NDM-1 encoded by a pNDM-BJ01-like plasmid p3SP-NDM in clinical Enterobacter aerogenes

Area of Science:

• Microbiology
• Genetics
• Infectious Diseases

Background:

• Carbapenem resistance is a growing global health threat.
• Enterobacter aerogenes is an opportunistic pathogen.
• NDM-1 carbapenemase confers resistance to a broad spectrum of beta-lactam antibiotics.

Purpose of the Study:

• To characterize a carbapenem-nonsusceptible Enterobacter aerogenes strain.
• To identify the genetic basis of carbapenem resistance in this strain.
• To investigate the plasmid carrying the NDM-1 carbapenemase and its relationship to other known plasmids.

Main Methods:

• Isolation and identification of the bacterial strain.
• Plasmid DNA extraction and sequencing.
• Comparative genomic analysis of the identified plasmid against public databases.

Main Results:

• A carbapenem-nonsusceptible Enterobacter aerogenes strain (3-SP) was isolated from a human pneumonia case.
• The strain produces NDM-1 carbapenemase carried on a novel conjugative plasmid, p3SP-NDM.
• p3SP-NDM is a pNDM-BJ01-like plasmid with minor genetic variations and an identical Tn125 element.
• This is the first report of a pNDM-BJ01-like plasmid identified in Enterobacteriaceae, distinct from those previously found exclusively in Acinetobacter.

Conclusions:

• The p3SP-NDM plasmid represents a significant finding, indicating potential inter-species plasmid transfer.
• The presence of NDM-1 in Enterobacteriaceae highlights the evolving landscape of antimicrobial resistance.
• Further surveillance is crucial to monitor the spread of such resistance mechanisms.