scholarly journals Competitive Binding Inhibition Enzyme-Linked Immunosorbent Assay That Uses the Secreted Aspartyl Proteinase of Candida albicans as an Antigenic Marker for Diagnosis of Disseminated Candidiasis

2003 ◽  
Vol 10 (5) ◽  
pp. 835-848 ◽  
Author(s):  
Christine J. Morrison ◽  
Steven F. Hurst ◽  
Errol Reiss
Keyword(s):  
Candida Albicans ◽  
Positive Predictive Value ◽  
Disease Progression ◽  
Immunosorbent Assay ◽  
Predictive Value ◽  
Significant Inhibition ◽  
Enzyme Linked Immunosorbent Assay ◽  
Binding Inhibition ◽  
Elisa Inhibition ◽  
Urine Specimens

ABSTRACT The secreted aspartyl proteinases (Saps) of Candida albicans have been implicated as virulence factors associated with adherence and tissue invasion. The potential use of proteinases as markers of invasive candidiasis led us to develop a competitive binding inhibition enzyme-linked immunosorbent assay (ELISA) to detect Sap in clinical specimens. Daily serum and urine specimens were collected from rabbits that had been immunosuppressed with cyclophosphamide and cortisone acetate and infected intravenously with 107 C. albicans blastoconidia. Disseminated infection was confirmed by organ culture and histopathology. Although ELISA inhibition was observed when serum specimens from these rabbits were used, more significant inhibition, which correlated with disease progression, occurred when urine specimens were used. Urine collected as early as 1 day after infection resulted in significant ELISA inhibition (mean inhibition ± standard error [SE] compared with preinfection control urine, 15.7% ± 2.7% [P < 0.01]), and inhibition increased on days 2 through 5 (29.4% ± 4.8% to 44.5% ± 3.5% [P < 0.001]). Urine specimens from immunosuppressed rabbits infected intravenously with Candida tropicalis, Candida parapsilosis, Candida krusei, Cryptococcus neoformans, Aspergillus fumigatus, or Staphylococcus aureus were negative in the assay despite culture-proven dissemination. Nonimmunosuppressed rabbits receiving oral tetracycline and gentamicin treatment were given 2 × 108 C. albicans blastoconidia orally or intraurethrally to establish colonization of the gastrointestinal tract or bladder, respectively, without systemic dissemination; urine specimens from these rabbits also gave negative ELISA results. Dissemination to the kidney and spleen occurred in one rabbit challenged by intragastric inoculation, and urine from this rabbit demonstrated significant inhibition in the ELISA (mean inhibition ± SE by day 3 after infection, 32.9% ± 2.7% [P < 0.001]). The overall test sensitivity was 83%, the specificity was 92%, the positive predictive value was 84%, the negative predictive value was 91%, and the efficiency was 89% (166 urine samples from 33 rabbits tested). The specificity, positive predictive value, and efficiency could be increased to 97, 95, and 92%, respectively, if at least two positive test results were required for a true positive designation. The ELISA was sensitive and specific for the detection of Sap in urine specimens from rabbits with disseminated C. albicans infection, discriminated between colonization and invasive disease, reflected disease progression and severity, and has the potential to be a noninvasive means to diagnose disseminated candidiasis.

scholarly journals Development of an Enzyme-Linked Immunosorbent Assay for Serodiagnosis of Ringworm Infection in Cattle

2013 ◽  
Vol 20 (8) ◽  
pp. 1150-1154 ◽  
Author(s):  
Elena Tatiana Băguţ ◽  
Ludivine Cambier ◽  
Marie-Pierre Heinen ◽  
Vasile Cozma ◽  
Michel Monod ◽  
...  
Keyword(s):  
Positive Predictive Value ◽  
Negative Predictive Value ◽  
Immunosorbent Assay ◽  
Predictive Value ◽  
Skin Lesions ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Predictive Values ◽  
Content Type ◽  
Ringworm Infection

ABSTRACTThe aim of this study was to develop an in-house enzyme-linked immunosorbent assay (ELISA) for the serological diagnosis of ringworm infection in cattle. We used available recombinant forms ofTrichophyton rubrumdipeptidyl peptidase V (TruDppV) andT. rubrumleucin aminopeptidase 2 (TruLap2), which are 98% identical toTrichophyton verrucosumorthologues. Field serum samples from 135 cattle with ringworm infection, as confirmed by direct microscopy, fluorescence microscopy, and PCR, and from 55 cattle without any apparent skin lesions or history of ringworm infection that served as negative controls were used. Sensitivities, specificities, and positive and negative predictive values were determined to evaluate the diagnostic value of our ELISA. Overall, the ELISAs based on recombinant TruDppV and TruLap2 discriminated well between infected animals and healthy controls. Highly significant differences (P< 0.0001, Mann-Whitney U test) were noted between optical density values obtained when sera from infected versus control cattle were tested. The ELISA developed for the detection of specific antibodies against DppV gave 89.6% sensitivity, 92.7% specificity, a 96.8% positive predictive value, and a 78.4% negative predictive value. The recombinant TruLap2-based ELISA displayed 88.1% sensitivity, 90.9% specificity, a 95.9% positive predictive value, and a 75.7% negative predictive value. To the best of our knowledge, this is the first ELISA based on recombinant antigens for assessing immune responses to ringworm infection in cattle; it is particularly suitable for epidemiological studies and also for the evaluation of vaccines and/or vaccination procedures.

scholarly journals Prevalence of feline coronavirus antibodies in cats in Bursa province, Turkey, by an enzyme-linked immunosorbent assay

2009 ◽  
Vol 11 (10) ◽  
pp. 881-884 ◽  
Author(s):  
Annamaria Pratelli ◽  
Kadir Yesilbag ◽  
Marcello Siniscalchi ◽  
Ebru Yalçm ◽  
Zeki Yilmaz
Keyword(s):  
Immunosorbent Assay ◽  
Predictive Value ◽  
Gold Standard ◽  
Population Based ◽  
Standard Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
High Association ◽  
Gold Standard Test ◽  
Feline Coronavirus

Feline sera from Bursa province (Turkey) were assayed for coronavirus antibody using an enzyme-linked immunosorbent assay (ELISA). The study was performed on 100 sera collected from cats belonging to catteries or community shelters and to households. The serum samples were initially tested with the virus neutralisation (VN) test and the results were then compared with the ELISA. The VN yielded 79 negative and 21 positive sera but the ELISA confirmed only 74 as negative. The ELISA-negative sera were also found to be free of feline coronoviruses-specific antibodies by Western blotting. Using the VN as the gold standard test, ELISA had a sensitivity of 100% and a specificity of 93.6%, with an overall agreement of 95%. The Kappa (κ) test indicated high association between the two tests (κ=0.86, 95% confidence interval (CI) 0.743–0.980). The positive predictive value (PPV) was 0.8, and the negative predictive value (NPV) was 0.93. The prevalence of FCoV II antibodies in the sampled population based on the gold standard was 62% (95% CI 0.44–0.77) among multi-cat environments, and 4% (95% CI 0.01–0.11) among single cat households.

scholarly journals Pneumococcal Type 22F Polysaccharide Absorption Improves the Specificity of a Pneumococcal-Polysaccharide Enzyme-Linked Immunosorbent Assay

2001 ◽  
Vol 8 (2) ◽  
pp. 266-272 ◽  
Author(s):  
Nelydia F. Concepcion ◽  
Carl E. Frasch
Keyword(s):  
Correlation Coefficient ◽  
Immunosorbent Assay ◽  
Pneumococcal Vaccination ◽  
Correlation Coefficients ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibody ◽  
Functional Activities ◽  
Antibody Titers ◽  
The Common ◽  
Elisa Inhibition

ABSTRACT The specificity of the immune response to the 23-valent pneumococcal-polysaccharide (PS) vaccine in healthy adults and to a pneumococcal conjugate vaccine in infants was examined by measuring immunoglobulin G (IgG) antibody titers by enzyme-linked immunosorbent assay (ELISA) and the opsonophagocytosis assay. ELISA measures total antipneumococcal IgG titers including the titers of functional and nonfunctional antibodies, while the opsonophagocytosis assay measures only functional-antibody titers. Twenty-four pairs of pre- and post-pneumococcal vaccination sera from adults were evaluated (ELISA) for levels of IgG antibodies against serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F. Twelve of the pairs were also examined (opsonophagocytosis assay) for their functional activities. The correlation coefficients between assay results for most types ranged from 0.75 to 0.90, but the correlation coefficient was only about 0.6 for serotypes 4 and 19F. The specificities of these antibodies were further examined by the use of competitive ELISA inhibition. A number of heterologous polysaccharides (types 11A, 12F, 15B, 22F, and 33A) were used as inhibitors. Most of the sera tested showed cross-reacting antibodies, in addition to those removed by pneumococcal C PS absorption. Our data suggest the presence of a common epitope that is found on most pneumococcal PS but that is not absorbed by purified C PS. Use of a heterologous pneumococcal PS (22F) to adsorb the antibodies to the common epitope increased the correlation between the IgG ELISA results and the opsonophagocytosis assay results. The correlation coefficient improve from 0.66 to 0.92 for type 4 and from 0.63 to 0.80 for type 19F. These common-epitope antibodies were largely absent in infants at 7 months of age, suggesting the carbohydrate nature of the epitope.

Immunodiagnostic potency of homologous antigens for natural Paramphistomum epiclitum infection in small ruminants in plate and paper enzyme linked immunosorbent assay

2017 ◽  
Author(s):  
Niranjan Kumar ◽  
Mehul M. Jadav ◽  
Bhupamani Das ◽  
Jaesh B. Solanki
Keyword(s):  
Molecular Weight ◽  
Immunosorbent Assay ◽  
Predictive Value ◽  
Small Ruminants ◽  
Enzyme Linked Immunosorbent Assay ◽  
Post Mortem ◽  
Secretory Antigen ◽  
Paramphistomum Epiclitum ◽  
Dot Elisa

The objective of the present work was to standardize and evaluate indirect plate and dot- enzyme linked immunosorbent assay (ELISA) using purified Paramphistomum epiclitum homologous antigens in the small ruminants. Electrophoretic separation of somatic antigen (PeSAg) in reducing condition on 15% polyacrylamide gel resolved into 16 proteins of the molecular weight ranging from 14 -100 kDa. Two step ethanolic precipitation of supernatant of in-vitro culture of the fluke yielded P. epiclitum excretory-secretory antigen (PeESAg) of molecular weight 28 kDa. The animals (Goats=123; Sheep=91) were broadly kept into post-mortem and faecal examined groups. At many occasion the PeSAg found to cross reacts with other helminths parasites thus minimizing the specificity of the tests and antigens. There was no any direct correlation between the parasites load and ELISA reactivity pattern. The noted prevalence rate after combining the results of post-mortem examination and PeESAg based ELISA (plate and paper/ dot) was 30.08% (37/123) in goats and 28.57% (26/91) in sheep. While using PeESAg, the calculated overall sensitivity% was 92.86 (goats)/ 100 (sheep) in both plate and dot-ELISA, specificity% was 91.58 (goats)/ 91.55 (sheep) in plate ELISA while 88.42 (goats)/ 92.96 (sheep) in dot-ELISA, positive predictive value% was 76.47 (goats)/ 76.92 (sheep) in plate ELISA while 70.27 (goats)/ 80 (sheep) in dot-ELISA and negative predictive value% was 97.75 (goats)/ 100 (sheep) in plate ELISA while 97.67 (goats)/ 100 (sheep) in dot-ELISA, these values were optimum for the field sera sample so the tests and PeESAg can be recommended for the detection P. epiclitum infection in the small ruminants.

Prospective sandwich enzyme-linked immunosorbent assay for serum galactomannan: early predictive value and clinical use in invasive aspergillosis

1996 ◽  
Vol 15 (3) ◽  
pp. 232-237 ◽  
Author(s):  
PIERRE ROHRLICH ◽  
JACQUELINE SARFATI ◽  
PATRICIA MARIANI ◽  
MICHEL DUVAL ◽  
AGNES CAROL ◽  
...  
Keyword(s):  
Invasive Aspergillosis ◽  
Immunosorbent Assay ◽  
Predictive Value ◽  
Enzyme Linked Immunosorbent Assay ◽  
Clinical Use

scholarly journals Pyuria in Institutionalized Elderly Subjects

1991 ◽  
Vol 2 (4) ◽  
pp. 142-146 ◽  
Author(s):  
K Rodgers ◽  
LE Nicolle ◽  
M McIntyre ◽  
GKM Harding ◽  
D Hoban ◽  
...  
Keyword(s):  
Positive Predictive Value ◽  
Predictive Value ◽  
Urine Culture ◽  
Leukocyte Count ◽  
Elderly Subjects ◽  
Institutionalized Elderly ◽  
Quantitative Level ◽  
Single Organism ◽  
Significant Bacteriuria ◽  
Urine Specimens

Two hundred and forty-three urine specimens from 76 elderly institutionalized residents were obtained for urine culture, quantitative leukocyte count and urinalysis. Significant bacteriuria was present in 153 specimens (63%), including 33 (22%) with more than one organism. Pyuria (greater than or equal to 10 leukocytes/mm3) was present in 214 specimens (88%), including 116 (97%) with single organism bacteriuria, 27 (82%) with multiple organism bacteriuria, and 71 (80%) without significant bacteriuria. The leukocyte esterase test had a positive predictive value of 99% for pyuria but a negative predictive value of only 30%. The quantitative level of pyuria was associated with the level of proteinuria and inversely with pH. A relatively constant level of pyuria tended to persist over months to years in a given individual if bacteriuria persisted. Pyuria is significantly associated with bacteriuria in the institutionalized elderly, but is also common in the nonbacteriuric. The clinical significance of pyuria requires further assessment.

scholarly journals Evaluation of a Novel Enzyme-Linked Immunosorbent Assay To Detect Immunoglobulin G Antibody to Enolase for Serodiagnosis of Invasive Candidiasis

2007 ◽  
Vol 14 (3) ◽  
pp. 318-319 ◽  
Author(s):  
Ana Laín ◽  
María D. Moragues ◽  
Juan Carlos García Ruiz ◽  
Joaquín Mendoza ◽  
Ana Camacho ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Immunosorbent Assay ◽  
Immunoglobulin G ◽  
Invasive Candidiasis ◽  
Enzyme Linked Immunosorbent Assay ◽  
Predictive Values ◽  
Sensitivity Specificity ◽  
Immunocompetent Patients

ABSTRACT The performance of a new test to detect antibodies to Candida albicans recombinant enolase was investigated in 47 immunocompromised and 51 immunocompetent patients. The sensitivity, specificity, and positive and negative predictive values of the test for the diagnosis of invasive candidiasis were 81.0, 83.9, 79.1, and 85.5%, respectively.

scholarly journals Diagnosis of invasive candidiasis by enzyme-linked immunosorbent assay using the N-terminal fragment of Candida albicans hyphal wall protein 1

2007 ◽  
Vol 7 (1) ◽  
pp. 35 ◽  
Author(s):  
Ana Laín ◽  
Natalia Elguezabal ◽  
Sonia Brena ◽  
Juan García-Ruiz ◽  
Amalia del Palacio ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Immunosorbent Assay ◽  
Invasive Candidiasis ◽  
Enzyme Linked Immunosorbent Assay ◽  
Terminal Fragment ◽  
Hyphal Wall

scholarly journals Comparison of an IgG-Specific Enzyme-Linked Immunosorbent Assay Cutoff of 0.4 Versus 0.8 and 1.0 Optical Density Units for Heparin-Induced Thrombocytopenia

2016 ◽  
Vol 23 (3) ◽  
pp. 282-286 ◽  
Author(s):  
Brianne M. Ritchie ◽  
Jean M. Connors ◽  
Katelyn W. Sylvester
Keyword(s):  
Optical Density ◽  
Immunosorbent Assay ◽  
Predictive Value ◽  
Retrospective Chart Review ◽  
Serotonin Release ◽  
Enzyme Linked Immunosorbent Assay ◽  
Platelet Factor ◽  
Heparin Induced Thrombocytopenia ◽  
Institutional Review ◽  
Sensitivity Specificity

Background: Previous studies have demonstrated optimized diagnostic accuracy in utilizing higher antiheparin–platelet factor 4 (PF4) enzyme-linked immunosorbent assay (ELISA) optical density (OD) thresholds for diagnosing heparin-induced thrombocytopenia (HIT). We describe the incidence of positive serotonin release assay (SRA) results, as well as performance characteristics, for antiheparin–PF4 ELISA thresholds ≥0.4, ≥0.8, and ≥1.0 OD units in the diagnosis of HIT at our institution. Methods: Following institutional review board approval, we conducted a single-center retrospective chart review on adult inpatients with a differential diagnosis of HIT evaluated by both antiheparin–PF4 ELISA and SRA from 2012 to 2014. The major endpoints were to assess incidence of positive SRA results, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy at antiheparin–PF4 ELISA values ≥0.4 OD units when compared to values ≥0.8 and ≥1.0 OD units. Clinical characteristics, including demographics, laboratory values, clinical and safety outcomes, length of stay, and mortality, were collected. Results: A total of 140 patients with 140 antiheparin–PF4 ELISA and SRA values were evaluated, of which 23 patients were SRA positive (16.4%) and 117 patients were SRA negative (83.6%). We identified a sensitivity of 91.3% versus 82.6% and 73.9%, specificity of 61.5% versus 87.2% and 91.5%, PPV of 31.8% versus 55.9% and 63.0%, NPV of 97.3% versus 96.2% and 94.7%, and accuracy of 66.4% versus 86.4% and 88.6% at antiheparin–PF4 ELISA thresholds ≥0.4, ≥0.8, and ≥1.0 OD units, respectively. Conclusion: Our study suggests an increased antiheparin–PF4 ELISA threshold of 0.8 or 1.0 OD units enhances specificity, PPV, and accuracy while maintaining NPV with decreased sensitivity.

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