Rapidec Carba NP Test Research Articles

Incidence of carbapenem-resistant Escherichia coli ST2437 of clinical origin harbouring blaOXA-144 gene: a report from India.

Carbapenem-resistant Escherichia coli has been categorized as a pathogen of critical priority by the World Health Organization as it is highly infectious with high mortality and morbidity rates and widespread transmission potential. Carbapenem resistance is primarily mediated by carbapenemase-encoding genes and, additionally, through intrinsic factors. In India, over the years, carbapenemase-encoding genes have been reported from diverse clinically significant pathogens. The present study identifies E. coli of clinical origin that harbours blaOXA-144. The study isolate was obtained from a tertiary referral hospital in northeast India. Carbapenemase production was investigated through culture on chromogenic agar and Rapidec Carba NP test as per manufacturer's instructions. Susceptibility of the isolate was performed by the Kirby-Bauer disc diffusion method and agar dilution method following CLSI guidelines. PCR targeting carbapenemase-encoding genes was performed, followed by transformation and conjugation experiments. Whole-genome sequencing of the isolate was done through the Illumina sequencing platform and the data were analysed using the Centre for Genomic Epidemiology database. BJD_EC180 is 6 919 180 bp in length and consists of six rRNA operons, 111 tRNA, and 6849 predicted protein-coding sequences. BJD_EC180 belonged to ST2437 and harboured the carbapenemase-encoding gene blaOXA-144 with ISAba1 upstream, along with multiple antibiotic resistance genes conferring clinical resistance towards beta-lactams, aminoglycosides, amphenicols, sulphonamides, tetracyclines, trimethoprim, and rifampin. Carbapenem-resistant E. coli harbouring blaOXA-144 associated with insertion sequence pose a serious health threat as their mobilization into carbapenem non-susceptible strains that will contribute to the resistance burden and therefore, needs urgent monitoring.

Detection of Carbapenem-resistance in CRE by Comparative Assessment of RAPIDEC® CARBA NP and Xpert™Carba-R Assay.

Carbapenem-resistant Enterobacteriaceae (CRE) infections resist nearly most available antimicrobials, resulting in poor clinical outcomes. Saudi Arabia has a relatively high CRE prevalence. This study aims to evaluate the sensitivity of Rapidec Carba NP test and GeneXpert Carba-R assay compared with conventional manners for detection of carbapenemase-producing Enterobacteriaceae. This is a cross-sectional study including a total of 90 CRE isolates examined at two tertiary hospitals in KSA from October 2020 to December 2021. Gram-negative Enterobacteriaceae were identified by using Vitek 2 system and were furtherly tested for imipenem and meropenem susceptibility by E- test strips, followed by Rapidec Carba NP test and the Xpert™Carba-R assay. Carbapenem-resistant K. pneumoniae (78.9%) and carbapenem-resistant E. coli (14.4%) were the two most common isolates species. Colistin (98.9%) and tigecycline (88.9%) were the most effective antibiotics against CRE isolates, followed by amikacin (52.2%), gentamicin (33.3%), cotrimoxazole (15.6%), and ciprofloxacin (8.9%). blaOXA-48 was the predominant carbapenemase gene (44.4%), followed by blaNDM (32.2%). blaKPC gene was not detected. The Rapidec Carba NP and the Xpert™Carba-R demonstrated an overall sensitivity of 69.3% and 88%, respectively, in comparison to gold standard detection of meropenem and imipenem resistance by Vitek 2 system and E- test strips. RAPIDEC® CARBA NP may be a beneficial screening test for detecting CRE, but for confirmation of the results, Xpert Carba-R assay is more sensitive, significantly lowering the turnaround time compared to reference traditional methods. The information on carbapenemase genes may be used for epidemiologic purposes and outbreak management.

Comparative Evaluation of Three Phenotypic Tests-Carba NP, Modified Carba NP and Rapidec Carba NP Test for Rapid Detection of Carbapenem Resistance in Blood Culture Isolates of Escherichia coli in an ICU Setting.

To determine the antibiotic resistance pattern, the prevalence of extended-spectrum beta-lactamases (ESBLs) and carbapenem resistance in blood culture isolates of E. coli. Further, we evaluated and compared Carba NP, Modified Carba NP and a kit-based Rapidec Carba NP test to detect carbapenem resistance rapidly. Twenty-six carbapenem-resistant strains and four susceptible strains were selected. The three methods mentioned above were evaluated as per Clinical Laboratory Standards Institute (CLSI). These tests are based on biochemical detection of the hydrolysis of the beta-lactam ring of a carbapenem-imipenem, followed by the colour change of a pH indicator. Carba NP test was positive in 24 out of 26 isolates; the Modified Carba NP and Rapidec Carba NP tests were positive for all the isolates (26/26). All the carbapenemase non-producers (100%, 04/04) were negative. Modified Carba NP is a more effortless and inexpensive alternative to the Carba NP test, allowing the detection of carbapenemase activity directly from bacterial cultures of Enterobacteriaceae. The test could be used in low-income countries with large reservoirs for carbapenemase producers and can be implemented in any laboratory worldwide.

First report of Molecular Epidemiology of Carbapenem Resistant Enterobacteriaceae from a Tertiary Level Hospital in Rajasthan, Western India

Background: Carbapenem Resistant Enterobacteriaceae (CRE) are emerging at an alarming rate and pose a significant global threat. Objective: To conduct phenotypic and genotypic characterization of CRE strains from Rajasthan, Western India. Methodology: This was a prospective observational study conducted in Department of Microbiology, Dr S.N. Medical College, Jodhpur, Rajasthan from October to December 2018. All clinical samples received during the study period were processed and bacterial identification and antimicrobial susceptibility tests were performed according to standard microbiological guidelines. A total of 14 non duplicate carbapenem resistant clinical isolates of E coli and K pneumoniae were included in the study and subjected to Rapidec Carba NP test. Carbapenemase‑ encoding genes were amplified by multiplex polymerase chain reaction (PCR). PCR amplified products from three random isolates were subjected to Sanger sequencing. Results: Amikacin remained active against 36% isolates. All isolates were found to be susceptible to colistin and tigecycline. Carbapenemase production by Rapidec Carba NP test was noted in all (14/14) study isolates. All isolates were found to harbour ≥ 1 carbapenemase gene. The most common resistance gene observed was blaoxa (86%) followed by blaNDM (79%). None of the CRE isolates included in our study showed production of KPC enzymes. The sequences were analysed using BLAST analysis and were confirmed to be matching to OXA-48/181 and NDM-1. Conclusions: Growing carbapenem resistance is an important issue which needs urgent attention and blaOXA is an emerging mechanism of resistance among clinical CRE isolates in our setting Keywords: Carbapenem resistant Enterobacteriaceae, Phenotypic tests, Carbapenemase gene, Polymerase chain reaction

Detection of Carbapenem-resistant Enterobacteriaceae by Real-Time PCR and Assessment of Hospitalization Related Risk Factors Associated with their Fecal Carriage: A Case-control Study

Opportunistic behavior of commensal bacteria during severe infection, especially of the intestine is always considered as a predisposing threat for the severely ill patient admitted to hospitals. A descriptive-analytical case-control study was carried out to detect the prevalence and risk factor analysis of fecal carriage of Carbapenem-resistant Enterobacteriaceae. Patients having fecal carriage of Carbapenem-resistant Enterobacteriaceae were considered as cases and patients who were without Carbapenem-resistant Enterobacteriaceae were taken as the control in a proportion of 1:4. Carbapenem-resistant Enterobacteriaceae (CRE) was confirmed by both conventional as well as molecular methods. Methods such as Combined Disk Test, mCIMtest, and RAPIDEC CarbaNP Test were used for phenotypic identification of CRE, Whereas Real-Time (RT)-PCR was used for the detection of bla-gene encoded for CRE (blaNDM1, blaVIM, blaKPC, blaIMP, and blaOXA48). All patients belonging to medicine wards were included in the study. we screened 436 patients during the study and found 160 patients suitable for our study, out of which 32 (20%) were cases and 128 (80%) were controls. We found a total number of 25 genes out of 16 isolates, where NDM 1 was identified in maximum numbers followed by KPC &VIM. Standard statistical analyses such as chi-squire and odd ratios were conducted to determine the risk factor of different variables. Stepwise multiple logistic regressions were carried out, where we found, that transfer from other wards to medicine ward, use of nebulizer and intravenous catheter, and use of multiple antibiotics were still statistically significant. Implementation of Multi-modal colonization prevention and control is the need for the present situation throughout the world.

Detection of intestinal colonization by carbapenem-resistant Enterobacteriaceae (CRE) among patients admitted to a tertiary care hospital in Egypt

BackgroundThe irrational use of carbapenems in the last years lead to the emergence of carbapenem-resistant Enterobacteriaceae (CRE). This study aimed at determining the prevalence of CRE intestinal carriage among admitted patients in a tertiary care hospital in Egypt, to characterize carbapenemase-producing genes and to identify possible risk factors of CRE colonization. One hundred rectal swabs were collected from patients within 48 h of hospital admission. Culture was done on chromogenic media and then identification and antibiotic susceptibility testing were done using Vitek 2 compact system. Carbapenemase production was confirmed by Rapidec Carba NP test and by multiplex PCR for blaOXA-48-like, blaNDM-like, blaVIM-like, blaIMP-like and blaKPC-like.ResultsA total number of 36 CRE isolates were recovered from 28 patients. Thus, the prevalence of CRE colonization was 28%. Escherichia coli (83%), followed by Klebsiella pneumoniae (17%) were the main species. History of recent hospitalization and prior antibiotic intake were statistically significant risk factors predisposing to CRE colonization. Rapidec Carba NP gave positive results in 29/36 CRE isolates, whereas seven isolates gave negative results; six of them harbored blaOXA-48-like. Overall, the blaOXA-48-like was detected in 24/36 (66.7%), followed by blaNDM-like in 11/36 (30.6%) and lastly blaVIM-like in 1/36 (2.8%).ConclusionsOur findings confirm that CRE colonization is disseminating in our healthcare facility, a fact that should be considered as possible pathogens causing infections in high risk patients. Strict infection control measures should be applied to all CRE carriers at hospital admission and a proper antimicrobial stewardship program should be followed in clinical settings.

Report on carbapenemase-producing rare sequence types of Escherichia coli and Enterobacter hormaechei

Introduction and Aim: Carbapenem Resistant Enterobacteriaceae (CRE) have emerged at an alarming rate. Multi locus sequence typing (MLST) is an important parameter for identifying drug resistant organisms. The present study was carried out for elucidating the mechanisms of CRE and MLSTs associated with CRE. Materials and Methods: CRE (n=14) were obtained from various clinical samples and subjected to Rapidec Carba NP (CNP) test and multiplex polymerase chain reaction (M-PCR) and five isolates proceeded for whole genome sequencing (WGS). ?-lactamase (bla) genes were analysed using Resfinder and CARD tool. Bioinformatics tools: mlplasmids, plasmid finder, mobile element finder, and Center for Genomic Epidemiology (CGE) toolbox were used. Results: All isolates (n=14) were positive for CNP and bla genes using M-PCR. Isolates (J21, J22, J23, J27) were identified as Escherichia coli while (J34) was Enterobacter hormaechei. MLST showed E. coli isolates (J21& J22) as ST648; E. coli (J23) was ST940; E. coli (J27) was ST 2851, and E. hormaechei (J34) was closest to ST1325. Genes blaTEM, blaNDM & blaampC were found to be present in all isolates; blaCTX-M was present in all E. coli isolates but not in E. hormaechei. blaOXA was present in E. coli (J23) and in E. hormaechei (J34); while ESBL blaSFO-1 in E. hormaechei (J34). Conclusion: ESBLs (blaTEM & blaCTXM) and metallo beta-lactamase -MBL (blaNDM) cause carbapenem resistance in rare sequence types of E. coli while; ESBL (blaSFO-1) and MBL (blaNDM) cause carbapenem resistance in E. hormaechei.

Detection of carbapenamase production by Rapidec carba NP test among Gram negative isolates in a tertiary care hospital

Detection of carbapenamase production by Rapidec carba NP test among Gram negative isolates in a tertiary care hospital

Resistance to bacterial infection, complication occurring after cardiac surgery

To analyze the occurrence of resistant bacterial infection in patients undergoing cardiac surgery hospitalized in the surgical specialty hospital, in Erbil city, Iraq. A prospective study was done on a total of 138 patients operated and hospitalized in an intensive care unit and surgical wards. Bacterial isolates identification was done according to cultural characteristics, microscopic examination, some biochemical tests, analytic Profile Index 20E& API Staph, confirmed with VITEK® 2 compact system (BioMérieux). Antimicrobial susceptibility for disc diffusion tested to 17 antimicrobial agents. Resistance isolates were confirmed phenotypically for carbapenemase by Rapidec Carba NP Test (bioMe´rieux SA, Marcy-l'E´toile, France) for ESBLs producers by ESBL screening test VITEK 2 system. Molecularly blaIMP blaTEM, blaKPC, AmpC and blaCTX-M were detected by PCR. In 134 patients, 28.3% of patients got infected post-operatively. The most frequent source of isolation was from ICU patients (75%). Isolated bacteria included gram-positive 29 (54.7%) and gram-negative bacteria 24 (45.3%). Most frequently: Staphylococcus aureus (24.4%), each of pseudomonas aeroginosa, Klebsiella pneumonia (15.1%), Streptococcus spp. (11.3%), Escherichia coli (9.4%). Whereas included Coagulase Negative Staphylococci species (CoNS) (13.2%) and Enterococci species (5.7) Statistical analysis showed significantly higher sensitive isolates as compared with resistance isolates. Resistance to Carbapenems calss was 18.9% and Cephalosporins class 41.5% of isolates. The antimicrobial resistance pattern indicated that MDR bacterial isolates (81.1%) were widespread. Of the 34 phenotypically ESBL positive isolates, the ESBL genes (AmpC, blaCTX-M, and blaTEM) were amplified in 7(20.6), 6(17.6) and 6(17.6) isolates respectively. Out of 8 K. pneumonia (37.5%) harboring both blaAmpC and bla-CTX-M genes, while 6(75%) carries blaTEM. The blaCTX-M gene was found in only 1 (12.5%) out of 8 isolates of P. aeruginosa. While blaAmpC genotyping revealed that 1(7.7%) out of 13 Staph. aureus isolates were harboring it. Finally, 3(60%) out of 5 E. coli isolates harboring both AmpC and bla-CTX-M genes. Cardiac surgery patients wound show increasingly emerging strains of ESBL-producing gram-negative bacteria K. pneumonia, P. aeruginosa and E. coli especially patients prolonged in the intensive care unit.

Detection of Carbapenemase Production by Rapidec Carba NP Test among Gram Negative Isolates in a Tertiary Care Hospital

Detection of Carbapenemase Production by Rapidec Carba NP Test among Gram Negative Isolates in a Tertiary Care Hospital

Evaluation of the compatibility of phenotypic and molecular methods used to determine carbapenem resistance in enterobacterales isolates

Aim: Carbapenems are one of the most important options for clinicians with few treatment options in the clinic due to their low side effects, rapid diffusion into tissues and use in all age groups. Therefore, it is important to be able to detect carbapenemase-producing isolates at an early stage for appropriate patient management and for infection prevention and control procedures. Antibiotic resistance genes and enzymes of microorganisms can be determined by phenotypic and molecular methods in clinical microbiology laboratories. Phenotypic methods are cheap, easy and easy to repeat but determination of resistance gene regions by molecular methods is costly, requires labour-experienced personnel and is time consuming. Determining whether the isolates possess the carbapenemase enzyme by phenotypic tests will provide convenience both for the patient and early initiation of the treatment and directing the clinician to the treatment. In this study, we aimed to evaluate the compatibility of phenotypic methods (carbapenemase inactivation method and Rapidec Carba NP) and molecular methods (Polymerase Chain Reaction) used to determine carbapenem resistance in Enterobacterales isolates. Material and Methods: Carbapenem resistant 60 and sensitive 20 Enterobacterales isolates were included in the study. E-test agar gradient diffusion, CIM, Rapidec Carba NP methods and PCR were studied. The agreement between the methods was determined by using the kappa (κ) coefficient with the cohen kappa analysis method.Results: In carbapenem resistant isolates, meropenem MIK50 and MIK90 determined as 32µg/ml, 64µg/ml, imipenem MIK50 and MIK90 determined as 32µg/ml, 128µg/ml, respectively. OXA-48 was positive in 54 (90%) isolates and NDM-1 in 6 (10%) isolates. The susceptibility of the isolates with OXA-48 carbapenemase gene region was 94.4% by CIM test and 92.6% by Rapidec Carba NP test, respectively. When the Kappa coefficient was evaluated, a very good agreement was observed between both tests and OXA-48. However, in the isolates with NDM-1 gene region, no compliance with CIM test was observed but Rapidec Carba NP test showed very good agreement. Conclusion: Rapid carbapenemase testing, such as Rapidec Carba NP and CIM, can play an important role in preventing the development of health-related outbreaks caused by carbapenemase-producing isolates, enabling faster prevention and control of infection.

Molecular detection of carbapenemase-producing Pseudomonas aeruginosa isolated from intensive care units of surgical specialty hospital in Erbil city

Background: The emergence and spread of carbapenem-resistant Pseudomonas aeruginosa (CRPA) is a serious cause of nosocomial infections in critically ill patients. Objectives: The aim of this study was to determine the prevalence of CRPA and carriage of class B Metallo-β-lactamase resistant genes in intensive care units (ICUs) from patients with surgical-site infection or ventilator-associated pneumonia at a Surgical Specialty Hospital in Erbil city. Materials and Methods: During 6 months' study, a total of 80 clinical samples were collected from ICUs. The identification of P. aeruginosa in clinical specimens was confirmed by polymerase chain reaction (PCR) amplification of a molecular marker–oprL gene. Antimicrobial susceptibility was performed using Vitek-identification system. Screening of carbapenemase-producer isolates was confirmed using Rapidec Carba NP test. CRPA isolates were tested for the presence of metallo-β-lactamase (MBL)-encoding genes, including: blaVIM, blaIMP, and blaNDMby using PCR. Results: A total of 50 (62.5%) P. aeruginosa isolates were identified with antibiotic resistance profile (4% pan drug resistant [PDR], 20% extensively drug resistant [XDR] and 76% multidrug resistant). Twelve (24%) isolates were CRPA positive, in which the most prevalent MBL-encoding gene was blaVIM (58.3%), blaNDM (41.7%), and blaIMP (33.3%). Conclusions: Alarmingly, high prevalence of CRPA with predominance of MBL-encoding genes was detected. The XDR and PDR resistance phenotypes have become highly prevalent for this nosocomial pathogen in ICU patients that may cause a therapeutic impasse. The MBL-encoding genes were predominant among clinical isolates of P. aeruginosa. These findings emphasize on adherence to infection prevention and control standard precautions, early detection of CRPA isolates and development of to effectively reduce the burden of carbapenem resistance.

Detection of carbapenemases, AmpC and ESBL genes in Acinetobacter isolates from ICUs by DNA microarray

The accumulation of multiple inherent and acquired resistance mechanisms in Acinetobacter spp. results in emergence of “pandrug resistant” strains which is one of the major concerns in healthcare sectors worldwide. Surveillance of the carbapenemase/ extended-spectrum β-lactamases (ESBLs) genes in A. baumannii by phenotypic methods is challenging especially in developing countries, like Pakistan. In this context, a novel microarray (CT 103XL Check-MDR) assay was used for simultaneous detection of genes encoding clinically important carbapenemases and ESBLs. The results were compared with the phenotypic methods including MHT, Rapidec Carba NP, EDTA+DDST and Rosco (KPC/MBL). The results of the microarray were also confirmed by PCR. All of the strains of A. baumannii (47) were resistant to imipenem and meropenem. Microarray and PCR results showed presence of OXA-23 in all the isolates of A. baumannii while 36.17% also harbored PER. Rosco kit test showed 100% sensitivity to detect carbapenemases but exhibited low specificity to classify them. Rapidec Carba NP test has 100% sensitivity and specificity to detect the carbapenemases when compared with microarray. Sensitivity and specificity of microarray assay were 100% for bla-genes in comparison to PCR. This reveals that Check-MDR CT103 XL assay is an accurate method for the identification of ESBLs and carbapenemase genes in A. baumannii in comparison to the other methods.

Evaluation of the RAPIDEC CARBA NP, Conventional CarbaNP, and the Modified Carbapenem Inactivation Method (mCIM) Tests for Phenotypic Detection of Carbapenemase-Producing Organisms

Decreased susceptibility to carbapenems is being increasingly reported among Gram-negative organisms worldwide. It is of critical importance for patient management and infection control purposes to detect carbapenemase-producing organisms rapidly and reliably. In this study, the performance of the commercially available RAPIDEC CARBA NP test (bioMérieux, Durham, NC) was evaluated against the performance of the conventional CarbaNP and the modified Carbapenem Inactivation Method (mCIM) for the detection of carbapenemase activity in Enterobacteriaceae and Pseudomonas aeruginosa. A total of 73 Enterobacteriaceae and 32 Pseudomonas aeruginosa isolates were tested for carbapenemase activity using the RAPIDEC CARBA NP, conventional CarbaNP, and mCIM methods. Using available whole-genome sequence information, this collection included 72 isolates with and 33 isolates without carbapenemase genes. The isolates harboring a carbapenemase gene encoded 20 class A, 47 class B, and 5 class D–type β-lactamases. All methods were performed using bacteria from a single overnight blood agar plate. The conventional CarbaNP and mCIM were performed according to guidelines from the Clinical and Laboratory Standards Institute. The RAPIDEC CARBA NP was performed per the manufacturer’s instructions. The RAPIDEC CARBA NP detected 65 of 72 (90%) carbapenemase-producing isolates; the seven isolates yielding false-negative results included five Enterobacteriaceae with blaOXA-48-like and two with blaKPC-4 genes. The sensitivity and specificity were 90.2% and 100%, respectively, for the RAPIDEC test; 94.4% and 100% for conventional CarbaNP; and 100% and 81.8% for mCIM. The conventional CarbaNP detected all carbapenemase producers except four OXA-48-like–producing isolates. The mCIM, which accurately detected all carbapenemase producers, yielded false-positive results in six isolates of P aeruginosa. Overall, the RAPIDEC CARBA NP was easy to use and required less hands-on time than the conventional CarbaNP and mCIM methods. However, the RAPIDEC CARBA NP showed decreased sensitivity for detecting low-level activity carbapenemases such as OXA-48-like enzymes and KPC-4.

First case of New Delhi metallo-β-lactamase in Klebsiella pneumoniae from Ecuador: An update for South America

ObjectivesTo describe a clinical case of Klebsiella pneumoniae harboring a New Delhi metallo-β-lactamase (NDM) plasmid in Ecuador and to present a map of reports of NDM isolates in South America. MethodsThe modified Hodge test, carbapenem inactivation method, imipenem–EDTA disk method (synergy), and Rapidec Carba NP test were used to identify antibiotic resistance mechanisms. The presence of resistance genes was explored with a conjugation assay, and molecular confirmation of NDM was performed by PCR and DNA sequencing. Plasmid characterization was conducted by PCR-based replicon typing. A literature review was performed in Google Scholar and PubMed to identify reports from South America. ResultsAn HIV-infected patient, who had never traveled abroad, developed a bloodstream infection caused by K. pneumoniae ST147 harboring the NDM-1 resistance gene in a plasmid from the IncA/C group. Local circulation of NDM has also been described in other South American countries, in particular in Colombia and Brazil, although published scientific records were not found for other countries. ConclusionsThis report presents the first evidence of autochthonous circulation of the NDM-1 resistance gene harbored by an IncA/C plasmid isolated from a K. pneumoniae ST147 in Ecuador. Efforts should be implemented to monitor and characterize the spatial and temporal distribution of NDM in Ecuador and other countries of South America.

OXA-244-Producing Escherichia coli Isolates, a Challenge for Clinical Microbiology Laboratories.

OXA-244 is a single-point-mutant derivative of OXA-48 displaying reduced carbapenemase activity. Here, we report the microbiological features of seven OXA-244-producing Escherichia coli isolates. Only one isolate grew on ChromID Carba Smart medium (bioMérieux), but six of the seven isolates grew on ChromID extended-spectrum-β-lactamase (ESBL) medium (bioMérieux), as they coproduced an ESBL and/or a plasmid-encoded cephalosporinase. The production of a carbapenemase was detected in 57.1%, 71.4%, 71.4%, and 100% of the E. coli isolates using the Carba NP test, the Rapidec Carba NP test (bioMérieux), a matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) hydrolysis assay (Bruker), and the OXA-48 K-SeT assay (Coris BioConcept), respectively. Our results indicate that OXA-244-producing E. coli isolates are difficult to detect, which may lead to their silent spread.

Occurrence of blaNDM-1 and blaNDM-5 in a Tertiary Referral Hospital of North India.

Antimicrobial resistance poses a great challenge to clinicians leaving very limited treatment options available. A panel of carbapenem-resistant bacterial isolates was selected based on Rapidec Carba NP test from a total of 900 samples, which were collected from different specialities hospitals of Kanpur, India. Carba NP-positive isolates were screened for carbapenemases, extended-spectrum beta-lactamases (ESBLs), quinolone resistance, and 16s methyltransferase genes. Presence of diverse blaNDM (blaNDM-1 and blaNDM-5) were detected and horizontal transferability was determined by transformation and conjugation assay. Elimination of blaNDM-1 and blaNDM-5 harboring plasmid was done by treating the isolates with sodium dodecyl sulfate. The transcriptional response of blaNDM-1 and blaNDM-5 under the exposure of imipenem, meropenem, and ertapenem stress was determined by quantitative real-time polymerase chain reaction. blaNDM harboring isolates were found to be horizontally transferable through IncFrepB and K type plasmid and could be successfully eliminated after the single treatment with sodium dodecyl sulfate. A distinct pattern of transcriptional response was observed for blaNDM-1 and blaNDM-5 under the pressure of carbapenem antibiotics where an upregulated expression of both blaNDM-1 and blaNDM-5 was observed. Minimum inhibitory concentration (MIC) results revealed that blaNDM harboring strains showed a high MIC range against imipenem, meropenem, ertapenem, cefepime, and aztreonam. Thus, prudent action should be taken to control the spread of these multidrug-resistant determinants or at least slowing down their lateral transfer in the hospital settings.

Evaluation of Diagnostic Performance of RAPIDEC CARBA NP Test for Carbapenemase-ProducingEnterobacteriaceae

Background: Extended-spectrum β-lactamase (ESBL)producing Enterobacteriaceae are resistant to most β-lactam antibiotics except carbapenems. In recent years, infrequently isolated Enterobacteriaceae that produce carbapenemase pose a serious threat in the selection of appropriate therapeutic antibiotics. The rapid detection method of carbapenemase-producing Enterobacteriaceae (CPE) is necessary to prevent the spread of CPE into healthcare facilities. Methods: One hundred clinical Enterobacteriaceae isolates (Klebsiella pneumoniae 40, Escherichia coli 40, others 20) showing susceptibility to carbapenems and positivity in the CLSI ESBL phenotypic test from November 2015 to March 2016 and 59 stocked Enterobacteriaceae isolates harboring resistance genes producing carbapenemase (K. pneumoniae 56, Enterobacter cloacae 2, E. coli 1; types of CPE: KPC 36, GES 12, NDM 6, VIM 2, OXA 2, IMP 1) were subjected to the RAPIDEC CARBA NP test (bioMerieux, France) and CPE phenotypic test using the modified Hodge test (MHT) and carbapenemase inhibition test. Results: All of the 100 Enterobacteriaceae isolates with carbapenem susceptibility and ESBL positivity were negative on the RAPIDEC CARBA NP test and CPE phenotypic test. Of 59 stock CPE isolates, 53 and 42 showed positive results to the RAPIDEC CARBA NP test and MHT, respectively. The sensitivity and specificity of the RAPIDEC CARBA NP test for detecting CPE were 89.8% and 100%, respectively. Conclusion: The RAPIDEC CARBA NP test is simple and produces a result within 3 hr. In conclusion, the test is a useful screen for detecting CPE because it shows high sensitivity and specificity for CPE detection. (Ann Clin Microbiol 2016;19:59-64)

Comparative Study of a Novel Biochemical Assay, the Rapidec Carba NP Test, for Detecting Carbapenemase-Producing Enterobacteriaceae

The novel biochemical test, the Rapidec Carba NP (RCNP), was evaluated using carbapenemase- and non-carbapenemase-producing Enterobacteriaceae isolates. The RCNP test was compared with the Carba NP test (CNP) and the modified Hodge test. Compared to the CNP test, the RCNP test had identical sensitivity (96%) and lower specificity (93% versus 100%). The medium used to culture the isolates significantly affected test sensitivity and specificity. The RCNP test was quicker and easier to perform than the other tests.

Evaluation of the Rapidec Carba NP Test Kit for Detection of Carbapenemase-Producing Gram-Negative Bacteria.

Recently, bioMérieux, France, introduced the Rapidec Carba NP test kit for rapid detection of carbapenemase-producing Gram-negative bacteria. This kit was evaluated in this study, and we report sensitivity, specificity, and positive and negative predictive values of 92.6%, 96.2%, 95.83%, and 92.6%, respectively. The test was easy to perform and interpret and relatively inexpensive ($5/Rs 300 per test) and provides a practical solution for early detection of carbapenemase-producing, multidrug-resistant Gram-negative bacteria.