Comparison of class 1 integrons from human and avian E. coli

Abstract number: P2017

Psichogiou M., Vasilakopoulou A., Petrikkos G., Tzouvelekis L., Kosmidis C., Charvalos E., Passiotou M., Avlami A., Daikos G.L.

Objectives: A prospective study for the identification and comparison of class 1 integrons in E. coli from three sources: farm poultry, hospitalised and non-hospitalized patients.

Methods: A total of 235 E. coli were collected; 80 from hospitalised patients, 90 from non-hospitalized patients with no prior hospitalisation in the preceding 3 months, and 65 from farm poultry. Identification of the isolates was performed by the Wider 1 automated system and susceptibilities to commonly used antimicrobial agents were determined by the Kirby-Bauer and broth microdilution methods. IntI1-specific polymerase chain reaction (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 of the XbaI digests of genomic bacterial DNA.

Results: The rate of integron carriage was 49.2% for E. coli derived from farm poultry, 26.2% and 11.1% for isolates recovered from hospitalised and non-hospitalized patients. The length of the integrons' variable regions ranged from 500 to 2700 bp. 96.8% of integron-carrying organisms exhibited resistance to more than two classes of antibiotics (MDR), whereas only 34.8% of non-integron-carrying organisms were MDR (P < 0.001). The most prevalent genes were the aad and dfr gene families detected in 71.4% and 65% of sequenced integrons respectively. Identical integrons were detected in E. coli of human and animal sources.

Conclusion: A large reservoir of integrons exists in E. coli of food-producing animals. The horizontal transfer of class 1 integrons among bacteria of animal and human origins seems to play an important role in the dissemination of antimicrobial resistance.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
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