Interspecies dissemination of the bla gene encoding PER-1 extended-spectrum β-lactamase

Area of Science:

• Microbiology
• Molecular Biology
• Antimicrobial Resistance

Background:

• Extended-spectrum β-lactamase (ESBL)-producing Gram-negative bacilli exhibit resistance to critical antibiotics like oxyimino-cephalosporins.
• The bla(PER-1) gene, encoding such resistance, has not been previously documented in Klebsiella pneumoniae.
• Horizontal gene transfer is a significant mechanism for the dissemination of antimicrobial resistance genes among bacteria.

Purpose of the Study:

• To investigate the interspecies dissemination of the bla(PER-1) gene.
• To identify the mechanism of bla(PER-1) gene transfer between different bacterial species.
• To characterize the genetic context of the bla(PER-1) gene in Klebsiella pneumoniae.

Main Methods:

• Investigated the presence and location of the bla(PER-1) gene in clinical isolates.
• Studied the role of the mobile genetic element Tn1213 in the horizontal transfer of the bla(PER-1) gene.
• Utilized plasmid analysis to determine the genetic element carrying the bla(PER-1) gene in Klebsiella pneumoniae.

Main Results:

• The bla(PER-1) gene was identified in a clinical isolate of Klebsiella pneumoniae.
• Evidence suggests horizontal transfer of the bla(PER-1) gene mediated by Tn1213 among Acinetobacter baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae.
• In the studied Klebsiella pneumoniae isolate, the bla(PER-1) gene was located on a 150-kbp incompatibility group A/C plasmid.

Conclusions:

• The bla(PER-1) gene can disseminate among different Gram-negative species, including Klebsiella pneumoniae, through horizontal gene transfer.
• The Tn1213 element plays a crucial role in the spread of the bla(PER-1) gene.
• The presence of bla(PER-1) on a transferable plasmid in Klebsiella pneumoniae highlights a potential public health concern for antimicrobial resistance.