Assessment of the performance of CHROMagar KPC and Xpert Carba-R assay for the detection of carbapenem-resistant bacteria in rectal swabs: First comparative study from Abu Dhabi, United Arab Emirates.

OBJECTIVES: The objective of this study was to evaluate the performance of CHROMagar™ KPC compared with Xpert® Carba-R assay for the detection of carbapenem-resistant bacterial isolates from rectal swabs. METHODS: Rectal swabs were obtained from patients admitted to Cleveland Clinic Abu Dhabi (United Arab Emirates) over a period of 7 months and were screened for carbapenem resistance by either culture on CHROMagar KPC or carbapenemase production using the Xpert Carba-R molecular method. Further testing for carbapenem susceptibility of isolates recovered from CHROMagar KPC was performed using VITEK®2. RESULTS: A total of 1813 rectal swabs were screened, of which 61 (3.4%) were positive for carbapenem resistance by either one or both methods. Both methods were equally efficient in detecting carbapenem resistance in 37/61 swabs (60.7%), mostly positive for Klebsiella pneumoniae (22 isolates), of which 40.9% (9/22) carried blaOXA-48-like and blaNDM. Xpert Carba-R assay detected 12 additional swabs with negative CHROMagar KPC culture and revealed additional carbapenemase-producing organisms carrying blaOXA-48-like and/or blaNDM. CHROMagar KPC recovered organisms in nine swabs not detected by the genotypic method, 44.4% of which were K. pneumoniae. Three swabs yielded false-positive results (carbapenem-susceptible organisms) by both methods. Sensitivity and specificity were, respectively, 75.4% and 99.8% for CHROMagar KPC and 80% and 99.8% for Xpert Carba-R. CONCLUSION: This comparative study of CHROMagar KPC versus Xpert Carba-R in rectal swabs showed a slightly higher sensitivity for the PCR-based method. Whilst CHROMagar KPC provides a less expensive screening method, Xpert Carba-R may be more accurate and faster.

Persistent candidemia despite appropriate fungal therapy: First case of Candida auris from the United Arab Emirates.

In this case, we report an elderly patient with multiple chronic conditions and prolonged intensive care unit (ICU) stays who had recurrent Candida auris (C. auris) in blood despite antifungal therapy. C. auris was misidentified using conventional automated identification system as Candida haemulonii resulting in delayed diagnosis. The isolate showed increasing minimum inhibitory concentrations (MICs) to different antifungal drugs and persisted in the patient's blood before the patient deceased. This is the first case of C. auris reported from the United Arab Emirates (UAE); laboratories should be aware of this Candida species and should confirm suspected cases since it is an emerging multi-drug resistant and health-care associated Candida.

Comparison of antimicrobial activity between ceftolozane-tazobactam and ceftazidime-avibactam against multidrug-resistant isolates of Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa.

OBJECTIVE: This study compared the activity of ceftolozane-tazobactam and ceftazidime-avibactam against 120 bacterial strains, including extended-spectrum beta-lactamase (ESBL) producers, carbapenem-resistant Enterobacteriaceae (CRE), and Pseudomonas aeruginosa, isolated from patients admitted to Cleveland Clinic Abu Dhabi, United Arab Emirates. METHODS: In vitro susceptibility was tested using the Etest strip minimum inhibitory concentration (MIC) method, and PCR was used to characterize the carbapenemase enzymes produced by CRE strains. RESULTS: All 29 ESBL isolates were susceptible to ceftazidime-avibactam (MIC50 0.125µg/ml), whereas all but one were susceptible to ceftolozane-tazobactam (MIC50 0.38µg/ml). Twenty-seven (45%) CRE isolates were susceptible to ceftazidime-avibactam (MIC50 ≥256µg/ml), whereas only six (10%) isolates were susceptible to ceftolozane-tazobactam (MIC50 ≥256µg/ml). Very few NDM-1 isolates were susceptible to ceftazidime-avibactam, whereas the majority of OXA-48 isolates were susceptible. Twenty-nine (94%) P. aeruginosa isolates were susceptible to ceftazidime-avibactam (MIC50 1.5µg/ml), whereas 30 (97%) isolates were susceptible to ceftolozane-tazobactam (MIC50 0.75µg/ml). CONCLUSIONS: Ceftolozane-tazobactam and ceftazidime-avibactam showed comparable activity against ESBL and P. aeruginosa, with ceftazidime-avibactam having lower MICs against ESBL isolates and ceftolozane-tazobactam having lower MICs against P. aeruginosa. Ceftazidime-avibactam showed better activity against all CRE isolates except for those carrying the NDM-1 enzyme.