Novel Class 1 Integrons in Multi-drug Resistant Isolates from Eastern China

Area of Science:

• Microbiology
• Genetics
• Molecular Biology

Background:

• Integrons are mobile genetic elements crucial for the dissemination of bacterial resistance genes.
• Understanding integron diversity is key to combating antimicrobial resistance.

Purpose of the Study:

• To investigate the occurrence and diversity of integrons in clinical multi-drug resistant Gram-negative isolates.
• To identify novel gene cassettes and integron structures in eastern China.

Main Methods:

• Screening of 120 Gram-negative isolates using PCR for integron detection.
• Characterization of gene cassettes via PCR-RFLP and DNA sequencing.
• Identification of novel gene cassettes and integron arrays.

Main Results:

• Class 1 integrons detected in 70.8% of isolates; no Class 2 or 3 integrons found.
• Nineteen resistant gene cassettes identified, including four novel variants (aacA3c, aacA4'-17, bla OXA-251, catB8::IS10).
• Fourteen cassette arrays identified, including three novel integrons (In712, In713, In714).

Conclusions:

• Novel integron structures suggest hospital environments facilitate gene cassette recombination.
• High integron prevalence in multi-drug resistant isolates underscores the urgent need for control strategies.
• Findings emphasize the critical role of integrons in bacterial drug resistance and the need for effective interventions.