Screening rectal swabs for carbapenemase genes.

Area of Science:

• Clinical Microbiology
• Infectious Diseases
• Molecular Diagnostics

Background:

• Antimicrobial resistance is a growing global health threat.
• Carbapenemase-producing Enterobacteriaceae (CPE) are of particular concern due to limited treatment options.
• Outbreak settings require rapid and accurate diagnostic tools.

Purpose of the Study:

• To evaluate the performance of PCR screening for carbapenemase genes (blaOXA-48, blaVIM, blaIMP, blaNDM, blaKPC) in an outbreak.
• To identify the prevalence of specific carbapenemase genes in patient samples during the outbreak.

Main Methods:

• Polymerase Chain Reaction (PCR) was used to screen 16,296 samples from 3,644 patients.
• Target genes included blaOXA-48, blaVIM, blaIMP, blaNDM, and blaKPC.
• Isolates were identified to species level.

Main Results:

• The blaOXA-48 gene was detected in samples from 43 patients across 9 Enterobacteriaceae species.
• The blaVIM gene was identified in five Pseudomonas aeruginosa isolates.
• The screening test achieved a 100% negative predictive value and an 86% positive predictive value.

Conclusions:

• PCR screening is effective for detecting carbapenemase genes in outbreak settings.
• blaOXA-48 and blaVIM are significant carbapenemase genes identified in this outbreak.
• The high negative predictive value supports the use of this screening method to rule out resistance.