Screening of carbapenemase-producing organisms and vancomycin-resistant enterococci by a molecular approach: impact...

The rapid detection of carriers of emerging extensively drug-resistant bacteria (eXDR), notably carbapenemase-producing organisms (CPOs) and vancomycin-resistant Enterococci, is crucial for controlling their spread and preventing infections.

To evaluate the impact of polymerase chain reaction (PCR) on turnaround time (TAT) for eXDR detection compared to culture methods under routine laboratory conditions, excluding night or weekend analyses.

A prospective before-and-after study was conducted at a French university hospital. Phase 1 (culture) occurred from February to September 2022, phase 2 (PCR) from September 2022 to March 2023. TAT was defined as the time from sample collection to result delivery to the infection control team and/or physician. Patients aged >18 years meeting specific screening criteria were included. Two PCR kits were utilized: the BD MAX Check-Points CPO kit and the VIASURE Vancomycin resistance Real Time PCR Detection Kit.

A total of 2049 and 1861 patients were included in phases 1 and 2, respectively. Sixteen patients tested eXDR positive for the first time in phase 1, and 25 in phase 2. The median TAT was significantly shorter in phase 2 (22.7 h; 16.0-41.3) compared to phase 1 (43.5 h; 31.9-69.7; P = 0.001). A significant decrease in the median number of contact patients was observed in phase 2 compared to phase 1. The number of total screening test secondary cases and the hospitalization costs were comparable regardless of the eXDR detection method.

Rapid rectal screening using PCR significantly reduces TAT for results in low-endemic contexts without increasing costs.