An Xpert screen to identify carbapenemases

Area of Science:

• Clinical microbiology
• Infectious disease epidemiology
• Molecular diagnostics

Background:

• Carbapenemase-producing Enterobacteriaceae (CPE) pose a significant public health threat.
• Preventing CPE spread requires effective surveillance and infection control strategies.
• Rapid diagnostic tools are needed to identify colonized patients quickly.

Purpose of the Study:

• To evaluate the performance of the Xpert MDRO-assay for detecting CPE in patients.
• To assess the utility of the assay in a clinical setting for active surveillance.

Main Methods:

• Rectal swabs were collected from 32 patients.
• The Xpert MDRO-assay was used to screen for CPE targets.
• Phenotypic methods were used for comparison where applicable.

Main Results:

• 71.85% of samples were positive for targets in the MDRO-assay.
• The assay identified specific carbapenemase genes: bla NDM (59.3%), bla NDM+VIM (9.37%), and bla VIM (3.1%).
• A proportion of samples (28%) were phenotypically negative for CRE and Xpert negative, with some having alternative resistance mechanisms (e.g., bla OXA).

Conclusions:

• The Xpert MDRO-assay is a rapid screening tool for CPE detection.
• The assay can identify CPE-harboring organisms within an hour.
• Implementation in tertiary-care facilities can aid in screening colonized patients and preventing transmission.