
CTRX 
ERTA 
IMI/MER2 
P/T 
TOB 

Weighted average 

2357

86 

74

85 

61 (77)3 

77 (98)3

964 

86 

89 

Citrobacter freundii 

57 

96

78

N/A

N/A

98 

100

N/A

82 

Enterobacter cloacae 

147 

87

90 

N/A

N/A

87 

95

N/A

89

Escherichia coli 

904

82 

64 

86

77 

99 

99 

92

86 

Klebsiella aerogenes 

72

97 

95

N/A

N/A

98 

91

N/A

97

Klebsiella oxytoca 

105 

89 

85

91 

82

97 

98 

85 

87 

Klebsiella pneumoniae 

331

79

72 

79 

74 

97 

98 

82 

85 

Proteus mirabilis 

172

94 

73 

99 

90 

100 

100

98 

88 

Pseudomonas aeruginosa 

486 

90 

81 

89 

N/A 

N/A 

89 

83 

97 

Serratia marcescens 

83

98 

89 

100 

96

98 

98

98 

97 

1Adult inpatient susceptibilities include data from 1/1/2024 - 12/31/2024; 2Reflects % susceptibility for imipenem-cilastatin in all situations except for Proteus mirabilis, where % susceptibility for meropenem (non-urine isolates, 85 total isolates) is reported; 3Parentheses excludes Pseudomonas isolates; 4Weighted average excludes 172 Proteus mirabilis isolates tested against imipenem