Rapid Detection Of Carbapenemase-producing Enterobacteriaceae Research Articles

A comparative evaluation of five phenotypic methods for identification of carbapenemase-producing Enterobacteriaceae: a modified carbapenemase detection test.

Rapid detection of carbapenemase-producing Enterobacteriaceae (CPE) is urgently needed to prevent their spread in healthcare settings. Here, we have evaluated the performance of the phenotypic methods for detection of carbapenemase production directly from bacterial cultures. A total of 99 clinical and rectal Enterobacteriaceae isolates were included (81 carrying known carbapenemase-encoding genes and 18 without carbapenemase production). All isolates were subjected to the five phenotypic tests including in-house Carba NP (iCarba NP), modified-Carba NP, E-Test MBL, modified Hodge test (MHT), and commercial combination disk test. Test results were read at different time points for iCarba NP and modified-Carba (1 min, 5 min, 15 min, 1 h and 2 h). The sensitivity and specificity of the iCarba NP were 78.87% and 100%, respectively, whereas those of the modified-Carba NP test were 95.06% and 94.44%, respectively. False-negative results were detected in four OXA-48 isolates with the use of modified-Carba NP, whereas one non-carbapenemase isolate had false-positive results. The sensitivity/specificity was 91.30%/100% and 80.25%/83.33% for the E-Test MBL and MHT, respectively. The sensitivity and specificity of the aminophenylboronic acid synergy test were 100% and 97.94%, respectively, whereas those of the dipicolinic acid synergy test were 82.61% and 96.23%, respectively. Rapid, simple, and reliable methods are needed for laboratory detection of CPE isolates to improve the detection and surveillance of these clinically relevant pathogens in an epidemiological context. We conclude that the modified-Carba NP test can be one of the reliable tests for the prediction of carbapenemase-producing bacteria.IMPORTANCEThe emergence of carbapenem resistance among Gram-negative bacteria is a serious global health threat. Here, we investigate the performance of the five phenotypic assays against carbapenemase-producing and carbapenemase-non-producing Enterobacteriaceae. Accurate and rapid detection of CPE isolates is critically required for clinical management and treatment of infections caused by these organisms. Among the five evaluated phenotypic tests, the mCNP test presented the highest sensitivity (95.06%) and, therefore, can be considered the best test to be used as a screening phenotypic methodology.

Diagnostic Accuracy of Carba NP test for Rapid Detection of Carbapenemase-Producing Enterobacteriaceae: Systematic Review and Meta-Analysis

Background: Carbapenem-Resistant Enterobacteriaceae is a major health concern that needs a fastresponse by rapid detection and management. The Polymerase chain reaction is the gold standard methodfor the detection of this infection, but it is expensive and needs special laboratory facilities, so there isan urgent demand for an alternative method characterized by cheap, rapid, and accurate. CARPA NP testhas been proposed as a rapid method for the detection of Carbapenemase-Producing Enterobacteriaceae,but its overall accuracy has not been systematically estimated. We performed a systematic review andmeta-analysis to evaluate the accuracy of CARPA NP test for the detection of Carbapenemase-ProducingEnterobacteriaceae.Methods: We searched Pubmed and Embase databases and eighteen studies met our inclusion criteria.We utilized summary receiver operating characteristic (SROC) to summarize the accuracy. Results: Thesensitivity and specificity of CARPA NP test were 0.96 (95% CI, 0.92 to 0.98) and 1.00 (95% CI, 0.97 to1.00) respectively, the positive likelihood ratio was 33.1 (95% CI, 24.3 to 45.1), the negative likelihood ratiowas 0.06 (95% CI, 0.05 to 0.07), and the diagnostic odds ratio was 573.46 (95% CI, 397.4 to 827.49).Conclusion: CARPA NP test has a high level of accuracy for the rapid detection of Carbapenemase-Producing Enterobacteriaceae. Additional studies are required to estimate the accuracy of Carba NP testwhen applied directly to clinical samples, especially in areas with high rates of carbapenemase-producingEnterobacteriaceae

Rapid detection of carbapenemase production in Enterobacteriaceae by different phenotypic methods

Introduction: Carbapenemase producing enterobacteriaceae (CPE) isolates have now emerged worldwide. Resistance to carbapenems is mainly due to production of beta-lactamases inactivating carbapenems (carbapenemases) included in classes A, B, C, or D of the Ambler classification. In Enterobacteriaceae carbapenemase encoding genes are often located on plasmids that contribute to a rapid spread among clinically relevant gram negative bacteria. Rapid and reliable detection of carbapenemase production is needed for therapeutic and control reasons. Aims: To compare the different phenotypic methods of carbapenemase detection namely, the modified paper strip carba NP method, the CLSI Carba NP method, the carbapenem inactivation method, and for rapid detection of CPE. Materials and methods: A total of 200 CPE from urine, pus, and blood cultures sent to the Microbiology Laboratory, R.G. Kar Medical College and Hospital (RGKMCH), were tested for the modified paper strip carba NP method, the CLSI Carba NP method, and the carbapenem inactivation method. Results and analysis: Out of 200 isolates, 108 isolates of Klebsiella spp and 92 isolates of Escherichia coli were compared for carbapenemase production by various phenotypic methods. In total, 100(93%) isolates of Klebsiella spp and 88 (95%) isolates of Escherichia coli showed positive results by paper strip and carba NP methods. A total of 96 (89%) isolates of Klebsiella spp and 84 (91%) isolates of Escherichia coli showed positive results by CLSI carba NP method. A total of 104 (96%) isolates of Klebsiella spp and 92 (100%) isolates of Escherichia coli showed positive results by CIM method. Conclusion: Rapid and accurate detection of carbapenemase producers are important for preventing their spread in health care settings. Although genotypic tests remain the gold standard but cannot practically be conducted because they are highly expensive and results are limited by the targets. The different phenotypic methods used in this study were inexpensive, rapid, highly sensitive, and specific. The modified paper strip Carba NP method in this study is a simple and rapid method compared to those performed by the CLSI method.

Nosocomial Outbreak Caused by NDM-5 and OXA-181 Carbapenemase Co-producing Escherichia coli.

Carbapenemase-producing Enterobacteriaceae (CPE) is an important and increasing threat to global health. From July to September 2017, 20 inpatients at a tertiary care hospital in Korea were either colonized or infected with carbapenem-resistant Escherichia coli strains. All of E. coli isolates co-produced blaNDM-5 and blaOXA-181 carbapenemase genes and shared ≥88% clonal relatedness on the basis of a cladistic calculation of the distribution of pulsed-field gel electrophoresis patterns. Rapid detection of CPE is one of the most important factors to prevent CPE dissemination because it takes long time for CPE to become negative.

Multicentre evaluation of the BYG Carba v2.0 test, a simplified electrochemical assay for the rapid laboratory detection of carbapenemase-producing Enterobacteriaceae

Rapid detection of carbapenemase-producing Enterobacteriaceae (CPE) represents a major challenge for microbiology laboratories. We evaluated the BYG Carba v2.0 using a simplified protocol, which detects CPE in less than 30 minutes. This new procedure reduces the hands-on-time from 5 to one minute and only requires a limited amount of material (one to three colonies) thereby preventing the need for subculturing bacterial isolates to reach a larger amount of pure biomass. This multicentre study involved four European reference laboratories. For the 1181 isolates tested across four centres, BYG Carba v2.0 yielded overall sensitivity and specificity of 96.3% (CI95: 94.5–97.5) and 99.7% (CI95: 98.6–100) respectively. Considering only the 670 consecutive isolates tested prospectively, the BYG Carba v2.0 displayed overall positive and negative predictive values of 99.7% (CI95: 95.4–98.9) and 97.5% (CI95: 94.9–98.8). Regarding time to positivity, 85% of CPE detected were positive within ten minutes. The BYG Carba v2.0 is a new highly simplified, rapid and accurate electrochemical assay discriminating between CPE and non-CPE in less than 30 min. The real-time quantified signal allows objective and traceable interpretation of the results.

Modification and evaluation of the Carba NP test by use of paper strip for simple and rapid detection of carbapenemase-producing Enterobacteriaceae.

Carbapenemase-producing Enterobacteriaceae (CPE) isolates have now emerged worldwide. We therefore modified the phenotypic Carba NP test by use of a filter paper strip for easily and rapidly identifying CPE in routine laboratory. A collection of 56 CPE and carbapenemase-producing Pseudomonas spp. isolates (including 28 NDM-1, 11 IMP-14a, 1 IMP-1, 1 IMP-4, 1 IMP-9, 1 IMP-15, 4 VIM-2, 1 VIM-1, 1 IMP-14a with VIM-2, 3 OXA-48, 3 OXA-181 and 1 KPC-2 producers) and 41 non-CPE isolates (including 19 ESBL, 7 pAmpC, 3 AmpC, 9 ESBL with pAmpC and 3 non-ESBL & non-AmpC producers) as confirmed by the PCR methods were tested by the paper strip method using pharmaceutical imipenem/cilastatin as a substrate. Bacterial colonies of each isolate were applied directly on filter paper strips dropped with either imipenem-phenol red (test strip) or phenol red solution alone (control strip). The reaction was read within 5min. This test failed to detect 3 OXA-181, 2 OXA-48 and 3 IMP-14a producers (85.7% sensitivity), whereas no false positives were seen (100% specificity). Further evaluation of the paper strip test in 267 CPE screening-positive isolates from three hospitals by their medical technologists showed 92.0% sensitivity (100% for NDM producers) and 100% specificity compared with the PCR methods. Because of its ease, rapidness and cost effective, the paper strip test has a potential for routine CPE testing in low-resource laboratories particularly in areas with high prevalence of NDM enzymes, leading to appropriate antimicrobial therapy and infection control strategy.

Evaluation of CHROMagar™ KPC for the detection of carbapenemase-producing Enterobacteriaceae in rectal surveillance cultures

In this study, the performance of the chromogenic medium CHROMagar™ KPC was evaluated and was compared with in-house-daily prepared McConkey agar plates supplemented with imipenem (1mg/L) for the detection of carbapenemase-producing Enterobacteriaceae. In this surveillance study, rectal swabs were cultured on both media and polymerase chain reaction (PCR) for blaKPC and blaVIM was used to confirm the genotype of growing colonies of Enterobacteriaceae. CHROMagar KPC was also tested with 17 genotypically characterised carbapenemase-producing and non-producing Gram-negative bacteria. It was shown that CHROMagar allows rapid detection of carbapenemase-producing Enterobacteriaceae, although blaKPC- and blaVIM-harbouring isolates could not be differentiated by colour or colony morphology. The positive and negative predictive values of the tested methods for the detection of carbapenemase-producing Enterobacteriaceae were, respectively, 100% and 98.8% for CHROMagar KPC and 94.7% and 88.6% for imipenem-supplemented McConkey agar. CHROMagar KPC medium is a useful screening medium for carbapenemase-producing Enterobacteriaceae in stools in settings with a high proportion of patients colonised with a variety of carbapenemase-producers.