Emergence of Multidrug-Resistant NDM-5-Producing ST307 Klebsiella pneumoniae in Uruguay, 2023

Area of Science:

• Microbiology and Infectious Diseases
• Genomics and Molecular Biology
• Public Health and Epidemiology

Background:

• Carbapenem and colistin-resistant Klebsiella pneumoniae are critical threats, causing high mortality in intensive care units.
• The emergence of NDM carbapenemase-producing strains necessitates detailed characterization to understand resistance mechanisms and epidemiology.

Purpose of the Study:

• To analyze five NDM carbapenemase-producing multidrug-resistant Klebsiella pneumoniae isolates from Uruguayan hospitals.
• To investigate antimicrobial resistance profiles, genetic relatedness, and virulence factors, including biofilm production and specific gene carriage.

Main Methods:

• Antimicrobial susceptibility testing, hypermucoviscosity analysis, and biofilm production assays were performed.
• Multilocus Sequence Typing (MLST), Polymerase Chain Reaction (PCR), and whole-genome sequencing (WGS) were employed for genetic analysis.
• Core genome single nucleotide polymorphism (SNP) analysis was used to assess strain relatedness.

Main Results:

• All isolates harbored the blaNDM-5 gene, belonged to ST307, were biofilm producers, and had a MgrB stop codon (Q30).
• Genomic analysis identified plasmids carrying blaNDM-5, blaCTX-M-15, rmtB, and qnrB1, alongside mobile genetic elements.
• Isolates possessed capsule locus KL102, iutA, and the type 3 fimbriae mrk operon; SNP analysis indicated two circulating ST307 strains.

Conclusions:

• This study reports the first Klebsiella pneumoniae ST307 isolates carrying blaNDM-5 in Uruguay, demonstrating significant antimicrobial resistance.
• The findings reveal the genetic plasticity of the high-risk ST307 clone and the presence of critical resistance genes (blaNDM-5, rmtB) for the first time in Uruguay.
• Urgent surveillance and intervention strategies are needed to combat the spread of these multidrug-resistant pathogens.