TABLE 5.
In vitro activities of antimicrobial agents against gram-negative aerobic organisms
| Organism (no. of isolates) | MIC50/MIC90 (μg/ml [% susceptible])a
|
||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ETP | IPM | P/T | A/C | CFL | CAZ | CIP | LVX | MXF | GM | AMK | DOX | T/S | |
| Enterobacteriaceae groupb (98) | ≤0.125/≤0.125 (99) | 0.25/2 (100) | ≤1/4 (96) | 8/>64 (55) | 8/>32 (52) | ≤0.5/≤0.5 (94) | ≤0.5/≤0.5 (94) | ≤0.5/1 (94) | ≤0.25/2 (94) | ≤2/≤2 (95) | ≤8/≤8 (99) | 2/16 (79) | ≤0.5/>4 (90) |
| Proteus-Providencia-Morganella groupc (55) | ≤0.125/≤0.125 (98) | 4/4 (100) | ≤1/≤1 (98) | 8/>64 (58) | ≤0.5/8 (93) | ≤0.5/≤0.5 (95) | ≤0.5/≤0.5 (95) | ≤0.25/2 (91) | ≤2/≤8 (98) | ≤2/≤2 (100) | >32/>32 (22) | ≤0.5/>4 (91) | |
| P. aeruginosa (43) | 8/16 (NId) | 1/4 (86) | 4/16 (98) | 1/4 (98) | ≤.5/1 (91) | ≤.5/8 (79) | 1/8 (74) | ≤2/4 (95) | ≤8/≤8 (100) | ||||
| S. maltophilia (15) | >16 (NI) | >16 (NI) | >128/>128 (NI) | 64/64 (NI) | 8/>32 (53) | 2/>8 (NI) | 1/>8 (80) | 0.5/4 (NI) | >32/>32 (NI) | 128/>128 (NI) | 4/4 (NI) | >4/>4 (20) | |
| Miscellaneous nonfermenting gram-negative rodse (24) | ≤.125/>16 (63) | 0.25/4 (92) | ≤1/>128 (79) | 4/>64 (67) | 4/>32 (79) | 1/>8 (58) | ≤0.5/>8 (83) | 1/>8 (71) | ≤2/8 (83) | ≤1/128 (79) | ≤1/>32 (75) | ≤0.5/>4 (75) | |
ETP, ertapenem; IPM, imipenem; P/T, piperacillin-tazobactam; A/C, amoxicillin-clavulanic acid; CFL, cephalexin; CAZ, ceftazidime; CIP, ciprofloxacin; LVX, levofloxacin; MXF, moxifloxacin; GM, gentamicin; AMK, amikacin; DOX, doxycycline; T/S, trimethoprim-sulfamethoxazole.
Escherichia coli (n = 20), Enterobacter cloacae (n = 21), Enterobacter aerogenes (n = 7), Enterobacter gergoviae (n = 1), Enterobacter intermedius (n = 1), Citrobacter freundii (n = 1), Citrobacter koseri (n = 4), Klebsiella oxytoca (n = 16), Klebsiella pneumoniae (n = 9), Pantoeae agglomerans (n = 3), and Serratia marcescens (n = 15).
Proteus mirabilis (n = 26), Proteus vulgaris (n = 4), Providencia rettgeri (n = 6), Providencia rustigianii (n = 1), Providencia stuartii (n = 1), and Morganella morganii (n = 17).
NI, no interpretation.
Alcaligenes faecalis (n = 10), Acinetobacter baumannii (n = 6), Acinetbacter calcoaceticus (n = 1), Brevundimonas diminuta (n = 1), Chryseobacterium sp. (n = 1), Myroides odoratum (n = 1), Paracoccus sp. (n = 1), Pseudomonas fluorescens (n = 2), and Shewanella putrefaciens (n = 1).