1605. Point Surveillance of Carbapenemase-Producing Bacteria in Rectal Swabs of ICU Patients Using A New Automated Real-Time PCR (RT-PCR) Assay
Session: Poster Abstract Session: ESBL and CRE Diagnostics
Saturday, October 10, 2015
Room: Poster Hall
Background: Infections with carbapenem-resistant bacteria (CRB), including CR Enterobacteriaceae (CRE), are very difficult to treat and can be deadly. Patients colonized by CRB should be promptly identified and cohorted. This study was designed to evaluate, in a clinical setting, the performance of GeneXpert Carba-R® Assay in detecting the prevalent carbapenem resistance genes from rectal swabs as well as determine their carriage rates.

Methods: In one month non-duplicate 74 paired rectal swabs were evaluated in the month of March 2015. The first swabs were analyzed using Xpert® Carba-R Assay in GX DX Systems; results were available for reading after 1h. The 2nd swabs were cultured on MacConkey agar plate on which a 10µg meropenem was placed and incubated for 18h. Isolates were identified by conventional methods and carbapenemase production confirmed by phenotypic and in-house PCR methods. Adequate positive and negative control strains were included in each run. All the internal controls performed weekly gave expected results. The carbapenemase genes of 5 known CRB analyzed were correctly detected.

Results: Samples of 9 out of 74 patients were Xpert® positive giving a point prevalence of 12.2%.  Seven (9.5%) were culture positive; 3 CRE (2 Klebsiella and 1 Enterobacter spp.) and 4 Acinetobacter baumannii. Three of 4 A. baumannii were positive for blaVIM and the other blaOXA-48. The 2 K. pneumoniae were positive for blaNDM while the E. aerogenes carried blaVIM and blaNDM genes simultaneously. Confirmatory synergy test and in house PCR were in agreement with Xpert® results.


The assay demonstrated exquisite specificity and sensitivity. In addition it demonstrated a very high prevalence of CRB in the rectums of ICU patients, a critical finding crucial for proper decision to cohort or not patients at admission.

Vincent Rotimi, MD, PhD, FRCPath, FIDSA1, Noura Al Merdasi, MD2, Wafaa Jamal, MD, PhD, FRCPath1, Lubna Abdulaziz, BSc2 and Aarti Chadha, MD2, (1)Microbiology, Faculty of Medicine, Kuwait University, Jabriya, Kuwait, (2)Microbiology Unit, Mubarak Al Kabir hospital, Kuwait, Jabriya, Kuwait


V. Rotimi, None

N. Al Merdasi, None

W. Jamal, None

L. Abdulaziz, None

A. Chadha, None

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