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Updated: Sep 25, 2026
Screening Foodstuffs for Class 1 Integrons and Gene Cassettes
Published on: June 19, 2015
Polymerase chain reaction screening for integrons can be used to complement resistance surveillance programs
Louisa A Jones1, Christopher J McIver, William D Rawlinson
1Virology Division, Department of Microbiology, SEALS, Prince of Wales Hospital, Randwick, New South Wales.
Abstract:
Integrons have been recognised as important contributors to the acquisition and dissemination of antibiotic resistance in Gram-negative bacteria. In a collection of 19 multi-antibiotic resistant Gram-negative clinical isolates, 47 per cent (9/19) of strains were found to contain one or more integron, using a polymerase chain reaction (PCR) based screening method. Resistance gene cassettes within the integrons were amplified, sequenced and characterised. Antibiotic susceptibility testing demonstrated that resistance phenotypes correlated with the resistance conferred by gene cassettes identified. PCR-screening for integrons and gene cassettes provides a rapid technique for the identification of genetic determinants of resistance in Gram-negative bacteria. Such screening could assist in guiding treatment regimens and complement existing antibiotic resistance surveillance programs by providing information on molecular mechanisms of both resistance and resistance dissemination.
Insights
Integrons significantly contribute to antibiotic resistance in Gram-negative bacteria. PCR screening rapidly identifies these integrons and resistance gene cassettes, aiding treatment and surveillance.
Area of Science:
- Microbiology
- Genetics
- Molecular Biology
Background:
- Integrons are key genetic elements driving antibiotic resistance acquisition and spread in Gram-negative bacteria.
- Multi-antibiotic resistant Gram-negative bacteria pose a significant clinical challenge.
Purpose of the Study:
- To investigate the prevalence of integrons in multi-antibiotic resistant Gram-negative clinical isolates.
- To characterize the resistance gene cassettes within identified integrons.
- To assess the utility of PCR-based screening for identifying antibiotic resistance determinants.
Main Methods:
- A collection of 19 multi-antibiotic resistant Gram-negative clinical isolates was screened for integrons using polymerase chain reaction (PCR).
- Resistance gene cassettes within positive integrons were amplified, sequenced, and characterized.
- Antibiotic susceptibility testing was performed on the isolates.
Main Results:
- Integrons were detected in 47% (9/19) of the multi-antibiotic resistant Gram-negative clinical isolates.
- Sequencing identified specific resistance gene cassettes within the integrons.
- Observed antibiotic resistance phenotypes correlated with the identified gene cassettes.
Conclusions:
- PCR-based screening is a rapid and effective method for detecting integrons and identifying genetic determinants of antibiotic resistance in Gram-negative bacteria.
- This screening approach can aid in guiding clinical treatment decisions.
- The findings complement existing antibiotic resistance surveillance programs by providing molecular insights into resistance mechanisms and dissemination.
