Receptor-binding domain-based immunoassays for serosurveillance differentiate efficiently between SARS-CoV2-exposed and non-exposed farmed mink.

During the COVID-19 pandemic, infection of farmed mink has become not only an economic issue but also a widespread public health concern. International agencies have advised the use of strict molecular and serosurveillance methods for monitoring the SARS-CoV2 status on mink farms. We developed 2 ELISAs and a duplex protein microarray immunoassay (MI), all in a double-recognition format (DR), to detect SARS-CoV2 antibodies specific to the receptor-binding domain (RBD) of the spike protein and to the full-length nucleoprotein (N) in mink sera.

A lateral flow assay for the rapid diagnosis of Mycobacterium bovis infection in wild boar.

The native Eurasian wild boar (Sus scrofa) is a reservoir of Mycobacterium bovis, the causative agent of animal tuberculosis (TB), a chronic disease in livestock, companion animals and wild mammals. Cases of M. bovis infection in wild boar or feral pig have been reported worldwide, making early detection a priority in the eradication of the disease.

Monitoring Anti-NS1 Antibodies in West Nile Virus-Infected and Vaccinated Horses.

West Nile virus (WNV) is a zoonotic arboviral pathogen affecting humans, birds, and horses. Vaccines are available for veterinary use, which efficiently prevent the infection in horses. Most common diagnostic tools rely on the identification of the agent (RT-PCR, virus isolation), or on the detection of antibodies (IgM and IgG) recognizing structural proteins of the virus or neutralizing virus infection in cell cultures (virus-neutralization tests).

A monoclonal antibody to DIII E protein allowing the differentiation of West Nile virus from other flaviviruses by a lateral flow assay.

West Nile Virus (WNV) belongs to the Flaviviridae family, genus Flavivirus, which includes other emerging arthropod-borne viruses (arboviruses) pathogenic for animals and/or humans. West Nile Virus is a genetically diverse RNA virus with at least 7 different recognized lineages. Following its recent introduction and subsequent expansion to the Americas, WNV is currently one of the most widely spread arboviruses in the world having recently re-emerged in the Mediterranean basin, Central and Eastern Europe.

Temporal analysis of the interference caused by paratuberculosis vaccination on the tuberculosis diagnostic tests in goats.

Vaccination against paratuberculosis (PTB) in goats is a cost-effective control strategy, and is also effective as regards preventing the onset of clinical cases. However, it causes interference in the diagnostic tests used in the control of tuberculosis (TB). A group of 99 goats from a herd with no history of TB or PTB infection was vaccinated against PTB at seven months of age.

The use of serological tests in combination with the intradermal tuberculin test maximizes the detection of tuberculosis infected goats.

The diagnosis of tuberculosis (TB) in goats is based mainly on the single and comparative intradermal tuberculin (SIT and CIT) tests and, exceptionally, on the interferon-gamma (IFN-γ) assay, however they are not perfect in terms of sensitivity and specificity. Nevertheless, various serological assays that provide a potential cost-effective approach for the control of TB are also available or under development, and a variety of results have been reported regarding the ability of these tests to detect infected animals, particularly in the early stages of infection. In the present study, SIT/CIT and IFN-γ tests and three different serological assays were evaluated during two consecutive herd testing events in a recently infected caprine herd (n = 447) with a high prevalence of infection in order to evaluate their performance and provide field data with which to improve the TB control programs in this species.

Diagnostic aptitude of West Nile virus-like particles expressed in insect cells.

West Nile virus is a globally spread zoonotic arbovirus. The laboratory diagnosis of WNV infection relies on virus identification by RT-PCR or on specific antibody detection by serological tests, such as ELISA or virus-neutralization. These methods usually require a preparation of the whole virus as antigen, entailing biosafety issues and therefore requiring BSL-3 facilities.

Absence of protection from West Nile virus disease and adverse effects in red legged partridges after non-structural NS1 protein administration.

The red-legged partridge (Alectoris rufa) is a competent host for West Nile virus (WNV) replication and highly susceptible to WNV disease. With the aim to assess in this species whether the inoculation of non-structural protein NS1 from WNV elicits a protective immune response against WNV infection, groups of partridges were inoculated with recombinant NS1 (NS1 group) or an unrelated recombinant protein (mock group), and challenged with infectious WNV. A third group received no inoculation prior to challenge (challenge group).

Evaluation of five serologic assays for bovine tuberculosis surveillance in domestic free-range pigs from southern Spain.

In countries where bovine tuberculosis (bTB) is still prevalent the contact among different animal species in extensive systems contributes to the circulation of Mycobacterium bovis (M. bovis) and other members of the Mycobacterium tuberculosis complex (MTC). Thus, free-range pigs can develop subclinical infections and may contribute to disease spread to bovine and wildlife.

Development of a duplex rapid assay for immunoglobulins M and G to evaluate the parvoviral immune status of clinically healthy dogs.

A duplex rapid assay for detection of serum antibodies to canine parvovirus (CPV) was developed. Canine immunoglobulin (Ig)M or IgG were captured in immunotubes with anti-canine IgM or IgG and detected with parvovirus VP2 recombinant protein followed by an anti-VP2 monoclonal antibody. The assay was tested using a collection of sera from dogs that were vaccinated against CPV on arrival at an animal shelter in Madrid, Spain.

Comparison of two commercial enzyme-linked immunosorbent assays for the diagnosis of Porcine reproductive and respiratory syndrome virus infection.

Early diagnosis of Porcine reproductive and respiratory syndrome virus (PRRSV) is critically important for control of the disease. Two new commercially available enzyme-linked immunosorbent assays (ELISAs) based on different methodologies have been developed. In the present report, the 2 ELISAs were compared using blood samples from experimentally and naturally infected pigs.

Development and evaluation of a new epitope-blocking ELISA for universal detection of antibodies to West Nile virus.

West Nile virus (WNV) is an emerging zoonotic pathogen with a wide range of hosts, including birds, horses and humans. The development and evaluation of the performance of a new enzyme-linked immunosorbent assay (ELISA) are described for rapid detection of WNV-specific antibodies in samples originating from an extensive range of vertebrates susceptible to WNV infection. The assay uses a monoclonal antibody (MAb) which binds whole virus particles and neutralizes infection in vitro by recognizing a neutralizing epitope within the envelope (E) glycoprotein of the virus.

Antigen-capture blocking enzyme-linked immunosorbent assay based on a baculovirus recombinant antigen to differentiate Transmissible gastroenteritis virus from Porcine respiratory coronavirus antibodies.

A new commercially available antigen-capture, blocking enzyme-linked immunosorbent assay (antigen-capture b-ELISA), based on baculovirus truncated-S recombinant protein of Transmissible gastroenteritis virus (TGEV) and 3 specific monoclonal antibodies, was developed and evaluated by examining a panel of 453 positive Porcine respiratory coronavirus (PRCoV), 31 positive TGEV, and 126 negative field sera by using another commercially available differential coronavirus b-ELISA as the reference technique to differentiate TGEV- from PRCoV-induced antibodies. The recombinant S protein-based ELISA appeared to be 100% sensitive for TGEV and PRCoV detection and highly specific for TGEV and PRCoV detection (100% and 92.06%, respectively), when qualitative results (positive or negative) were compared with those of the reference technique.

Development of a sensitive and specific indirect enzyme-linked immunosorbent assay based on a baculovirus recombinant antigen for detection of specific antibodies against Ehrlichia canis.

An indirect enzyme-linked immunosorbent assay (ELISA) based on baculovirus recombinant P30 protein of Ehrlichia canis and the 1BH4 anticanine IgG monoclonal antibody was developed and evaluated by examining a panel of 98 positive and 157 negative sera using the indirect fluorescent antibody (IFA) test as the reference technique. The P30-based ELISA appeared to be sensitive and specific (77.55% and 95.

Optimization of the modification of carrier proteins with aminated haptens.

In this report we show that succinic groups are far more reactive to amino compounds than the carboxylic groups derived from Asp and Glu on the protein when using coupling via 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDCI) (even by an 8 fold factor). Accordingly, a new carrier-protein was designed where both natural amino and carboxylic moieties were transformed into succinic residues. To prepare this hypersuccinylated carrier, all exposed carboxylic acids were first transformed into amino groups by reaction with ethylendiamine after activation with EDCI.