Biology subjects

Vaillant, A. A. J.

Publications and source records attributed to Vaillant, A. A. J..

3 recordsLinked to original sources

bioRxiv2020

Universal enzyme-linked immunosorbent assays (ELISA) and utility in the immunodiagnosis of Salmonellosis

The aim of this study was to confirm the feasibility of using hybrid immunoglobulin-binding reagents in ELISAs for IgG/IgY detection and detection of specific antibodies against an infectious microorganism (Salmonella spp.) in various animal species using a universal diagnostic ELISA. Hybrid immunoglobulin-binding bacterial proteins (IBP), including recombinant protein LA, recombinant protein LG, and recombinant protein AG, have been produced to improve their binding affinity to a much larger number of immunoglobulins. Thus, this hybrid bacterial protein represents a powerful tool for the binding, detection, and purification of immunoglobulins and their fragments. However, SpLA-LG-peroxidase and SpLAG-anti-IgYperoxidase were produced using the periodate method. These compounds have been shown to be effective as reagents. Their binding affinity to immunoglobulins surpasses that of previously reported hybrid IgG-binding proteins, including the most known SpAG, SpLA, and SpLG. The IgY fraction was isolated from the egg yolks of various birds, including chicken, bantam hen, guinea hen, quail, goose, duck, wild and domestic pigeons, parakeets, cattle egrets, pheasants, and ostrich. The IgY fraction was isolated using the chloroform-polyethylene glycol (PEG) method. An ELISA for anti-Salmonella spp. antibodies was employed with some modifications to determine the presence of antibodies in humans, laying hens, geese, quails, and pigeons. Salmonella is a motile, flagellated, rod-shaped zoonotic pathogen that can survive in the presence or absence of oxygen. They belong to the family Enterobacteriaceae and are implicated in typhoid fever and food-borne illnesses. This pathogen is associated with several diseases, which may become fatal and negatively impact the health of individuals and various economies globally. The poultry industry is most vulnerable to the influence of this pernicious microbe. The authors concluded that universal enzyme-linked immunosorbent assays were effective and reproducible in detecting immunoglobulins from both avian and mammalian species, but ELISA using the SpLAG-anti-IgY-HRP conjugate only reacted with the whole panel of animal antibodies. This conjugate was further used to standardize a universal ELISA for the determination of anti-Salmonella antibodies, in which human and avian species were serologically assessed.

immunology↗

bioRxiv2020

Use of immunoglobulin-binding bacterial proteins in immunodetection.

One of the aim of this study was to make universal chimeric conjugates to react with both avian and mammalian immunoglobulins in enzyme-linked immunosorbent assays (ELISAs). The periodate method was used in the conjugation process of cross-linking horseradish peroxidase to immunoglobulin-binding proteins (IBP) including staphylococcal protein A (SpA), streptococcal protein G (SpG) and peptostreptococcal protein L (SpL). By mixing up these three conjugates another four hybrid protein conjugates were created including protein LA (SpLA), protein LG (SpLG), protein AG (SpAG) and protein LAG (PLAG). Thirty-five ELISAs were standardized by a probabilistic combination of these immunoreagents. By using a panel of mainly mammalian immunoglobulins their reproducibility was checked by the determination of coefficient of variations (CV) for each one of the IgG-IBP binding. The source of immunoglobulins was their purification by affinity chromatography using a commercially available kit (PURE-1A). The other aim was to immunize chicken with the peptide fragment 254-274 of gp120 to produce anti-HIV peptide hyper-immune egg. Cats and rats were fed these eggs for a determined period until they produced the anti-HIV peptide antibody, which was tested by an indirect SpLA-ELISA and dot blot analysis that corroborated the production of anti-HIV antibodies by the mammalian species including positive humans samples for HIV. We conclude that the single and hybrid immunoglobulin-binding protein were effective in their binding capacity to immunoglobulins from a variety of mammalian species. The potential use of this proteins is in the arena of immunodiagnosis and immunoglobulin detection. Dot blot analysis proves effective in the detection of HIV anti-gp120 antibodies in several animal species. These antibodies can be used as reagents in the development of immunodiagnostic tests or experimental vaccines.

immunology↗

bioRxiv2020

Immunogenicity studies of various experimental vaccines in chickens.

In this paper, the main objective was to raise chickens antibodies against three crucial public health microorganisms: the human immunodeficiency virus-1, Salmonella spp, and Staphylococcus aureus. Immunogens were prepared from the said microorganisms. Chickens were vaccinated either orally or intramuscularly. After a booster immunization, mostly eggs were collected and assess for the presence of specific antibodies. The most important results were the production of a large amount of anti-HIV antibodies in chickens eggs, and also the synthesis of anti-protein A antibodies with the ability to inhibit the growth of S. aureus in vitro and to serve as anti-anti-idiotypic antibodies with the capacity of neutralizing the original antigen. Enzyme-linked immune absorbent assays detected the presence of these antibodies as anti-Salmonella antibodies that were critical in reducing the bacterial load in the stomach and caeca compared with a control group. The vaccines were effective and safe, but more laboratory work, and economics have to be carried out to start a human trial.

immunology↗