[Analysis of class I integrons in metalloenzyme-producing Pseudomonas aeruginosa]

Area of Science:

• Microbiology
• Molecular Biology
• Genetics

Background:

• Pseudomonas aeruginosa is an opportunistic pathogen known for its antimicrobial resistance.
• Metalloenzymes contribute to antibiotic resistance in bacteria.
• Integrons and gene cassettes play a role in the acquisition and dissemination of resistance genes.

Purpose of the Study:

• To investigate the prevalence of class I integrons and integrated gene cassettes in metalloenzyme-producing Pseudomonas aeruginosa.
• To identify specific metalloenzyme genes, such as bla(IMP-1) and bla(VIM), in clinical isolates.
• To characterize the genetic elements associated with antimicrobial resistance in these strains.

Main Methods:

• Polymerase Chain Reaction (PCR) was used to detect bla(IMP-1) and bla(VIM) genes.
• PCR was employed to identify class I integrons (IntI1) and integrated gene cassettes.
• Sequence analysis was performed on positive strains to confirm findings.

Main Results:

• One isolate was positive for both bla(IMP-1) and class I integrons.
• Fifty-five strains tested positive for bla(VIM), with 26 also positive for class I integrons.
• Among the class I integron-positive strains, 18 harbored integrated gene cassettes, categorized into 5 types.

Conclusions:

• This study reports the first identification of IMP-1-producing Pseudomonas aeruginosa carrying bla(Int)1 in West China.
• Class I integrons are prevalent in the studied Pseudomonas aeruginosa isolates.
• Approximately 69.2% of these strains carry gene cassettes, indicating a significant role in the clinical spread of drug-resistant genes.