Comparison between available serologic tests for detecting antibodies againstAnaplasma phagocytophilumandBorrelia burgdorferiin horses in Canada

To investigate the agreement between available serologic tests for the detection of antibodies against Anaplasma phagocytophilum and Borrelia burgdorferi, 50 serum samples from horses of unknown clinical status and at low risk for infection were tested. In addition to a point-of-care enzyme-linked immunosorbent assay (pocELISA), the evaluated tests included 2 indirect fluorescent antibody tests (IFATs) for antibodies against A. phagocytophilum and an IFAT, an ELISA confirmed with Western blot, and the Lyme multiplex assay for antibodies against B. burgdorferi. For each pair-wise comparison between serologic tests, the difference in the proportion of seropositive results as well as kappa and the prevalence-adjusted, bias-adjusted kappa were calculated. The proportion of seropositive results differed significantly in each pairwise comparison of tests for detection of antibodies against A. phagocytophilum, and between the pocELISA and IFAT as well as between the pocELISA and Lyme multiplex assay for detection of antibodies against B. burgdorferi. Agreement based on kappa varied from poor to fair while agreement was improved when evaluating prevalence-adjusted, bias-adjusted kappa. Lack of agreement may be explained by differences in methodology between the evaluated tests, cross-reactivity or false-positive and false-negative tests. In addition to the limitations of serologic test interpretation in the absence of clinical disease, this data suggest that screening of horses for exposure to tick-borne diseases in nonendemic areas may not be warranted.

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Novel Indirect Fluorescent Antibody Test for Lyme Disease

Journal of Veterinary Diagnostic Investigation ◽

10.1177/104063879600800209 ◽

1996 ◽

Vol 8 (2) ◽

pp. 196-201 ◽

Cited By ~ 1

Author(s):

Margaret A. Chambers ◽

Larry J. Swango ◽

James C. Wright

Keyword(s):

Human Error ◽

Fluorescent Antibody ◽

Antibody Test ◽

Cross Reactivity ◽

Enzyme Linked Immunosorbent Assay ◽

Indirect Fluorescent Antibody ◽

Serum Samples ◽

Specific Pathogen ◽

Membrane Bound ◽

Animal Use

An indirect fluorescent antibody (IFA) test was developed using a novel format of Borrelia burgdorferi organisms adhered to a monolayer of cultured endothelial cells derived from an equine tumor. Sensitivity and specificity of the new IFA test for detecting anti- B. burgdorferi antibodies were evaluated using sera from dogs inoculated with live B. burgdorferi or vaccinated with B. burgdorferi bacterin or leptobacterins and from unvaccinated specific-pathogen-free (SPF) dogs. To compare the new IFA test with existing tests, serum samples were submitted to independent laboratories to be tested by enzyme-linked immunosorbent assay (ELISA) and a traditional IFA test. Samples were also tested with 2 commercially available membrane-bound ELISA kits. Both Borrelia-inoculated dogs and dogs vaccinated with B. burgdorferi bacterin developed levels of antibody detectable by the new IFA test. Dogs vaccinated with a combination canine vaccine or leptobacterin for food animal use developed detectable levels of antibody against Leptospira but remained seronegative for Borrelia by the new IFA test, as did the unvaccinated SPF dogs. The new IFA test was sensitive, detecting antibodies against B. burgdorferi as early as 7 days postinoculation. It was also specific, showing no cross-reactivity with anti- Leptospira antibodies induced by vaccination with leptobacterins. The new IFA test compared favorably with both the standardized traditional IFA test and ELISA. Results from both membrane-bound ELISA kits were not consistent when compared with each other or with the new IFA test. The new IFA test had low nonspecific fluorescence, which made it easier to evaluate and reduced the human error and variability of test results.

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Combined Use of Indirect ELISA and Western Blotting with Recombinant Hepatocellular Carcinoma-Associated Antigen 59 Is a Potential Immunodiagnostic Tool for the Detection of Prepatent Haemonchus contortus Infection in Goat

Animals ◽

10.3390/ani9080548 ◽

2019 ◽

Vol 9 (8) ◽

pp. 548 ◽

Cited By ~ 7

Author(s):

Muhammad Ali-ul-Husnain Naqvi ◽

Sana Zahra Naqvi ◽

Muhammad Ali Memon ◽

Kalibixiati Aimulajiang ◽

Muhammad Haseeb ◽

...

Keyword(s):

Western Blot ◽

Western Blotting ◽

Haemonchus Contortus ◽

Indirect Elisa ◽

Fasciola Hepatica ◽

False Negative ◽

Cross Reactivity ◽

Enzyme Linked Immunosorbent Assay ◽

Serum Samples ◽

Combined Use

Haemonchus contortus is recognized as one of the important health problems in small ruminants, leading to reduced production and economic loss for farmers worldwide. Prepatent diagnosis of H. contortus infection is crucial to improve control strategies as this helminth may remove up to one-fifth of total erythrocytes and may cause anemia, edema, diarrhea, and ultimately death in young animals. In this study, one of the excretory and secretory products, rHc-HCA59, was purified and used as antigen to detect specific antibodies in H. contortus infected goats during prepatent stage of infection using indirect enzyme linked immunosorbent assay (ELISA) as screening test. All goats (n = 38) were housed indoor, experimentally infected with 8000 infective larvae (L3) of H. contortus, and serum samples were collected prior to infection and at 14th day of infection. Immunoblotting was performed to confirm the results of indirect ELISA, evaluate the cross reactivity against rHc-HCA59 in sera of most common co-infecting parasites and rectify the false negative samples. Furthermore, three different batches of rHc-HCA59 were produced to evaluate the repeatability of ELISA. No eggs were detected in feces of all goats collected at 7th and 14th day of infection but, H. contortus eggs were detected at 21 days post infection in the feces. Indirect ELISA performed in this study showed 87% sensitivity and 100% specificity. The western blot analysis confirmed immunoreactivity in serum samples which scored positive in indirect ELISA and recognized the samples as negative which had OD450 lower than negative cut-off value in indirect ELISA. Furthermore, all false negative sera (n = 5) that had OD450 value between positive and negative cut-off value in rHc-HCA59 based ELISA were clearly positive in western blot. Moreover, no cross-reactivity was detected in ELISA and western blotting against rHc-HCA59 in positive sera of Toxoplasma gondii, Fasciola hepatica, and Trichinella spiralis. The results of this study concluded that combined use of indirect ELISA and western blotting with rHc-HCA59 is a potential immunodiagnostic tool for the detection of H. contortus infection during prepatent period in goats.

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Laboratory Diagnosis of African Horse Sickness: Comparison of Serological Techniques and Evaluation of Storage Methods of Samples for Virus Isolation

Journal of Veterinary Diagnostic Investigation ◽

10.1177/104063879000200108 ◽

1990 ◽

Vol 2 (1) ◽

pp. 44-50 ◽

Cited By ~ 34

Author(s):

Carol House ◽

Peter E. Mikiciuk ◽

Mary Lou Beminger

Keyword(s):

Virus Isolation ◽

Fluorescent Antibody ◽

False Negative ◽

Laboratory Diagnosis ◽

Enzyme Linked Immunosorbent Assay ◽

African Horse Sickness ◽

Serum Samples ◽

Negative Results ◽

Field Samples ◽

Storage Methods

Five serological methods of diagnosing African horse sickness were evaluated, using a battery of serum samples from experimental horses vaccinated and challenged with each serotype of African horse sickness virus (AHSV1 through AHSV9): agar gel immunodiffusion (AGID), indirect fluorescent antibody (IFA), complement fixation (CF), virus neutralization (VN), and enzyme-linked immunosorbent assay (ELISA). The 5 tests were also compared using a panel of field samples, convalescent equine sera with antibodies to domestic equine viral diseases, and sera from horses awaiting export. The ELISA described in this paper was group specific. It did not require calibration with a standard positive serum but did yield elevated values with negative sera that were repeatedly frozen and thawed or heat inactivated. The IFA test was sensitive but could not be used on some field sera as the control cells exhibited fluorescence, possibly due to the animal being recently vaccinated with cell culture material. Sixty-two experimental sera were compared by VN, CF, AGID, and ELISA. Forty sera, 10 positive and 30 negative, were correctly classified by the 5 serologic assays. The 22 remaining sera gave mixed reactions. The AGID had no false positive results but had false negative results for up to 20% of the samples, depending upon the comparison. The VN, CF, and ELISA were similar in their variability. The length of time that virus could be recovered from a viremic blood sample was compared in an evaluation of storage methods for virus isolation samples. Washed erythrocytes were held at 4 C, washed erythrocytes plus stabilizer were held at −70 C, and blood that was drawn into a preservative (oxalate/phenol/glycerol) was held at 4 C. Virus was isolated for 12 months from a sample stored as washed erythrocytes at 4 C but for only 6 months from the same blood stored by the other 2 methods.

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Simultaneous Detection of Antibodies to Mouse Hepatitis Virus Recombinant Structural Proteins by a Microsphere-Based Multiplex Fluorescence Immunoassay

Clinical and Vaccine Immunology ◽

10.1128/cvi.00467-10 ◽

2011 ◽

Vol 18 (5) ◽

pp. 758-766 ◽

Cited By ~ 4

Author(s):

Satoshi Kunita ◽

Kanako Kato ◽

Miyuki Ishida ◽

Kozue Hagiwara ◽

Shuko Kameda ◽

...

Keyword(s):

False Positive ◽

Hepatitis Virus ◽

Fluorescent Antibody ◽

Laboratory Mouse ◽

False Negative ◽

Mouse Hepatitis Virus ◽

Simultaneous Detection ◽

False Negative Rate ◽

Enzyme Linked Immunosorbent Assay ◽

Serum Samples

ABSTRACTWe describe a new microsphere-based multiplex fluorescent immunoassay (MFI) using recombinant mouse hepatitis virus (MHV) proteins to detect antibodies to coronaviruses in mouse and rat sera. All the recombinant proteins, including nucleocapsid (N) and 3 subunits of spike protein, S1, S2, and Smid, showed positive reactivity in MFI with mouse antisera to 4 MHV strains (MHV-S, -A59, -JHM, and -Nu67) and rat antiserum to a strain of sialodacryoadenitis virus (SDAV-681). The MFI was evaluated for its diagnostic power, with panels of mouse sera classified as positive or negative for anti-MHV antibodies by enzyme-linked immunosorbent assay (ELISA) using MHV virion antigen and indirect fluorescent antibody assay. The reactivities of 236 naturally infected mouse sera were examined; 227 samples were positive by MFI using S2 antigen (96% sensitivity), and 208 samples were positive using N antigen (88% sensitivity). Based on the assessment by MFI using the S2 and N antigens, only 3 serum samples showed double-negative results, indicating a false-negative rate of 1.3%. In 126 uninfected mouse sera, including 34 ELISA false-positive sera, only 7 samples showed false-positive results by MFI using either the S2 or N antigen (94% specificity). Similarly, the S2 and N antigen-based MFI was 98% sensitive and 100% specific in detecting anticoronavirus antibodies in rat sera. Thus, this MFI-based serologic assay using the S2 and N antigens promises to be a reliable diagnostic method, representing a highly sensitive and specific alternative to traditional ELISA for detection of coronavirus infections in laboratory mouse and rat colonies.

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A Label and Probe-Free Zika Virus Immunosensor Prussian Blue@carbon Nanotube-Based for Amperometric Detection of the NS2B Protein

Biosensors ◽

10.3390/bios11050157 ◽

2021 ◽

Vol 11 (5) ◽

pp. 157

Author(s):

Bárbara V. M. Silva ◽

Marli T. Cordeiro ◽

Marco A. B. Rodrigues ◽

Ernesto T. A. Marques ◽

Rosa F. Dutra

Keyword(s):

Carbon Nanotube ◽

Prussian Blue ◽

Zika Virus ◽

Point Of Care ◽

Amperometric Detection ◽

Cross Reactivity ◽

Structural Protein ◽

Serum Samples ◽

Polypyrrole Composite ◽

Congenital Disabilities

Zika virus (ZIKV) is a mosquito-borne infection, predominant in tropical and subtropical regions causing international concern due to the ZIKV disease having been associated with congenital disabilities, especially microcephaly and other congenital abnormalities in the fetus and newborns. Development of strategies that minimize the devastating impact by monitoring and preventing ZIKV transmission through sexual intercourse, especially in pregnant women, since no vaccine is yet available for the prevention or treatment, is critically important. ZIKV infection is generally asymptomatic and cross-reactivity with dengue virus (DENV) is a global concern. An innovative screen-printed electrode (SPE) was developed for amperometric detection of the non-structural protein (NS2B) of ZIKV by exploring the intrinsic redox catalytic activity of Prussian blue (PB), incorporated into a carbon nanotube–polypyrrole composite. Thus, this immunosensor has the advantage of electrochemical detection without adding any redox-probe solution (probe-less detection), allowing a point-of-care diagnosis. It was responsive to serum samples of only ZIKV positive patients and non-responsive to negative ZIKV patients, even if the sample was DENV positive, indicating a possible differential diagnosis between them by NS2B. All samples used here were confirmed by CDC protocols, and immunosensor responses were also checked in the supernatant of C6/36 and in Vero cell cultures infected with ZIKV.

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Dogs as Sentinels for Flavivirus Exposure in Urban, Peri-Urban and Rural Hanoi, Vietnam

Viruses ◽

10.3390/v13030507 ◽

2021 ◽

Vol 13 (3) ◽

pp. 507

Author(s):

Long Pham-Thanh ◽

Thang Nguyen-Tien ◽

Ulf Magnusson ◽

Vuong Bui-Nghia ◽

Anh Bui-Ngoc ◽

...

Keyword(s):

Mosquito Control ◽

Risk Mitigation ◽

Significant Risk ◽

Cross Sectional Study ◽

Cross Reactivity ◽

Enzyme Linked Immunosorbent Assay ◽

Serum Samples ◽

Cross Sectional ◽

Major Health ◽

Household Level

Diseases caused by flaviviruses, including dengue fever and Japanese encephalitis, are major health problems in Vietnam. This cross-sectional study explored the feasibility of domestic dogs as sentinels to better understand risks of mosquito-borne diseases in Hanoi city. A total of 475 dogs serum samples from 221 households in six districts of Hanoi were analyzed by a competitive enzyme-linked immunosorbent assay (cELISA) for antibodies to the pr-E protein of West Nile virus and other flaviviruses due to cross-reactivity. The overall flavivirus seroprevalence in the dog population was 70.7% (95% CI = 66.4–74.8%). At the animal level, significant associations between seropositive dogs and district location, age, breed and keeping practice were determined. At the household level, the major risk factors were rural and peri-urban locations, presence of pigs, coil burning and households without mosquito-borne disease experience (p < 0.05). Mosquito control by using larvicides or electric traps could lower seropositivity, but other measures did not contribute to significant risk mitigation of flavivirus exposure in dogs. These results will support better control of mosquito-borne diseases in Hanoi, and they indicate that dogs can be used as sentinels for flavivirus exposure.

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Fluorescent antibody techniques have allowed for the direct identification and enumeration of individual bacteria in environmental samples without requiring prior growth in culture media (Bahlool and Schmidt 1980, Cloete and Steyn 1988, Macario et al. 1989). The technique involves the use of specific antibodies raised against surface markers of defined pure cultures that are either labelled directly with fluorescent dye molecules or via a fluorescent secondary antibody. This approach has yielded important insights into the spatial distribution of microorganisms, but it suffers from a number of disadvantages. For example, expression of the antigen may be influenced by environmental factors; false-positive and false-negative results may be obtained due to cross-reactivity or lack of reaction; non-specific binding of antibodies may result in high levels of background fluorescence; and production of specific antibodies requires a pure culture of the organism of interest (Cloete and de Bruyn Various recombinant DNA techniques have subsequently been developed that are independent of cultivation methods (Fig. 1). These techniques provide ways of detecting and quantifying specific phylogenetic groups of microbes on 16S rDNA sequences, and relevant structural genes provide ways of monitoring microbial populations of environmental and industrial systems. In addition to these tools, a number of emerging technologies such as the use of biomarker genes are being increasingly used to monitor with great precision and accuracy the behaviour of microbes in the environment.

Recent Advances in Marine Biotechnology, Vol. 8 ◽

10.1201/9781482279986-12 ◽

2003 ◽

pp. 218-219

Keyword(s):

Recombinant Dna ◽

Culture Media ◽

Specific Binding ◽

Fluorescent Antibody ◽

False Negative ◽

Cross Reactivity ◽

Phylogenetic Groups ◽

Specific Antibodies ◽

Negative Results ◽

Recombinant Dna Techniques

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Development of a Smartphone-Based Nanozyme-Linked Immunosorbent Assay for Quantitative Detection of SARS-CoV-2 Nucleocapsid Phosphoprotein in Blood

Frontiers in Microbiology ◽

10.3389/fmicb.2021.692831 ◽

2021 ◽

Vol 12 ◽

Author(s):

Bochao Liu ◽

Ze Wu ◽

Chaolan Liang ◽

Jinhui Lu ◽

Jinfeng Li ◽

...

Keyword(s):

Immunosorbent Assay ◽

Cross Reactivity ◽

Quantitative Detection ◽

Enzyme Linked Immunosorbent Assay ◽

Serum Samples ◽

Primary Screening ◽

Global Pandemic ◽

Novel Coronavirus ◽

Acid Test ◽

Control Samples

Since December 2019, a novel coronavirus (SARS-CoV-2) has resulted in a global pandemic of coronavirus disease (COVID-19). Although viral nucleic acid test (NAT) has been applied predominantly to detect SARS-CoV-2 RNA for confirmation diagnosis of COVID-19, an urgent need for alternative, rapid, and sensitive immunoassays is required for primary screening of virus. In this study, we developed a smartphone-based nanozyme-linked immunosorbent assay (SP-NLISA) for detecting the specific nucleocapsid phosphoprotein (NP) of SARS-CoV-2 in 37 serum samples from 20 COVID-19 patients who were diagnosed by NAT previously. By using SP-NLISA, 28/37 (75.7%) serum samples were detected for NP antigens and no cross-reactivity with blood donors’ control samples collected from different areas of China. In a control assay using the conventional enzyme-linked immunosorbent assay (ELISA), only 7/37 (18.91%) serum samples were detected for NP antigens and no cross-reactivity with control samples. SP-NLISA could be used for rapid detection of SARS-CoV-2 NP antigen in primary screening of SARS-CoV-2 infected individuals.

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A Rapid Immunochromatography Test Based on Hcp1 Is a Potential Point-of-Care Test for Serological Diagnosis of Melioidosis

Journal of Clinical Microbiology ◽

10.1128/jcm.00346-18 ◽

2018 ◽

Vol 56 (8) ◽

Cited By ~ 8

Author(s):

Phornpun Phokrai ◽

Wisansanee Karoonboonyanan ◽

Nida Thanapattarapairoj ◽

Chidchanok Promkong ◽

Adul Dulsuk ◽

...

Keyword(s):

Point Of Care ◽

Clinical Manifestations ◽

Antibody Detection ◽

Enzyme Linked Immunosorbent Assay ◽

Target Antigen ◽

Northeast Thailand ◽

Serum Samples ◽

Serological Method ◽

Healthy Donors ◽

Wide Range

ABSTRACTMelioidosis is a fatal infectious disease caused by the environmental bacteriumBurkholderia pseudomallei. It is highly endemic in Asia and northern Australia but neglected in many other tropical countries. Melioidosis patients have a wide range of clinical manifestations, and definitive diagnosis requires bacterial culture, which can be time-consuming. A reliable rapid serological tool is greatly needed for disease surveillance and diagnosis. We previously demonstrated by enzyme-linked immunosorbent assay (ELISA) that a hemolysin-coregulated protein (Hcp1) is a promising target for serodiagnosis of melioidosis. In this study, we developed a rapid immunochromatography test (ICT) using Hcp1 as the target antigen (Hcp1-ICT). We evaluated this test for specific antibody detection using serum samples obtained from 4 groups of human subjects, including the following: (i) 487 culture-confirmed melioidosis patients from four hospitals in northeast Thailand; (ii) 202 healthy donors from northeast Thailand; (iii) 90 U.S. healthy donors; and (iv) 207 patients infected with other organisms. Compared to culture results as a gold standard, the sensitivity of ICT for all hospitals was 88.3%. The specificities for Thai donors and U.S. donors were 86.1% and 100%, respectively, and the specificity for other infections was 91.8%. The results of the Hcp1-ICT demonstrated 92.4% agreement with the Hcp1-ELISA results with a kappa value of 0.829, indicating that the method is much improved compared with the current serological method, the indirect hemagglutination assay (IHA) (69.5% sensitivity and 67.6% specificity for Thais). The Hcp1-ICT represents a potential point-of-care (POC) test and may be used to replace the IHA for screening of melioidosis in hospitals as well as in resource-limited areas.

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Subtractive Phage Display Selection from Canine Visceral Leishmaniasis Identifies Novel Epitopes That Mimic Leishmania infantum Antigens with Potential Serodiagnosis Applications

Clinical and Vaccine Immunology ◽

10.1128/cvi.00583-13 ◽

2013 ◽

Vol 21 (1) ◽

pp. 96-106 ◽

Cited By ~ 18

Author(s):

Lourena E. Costa ◽

Mayara I. S. Lima ◽

Miguel A. Chávez-Fumagalli ◽

Daniel Menezes-Souza ◽

Vivian T. Martins ◽

...

Keyword(s):

Visceral Leishmaniasis ◽

Phage Display ◽

Leishmania Infantum ◽

Cross Reactivity ◽

Enzyme Linked Immunosorbent Assay ◽

Serum Samples ◽

Phage Display Technology ◽

Predictive Values ◽

Content Type ◽

Phage Elisa

ABSTRACTVisceral leishmaniasis (VL) is a zoonotic disease that is endemic to Brazil, where dogs are the main domestic parasite reservoirs, and the percentages of infected dogs living in regions where canine VL (CVL) is endemic have ranged from 10% to 62%. Despite technological advances, some problems have been reported with CVL serodiagnosis. The present study describes a sequential subtractive selection through phage display technology from polyclonal antibodies of negative and positive sera that resulted in the identification of potential bacteriophage-fused peptides that were highly sensitive and specific to antibodies of CVL. A negative selection was performed in which phage clones were adhered to purified IgGs from healthy andTrypanosoma cruzi-infected dogs to eliminate cross-reactive phages. The remaining supernatant nonadhered phages were submitted to positive selection against IgG from the blood serum of dogs that were infected withLeishmania infantum. Phage clones that adhered to purified IgGs from the CVL-infected serum samples were selected. Eighteen clones were identified and their reactivities tested by a phage enzyme-linked immunosorbent assay (phage-ELISA) against the serum samples from infected dogs (n= 31) compared to those from vaccinated dogs (n= 21), experimentally infected dogs with cross-reactive parasites (n= 23), and healthy controls (n= 17). Eight clones presented sensitivity, specificity, and positive and negative predictive values of 100%, and they showed no cross-reactivity withT. cruzi- orEhrlichia canis-infected dogs or with dogs vaccinated with two different commercial CVL vaccines in Brazil. Our study identified eight mimotopes ofL. infantumantigens with 100% accuracy for CVL serodiagnosis. The use of these mimotopes by phage-ELISA proved to be an excellent assay that was reproducible, simple, fast, and inexpensive, and it can be applied in CVL-monitoring programs.

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