Xpert vana vanb

Chromogenic medium (ChromID VRE agar plate, Biomerieux) was used for detection and differentiation of VRE from screening swabs. Identification of Enterococci in bloodstream isolates was based on VITEK 2 (Biomerieux). Genetic testing for vanA and vanB were not routine during the study period. Clinical isolates were deemed to be vanB if phenotypically susceptible to teicoplanin and resistant to vancomycin by VITEK 2 (Biomerieux) using Clinical and Laboratory Standards Institute (CLSI) guidelines (CLSI 2015, version M100-S25). Isolates resistant to teicoplanin were confirmed to be vanA by PCR (Xpert vanA/vanB, Cepheid, Sunnyvale, USA).

Swabs were performed using sterile transport swab (ref. 139C) on specific media (liquid Stuart, Venturi Transystem® by COPAN Italia, Brescia, Italy).
Each swab was cultivated on specific selective media (chromID® VRE and chromID® CARBA SMART by bioMérieux, Marcy l’Etoile, France), and on regular MDRO agar plates according to manufacturer. No enrichment cultures were used.
Moreover, at admission colonization was systematically confirmed by PCR testing (PCR Xpert CarbaR and Xpert VanA/VanB by Cepheid, Maurens-Scopont®, France) and during follow-up in case of negative culture on the demand of physician.

For screening, we use the eSwab kit for aerobic, anaerobic, and fastidious bacteria (Copan, Brescia, Italy). Nasal and oropharyngeal swabs were used for MRSA screening, as rectal swabs or stool specimens were used for VRE and MDRGN screenings.
MRSA testing was performed by PCR using the Xpert® MRSA NxG (Cepheid, Sunnyvale, USA) kit. The detection of carbapenemases was carried out with the Xpert® Carba-R PCR kit (Cepheid, Sunnyvale, USA), and vancomycin resistances were detected by the Xpert® vanA/vanB (Cepheid, Sunnyvale, USA) PCR.