Serological Investigation and Genetic Characteristics of Pseudorabies Virus in Hunan Province of China From 2016 to 2020

Pseudorabies (PR), caused by variant pseudorabies virus (PRV), is an economically important viral disease in China. Recently, PRV infection in humans has also received attention worldwide. To investigate the PRV infection in Hunan province, China, we collected a total of 18,138 serum specimens from 808 PRV-vaccinated pig farms cross this region during 2016–2020, and we detected the presence of PRV glycoprotein B (gB) and gE-specific antibodies. The enzyme-linked immunosorbent assay (ELISA) results revealed that 80.47% (14,596/18,138, 95 CI 79.9–81.0) and 23.55% (4,271/18,138, 95 CI 22.9–24.2) of serum samples were positive for PRV gB and gE-specific antibodies, respectively. Further analysis indicated that the seroprevalence of wild PRV infection was associated with the season and breeding scale (p < 0.01). In addition, five PRV strains were isolated from PRV-positive samples in Vero cells and the virus titers varied from 106.5 to 107.51 TCID50/0.1 ml. The phylogenetic analysis revealed that one isolate was a classical strain of PRV genotype II, and four other isolates belonged to the variants of genotype II. Collectively, the data indicate that the prevalence of PRV remains high in pigs in Hunan province, and the variant PRV strains are the major genotypes affecting the development of the pig industry.

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PEDV Infection Generates Conformation-Specific Antibodies That Can Be Effectively Detected by a Cell-Based ELISA

Viruses ◽

10.3390/v13020303 ◽

2021 ◽

Vol 13 (2) ◽

pp. 303

Author(s):

Wei-Ting Hsu ◽

Chia-Yu Chang ◽

Chih-Hsuan Tsai ◽

Sung-Chan Wei ◽

Huei-Ru Lo ◽

...

Keyword(s):

Recombinant Baculovirus ◽

Immunocytochemical Staining ◽

Enzyme Linked Immunosorbent Assay ◽

Serum Samples ◽

Perfect Agreement ◽

Specific Antibodies ◽

Diarrhea Virus ◽

Serological Studies ◽

A Cell ◽

Infected Insect

Porcine epidemic diarrhea virus (PEDV) is a coronavirus that causes serious and highly contagious enteric disease in swine worldwide. In this study, we constructed a recombinant baculovirus (S-Bac) expressing full-length spike protein of the virulent epidemic genotype 2b (G2b) PEDV strain for serological studies of infected pigs. We found that most spike-specific antibodies produced upon PEDV infection in pigs are conformation-specific and they could be detected on S-Bac-infected insect cells by immunofluorescent assay, but they were insensitive to Western blot analysis, the typical method for antiserum analysis. These results indicated that spike conformation is crucial for serum recognition. Since it is difficult to purify trimeric spike membrane protein for conventional enzyme-linked immunosorbent assay (ELISA), we used S-Bac to generate a novel cell-based ELISA for convenient PEDV detection. We analyzed 100 pig serum samples, and our cell-based ELISA exhibited a sensitivity of 100%, a specificity of 97%, and almost perfect agreement [Cohen’s kappa coefficient value (κ) = 0.98] with immunocytochemical staining results. Our cell-based ELISA rapidly presented antigen for proper detection of conformation-specific antibodies, making PEDV detection more convenient, and it will be useful for detecting many viral diseases in the future.

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Standardization of dot-ELISA for the serological diagnosis of toxocariasis and comparision of the assay with ELISA

Revista do Instituto de Medicina Tropical de São Paulo ◽

10.1590/s0036-46651992000100010 ◽

1992 ◽

Vol 34 (1) ◽

pp. 55-60 ◽

Cited By ~ 34

Author(s):

Eide Dias Camargo ◽

Paulo Mutuko Nakamura ◽

Adelaide José Vaz ◽

Marcos Vinícius da Silva ◽

Pedro Paulo Chieffi ◽

...

Keyword(s):

Low Cost ◽

Clinical Signs ◽

Toxocara Canis ◽

Enzyme Linked Immunosorbent Assay ◽

Serum Samples ◽

Specific Antibodies ◽

Normal Individuals ◽

Before And After ◽

Dot Elisa ◽

Stability Time

The dot-enzyme-linked immunosorbent assay (dot-ELISA) was standardized using somatic (S) and excretory-secretory (ES) antigens of Toxocara-canis for the detection of specific antibodies in 22 serum samples from children aged 1 to 15 years, with clinical signs of toxocariasis. Fourteen serum samples from apparently normal individuals and 28 sera from patients with other pathologies were used as controls. All samples were used before and after absorption with Ascaris suum extract. When the results were evaluated in comparison with ELISA, the two tests were found to have similar sensitivity, but dot-ELISA was found to be more specific in the presence of the two antigens studied. Dot-ELISA proved to be effective for the diagnosis of human toxocariasis, presenting advantages in terms of yield, stability, time and ease of execution and low cost.

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Correlation of serostatus and viraemia levels among Indian dengue patients at the time of first diagnosis

Transactions of the Royal Society of Tropical Medicine and Hygiene ◽

10.1093/trstmh/traa027 ◽

2020 ◽

Vol 114 (7) ◽

pp. 513-520

Author(s):

Ruta Kulkarni ◽

Shubham Shrivastava ◽

Harshad P Patil ◽

Divya Tiraki ◽

Akhilesh Chandra Mishra ◽

...

Keyword(s):

Public Health Problem ◽

Vero Cells ◽

Immunoglobulin M ◽

Enzyme Linked Immunosorbent Assay ◽

Serological Markers ◽

Serum Samples ◽

Infectious Dose ◽

Therapeutic Monoclonal Antibodies ◽

Tissue Culture Infectious Dose ◽

First Diagnosis

Abstract Background Dengue is a public health problem worldwide. Therapeutic monoclonal antibodies (MAbs) against dengue virus (DENV) are likely to be available soon. In view of the feasibility issues pertaining to pretreatment viraemia quantitation for therapy decisions, we conducted this study for investigation of a correlation between patient serostatus (NS1/immunoglobulin M [IgM]/IgG) and viraemia levels among Indian dengue patients at the time of first diagnosis. Methods The study included 297 serum samples from dengue patients in Pune, India. The samples were tested for NS1, IgM and IgG (capture enzyme-linked immunosorbent assay [ELISA] for identifying secondary dengue) using Panbio ELISAs. Quantitation of viraemia was conducted using an NS1 ELISA-based 50% tissue culture infectious dose (TCID50) test in Vero cells. Results Viraemia was detectable only among NS1-positive patients (n = 229, range 0.5–8.3 logTCID50/ml) with a mean titre of 1.9 logTCID50/ml. Among the NS1-positive patients, DENV titres were higher in IgM-negative than IgM-positive patients (p < 0.0001) and in primary (IgG < 18 Panbio units) versus secondary (IgG > 22 Panbio units) dengue patients (p = 0.002). Virus titres were higher during the first 3 days of illness and decreased later (p = 0.005). Conclusions The study provides a range of infectious DENV titres in relation to serologic status among dengue patients in India. The data suggest the possibility of using serological markers (NS1/IgM) as a basis for treatment decisions.

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DETECTION OF SPECIFIC ANTIBODIES TO THE NUCLEOCAPSID PROTEIN FRAGMENTS OF SEVERE ACUTE RESPIRATORY SYNDROME-CORONAVIRUS AND SCOTOPHILUS BAT CORONAVIRUS-512 IN THREE INSECTIVOROUS BAT SPECIES

Taiwan Veterinary Journal ◽

10.1142/s1682648518500063 ◽

2018 ◽

Vol 44 (04) ◽

pp. 179-188 ◽

Cited By ~ 2

Author(s):

Yi-Ning Chen ◽

Bo-Gang Su ◽

Hung-Chang Chen ◽

Cheng-Han Chou ◽

Hsi-Chi Cheng

Keyword(s):

Severe Acute Respiratory Syndrome ◽

Nucleocapsid Protein ◽

Enzyme Linked Immunosorbent Assay ◽

Serum Samples ◽

Protein Fragments ◽

Specific Antibodies ◽

History Of ◽

Polymerase Chain ◽

Carboxyl Terminal ◽

Bat Coronavirus

Bats are the natural reservoirs of severe acute respiratory syndrome-coronavirus (SARS-CoV). Six Alphacoronavirus and five Betacoronavirus have been detected in many bat species, including SARS-related CoV and Middle East respiratory syndrome (MERS)-related CoV. In Taiwan, SARS-related CoV, belonging to Betacoronavirus, has been detected in Rhinolophus monoceros. Scotophilus bat CoV-512, belonging to Alphacoronavirus, has been detected in Scotophilus kuhlii, Miniopterus fuliginosus, and Rhinolophus monoceros by using reverse transcription polymerase chain reaction (RT-PCR). To understand the infection history of CoV in these three insectivorous bat populations, CoV-specific antibodies were surveyed by using western blot (WB) analysis and indirect enzyme-linked immunosorbent assay (ELISA). The carboxyl terminal fragment of nucleocapsid protein (N3) of SARS-CoV and Scotophilus bat CoV-512 were used as the antigen in the assays. Of the 52 serum samples obtained from Scotophilus kuhlii, 29 samples (56%) were tested positive for Scotophilus bat CoV-512-specific antibodies through ELISA. Of the 63 serum samples obtained from Rhinolophus monoceros, 9 samples were tested positive for only SARS-CoV-specific antibodies, 7 samples were tested positive for only Scotophilus bat CoV-512-specific antibodies, and 16 samples (25.4%) were tested positive for both antibodies through WB analysis. Only 1 of 18 Miniopterus bat serum samples tested positive for Scotophilus bat CoV-512-specific antibodies through ELISA. Lactating female bats had higher positive rates of CoV-specific antibodies than non-lactating female and male bats did. Our findings were crucial for understanding CoV infection history in three insectivorous bat species and important for the control of bat-borne zoonosis diseases.

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Development of an enzyme-linked immunosorbent assay (ELISA) for the detection of specific antibodies against an H7N7 and an H3N8 equine influenza virus

Journal of Hygiene ◽

10.1017/s0022172400065189 ◽

1984 ◽

Vol 93 (3) ◽

pp. 609-620 ◽

Cited By ~ 4

Author(s):

M. S. Denyer ◽

J. R. Crowther ◽

R. C. Wardley ◽

R. Burrows

Keyword(s):

Influenza Virus ◽

Immunosorbent Assay ◽

Solid Phase ◽

Allantoic Fluid ◽

Influenza Viruses ◽

Enzyme Linked Immunosorbent Assay ◽

Equine Influenza Virus ◽

Serum Samples ◽

Specific Antibodies ◽

Equine Influenza

SummaryThis paper describes a solid-phase microtitre plate enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies to equine influenza viruses. Using egg-grown influenza viruses as the antigens attached to the solid phase, crossreactions were observed between an H7N7 equine virus (designated A1) and an H3N8 equine influenza virus (designated A2) when untreated antisera were tested. Absorption of antisera with egg-grown A/Porcine/Shope/1/33 influenza virus eliminated cross-reactive antibodies so that specific detection of anti-equine influenza A1 or A2 antibodies was possible.Examination of horse sera following vaccination with A1 and/or A2 isolates showed that antibodies were produced against antigen associated with egg allantoic fluid as well as against virus. Such antibodies were eliminated following the absorption of antisera with porcine influenza virus. Results using sera from horses with known vaccination histories confirmed that the ELISA preferentially detected antibodies homologous to the antigen attached to the solid phase and methods to evaluate the current serological state of individual horses by relating the titres of specific antibodies against equine influenza A1 and A2 isolates are shown. This ELISA provides a simple and rapid method of assessing specific antibodies from horse sera and offers advantages over the ‘routine’ HI and SRH assessments since it gives high precision, is economical of reagents and has the capacity to handle large numbers of serum samples.

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Evaluation of a Blocking ELISA Using a Urease Conjugate for the Detection of Antibodies to Pseudorabies Virus

Journal of Veterinary Diagnostic Investigation ◽

10.1177/104063870001200313 ◽

2000 ◽

Vol 12 (3) ◽

pp. 266-268 ◽

Cited By ~ 3

Author(s):

Maria Gabriela Echeverría ◽

Edgardo Omar Nosetto ◽

Maria Elisa Etcheverrigaray

Keyword(s):

Sensitivity And Specificity ◽

Immunosorbent Assay ◽

Pseudorabies Virus ◽

Visual Assessment ◽

Field Conditions ◽

Virus Neutralization ◽

Enzyme Linked Immunosorbent Assay ◽

Serum Samples ◽

Blocking Elisa ◽

Elisa Format

A blocking enzyme-linked immunosorbent assay (ELISA) using a urease conjugate (U-B-ELISA) was evaluated for screening sera for antibodies to pseudorabies virus under field conditions. A total of 764 serum samples were analyzed by U-B-ELISA. Of these, 264 were evaluated by both virus neutralization and U-B-ELISA, and the results were compared. U-B-ELISA showed 98.5% and 98.9% sensitivity and specificity, respectively. This test combines the sensitivity and specificity of the blocking ELISA format while allowing visual assessment of results.

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Seroprevalence and Clinical Presentation of Chikungunya Virus Infection among Febrile Outpatients Seeking Health Care in Mzuzu City, Malawi

10.20944/preprints202105.0387.v1 ◽

2021 ◽

Author(s):

Flywell Kawonga ◽

Gerald Misinzo ◽

Dylo Pemba ◽

Leonard Mboera ◽

Isaac Thom Shawa

Keyword(s):

Chikungunya Virus ◽

Clinical Presentation ◽

Age Groups ◽

Clinical Signs ◽

Signs And Symptoms ◽

Viral Disease ◽

Elisa Test ◽

Enzyme Linked Immunosorbent Assay ◽

Serum Samples ◽

Igm Antibodies

Chikungunya is a mosquito-borne viral disease caused by Chikungunya virus (CHIKV. We conducted this study determine the seroprevalence and clinical presentation of Chikungunya infection among outpatients seeking healthcare in Mzuzu City, Malawi. Blood samples were collected from malaria negative and non-septic febrile outpatients with fevers ≥38 °C, for not more than 5 days. The enzyme- linked immunosorbent assay (ELISA) test was used to detect anti-CHIKV IgM antibodies and its results were used to determine seroprevalence of Chikungunya. A total of 119 serum samples were tested, of these, 73 (61.3%) tested positive for anti-CHIKV IgM antibodies by ELISA. Laboratory requisition forms were used to capture demographic information such as age, sex, clinical signs and symptoms presented by the enrolled patients. Age groups of 1-9, 10- 19, 20- 29, 30- 39, 40- 49, and ≥50 years had 17.8% (n= 13), 12.3 %,( n=9), 15.1%) (n=11), 19.2%; (n=14), 17.8% (n=13) and 17.8% (n=13) proportion of seroprevalence respectively. Most of the CHIKV infected individuals presented with fever (52.05%), joint pain (45.21%) and abdominal pain (42.67%). The presence of anti- CHIKV IgM antibodies suggest the presence of recent CHIKV infection and therefore accurate laboratory assays are highly recommended for CHIKV diagnosis and appropriate management of febrile patients.

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Aujeszky’s Disease in South-Italian Wild Boars (Sus Scrofa): A Serological Survey

Animals ◽

10.3390/ani11113298 ◽

2021 ◽

Vol 11 (11) ◽

pp. 3298

Author(s):

Gianmarco Ferrara ◽

Consiglia Longobardi ◽

Filomena D’Ambrosi ◽

Maria Grazia Amoroso ◽

Nicola D’Alessio ◽

...

Keyword(s):

Wild Boar ◽

Sus Scrofa ◽

Pseudorabies Virus ◽

Viral Disease ◽

Serum Samples ◽

Hunting Season ◽

Campania Region ◽

Wild Boars ◽

Aujeszky's Disease ◽

Aujeszky’S Disease

Aujeszky’s disease (AD, pseudorabies) is a viral disease of suids caused by Suid Herpesvirus 1 (SHV-1) also referred as Aujeszky’s disease virus (ADV) or Pseudorabies virus (ADV). Domestic pig and Wild boar (Sus scrofa) are the natural host, but many species can be infected with ADV. The aim of our study was to evaluate seroprevalence of AD in wild boar hunted in the Campania Region, during the 2016–2017 hunting season. A total of 503 serum samples from wild boars hunted in the provinces of Campania Region (Southern Italy) were collected and were tested for antibody against ADV using an AD, blocking ELISA assay. A Seroprevalence of 23.85% (120/503, 95% Confidence Interval (CI): 20.15–27.55) was found. Gender was not significantly associated with of ADV seropositivity (p > 0.05), while the presence of ADV antibodies was statistically associated with age (>36-month, p < 0.0001) and location (Avellino, p = 0.0161). Our prevalence values are like those obtained in 2010 in our laboratory (30.7%), demonstrating a constant circulation of ADV in the area.

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Detection of Specific Antibodies to an Antigenic Mannoprotein for Diagnosis of Penicillium marneffeiPenicilliosis

Journal of Clinical Microbiology ◽

10.1128/jcm.36.10.3028-3031.1998 ◽

1998 ◽

Vol 36 (10) ◽

pp. 3028-3031 ◽

Cited By ~ 42

Author(s):

Liang Cao ◽

Da-Liang Chen ◽

Cindy Lee ◽

Che-Man Chan ◽

King-Man Chan ◽

...

Keyword(s):

Specific Antibody ◽

Blood Donors ◽

Antibody Test ◽

High Specificity ◽

Pathogenic Fungi ◽

Enzyme Linked Immunosorbent Assay ◽

Serum Samples ◽

Specific Antibodies ◽

Immunodeficiency Virus ◽

Positive Results

The disseminated and progressive fungal disease Penicillium marneffei penicilliosis is one of the most common infectious diseases in AIDS patients in Southeast Asia. To diagnose systemic penicilliosis, we developed an enzyme-linked immunosorbent assay (ELISA)-based antibody test with Mp1p, a purified recombinant antigenic mannoprotein of P. marneffei. Evaluation of the test with guinea pig sera against P. marneffei and other pathogenic fungi indicated that this assay was specific for P. marneffei. Clinical evaluation revealed that high levels of specific antibody were detected in two immunocompetent penicilliosis patients. Furthermore, approximately 80% (14 of 17) of the documented penicilliosis patients with human immunodeficiency virus tested positive for the specific antibody. No false-positive results were found for serum samples from 90 healthy blood donors, 20 patients with typhoid fever, and 55 patients with tuberculosis, indicating a high specificity of the test. Thus, this ELISA-based test for the detection of anti-Mp1p antibody can be of significant value as a diagnostic for penicilliosis.

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Serological Investigations of Bluetongue Virus (BTV) among Sheep and Goats in Kassala State, Eastern Sudan

Veterinary Medicine International ◽

10.1155/2020/8863971 ◽

2020 ◽

Vol 2020 ◽

pp. 1-7

Author(s):

Molhima M. Elmahi ◽

Abdel Rahim E. Karrar ◽

Amira M. Elhassan ◽

Mohammed O. Hussien ◽

Khalid A. Enan ◽

...

Keyword(s):

Risk Factors ◽

Winter Season ◽

Viral Disease ◽

Enzyme Linked Immunosorbent Assay ◽

Serum Samples ◽

Sheep And Goats ◽

Domestic Ruminants ◽

The Family ◽

Vector Borne ◽

Center Section

Bluetongue (BT) is an infectious, noncontagious, vector-borne viral disease of wild and domestic ruminants. BTV is a member of the Orbivirus genus of the family Reoviridae. The present study aimed to investigate the seroprevalence of BTV in sheep and goats in Kassala State, Sudan. It also aimed to determine risk factors associated with BTV infection. The study was carried out by a structured questionnaire survey, and a total of 809 serum samples were collected from sheep (n = 459) and goats (n = 350) from 9 different localities in Kassala state. These samples were analyzed using a competitive enzyme-linked immunosorbent assay (cELISA) for the detection of BTV antibodies. The overall seroprevalence of BTV was 91.2% (738/809). In goats, the prevalence of BTV antibodies was comparatively higher (100%) than in sheep (84.5%). The prevalence differed between localities and was the highest in the center section of Kassala and Western Kassala (100%). Animals aged 6–11 months were highly infected (93.9%) compared to 1-year-old (85.5%). Caprine species was more likely to be infected (100%) than ovine (84.5%), and females were highly infected (92.8%) than males (85.5%). BTV infections were higher in the winter season (91.4%). Risk factors that showed significant associations with cELISA positivity included locality and sex (p≤0.003) and species and age (p≤0.000). Factors significantly associated with cELISA positivity in multivariate analysis were localities, species, age, and sex. BTV infection is prevalent in sheep and goat populations in Kassala state.

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