Objective: This study assessed qualities of microbiological screening methods in term of intrinsic value and length of analysis in order to set up the most efficient strategy for GRE control.
Methods: This observational study was based on the comparison of 3 culture techniques: a Bile esculin agar containing 8mg/liter vancomycin (BEV) medium, the BEV after enrichment (ENR) and the chromogen medium ChromID VRE® (CID; bioMérieux). These methods were assessed on stool samples from inpatients hospitalized in ICU and hematology of 3 hospitals in
Results: During this study, 137 stool samples of 131 patients were included. 50.4% came from ICU and 35% from Hematology. 37 GRE among 68 strains were isolated on BEV. 37 GRE among 54 strains were isolated on ENR. Finally, 40 GRE among 91 strains were isolated on CID. A capture recapture method allowed us to estimate the overall number of colonized patients in the population studied to about 42. Sensibilities obtained in comparison with CID after 48h chosen as the GS varied from 87.5% with the ENR to 95% with the CID after 24h. LR+/LR-rates varied from 326.4 to +∞. The Youden index varied from 0.93 for the ENR to 0.97 for the CID after 24h. The median lead time to isolate a strain of GRE varied from 20 [20-23] to 44 [44-47] hours. Results were available after 34 [34-58] hours with the CID vs 70 [68-91] hours with the ENR.
Conclusions: The CID appeared as the best technique in term of quality and delay of analysis. During an outbreak of GRE carriage, the inclusion of the CID in first intention in a screening strategy could allow getting a quick view of the situation. During this study, the enrichment didn’t increase the sensibility of BEV. These techniques will be compared with molecular methods based on simplex and multiplex PCR.