Clinical and Bacteriological Characteristics of IMP-type Metallo-Beta-Lactamase-Producing Pseudomonas Aeruginosa

Clin Infect Dis. 2003 Jul 1;37(1):26-32. doi: 10.1086/375594. Epub 2003 Jun 24.


IMP-type metallo-beta-lactamase-producing bacteria have recently emerged worldwide. We conducted a case-control study in which 69 inpatients harboring bla(IMP)-positive Pseudomonas aeruginosa and 247 control subjects with bla(IMP)-negative pathogens were investigated. Prolonged hospitalization, antineoplastic chemotherapy, corticosteroid therapy (P=.001), and indwelling urinary catheters (P=.04) were risk factors for isolation of bla(IMP)-positive pathogens. The predominant source was urine (P=.001). The duration of antibiotic treatment and the total dose (including of carbapenems) were significantly greater among case patients than among control subjects (P<.01). bla(IMP)-positive P. aeruginosa isolates were more frequently resistant to multiple drugs (P=.001) and caused more infections (P=.001) than bla(IMP)-negative pathogens. There were no significant differences in bacteriological outcome (P=.94); however, infection-related death was more frequent among case patients than among control subjects (P=.023). These results suggest that precautionary measures against the spread of bla(IMP)-positive isolates are needed, because, for most of such pathogens, no antibiotic is potent enough to be used as a single agent in treatment of infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Case-Control Studies
  • Humans
  • Microbial Sensitivity Tests
  • Pseudomonas aeruginosa / drug effects
  • Pseudomonas aeruginosa / enzymology*
  • beta-Lactam Resistance / physiology*
  • beta-Lactamases / analysis*


  • Anti-Bacterial Agents
  • beta-lactamase IMP-1
  • beta-Lactamases