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Screening Foodstuffs for Class 1 Integrons and Gene Cassettes
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Screening Foodstuffs for Class 1 Integrons and Gene Cassettes

Published on: June 19, 2015

Class 1 integrons in Pseudomonas aeruginosa isolates from clinical settings in Amazon region, Brazil

Erica L Fonseca1, Verônica V Vieira, Rosângela Cipriano

  • 1Department of Genetics, Instituto Oswaldo Cruz, FIOCRUZ, Avenida Brazil 4365, P.O. Box 926, CEP 21045-100, Rio de Janeiro, Brazil.

FEMS Immunology and Medical Microbiology
|May 24, 2005
PubMed

Insights

Class 1 integrons were found in 41.5% of clinical Pseudomonas aeruginosa isolates in the Brazilian Amazon. While common, integron presence showed no strong link to multidrug resistance in these bacteria.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Genetics

Background:

  • Pseudomonas aeruginosa is an opportunistic pathogen frequently associated with hospital-acquired infections.
  • Integrons and associated gene cassettes are key mechanisms for the dissemination of antimicrobial resistance genes.
  • Understanding integron prevalence in clinical isolates is crucial for monitoring resistance trends.

Purpose of the Study:

  • To investigate the prevalence of class 1 integrons and their gene cassette content in clinical Pseudomonas aeruginosa isolates from the Brazilian Amazon.
  • To analyze the correlation between integron carriage and multidrug resistance in these isolates.

Main Methods:

  • Polymerase Chain Reaction (PCR) was used to screen 106 clinical Pseudomonas aeruginosa isolates for class 1 integrons.
  • Gene cassette presence and types (e.g., aacA, blaOXA) were identified.
  • Restriction fragment-length polymorphism (RFLP) analysis was performed on integron variable regions.
  • Multidrug resistance profiles were determined for all isolates.

Main Results:

  • Class 1 integrons were detected in 41.5% (44/106) of the isolates.
  • Among isolates with class 1 integrons, 66% (29/44) carried gene cassettes, with aacA and blaOXA family genes being the most frequent.
  • A significant proportion (34%) of class 1 integron-positive strains lacked detectable gene cassettes.
  • RFLP analysis revealed both conserved and heterogeneous integron structures.
  • Multidrug resistance was prevalent (71%), but no strong correlation was found with the presence of class 1 integrons.

Conclusions:

  • This study reports for the first time the prevalence and gene cassette content of class 1 integrons in clinical Pseudomonas aeruginosa from the Brazilian Amazon.
  • The findings highlight the presence of integrons in a substantial portion of clinical isolates, alongside diverse gene cassette structures.
  • The lack of a strong correlation between integron presence and multidrug resistance suggests other resistance mechanisms may be at play in this P. aeruginosa population.

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