Characterization of Pseudomonas aeruginosa isolates from patients with urinary tract infections during antibiotic therapy

Microb Drug Resist. 2003 Summer;9(2):223-9. doi: 10.1089/107662903765826831.

Abstract

We characterized susceptibilities and genotypes in a series of Pseudomonas aeruginosa isolates from five cases of urinary tract infections (UTIs) to evaluate clonal shifts of carbapenem resistance. In one case, a series of isolates showed different susceptibility patterns for carbapenems but an identical genotype. In another case, genotypes varied among 4 P. aeruginosa isolates from recurrent UTIs over 9 months. Although the patient had been treated with no antibiotic immediately before isolation, the susceptibility patterns for carbapenems and ceftazidime varied. Further analysis in these two cases of outer membrane protein profiles showed that loss of OprD production resulted in reduced susceptibilities to carbapenems in all of the carbapenem-resistant isolates. Loss of OprD production was likely due to oprD gene inactivation in both of cases, since the carbapenem-resistant isolates showed no cross resistance to levofloxacin and chloramphenicol compared with the carbapenem-susceptible isolates. There was another case in which all isolates showed similar susceptibility patterns for carbapenems and ceftazidime, and an identical genotype during the intermittent use of antibiotics over 5 months. In two cases, a single course of antibiotic therapy resulted in eradication of P. aeruginosa. Our results suggest that clonal shifts of carbapenem resistance in P. aeruginosa may result from loss of OprD during antibiotic treatment. Therefore, it is important for clinicians to monitor susceptibilities to antibiotics, especially carbapenems, in P. aeruginosa isolated during therapy.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Anti-Bacterial Agents / therapeutic use*
  • Bacterial Outer Membrane Proteins / genetics
  • Carbapenems / pharmacology
  • Drug Resistance, Bacterial
  • Electrophoresis, Gel, Pulsed-Field
  • Electrophoresis, Polyacrylamide Gel
  • Female
  • Genotype
  • Gynecologic Surgical Procedures
  • Humans
  • Microbial Sensitivity Tests
  • Middle Aged
  • Mutation / genetics
  • Postoperative Complications / microbiology
  • Pseudomonas Infections / drug therapy
  • Pseudomonas Infections / microbiology*
  • Pseudomonas aeruginosa / drug effects*
  • Pseudomonas aeruginosa / genetics
  • Random Amplified Polymorphic DNA Technique
  • Treatment Outcome
  • Urinary Tract Infections / drug therapy
  • Urinary Tract Infections / microbiology*

Substances

  • Anti-Bacterial Agents
  • Bacterial Outer Membrane Proteins
  • Carbapenems