scholarly journals Preparation and Evaluation of Combined Detection of Norovirus GI and GII: An Innovative Fluorescent Particles Test Strip

2018 ◽  
Vol 2018 ◽  
pp. 1-5
Author(s):  
Lifang Zhang ◽  
Yanxia Peng ◽  
Na Jiang ◽  
Lei Shi ◽  
Jieping Lin ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Reference Method ◽  
Test Strip ◽  
Gastrointestinal Infection ◽  
Double Antibody ◽  
Test Card ◽  
Fluorescent Particles ◽  
Combined Detection ◽  
Preparation And Evaluation ◽  
Good Detection

This study was designed to prepare and evaluate the sensitivity and specificity of a Norovirus GI and GII fluorescent particles combined detection test strip method. Using selected chromatographic materials and antibodies specific to Norovirus GI and GII, the Norovirus GI and GII fluorescent particles combined detection test strip (tested method) was prepared as a conventional double antibody sandwich. The samples assayed included cultured rotavirus and 465 specimens from patients with symptoms of gastrointestinal infection. Norovirus was detected using the tested method and a reference method (CerTest Norovirus GI-GII test card). The results indicated that the sensitivity of the tested method was 4 (for GI detection) or 8 times (for GII detection) greater than the reference method. Neither of the two methods cross-reacted with rotavirus and so on. For specimens, 29 were found to be negative by the reference method and positive by the tested method, and 8 were found to be negative by the tested method and positive by the reference method. Furthermore, a retesting of these samples by qPCR showed that 28 of the 29 were positive, and 3 of the 8 were positive. In summary, the Norovirus GI and GII fluorescent particles combined detection test strip was successfully prepared and had good detection performance.

scholarly journals A Paper-Based IL-6 Test Strip Coupled With a Spectrum-Based Optical Reader for Differentiating Influenza Severity in Children

2021 ◽  
Vol 9 ◽  
Author(s):  
Sheng-Wen Lin ◽  
Ching-Fen Shen ◽  
Ching-Chuan Liu ◽  
Chao-Min Cheng
Keyword(s):  
Patient Outcome ◽  
Influenza Virus ◽  
Early Diagnosis ◽  
Sensitivity And Specificity ◽  
Interleukin 6 ◽  
Test Strip ◽  
Assay Method ◽  
Virus Infections ◽  
Serum Samples ◽  
Optical Reader

Influenza virus infection is a major worldwide public health problem. Influenza virus infections are associated with a high hospitalization rate in children between the ages of 5 and 14. The predominant reason for poor influenza prognosis is the lack of any effective means for early diagnosis. Early diagnosis of severe illness is critical to improving patient outcome, and could be especially useful in areas with limited medical resources. Accurate, inexpensive, and easy-to-use diagnostic tools could improve early diagnosis and patient outcome, and reduce overall healthcare costs. We developed an interleukin-6 paper-based test strip that used colloidal gold-conjugated antibodies to detect human interleukin-6 protein. These complexes were captured on a paper-based test strip patterned with perpendicular T lines that were pre-coated with anti-human interleukin-6 antibodies. Applied serum samples interacted with these antibodies and presented as colored bands that could be read using a spectrum-based optical reader. The full-spectrum of the reflected light interleukin-6 protein signal could be obtained from the spectral optics module, and the standard could be used to quantitatively analyze interleukin 6 level in serum. We retrospectively evaluated 10 children (23 serum samples) with severe influenza virus infections, 26 children (26 serum samples) with mild influenza virus infections, and 10 healthy children (10 serum samples). Our system, the combined use of a paper-based test strip and a spectrum-based optical reader, provided both qualitative and quantitative information. When used with the optical reader, the detection limit was improved from a qualitative, naked-eye level of 400 pg/ml to a quantitative, optical reader level of 76.85 pg/ml. After monitoring serum interleukin-6 level via our system, we found a high correlation between our system results and those obtainable using a conventional sandwich enzyme-linked immunosorbent assay method (Rho = 0.706, p < 0.001). The sensitivity and specificity for differentiating between severe and mild influenza using our combined method (test strip coupled with optical reader) were 78.3 and 50.0%, respectively. When interleukin-6 was combined with serum C-reaction protein, the sensitivity and specificity were 85.7 and 95.5%, and the receiver operating characteristic area-under-the-curve was quite high (AUC = 0.911, p < 0.001). The potential advantages of our system, i.e., a paper-based test strip coupled with a spectrum-based optical reader, are as follows: 1) simple user operation; 2) rapid turnaround times–within 20 min; 3) high detection performance; and, 4) low-cost fabrication.

Bacteriophage-Based Enrichment Coupled to Immunochromatographic Strip–Based Detection for the Determination of Salmonella in Meat and Poultry

2007 ◽  
Vol 70 (10) ◽  
pp. 2235-2242 ◽  
Author(s):  
MARK T. MULDOON ◽  
GEORGE TEANEY ◽  
JINGKUN LI ◽  
DALE V. ONISK ◽  
JAMES W. STAVE
Keyword(s):  
Reference Method ◽  
Test Strip ◽  
False Positives ◽  
Food Sources ◽  
Detection Methods ◽  
Immunochromatographic Strip ◽  
Conventional Culture ◽  
Sample Enrichment ◽  
Enrichment Step

Immunochemical-based methods for the detection of Salmonella in food can be complicated by the presence of closely related, immunocrossreactive non-Salmonella species in the sample that may cause false-positive results. To circumvent this problem, specific bacteriophages against immunocrossreactive, non-Salmonella bacteria were used in the sample enrichment step to suppress their growth and improve the performance of an immunochromatographic strip–based detection method for Salmonella. Cross-reactive bacteria were isolated from various food sources and were characterized with a panel of Salmonella somatic O antigen–specific monoclonal antibodies. These cross-reactive bacteria were primarily Citrobacter spp. and Escherichia coli with serology shared with Salmonella serogroups B, D, and F. These bacteria were used as hosts for the isolation of specific lytic bacteriophages. When formulated with the primary enrichment, the bacteriophage cocktail significantly reduced false positives with a broadly reactive immunochromatographic test strip. This was demonstrated in both artificially and naturally contaminated meat. False positives in naturally contaminated beef samples were reduced from 32 of 115 samples tested to zero. In raw meat and poultry with a relatively high bioburden (>105 CFU/g), the use of the bacteriophage-based enrichment procedure gave improved recovery of Salmonella compared with the conventional culture-based reference method. This was observed when coupled to either test strip–based or selective agar–based detection. The use of specific bacteriophages for the control of immunocrossreactive and competitive microflora during the food sample enrichment step provides a new approach for enhancing the performance of both immunological- and cultural-based detection methods.

scholarly journals Urea-Fibrinogen Slide Coagulase Test – A Simple Alternative Method for the Rapid Identification of Staphylococcus aureus

2017 ◽  
Vol 10 (1) ◽  
pp. 5-10
Author(s):  
Binita Koirala Sharma ◽  
S Gokhale ◽  
K Sharma
Keyword(s):  
Staphylococcus Aureus ◽  
Sensitivity And Specificity ◽  
Reference Method ◽  
Cost Effective ◽  
Rapid Identification ◽  
Accurate Identification ◽  
Predictive Values ◽  
Negative Results ◽  
Animal Pathogens ◽  
Sensitivity Specificity

Introduction: The accurate identification of Staphylococcus aureus clinical isolates requires a series of tests. Morphological features and slide coagulase test are two criteria on which S. aureus are identified. Resort to tube coagulase test is sought when results of slide coagulase test are equivocal or doubtful. Both coagulase tests detect the enzymes that convert fibrinogen into fibrin. Human, rabbit or sheep pooled plasma is used as substrate for both tests. Slide coagulase test is simpler and faster as compared to tube coagulase test. The plasma could be carrier of many human and animal pathogens like HIV, HBV, HCV etc. Storage of plasma for longer duration is fraught with chances of contamination. Improperly stored plasma can lead to false positive or negative results. Citrated plasma may be unsuitable for this test if contaminated with citrate utilizing bacteria. Considering the role of S. aureus as a common etiological agent in nosocomial and community infections, there is a need of implementing rapid, easy and cost-effective phenotypic test.Objectives: Considering the disadvantages and risks associated with fresh plasma, this study aims to launch for safer, more reliable substitute with longer shelf life that may provide reliable results for prompt identification of S. aureus by slide coagulase test.Methods: The present work evaluates slide coagulase test (SCT), and urea fibrinogen slide coagulase test (UF-SCT) for S. aureus detection considering Tube coagulase test (TCT) as the reference method. Sensitivity, specificity, positive predictive value and negative predictive values of SCT and UF-SCT were calculated using TCT as gold standard. Results: A total of 150 staphylococcal isolates from different clinical specimens ere selected for the evaluation of coagulase tests. All the specimens were subjected to SCT, UF-SCT and TCT. The UF-SCT showed better sensitivity (95.04%), specificity (100%), PPV (100%), and NPV (82.85%) with reference to TCT. UF-SCT showed similar sensitivity and specificity to SCT. None of the isolates were negative in UF-SCT and positive in SCT. Since UF-SCT does not incorporate plasma directly and at the same time has a very good sensitivity and specificity, it is recommended that UF-SCT could replace SCT for identification of S. aureus.Conclusion: The findings of present study shall encourage laboratories to use the urea-fibrinogen slide coagulase test routinely for the rapid identification of S aureus.Journal of Gandaki Medical College  Vol. 10, No. 1, 2017, Page: 5-10

Sensitivity and specificity of cystic fibrosis-related diabetes screening methods: which test should be the reference method?

2017 ◽  
Vol 30 (8) ◽  
Author(s):  
Valérie Boudreau ◽  
Catherine Lehoux Dubois ◽  
Katherine Desjardins ◽  
Marjolaine Mailhot ◽  
François Tremblay ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Sensitivity And Specificity ◽  
Reference Method ◽  
Screening Methods ◽  
Diabetes Screening

scholarly journals Multicenter Evaluation of Meridian Bioscience HSV 1&2 Molecular Assay for Detection of Herpes Simplex Virus 1 and 2 from Clinical Cutaneous and Mucocutaneous Specimens

2016 ◽  
Vol 54 (8) ◽  
pp. 2008-2013 ◽  
Author(s):  
Matthew L. Faron ◽  
Nathan A. Ledeboer ◽  
Anami Patel ◽  
Safedin H. Beqa ◽  
Belinda Yen-Lieberman ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Sensitivity And Specificity ◽  
False Negative ◽  
Reference Method ◽  
Lamp Assay ◽  
Laboratory Diagnosis ◽  
Gene Assay ◽  
Simplex Virus ◽  
Hsv 1

Herpes simplex virus (HSV) causes acute and relapsing symptoms characterized by ulcerative lesions. Laboratory diagnosis of HSV in cutaneous or mucocutaneous lesions has historically been performed with the use of viral cell culture systems; however, these tests are laborious and suffer decreased sensitivity for advanced-stage lesions. The recent availability of FDA-cleared moderately complex assays has resulted in the increased use of molecular diagnostics for the routine detection of HSV in superficial swab specimens. We performed a clinical evaluation of the recently FDA-clearedillumigene HSV 1&2 loop-mediated isothermal amplification (LAMP) assay (Meridian Bioscience, Cincinnati OH) for the detection and differentiation of HSV-1 and HSV-2 in cutaneous and mucocutaneous swab specimens. A total of 1,153 clinical swab specimens were collected and tested at 7 different clinical centers. Each specimen was tested for the presence of HSV-1 and HSV-2 using theillumigene assay, and results were compared to those of the enzyme-linked virus-inducible system (ELVIS) as the reference method. Overall, theillumigene assay demonstrated a sensitivity and specificity of 94.8% and 95.5%, respectively, for the detection of HSV-1. Detection of HSV-2 was similar, with a sensitivity of 98.9% and a specificity of 95.5%. Discrepant analysis was performed using an alternative molecular test (AmpliVue HSV1+2 assay; Quidel Molecular, San Diego, CA) on 91/99 specimens that were recorded as false positive (FP) or false negative (FN) compared to the reference method. In total, 57/78 (73%) FP and 9/13 (69%) FNillumigene results were supported by the AmpliVue result. Theillumigene HSV 1&2 assay demonstrated high sensitivity and specificity to detect and differentiate HSV in clinical specimens and identified 57 additional specimens that were positive for HSV compared to culture. The use of LAMP eliminates the need for the cycling of temperatures and provides results in less than 60 min, with approximately 2 min of hands-on time per specimen.

Screening urine before microscopy, by automated test-strip preselection: clinical evaluation of the improved Rapimat II/T (Behring).

1988 ◽  
Vol 34 (8) ◽  
pp. 1600-1602 ◽  
Author(s):  
D Kutter ◽  
C Braun ◽  
F Gallego ◽  
S Stirn-Thoma
Keyword(s):  
Sensitivity And Specificity ◽  
Clinical Evaluation ◽  
Test Strip ◽  
Quantitative Microscopy ◽  
Automated Test

Abstract In many laboratories, microscopy of urines is restricted to specimens selected on the basis of positive tests, mainly for protein, blood, nitrite, and leukocyte esterase. Here, we analyzed several hundred specimens by use of multiple dipsticks, read in an improved reflectometer. By comparing the results with quantitative microscopy, it could be shown that this system allows selection, with acceptable sensitivity and specificity, of those specimens that are likely to contain clinically important microscopic elements.

scholarly journals Assessment of a glycated hemoglobin point-of-care analyzer (A1CNow+) in comparison with an immunoturbidimetric method: a diagnostic accuracy study

2015 ◽  
Vol 133 (6) ◽  
pp. 460-464 ◽  
Author(s):  
Aurélie Affret ◽  
Luiz Henrique Maciel Griz ◽  
Eduarda Ângela Pessoa Cesse ◽  
Yuri da Silva Specht ◽  
Eduardo Maia Freese de Carvalho ◽  
...  
Keyword(s):  
Glycemic Control ◽  
Sensitivity And Specificity ◽  
Glycated Hemoglobin ◽  
Point Of Care ◽  
Venous Blood ◽  
Reference Method ◽  
University Hospital ◽  
Diabetic Patients ◽  
Good Glycemic Control ◽  
Accuracy Study

CONTEXT AND OBJECTIVE: To monitor glycemic control in diabetic patients, regular measurement of glycated hemoglobin (HbA1c) is recommended, but this can be difficult in remote places without access to laboratories. Portable point-of-care testing devices can prove a useful alternative. Our study aimed to assess the performance of one of them: A1CNow+, from Bayer. DESIGN AND SETTING: Cross-sectional accuracy study conducted at a university hospital in Brazil. METHODS: We made three successive measurements of capillary HbA1c using the A1CNow+ in 55 diabetic volunteers, while the same measurement was made on venous blood using the hospital reference method (Vitros 5,1 FS). We used the Bland-Altman graphical method to assess the A1CNow+ in relation to the Vitros 5,1 FS method. We also evaluated clinical usefulness by calculating the sensitivity and specificity of A1CNow+ for detecting patients with HbA1c lower than 7%, which is the usual limit for good glycemic control. RESULTS: The coefficient of variation between repeat testing for the A1CNow+ was 3.6%. The mean difference between A1CNow+ and Vitros 5,1 FS was +0.67% (95% confidence interval, CI: +0.52 to +0.81). The agreement limits of our Bland-Altman graph were -0.45 (95% CI: -0.71 to -0.19) and +1.82 (95% CI: +1.52 to +2.05). The sensitivity and specificity in relation to the 7% limit were respectively 100% and 67.7%. CONCLUSIONS: Although the A1CNow+ had good sensitivity, its accuracy was insufficient for use as a replacement for laboratory measurements of HbA1c, for glycemic control monitoring in diabetic patients.

scholarly journals Development of a New Combination Platform for the Early Screening of Gastric Cancer Using Serum Biomarkers

2021 ◽  
pp. 1-8
Author(s):  
Weiqun Rao ◽  
Limin Ding ◽  
Honglang Li ◽  
Guoxing Xie ◽  
Weiqun Rao ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Latex Particle ◽  
Sandwich Elisa ◽  
Serum Levels ◽  
New Combination ◽  
Healthy Individuals ◽  
Gastric Diseases ◽  
Early Screening ◽  
Detection Model ◽  
Combined Detection

Objective: The combination of pepsinogens (PG I/II) and gastrin-17 (G17) has been used to screen GC in many countries, without satisfactory levels of sensitivity or specificity. The aim of this study was to find a better marker and a new modality in screening early GC. Methods: We measured the serum levels of PG I/II, G17, and prealbumin (PA) from the serum of 481 healthy individuals, 407 benign gastric diseases (BGD), and 416 GC patients using a latex particle-enhanced turbidimetric immunoassay and Sandwich ELISA. Logistic regression analysis was used to obtain the sensitivity and specificity of the combined detection model. Results: When PA was combined with the other biomarkers, the sensitivity and specificity were significantly improved in the ROC curve. The combination of PA+G17+PGI+PGR was the best diagnostic combination for both early and late GC. The AUC, sensitivity, and specificity of the combination for discriminating between early GC and healthy individuals were 0.796, 72.1% and 74.2% respectively. For distinguishing patients with early GC from BGD, the AUC, sensitivity and specificity of the combination were 0.696, 66.7% and 65.4%, respectively. The combination of PA+G17+PGI+PGR improved both the sensitivity and the specificity of GC diagnosis compared with those of the traditional combination of G17+PGI+ PGII +PGR. Conclusion: PA is a valuable indicator for GC and interacts synergistically with PG and G17 in screening for early GC. The new combination platform PA+G17+PGI+PGR may be a potential way for the early screening of GC.

scholarly journals RapidChek SELECTTMSalmonella Enteritidis Test System for the Detection of Salmonella Enteritidis in Poultry House Drag Swabs, Shell Egg Pools, and Chicken Carcass Rinsates

2011 ◽  
Vol 94 (4) ◽  
pp. 1138-1153 ◽  
Author(s):  
Mark T Muldoon ◽  
Verapaz Gonzalez ◽  
Meredith I Sutzko ◽  
Ann-Christine Olsson Allen ◽  
Samantha Creamer ◽  
...  
Keyword(s):  
Salmonella Enteritidis ◽  
Reference Method ◽  
Test Strip ◽  
Test System ◽  
Test Method ◽  
Poultry House ◽  
Chicken Carcass ◽  
Two Samples ◽  
Secondary Enrichment ◽  
Inspection Service

Abstract The RapidChek SELECTTMSalmonella Enteritidis Test System was validated for the detection of Salmonella Enteritidis (SE) in poultry house drag swabs, shell egg pools, and chicken carcass rinsates. The method utilizes RapidChek SELECTTMSalmonella (AOAC PTM License No. 080601) proprietary primary and secondary enrichment media. Following enrichment, an immunochromatographic test strip is inserted into the tube containing the secondary enrichment broth, developed for 10 min, and interpreted. Salmonella Enteritidis-inoculated samples (1–5 CFU SE/analytical unit) were tested by the test method as well as the appropriate cultural reference method U.S. Food and Drug Administration-Bacteriological Analytical Manual (drag swabs and egg pools) or U.S. Department of Agriculture-Food Safety and Inspection Service (chicken carcass rinsates). A total of 80 samples were tested by both methods in the study. Fifty-two samples were positive by the RapidChek SELECT Salmonella Enteritidis method and 38 were found positive by the respective reference method. The sensitivity of the method was 100% and the specificity was 100%. The accuracy of the test method was 137%, indicating that the method was more sensitive than the reference method. The RapidChek SELECT Salmonella Enteritidis method was tested with 82 Salmonella Group D1 strains including 63 Salmonella Enteritidis strains as well as 32 non-Salmonella Group D1 strains representing 10 bacteria genera. The test method detected all 82 Group D1 strains (100% sensitivity). None of the non-Salmonella Group D1 or other genera of bacteria were detected, indicating a specificity of 100%. The method was shown to be highly robust and stable under control and accelerated stability conditions.

scholarly journals Comparative Evaluation of Colistin Susceptibility Testing Methods among Carbapenem-Nonsusceptible Klebsiella pneumoniae and Acinetobacter baumannii Clinical Isolates

2015 ◽  
Vol 59 (8) ◽  
pp. 4625-4630 ◽  
Author(s):  
Konstantina Dafopoulou ◽  
Olympia Zarkotou ◽  
Evangelia Dimitroulia ◽  
Christos Hadjichristodoulou ◽  
Vasiliki Gennimata ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Acinetobacter Baumannii ◽  
Susceptibility Testing ◽  
Reference Method ◽  
Test Strip ◽  
Clinical Isolates ◽  
Content Type ◽  
Gradient Diffusion ◽  
Agar Dilution ◽  
Resistant Strains

ABSTRACTWe compared six colistin susceptibility testing (ST) methods on 61 carbapenem-nonsusceptibleKlebsiella pneumoniae(n= 41) andAcinetobacter baumannii(n= 20) clinical isolates with provisionally elevated colistin MICs by routine ST. Colistin MICs were determined by broth microdilution (BMD), BMD with 0.002% polysorbate 80 (P80) (BMD-P80), agar dilution (AD), Etest, Vitek2, and MIC test strip (MTS). BMD was used as the reference method for comparison. The EUCAST-recommended susceptible and resistant breakpoints of ≤2 and >2 μg/ml, respectively, were applied for bothK. pneumoniaeandA. baumannii. The proportions of colistin-resistant strains were 95.1, 77, 96.7, 57.4, 65.6, and 98.4% by BMD, BMD-P80, AD, Etest, MTS, and Vitek2, respectively. The Etest and MTS methods produced excessive rates of very major errors (VMEs) (39.3 and 31.1%, respectively), while BMD-P80 produced 18% VMEs, AD produced 3.3% VMEs, and Vitek2 produced no VMEs. Major errors (MEs) were rather limited by all tested methods. These data show that gradient diffusion methods may lead to inappropriate colistin therapy. Clinical laboratories should consider the use of automated systems, such as Vitek2, or dilution methods for colistin ST.

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