Open AccessEnterobacteriaceae Bloodstream Infections: Presence of Integrons, Risk Factors, and Outcome
Author(s) -
George L. Daikos,
Chris Kosmidis,
Panayotis T. Tassios,
George Petrikkos,
Alexandra Vasilakopoulou,
Mina Psychogiou,
Ioanna Stefanou,
A. Avlami,
Nikolaos Katsilambros
Publication year - 2007
Publication title -
antimicrobial agents and chemotherapy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.07
H-Index - 259
eISSN - 1070-6283
pISSN - 0066-4804
DOI - 10.1128/aac.00044-07
Subject(s) - integron , odds ratio , carriage , enterobacteriaceae , microbiology and biotechnology , biology , medicine , confidence interval , antibiotic resistance , antibiotics , escherichia coli , genetics , pathology , gene
A prospective observational study was conducted to identify factors associated with bloodstream infections (BSIs) caused by integron-carryingEnterobacteriaceae and to evaluate the clinical significance of integron carriage. Consecutive patients withEnterobacteriaceae BSIs were identified and followed up until discharge or death. Identification of blood isolates and susceptibility testing were performed by the Wider I automated system.int-1 -specific PCR, conserved-segment PCR, and DNA sequencing were used to determine the presence, length, and content of integrons. The relatedness among the isolates was examined by pulsed-field gel electrophoresis. Two hundred fifty episodes ofEnterobacteriaceae BSI occurred in 233 patients; 109 (43.6%) were nosocomial, 82 (32.8%) were community acquired, and 59 (23.6%) were health care associated. Integrons were detected in 11 (13.4%) community-acquired, 24 (40.7%) health care-associated, and 46 (42.2%) nosocomial isolates. Integron-carrying organisms were more likely to exhibit resistance to three or more classes of antimicrobials (odds ratio [OR], 9.84; 95% confidence interval [95% CI], 5.31 to 18.23;P < 0.001) or to produce extended-spectrum β-lactamases (OR, 5.75; 95% CI, 2.38 to 13.89;P < 0.001) or a VIM-type metallo-β-lactamase (P , 0.003). Inter- or intraspecies integron transfer and cross-transmission of integron-carrying clones were observed. Use of cotrimoxazole (OR, 4.77; 95% CI, 1.81 to 12.54;P < 0.001) and a nosocomial or other health care setting (OR, 3.07; 95% CI, 1.30 to 7.22;P , 0.01) were independently associated with BSIs caused by integron-carryingEnterobacteriaceae . Patients with a nonurinary source of bacteremia (OR, 9.46; 95% CI, 2.77 to 32.32;P < 0.001) and a Pitt bacteremia score of ≥4 (OR, 23.36; 95% CI, 7.97 to 68.44;P < 0.001) had a significantly higher 14-day mortality rate, whereas integron carriage did not affect clinical outcomes. These findings may have implications affecting antibiotic policies and infection control measures.