Evaluation of NG-Test Carba 5 for Rapid Phenotypic Detection and Differentiation of Five Common Carbapenemase Families: Results of a Multicenter Clinical Evaluation

ABSTRACT NG-Test Carba 5 is a rapid in vitro multiplex immunoassay for the phenotypic detection and differentiation of five common carbapenemase families (KPC, OXA-48-like, VIM, IMP, and NDM) directly from bacterial colonies. The assay is simple to perform and has recently received U.S. Food and Drug Administration clearance. A method comparison study was performed at geographically diverse medical centers (n = 3) in the United States, where 309 Enterobacterales and Pseudomonas aeruginosa isolates were evaluated by NG-Test Carba 5 (NG Biotech, Guipry, France), the Xpert Carba-R assay (Cepheid, Inc., Sunnyvale, CA), the modified carbapenem inactivation method (mCIM), the EDTA-modified carbapenem inactivation method, and disk diffusion with carbapenems. Colonies from tryptic soy agar with 5% sheep blood (blood agar) and MacConkey agar were tested, and the results were compared to those obtained by a composite reference method. Additionally, a fourth medical center performed a medium comparison study by evaluating the performance characteristics of NG-Test Carba 5 from blood, MacConkey, and Mueller-Hinton agars with 110 isolates of Enterobacterales and P. aeruginosa. These results were compared to the expected genotypic and mCIM results. For the multicenter method comparison study, the overall positive percent agreement (PPA) and the overall negative percent agreement (NPA) of NG-Test Carba 5 with the composite reference method were 100% for both blood and MacConkey agars. The medium comparison study at the fourth site showed that the PPA ranged from 98.9% to 100% and that the NPA ranged from 95.2% to 100% for blood, MacConkey, and Mueller-Hinton agars. NG-Test Carba 5 accurately detected and differentiated five common carbapenemase families from Enterobacterales and P. aeruginosa colonies on commonly used agar media. The results of this test will support a streamlined laboratory work flow and will expedite therapeutic and infection control decisions.

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IFCC Reference System for Measurement of Hemoglobin A1c in Human Blood and the National Standardization Schemes in the United States, Japan, and Sweden: A Method-Comparison Study

Clinical Chemistry ◽

10.1373/clinchem.2003.024802 ◽

2004 ◽

Vol 50 (1) ◽

pp. 166-174 ◽

Cited By ~ 440

Author(s):

Wieland Hoelzel ◽

Cas Weykamp ◽

Jan-Olof Jeppsson ◽

Kor Miedema ◽

John R Barr ◽

...

Keyword(s):

Reference System ◽

Clinical Chemistry ◽

Method Comparison ◽

Reference Method ◽

The United States ◽

Reference Laboratory ◽

Regression Equations ◽

National Programs ◽

Method Comparison Study ◽

The Relationship

Abstract Background: The national programs for the harmonization of hemoglobin (Hb)A1c measurements in the US [National Glycohemoglobin Standardization Program (NGSP)], Japan [Japanese Diabetes Society (JDS)/Japanese Society of Clinical Chemistry (JSCC)], and Sweden are based on different designated comparison methods (DCMs). The future basis for international standardization will be the reference system developed by the IFCC Working Group on HbA1c Standardization. The aim of the present study was to determine the relationships between the IFCC Reference Method (RM) and the DCMs. Methods: Four method-comparison studies were performed in 2001–2003. In each study five to eight pooled blood samples were measured by 11 reference laboratories of the IFCC Network of Reference Laboratories, 9 Secondary Reference Laboratories of the NGSP, 3 reference laboratories of the JDS/JSCC program, and a Swedish reference laboratory. Regression equations were determined for the relationship between the IFCC RM and each of the DCMs. Results: Significant differences were observed between the HbA1c results of the IFCC RM and those of the DCMs. Significant differences were also demonstrated between the three DCMs. However, in all cases the relationship of the DCMs with the RM were linear. There were no statistically significant differences between the regression equations calculated for each of the four studies; therefore, the results could be combined. The relationship is described by the following regression equations: NGSP-HbA1c = 0.915(IFCC-HbA1c) + 2.15% (r2 = 0.998); JDS/JSCC-HbA1c = 0.927(IFCC-HbA1c) + 1.73% (r2 = 0.997); Swedish-HbA1c = 0.989(IFCC-HbA1c) + 0.88% (r2 = 0.996). Conclusion: There is a firm and reproducible link between the IFCC RM and DCM HbA1c values.

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Carbapenemase Detection among Carbapenem-Resistant Glucose-Nonfermenting Gram-Negative Bacilli

Journal of Clinical Microbiology ◽

10.1128/jcm.00775-17 ◽

2017 ◽

Vol 55 (9) ◽

pp. 2858-2864 ◽

Cited By ~ 20

Author(s):

Patricia J. Simner ◽

Belita N. A. Opene ◽

Krizia K. Chambers ◽

Matthew E. Naumann ◽

Karen C. Carroll ◽

...

Keyword(s):

Method Comparison ◽

Comparison Study ◽

Gram Negative ◽

Content Type ◽

Carbapenem Resistant ◽

Class D ◽

Class B ◽

Synergy Test ◽

Method Comparison Study ◽

Phenotypic Tests

ABSTRACT Accurate detection of carbapenemase-producing glucose-nonfermenting Gram-negative bacilli (CPNFs), including Pseudomonas aeruginosa and Acinetobacter baumannii , is necessary to prevent their dissemination within health care settings. We performed a method comparison study of 11 phenotypic carbapenemase detection assays to evaluate their accuracy for the detection of CPNFs. A total of 96 carbapenem-resistant glucose-nonfermenting isolates were included, of which 29% produced carbapenemases. All CPNFs were molecularly characterized to identify β-lactamase genes. A total of 86% of the carbapenemase-producing P. aeruginosa isolates produced class B carbapenemases. Several assays performed with a sensitivity of >90% for the detection of carbapenemase-producing P. aeruginosa , including all rapid chromogenic assays and the modified carbapenem inactivation method. Most included assays, with the exception of the Manual Blue Carba assay, the Modified Carba NP assay, the boronic acid synergy test, and the metallo-β-lactamase Etest, had specificities of >90% for detecting carbapenemase-producing P. aeruginosa . Class D carbapenemases were the most prevalent carbapenemases among the carbapenemase-producing A. baumannii strains, with 60% of the carbapenemase-producing A. baumannii isolates producing acquired OXA-type carbapenemases. Although several assays achieved >90% specificity in identifying carbapenemase-producing A. baumannii , no assays achieved a sensitivity of greater than 90%. Our findings suggest that the available phenotypic tests generally appear to have excellent sensitivity and specificity for detecting carbapenemase-producing P. aeruginosa isolates. However, further modifications to existing assays or novel assays may be necessary to accurately detect carbapenemase-producing A. baumannii .

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Method Comparison of In Vitro Wound Area Measurements

Current Directions in Biomedical Engineering ◽

10.1515/cdbme-2018-0075 ◽

2018 ◽

Vol 4 (1) ◽

pp. 309-312

Author(s):

Ahmed Gdoura ◽

Jacquelyn D. Parente ◽

Sabine Hensler ◽

Sabine Krüger-Ziolek ◽

Claudia Kuehlbach ◽

...

Keyword(s):

Image Analysis ◽

Method Comparison ◽

Contour Method ◽

Comparison Study ◽

Analysis Method ◽

Image Analysis Method ◽

Wound Area ◽

Method Comparison Study ◽

Tolerance Method

AbstractWound area is a primary outcome measure in wound healing studies. This method comparison study evaluates differences of wound area measurements of a newly developed image analysis method based on wound edge contour to an existing method based on contrast tolerance. Digital images of 64 wounds were taken immediately after wounding matured in vitro 3D organotypic tissues with a biopsy punch. Wound area measurements were calculated using each image analysis method and then normalized. The method comparison study evaluates the difference of each paired measurements for all 64 wound areas. Measurement differences are demonstrated and evaluated in normalized data boxplots, scatter plots with a line of equality, data histogram and Normal probability plots, and a Bland-Altman plot of paired measure difference against mean. The measured wound areas using the tolerance method have large variability in comparison to the contour method measures. The tolerance method measures often underestimate and overestimate what is assumed to be an approximately repeatable initial wound size. Skewness in comparison plots are due to the ‘fat tails’ introduced by the variability of measurements of the tolerance method. In contrast, the contour method results in larger wound area measurements on average at a statistically significant level of difference. The relatively less variable range of contour method measurements suggest this method has more potential to agree with the ‘true’ wound area. Future work to improve the method are proposed for application of image analysis methods to distinguish true wound area and measurement error in time for wound healing treatment-control experiments.

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A new method to assess the influence of textiles properties on human thermophysiology. Part I

International Journal of Clothing Science and Technology ◽

10.1108/ijcst-02-2014-0020 ◽

2015 ◽

Vol 27 (2) ◽

pp. 272-282 ◽

Cited By ~ 14

Author(s):

Simon Annaheim ◽

Li-chu Wang ◽

Agnieszka Psikuta ◽

Matthew Patrick Morrissey ◽

Martin Alois Camenzind ◽

...

Keyword(s):

Thermal Resistance ◽

Method Comparison ◽

Similar Data ◽

Comparison Study ◽

Content Type ◽

Industry Standard ◽

Three Phase ◽

High Thermal Resistance ◽

Dry Thermal Resistance ◽

Method Comparison Study

Purpose – The purpose of this paper is to determine the validity and inter-/intra-laboratory repeatability of the first part of a novel, three-phase experimental procedure using a sweating Torso device. Design/methodology/approach – Results from a method comparison study (comparison with the industry-standard sweating guarded hotplate method) and an inter-laboratory comparison study are presented. Findings – A high correlation was observed for thermal resistance in the method comparison study (r=0.97, p<0.01) as well as in the inter-laboratory comparison study (r=0.99, p<0.01). Research limitations/implications – The authors conclude that the first phase of the standardised procedure for the sweating Torso provides reliable data for the determination of the dry thermal resistance of single and multi-layer textiles, and is therefore suitable as standard method to be used by different laboratories with this type of device. Further work is required to validate the applicability of the method for textiles with high thermal resistance. Originality/value – This study provides the first “round-robin” data for measuring thermal resistance using a Torso device. In future publications the authors will provide similar data examining the repeatability of measurements that quantify combined heat and mass transfer.

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Evaluation of the Solus One Listeria Method for the Detection of Listeria Species on Environmental Surfaces

Journal of AOAC International ◽

10.5740/jaoacint.18-0199 ◽

2019 ◽

Vol 102 (2) ◽

pp. 570-579

Author(s):

Elizabeth Tonner ◽

Siobhan Kelly ◽

Simon Illingworth ◽

Nevin Perera ◽

Benjamin Bastin ◽

...

Keyword(s):

Stainless Steel ◽

Preparation Method ◽

Method Comparison ◽

Reference Method ◽

Test System ◽

Probability Of Detection ◽

Comparison Study ◽

Listeria Species ◽

Environmental Surfaces ◽

Method Comparison Study

Abstract Background: Solus One Listeria is designed to accurately detect Listeria species (Listeria grayi, L. innocua, L. ivanovii, L. marthii, L. monocytogenes, L. seeligeri, and L. welshimeri) from stainless steel and plastic environmental surface matrixes using an antibody-based technology test system paired with proprietary SOLO+ media and combined with manual or automated sample preparation method. Objective: Solus One Listeria was evaluated for inclusivity and exclusivity and a matrix comparison study fortwo environmental surfaces. Methods: Solus One Listeria was comparedwith the following reference method for the method comparison study: the U.S. Food and Drug Administration Bacteriological Analytical Manual Chapter 10 from stainless steel and plastic environmental surfaces. Both the manual and automatedpreparation methods were performed for stainless steel and plastic environmental surfaces. Results: For the inclusivity and exclusivityevaluation, Solus One Listeria correctly identified all 50 target organism isolates and correctly excluded all 30 nontarget strains that were analyzed. In the method comparison study, bothSolus One Listeria manual and automated preparation methods demonstrated no significant differences based on probability of detection statistical analysis between presumptive and confirmed results or between candidate and reference methodresults for two environmental surfaces after 22–30 h of enrichment time. Probability of detection analysis of Solus One Listeria method robustness, product consistency (lot-to-lot), and stability studies using the automated preparation method demonstrated no statistically significant differences. Conclusions: The data from the study support the product claims of Solus One Listeria for the accurate detection of Listeria species, using both the manual and automated methods (using theDynex DS2 instrument), on both environmental surfaces analyzed.

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Evaluation of the illumigene Mycoplasma Direct DNA Amplification Assay

Journal of Clinical Microbiology ◽

10.1128/jcm.01930-17 ◽

2018 ◽

Vol 56 (7) ◽

Cited By ~ 1

Author(s):

Neena Kanwar ◽

Morgan A. Pence ◽

Donna Mayne ◽

Jeffrey Michael ◽

Rangaraj Selvarangan

Keyword(s):

Direct Detection ◽

False Negative ◽

Reference Method ◽

Dna Amplification ◽

The United States ◽

Community Acquired Pneumonia ◽

Content Type ◽

Amplification Assay ◽

Respiratory Specimens

ABSTRACT Mycoplasma pneumoniae is a common cause of community-acquired pneumonia. The illumigene Mycoplasma Direct (iMD) DNA amplification assay is a qualitative in vitro test utilizing loop-mediated isothermal amplification (LAMP) technology for the direct detection of M. pneumoniae DNA in respiratory specimens. The iMD assay does not require the preextraction of nucleic acids from specimens, which is a prerequisite step for the previously approved illumigene Mycoplasma (iM) assay. The aim of this prospective multicenter study was to evaluate the performance characteristics of the newly developed iMD assay, compared with the iM assay. Subjects with symptoms of upper respiratory illnesses suggesting M. pneumoniae infection were enrolled at three sites in the United States. Respiratory specimens were obtained using dual throat swabs. One swab was tested with the iMD assay at each enrollment site. Reference testing with the iM assay was performed by the manufacturer. Among 456 specimens tested, the iM reference method detected M. pneumoniae in 25 specimens (5.5%), while the iMD assay identified 34 specimens (7.5%) as M. pneumoniae positive. There were 10 false-positive results and 1 false-negative result with the iMD assay. The overall positive and negative agreement rates were 96.0% (95% confidence interval [CI], 80.5 to 99.3%) and 97.7% (95% CI, 95.8 to 98.7%), respectively. The overall agreement rate was determined to be 97.6% (95% CI, 95.7 to 98.6%). We conclude that the iMD test results were comparable to the iM assay results. The removal of the DNA extraction step for the iMD assay simplifies testing, saves time, and reduces the costs of detecting M. pneumoniae from throat swabs, compared to the iM assay.

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