Chromid carbapenemase agar

The selective agar plates used for MDRE detection were McConkey with ciprofloxacin 0,5 mg/l and gentamicin 2 mg/l (Mediaproducts BV), a ChromID ESBL and a ChromID Carbapenemase agar (both bioMérieux). Presence of ESBL was confirmed with cefotaxime-clavulanate, ceftazidime- clavulanate and cefepime-clavulanate Etest strips (bioMérieux). Possible CPE was confirmed by CIM test and PCR and typed by the national reference network for CPE at the RIVM (National Institute for Public Health) [3 (link)].

Similarly as for MRSA, MDRE can be detected both actively and passively. All Enterobacteriaceae isolated from clinical cultures were selected. As for MRSA routine MDRE screening of asylum seekers, started only halfway the study period. MDRE screening was performed using rectal swabs, which were processed within one day after collection. A growth control on blood agar and three selective solid media, a McConkey with ciprofloxacin 0,5 mg/l and gentamicin 2 mg/l (Mediaproducts BV), a ChromID ESBL and a ChromID Carbapenemase agar (both bioMérieux) were incubated.
Three patterns of MDRE were distinguished: Extended Spectrum Beta-Lactamase (ESBL), Fluoroquinolone plus Aminoglycoside Resistant Enterobacteriaceae (QARE) and carbapenemase-producing Enterobacteriaceae (CPE). Suspicious colonies were identified on species level by using MALDI-TOF. Only after a correct and plausible identification, the antibiotic susceptibility of Enterobacteriaceae was tested with the Vitek 2 system.
The antibiotic susceptibility of Enterobacteriaceae was tested with the Vitek 2 system. Presence of ESBL was confirmed with cefotaxime-clavulanate, ceftazidime- clavulanate and cefepime-clavulanate E tests (bioMérieux) [14 ]. Possible CPE was confirmed by PCR (Check-Points, Check-MDR CT102).