Inactivation ofZaire ebolavirusVariant Makona in Human Serum Samples Analyzed by Enzyme-Linked Immunosorbent Assay

ABSTRACTAnthrax, caused byBacillus anthracis, is primarily a zoonotic disease. Being a public health problem also in several developing countries, its early diagnosis is very important in human cases. In this study, we describe the use of an indirect enzyme-linked immunosorbent assay (ELISA) for detection of anti-lethal factor (anti-LF) IgG in human serum samples. A panel of 203 human serum samples consisting of 50 samples from patients with confirmed cutaneous anthrax, 93 samples from healthy controls from areas of India where anthrax is nonendemic, 44 samples from controls from an area of India where anthrax is endemic, and 16 patients with a disease confirmed not to be anthrax were evaluated with an anti-LF ELISA. The combined mean anti-LF ELISA titer for the three control groups was 0.136 ELISA unit (EU), with a 95% confidence interval (CI) of 0.120 to 0.151 EU. The observed sensitivity and specificity of the ELISA were 100% (95% CI, 92.89 to 100%) and 97.39% (95% CI, 93.44 to 99.28%), respectively, at a cutoff value of 0.375 EU, as decided by receiver operating characteristic (ROC) curve analysis. The likelihood ratio was found to be 49.98. The positive predictive value (PPV), negative predictive value (NPV), efficiency, and Youden's index (J) for reliability of the assay were 92.5%, 100%, 98.02%, and 0.97, respectively. The false-positive predictive rate and false-negative predictive rate of the assay were 2.61% and 0%. The assay could be a very useful tool for early diagnosis of cutaneous anthrax cases, as antibodies against LF appear much earlier than those against other anthrax toxins in human serum samples.

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Seroprevalence of Jamestown Canyon virus in the Japanese general population

BMC Infectious Diseases ◽

10.1186/s12879-020-05517-2 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Hirofumi Kato ◽

Masaaki Satoh ◽

Madoka Kawahara ◽

Satoshi Kitaura ◽

Tomoki Yoshikawa ◽

...

Keyword(s):

General Population ◽

Human Serum ◽

Health Agency ◽

Febrile Illness ◽

Central Nervous System Disease ◽

Enzyme Linked Immunosorbent Assay ◽

Antibody Assay ◽

Serum Samples ◽

Human Serum Samples ◽

Jamestown Canyon Virus

Abstract Background Jamestown Canyon virus (JCV) is a mosquito-borne orthobunyavirus that causes acute febrile illness, meningitis, and meningoencephalitis, mainly among adults. JCV is widely distributed in North America and the number of JCV cases in the U.S. has increased in recent years. Therefore, the central nervous system disease caused by JCV can be considered a potentially re-emerging viral disease. However, the seroprevalence of JCV is unknown in Japan. The purpose of this study is to evaluate the seroprevalence of JCV in the Japanese population. Methods We used an IgG enzyme-linked immunosorbent assay (IgG-ELISA) with JCV-infected cell-lysates and/or a neutralizing (NT) antibody assay. The cut-off value of IgG-ELISA was determined using IgG-ELISA to analyze serum specimens from 37 healthy Japanese donors. IgG-ELISA was validated by assessing its sensitivity and specificity, using 38 human serum samples previously tested for the presence or absence of antibodies against JCV and snowshoe hare virus (SSHV), in an in-house NT antibody assay conducted by the Public Health Agency of Canada. The seroepidemiological study was performed using IgG-ELISA and NT antibody assay to analyze 246 human serum samples from the serum bank of the National Institute of Infectious Diseases (NIID) in Japan. Results The cut-off value of IgG-ELISA was determined at 0.20, based on the mean (− 0.075) and standard deviation (0.092) values using Japanese donors’ sera. The sensitivity and the specificity of IgG-ELISA determined using 25 JCV-positive and 4 JCV-negative serum samples were 96 and 100%, respectively. Analysis of the 246 Japanese serum samples revealed that no specimen showed a higher value than the cut-off value of IgG-ELISA, and no sample tested positive by the NT antibody assay. Conclusions Our results showed that JCV is not circulating significantly in Japan. To the best of our knowledge, this is the first report to demonstrate the seroprevalence of JCV in the general population in Japan.

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Development of the ELISA Test System for Quantitative Determination of IgG to the Varizella zoster virus in Human Serum and Assessment of its Diagnostic Efficiency

Epidemiology and Vaccinal Prevention ◽

10.31631/2073-3046-2021-20-6-72-80 ◽

2022 ◽

Vol 20 (6) ◽

pp. 72-80

Author(s):

L. N. Lukhverchyk ◽

G. L. Alatortseva ◽

L. N. Nesterenko ◽

V. Y. Kabargina ◽

V. V. Dotsenko ◽

...

Keyword(s):

Herpes Zoster ◽

Blood Serum ◽

Human Serum ◽

Immunosorbent Assay ◽

Test System ◽

Enzyme Linked Immunosorbent Assay ◽

Diagnostic Efficiency ◽

Functional Characteristics ◽

Serum Samples ◽

Population Immunity

Relevance. The introduction of Varicella vaccine prophylaxis explains the need to develop a methodology for monitoring the vaccination effectiveness and the intensity of population immunity. This problem can be solved using quantitative immunoassay methods. Aim. Development of an enzyme-linked immunosorbent assay for the concentration of class G immunoglobulins (AB) to Varicella zoster virus (VZV) determining and assessing its functional characteristics and diagnostic efficiency. Materials and methods. Recombinant antigen GE VZV. WHO International Standard for Antibodies to VZV W1044. Blood serum samples from healthy people and patients with Chickenpox and Herpes zoster, blood serum samples containing IgG antibodies to herpes simplex viruses of the first and second types, cytomegalovirus, Epstein-Barr virus. Anti-VZV ELISA (IgG) reagent kit (Euroimmun, Germany). Indirect enzyme-linked immunosorbent assay. Immunization of animals with recombinant antigen GE, isolation, and purification of specific antibodies. Conjugation of monoclonal antibodies to human IgG with antibodies to antigen GE and with horseradish peroxidase. Results. An enzyme-linked immunosorbent assay in «an indirect» format has been developed to determine the specific antibodies to VZV concentration (IU/ml) in human serum/plasma. An artificial calibrator for determining the concentration of AB-VZV had been synthesized and standardized according to the International WHO-standard W1044. The main functional characteristics of the developed enzyme-linked immunosorbent assay are determined in accordance with GOST 51352-2013. The diagnostic kit was tested on blood serum samples from children with chickenpox (n = 43), adults with Herpes zoster (n = 158), healthy individuals (n = 781). The diagnostic sensitivity of the test system was 85%, the diagnostic specificity was 87% according to the ROC analysis. The absence of cross-reactivity of the test system was shown on samples with serological markers of other herpesvirus infections (n = 94). Comparative trials of the developed test system and its commercial analog, the Anti-VZV ELISA (IgG) reagent kit, did not reveal statistically significant differences between their functional characteristics. Conclusions. The developed test system for determining of the AB-VZV concentration in human serum/plasma in terms of its functional characteristics meets the GOST requirements, is characterized by high diagnostic efficiency, can be used to monitor the effectiveness of vaccine prophylaxis and strength of population immunity, as well as to assess the immune response in chickenpox and Herpes zoster.

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Analysis of UK Sera for Aflatoxin by Enzyme-linked Immunosorbent Assay

Human Toxicology ◽

10.1177/096032718800700410 ◽

1988 ◽

Vol 7 (4) ◽

pp. 353-356 ◽

Cited By ~ 18

Author(s):

A.P. Wilkinson ◽

D.W. Denning ◽

M.R.A. Morgan

Keyword(s):

Human Serum ◽

Direct Measurement ◽

Immunosorbent Assay ◽

Human Exposure ◽

Blood Donors ◽

Enzyme Linked Immunosorbent Assay ◽

Fungal Metabolites ◽

Serum Samples ◽

Imported Food ◽

The Uk

1 Aflatoxins are toxic, carcinogenic secondary fungal metabolites produced by certain moulds that commonly infest foods. Measurement of aflatoxins in human serum would give a direct measurement of exposure. 2 Twenty-seven serum samples from UK blood donors were found to contain aflatoxin levels not greater than 64 pmol/1 (20 pg/ml) by an enzyme-linked immunosorbent assay. 3 These findings may indicate that present UK guideline tolerances for aflatoxin in imported food are effective in limiting human exposure to toxic aflatoxins in the UK diet, though further work would be needed to confirm this. In particular, sub-populations suspected of being at higher risk may need special considerations.

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Antibody Responses to Escherichia coli O157 and Other Lipopolysaccharides in Healthy Children and Adults

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.10.5.797-801.2003 ◽

2003 ◽

Vol 10 (5) ◽

pp. 797-801 ◽

Cited By ~ 15

Author(s):

Armando Navarro ◽

Carlos Eslava ◽

Ulises Hernandez ◽

Jose Luis Navarro-Henze ◽

Magali Aviles ◽

...

Keyword(s):

Escherichia Coli ◽

Human Serum ◽

Western Blotting ◽

Rabbit Serum ◽

Enzyme Linked Immunosorbent Assay ◽

Healthy Children ◽

Serum Samples ◽

E Coli ◽

Human Serum Samples ◽

Bactericidal Activities

ABSTRACT In Mexico, diarrheal disease due to different serotypes of Escherichia coli is highly prevalent, with only sporadic isolation of O157 non-H7 strains. This could be due to exposure to the O157 or related E. coli lipopolysaccharide (LPS), such as O7 or O116, at an early age. By using enzyme-linked immunosorbent assay (ELISA) and Western blotting, the present study analyzed 605 serum samples from Mexican adults and infants without clinical symptoms of disease for the presence of antibodies to these three E. coli LPSs. The bactericidal activities of homologous and heterologous rabbit and human serum samples against O7, O116, and O157 E. coli LPSs were also determined. By using a cutoff point of 0.7, it was found by the ELISAs that 28 of 562 (5%) of the serum samples from adolescents and adults and 2 of 43 (5%) of the serum samples from infants less than 1 year of age reacted with the O157 LPS. By using cutoff points between 0.4 and 0.699, the proportion of serum samples from both age groups that reacted with the O157 LPS increased to 20%. Western blotting analysis of selected serum samples that showed an intermediate response against the O157 LPS by the ELISAs showed that 61 of 88 (69%) reacted with the same LPS. A similar result was observed for maternal milk samples. The bactericidal activities of rabbit serum samples against the O7, O116, and O157 LPSs showed that they were positive for both homologous and heterologous antigens. Similar results were observed with the human serum samples. O157 non-H7 strains were identified in only 10% of the E. coli strains isolated from 263 Mexican children with and without diarrhea over the past 15 years. This absence of O157:H7 strains in Mexico may be associated with the presence of antibodies against O157 or related E. coli LPSs.

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Performance of soluble Klotho assays in clinical samples of kidney disease

Clinical Kidney Journal ◽

10.1093/ckj/sfz085 ◽

2019 ◽

Vol 13 (2) ◽

pp. 235-244 ◽

Cited By ~ 8

Author(s):

Javier A Neyra ◽

Orson W Moe ◽

Johanne Pastor ◽

Fabiola Gianella ◽

Sachdev S Sidhu ◽

...

Keyword(s):

Kidney Disease ◽

Protease Inhibitor ◽

Human Serum ◽

Kidney Function ◽

Enzyme Linked Immunosorbent Assay ◽

Serum Samples ◽

Freeze Thaw ◽

Human Serum Samples ◽

Thaw Cycle ◽

Freeze Thaw Cycle

Abstract Background Soluble Klotho has multiple systemic salutary effects. In animals, both acute and chronic kidney disease models display systemic Klotho deficiency. As such, there is considerable interest in investigating soluble Klotho as a biomarker in patients with different types and severity of kidney diseases. Unfortunately, there remains uncertainty regarding the best method to measure soluble Klotho in human serum samples. Methods Using human serum samples obtained from several clinical cohorts with a wide range of kidney function, we measured soluble Klotho using a commercial enzyme-linked immunosorbent assay (ELISA) as well as with an immunoprecipitation–immunoblot (IP–IB) assay utilizing a synthetic antibody with high affinity and specificity for Klotho. Recovery of spiking with a known amount of exogenous Klotho was tested. A subset of samples was analyzed with and without the addition of a protease inhibitor cocktail at the time of collection or after the first freeze–thaw cycle to determine if these maneuvers influenced performance. Results The IP–IB assay was superior to the ELISA at recovery of exogenous Klotho (81–115% versus 60–81%) across the spectrum of kidney function. Klotho measurements by IP–IB were highly correlated with estimated glomerular filtration rate (eGFR) (R = 0.80, P < 0.001) in comparison with the commercial ELISA, which exhibited minimal correlation with eGFR (R = 0.18, P = 0.12). Use of a protease inhibitor cocktail neither improved nor impaired performance of the IP–IB assay; however, subsequent freeze–thaw cycle resulted in a significant reduction in Klotho recovery and dissipated the correlation between Klotho levels and eGFR. With the ELISA, the use of protease inhibitor cocktail resulted in an increase in intrasubject variability. Conclusions The IP–IB assay is preferable to the commercial ELISA to measure soluble Klotho concentrations in never-thawed serum samples of humans with varying severity of kidney disease. However, due to the labor-intensive nature of the IP–IB assay, further research is needed to secure an assay suitable for high-throughput work.

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Detection of tetanus toxoid antibodies in human sera in New Zealand by ELISA

Epidemiology and Infection ◽

10.1017/s0950268800061914 ◽

1987 ◽

Vol 98 (2) ◽

pp. 199-202 ◽

Cited By ~ 5

Author(s):

R. C. H. Lau

Keyword(s):

New Zealand ◽

Human Serum ◽

Immunosorbent Assay ◽

Tetanus Toxoid ◽

Indirect Elisa ◽

Enzyme Linked Immunosorbent Assay ◽

Age Group ◽

Igg Antibodies ◽

Serum Samples ◽

Human Sera

SUMMARYAn enzyme-linked immunosorbent assay (ELISA) incorporating the sensitive biotin-streptavidin system was developed to detect IgG antibodies to tetanus toxoid in human serum. Serum samples obtained from 557 normal persons aged 1–65 years from different areas in New Zealand were tested. The proportion of those immune ranged from 60–93% in males, and from 46–86% in females. In the 1–9 years age group 85% were immune. The indirect ELISA is suitable for serological surveys as it is simple to perform, economical and reproducible.

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