Detection of Carbapenemase-producingEnterobacteriaceae in KK Women's and Children's Hospital, Singapore. (#415)
Carbapenemase-producing Enterobacteriaceae (CPE) are an emerging problem in hospitals. Patients transferred between healthcare facilities may require isolation to rule out multidrug resistant organisms. This can put a strain on resources due to the limited number of isolation beds available. Thus, there is a need to have a rapid, inexpensive and reliable diagnostic test to detect the presence of CPEs. We had evaluated a recently published test (CarbaNP) developed by Nordmann et.al. (2012) and introduced it to identify CPE from patient samples in our hospital. Rectal swabs or stool from patients were streaked onto ChromID Carba medium (Biomerieux) and incubated at 35°C overnight. Suspected pink and bluish-green colonies from the ChromID Carba medium were isolated on sheep blood agar and sensitivity test was done for meropenem. Meropenem resistant colonies were subsequently tested using CarbaNP test, Modified Hodge Test and Rosco KPC/MBL Confirm Kit (Rosco Diagnostica, Denmark) with Temocillin tablet. Polymerase-Chain reaction (PCR) was performed on CarbaNP positive samples to confirm the presence of New Delhi metallo-beta-lactamase (NDM), Klebsiella pneumoniae carbapenemase (KPC) and OXA48-like carbapenemase. One percent (4/445) of the samples collected in 2014 were positive for the CarbaNP test. They were all NDM positive by PCR method. None of the strains were found to contain other carbapenemase genes such as OXA48 or KPC. Although there were few positives, we found the introduction of the CarbaNP test to be useful as we could rule out the presence of CPE a day earlier than the Modified Hodge Test or Rosco KPC/MBL Confirm Kit. This will help to minimize the spread of CPE and improve patient management.