Yolk Antibodies Research Articles

Immunological properties of the chicken egg yolk (IgY) antibodies against Vietnamese cobra Naja Naja venom

Venomous snake bite is common poisonous accident and important medical problem around the world. The snake anti-venom is only type-specific protection to each venom type that was used to immunize. In this study, the chicken egg yolk (IgY) antibodies against the Vietnamese cobra Naja Naja venom was developed and evaluated in in-vitro (ELISA and SDS-PAGE) and in-vivo (hen and mice immunization). In particularly, the LD50 of the Vietnamese cobra Naja Naja venom was determined at 1.46 g kg−1 body weight of the Swiss mice. The ISA Brown layers of 16 to 18-week-old were immunized intramuscularly with the Vietnamese cobra Naja Naja venom at 0.5 mg kg−1 body weight of the layers. The specific anti-venom antibodies were presented in both serum and egg yolk at 14 days, reached to highest antibody titer at 49 to 56 days and lasted up to 111 days post-immunization. The IgY antibodies purified from the egg yolk revealed potential neutralization and protection of Vero cells and Swiss mice from toxicity of the Vietnamese cobra Naja Naja venom. To the best of our knowledge, this study result is the first cobra snake anti-venom developed in laying hens against the Vietnamese cobra Naja Naja venom. Further study is needed to whether this specific IgY anti-venom antibodies can be used as an antibody therapy for treatment of venomous snake bites in the future.

PSVIII-2 Antibody yield for polyclonal egg yolk antibody (IgY) production in laying hens

Abstract Antibody production in egg yolks of immunized laying hens is an alternative to conventional mammalian production. Antibody yield peak and duration have not been described for immunoglobulin Y technology using Freund’s incomplete adjuvant (FIA) and C-phosphate-guanosine oligodeoxynucleotides (CpG-ODN) without the inclusion of Freund’s complete adjuvant for enhancing the immune response to an interleukin-10 (IL-10) peptide. This study sought to describe the antibody titer production for an 8 amino acid sequence from the surface of the bovine IL-10 protein (VMPQAENG) as the antigen emulsified with CpG-ODN and FIA in phosphate buffered saline (PBS). 60 hens were assigned to receive the complete vaccine (Peptide), 20 received the vaccine without the IL-10 peptide (Control), and 8 received a PBS injection (Blank). Hens were immunized with 0.25 mL in 4 locations, each breast and each thigh on days 1, 15 and 29. The complete vaccine delivered 0.6 mg IL-10 peptide, 8 µg CpG-ODN, and 0.33 mL FIA per hen on each vaccination day. Eggs were collected regularly until 175 days after the first immunization and the anti IL-10 peptide activities of the yolk were determined by ELISA. Egg titers by treatment were analyzed with a repeated measures ANOVA in SAS. The supplementation of FIA with CpG-ODN produced high titers, of over 100 µg of antibody per mL of yolk (µg Ab/mL yolk), around day 33 through day 76, with a slow decline through day 175 when average titers remained above 40 µg Ab/mL yolk. Peptide egg titers were significantly higher than Blank or Control titers from day 31 though day 175 (P < 0.0001). Titers recovered from Marcq et al. (2015) with similar methods were 1.5 to 7 times lower than these results over the same number of days.

Chicken Egg Yolk Antibodies (IgYs) block the binding of multiple SARS-CoV-2 spike protein variants to human ACE2

The SARS-CoV-2 virus is still spreading worldwide, and there is an urgent need to effectively prevent and control this pandemic. This study evaluated the potential efficacy of Egg Yolk Antibodies (IgY) as a neutralizing agent against the SARS-CoV-2. We investigated the neutralizing effect of anti-spike-S1 IgYs on the SARS-CoV-2 pseudovirus, as well as its inhibitory effect on the binding of the coronavirus spike protein mutants to human ACE2. Our results show that the anti-Spike-S1 IgYs showed significant neutralizing potency against SARS-CoV-2 pseudovirus, various spike protein mutants, and even SARS-CoV in vitro. It might be a feasible tool for the prevention and control of ongoing COVID-19.

Anti-S1 MERS-COV IgY Specific Antibodies Decreases Lung Inflammation and Viral Antigen Positive Cells in the Human Transgenic Mouse Model.

The Middle East respiratory syndrome coronavirus (MERS-CoV) was identified in 2012 and causes severe and often fatal acute respiratory illness in humans. No approved prophylactic and therapeutic interventions are currently available. In this study, we have developed egg yolk antibodies (immunoglobulin Y (IgY)) specific for MERS-CoV spike protein (S1) in order to evaluate their neutralizing efficiency against MERS-CoV infection. S1-specific immunoglobulins were produced by injecting chickens with purified recombinant S1 protein of MERS-CoV at a high titer (5.7 mg/mL egg yolk) at week 7 post immunization. Western blotting and immune-dot blot assays demonstrated that the IgY antibody specifically bound to the MERS-CoV S1 protein. Anti-S1 antibodies were also able to recognize MERS-COV inside cells, as demonstrated by an immunofluorescence assay. Plaque reduction and microneutralization assays showed the neutralization of MERS-COV in Vero cells by anti-S1 IgY antibodies and non-significantly reduced virus titers in the lungs of MERS-CoV-infected mice during early infection, with a nonsignificant decrease in weight loss. However, a statistically significant (p = 0.0196) quantitative reduction in viral antigen expression and marked reduction in inflammation were observed in lung tissue. Collectively, our data suggest that the anti-MERS-CoV S1 IgY could serve as a potential candidate for the passive treatment of MERS-CoV infection.

A Comparative Study on Egg Yolk IgY Production with Different Adjuvants and their Inhibitory Effects on Staphylococcus aureus.

Objectives: Atopic dermatitis (AD) is one of the most common skin disorders in infants and children and is often aggravated by increased Staphylococcus aureus (S. aureus) colonization. An inhibitory effect of a specific egg yolk antibody (IgY) on S. aureus growth was demonstrated in this study. Furthermore, the effects of water- or oil-based adjuvants on the preparation of anti-S. aureus IgY and hen immunization were compared.Methods: Hens were immunized intramuscularly with formalin-killed S. aureus mixed with either a water-soluble polysaccharide λ-carrageenan, oil-based Freund's complete adjuvant (FCA), or Freund's incomplete adjuvant (FIA). Anti-S. aureus IgYs (FIA-IgY, FCA/FIA-IgY, and λCarra-IgY) were purified from the egg yolk of immunized hen eggs, and the activity of the IgY against S. aureus antigen was measured by ELISA. The proportion of each IgY that was absorbed by S. aureus was also determined. Then, the effect of purified anti-S. aureus IgY on S. aureus growth inhibition was investigated in vitro.Results: The yolk of eggs and purified FIA-IgY from the FIA group showed the highest antibody activity, followed by FCA/FIA-IgY and λCarra-IgY. The proportion of each IgY that was absorbed by S. aureus antigen was as follows: FIA-IgY (18.1%), FCA/FIA-IgY (12.9%), and λCarra-IgY (7.0%). Only FIA-IgY significantly inhibited S. aureus growth in liquid medium.Conclusion: A specific IgY that was produced using the FIA adjutant inhibited S. aureus growth. Although water-soluble λ-carrageenan showed an adjuvant effect on anti-S. aureus IgY induction in egg yolk, but did not inhibit S. aureus growth. The use of the oil adjuvant FIA was necessary in the preparation of anti-S. aureus IgY as a treatment for AD symptoms.

Protective effects of egg yolk immunoglobulins (IgYs) developed against recombinant immunogens CtxB, OmpW and TcpA on infant mice infected with Vibrio cholerae

Vibrio cholerae causes cholera and other infections, especially in children under five years of age. Cholera toxin (CT), toxin-coregulated pilus (TCP) and outer membrane protein W (OmpW) are three major virulence factors of this bacterium. The emergence of antimicrobial-resistant (AMR) strains and the absence of a comprehensive and flawless vaccine, has prompted other treatments. There are several advantages of egg yolk antibodies (IgY) over other immunotherapy agents, such as economic feasibility, high yield simple production, and better immune responsiveness to mammalian antigens due to phylogenetic distance. Accordingly, in the present study, IgYs against recombinant proteins CtxB (responsible for the CT binding to eukaryotic cells), TcpA (enhances bacterial attachment to enterocytes) and OmpW were produced, in single, coupled or combined forms, to evaluate and compare their protectivity potency. Immunoreactivity of IgYs were examined through protein and whole cell ELISA, their specificity was confirmed by western blotting, and their neutralizing effects on CT was evaluated in Y1 cell culture. Produced IgYs were gavage administered to different groups of infant mice infected with V. cholerae. The results indicated that IgYs produced against CtxB had the highest titers, and were able to neutralize cytotoxicity effects in Y1 cell culture, while the highest protection in the mice challenge was obtained by IgY-TcpA. No considerable increase was observed in immunoreactivity or protectivity of antibodies produced against combined antigens. The produced IgYs showed a good antigen-specificity and protectivity which can be used in passive immunotherapy against cholera.

Production and Purification of IgY antibodies from egg yolk

Polyclonal antibodies from vaccinated mammalian have made a significant contribution to scientific research and diagnosis. The fact that recent technologies allow the production of antibodies in egg yolks laid by hens has led to the development of an alternative to antibody production that is less dangerous to animals. The results of this study showed that it is possible to produce a large amount of IgY antibody to bovine serum albumin (BSA), content of about 8 mg/mL of egg yolk emulsion. The anti-BSA IgY antibodies with high purity and anti-BSA activity.

Collocation of avian and mammal antibodies to develop a rapid and sensitive diagnostic tool for Russell's Vipers Snakebite.

Russell’s vipers (RVs) envenoming is an important public health issue in South-East Asia. Disseminated intravascular coagulopathy, systemic bleeding, hemolysis, and acute renal injury are obvious problems that develop in most cases, and neuromuscular junction blocks are an additional problem caused by western RV snakebite. The complex presentations usually are an obstacle to early diagnosis and antivenom administration. Here, we tried to produce highly specific antibodies in goose yolks for use in a paper-based microfluidic diagnostic kit, immunochromatographic test of viper (ICT-Viper), to distinguish RVs from other vipers and even cobra snakebite in Asia. We used indirect ELISA to monitor specific goose IgY production and western blotting to illustrate the interaction of avian or mammal antibody with venom proteins. The ICT-Viper was tested not only in prepared samples but also in stored patient serum to demonstrate its preliminary efficacy. The results revealed that specific anti-Daboia russelii IgY could be raised in goose eggs effectively without inducing adverse effects. When it was collocated with horse anti-Daboia siamensis antibody, which broadly reacted with most of the venom proteins of both types of Russell’s viper, the false cross-reactivity was reduced, and the test showed good performance. The limit of detection was reduced to 10 ng/ml in vitro, and the test showed good detection ability in clinical snake envenoming case samples. The ICT-Viper performed well and could be combined with a cobra venom detection kit (ICT-Cobra) to create a multiple detection strip (ICT-VC), which broadens its applications while maintaining its detection ability for snake envenomation identification. Nonetheless, the use of the ICT-Viper in the South-East Asia region is pending additional laboratory and field investigations and regional collaboration. We believe that the development of this practical diagnostic tool marks the beginning of positive efforts to face the global snakebite issue.

Effects of posthatch feed deprivation on residual yolk absorption, macronutrients synthesis, and organ development in broiler chicks

The aim of the research was to evaluate the dynamic changes of early posthatch starvation on residual yolk absorption, synthesis of macronutrients (protein, lipid, and glycogen), and organ development in broiler chicks. A total of 720 1-day-old chicks (Lingnan Yellow) were randomly assigned to 3 treatments: group A (nonfasted), group B (fasting for 24 h after placement), and group C (fasting for 48 h after placement). The trial lasted for 168 h, and water was provided ad libitum all the time. Sampling was performed at 0, 24, 48, 72, 120, and 168 h. Nonfasting (group A) promoted (P < 0.05) the absorption of amino acids, fatty acids, mineral elements, protein, and maternal antibody in the residual yolk of broiler chicks. The concentration of insulin-like growth factor 1 in plasma and the liver was higher (P < 0.05) in group A. Nonfasting enhanced (P < 0.05) the synthesis of protein and glycogen in the breast muscle and liver; the relative weights of the liver, pancreas, and spleen; and body weight, but retarded (P < 0.05) the synthesis of triglyceride in the liver. The results indicated that nonfasting (group A) after placement promoted the absorption of residual yolk and synthesis of protein and glycogen in the breast muscle and liver, whereas early feed deprivation promoted the synthesis of lipid in the liver. Thereby, nonfasting after placement promoted organ development and body growth of broiler chicks.

Production of Phage Display-Derived Peptide and the Application for Detecting Vibrio parahaemolyticus by Combined PCR Technology

Vibrio parahaemolyticus (V. parahaemolyticus) is one of the most common and widely distributed food-borne bacteria. Thus, it is necessary to establish a rapid, specific, and sensitive detection approach for V. parahaemolyticus. The strategy of combining immunomagnetic separation method (IMS) and polymerase chain reaction (PCR) measure was established successfully for V. parahaemolyticus detection, because ordinary IMS always has restriction on employing conventional antibodies for their labor-intensive procedure, batch-to-batch variation in functionality, and limited shelf-life. Herein, we have generated a novel phage display-derived peptide with an amino acid sequence of MPRLPPA and use it as bio-recognition probe in IMS. The peptide was evaluated to have the advantages of high specificity, sensitivity, easy reproduction, and well-defined ability. When compared with the rabbit polyclone IgG antibodies (IgG)-IMS and chicken egg yolk antibodies (IgY)-IMS, peptide-IMS has absolute superiorities in terms of the dosages, detection time, and capture efficiency. It has the ability to take the place of traditional antibody and unquestionable value of reusing. Furthermore, the detection system of peptide-IMS-PCR possessed high specificity with a limit of detection (LOD) of 102 CFU/mL in pure culture and 103 CFU/mL in oyster. Thus, we successfully synthesize peptide against V. parahaemolyticus and applied it to establish a sensitive and specific detecting method for V. parahaemolyticus.

Production of egg yolk antibody (IgY) against shiga-like toxin (stx) and evaluation of its prophylaxis potency in mice

ObjectiveEnterohemorrhagic Escherichia coli (E. coli O157: H7) is an enteric pathogen, transmitted through contaminated water and food. Pathogenic factors include bacterial adhesion, invasion of intestinal epithelial and epithelium cells. The pathogenicity of EHEC is due to the production of Shiga-like toxin (Stx). This toxin binds to the ribosome and inhibits the synthesis of proteins. EHEC causes hemorrhagic colitis (HC) and hemolytic uremic syndrome (HUS). The EHEC treatment with antibiotics leads to resistance. The best way to solve this problem is to use specific antibodies and prophylaxis. Egg yolk antibody (IgY) is a suitable method for prophylaxis. Hence, the aim of this study was to investigate the production of IgY against Stx toxin and its prophylaxis. ResultThe produced antibodies were confirmed by SDS-PAGE and ELISA. IgY was obtained at a concentration of about 5 mg/ml (30 mg of each egg) and a purity of more than 90%. Toxin and antibody challenge was performed in mice. The obtained IgY was able to neutralize the effect of Stx at 2 mg/mice. ConclusionThis challenge showed that an antibody produced with an acceptable percentage was able to neutralize the effect of Stx.

Production of an alternative antivenom based on egg yolk antibodies AGAINST Crotalus durissus terrificus

Production of an alternative antivenom based on egg yolk antibodies AGAINST Crotalus durissus terrificus

The effect of capsulated and noncapsulated egg-yolk–specific antibody to reduce colonization in the intestine of Salmonella enterica ssp. enterica serovar Infantis–challenged broiler chickens

The antibacterial properties of egg yolk antibodies have been known for many years. Enhanced antibiotic resistance has resulted in increased need for using these antibodies as an alternative. In the present study, generation, capsulation, and inhibition growth properties of IgY directed against Salmonella enterica subsp. enterica serovar Infantis (SI) were evaluated. White Leghorn layer hens were immunized using whole cell of inactivated SI. Salmonella Infantis–specific antibody activities in sera and egg yolk were determined by ELISA. A total of 480 one-day-old male “Cobb 500” chicks were randomly divided into 8 groups, with 6 replications of 10 birds kept for 21 D. All birds from 7 challenged groups were orally inoculated with 1 mL of SI suspension (1 × 107 CFU/mL) at 3 and 4 D of age. Two groups were dietary supplemented with 5 g/kg immune powdered yolk or nonimmune powdered yolk. One group was dietary supplemented with 12.8 g/kg capsulated immune yolk (CIY). Two groups were given 8.3 mL/L of immune water-soluble yolk or nonimmune water-soluble yolk fraction in drinking water. In the antibiotic group, 1 mL/L Enrofloxacin 10% was added to drinking water. All supplements except for the antibiotic (on Day 4 for 10 D) were added on day one and continued during the experiment. Negative and positive control groups received no supplements. During the experiment, among the challenged groups, the minimum SI cecal colonization and the lowest isolation of SI from the liver (P < 0.01) was observed in the antibiotic group. Following antibiotic group, in the group receiving CIY, colonization of bacteria in ceca and liver was significantly reduced during the second and third weeks of the experiment (P < 0.01). According to the results, capsulated specific IgY has a beneficial effect in reducing the colonization of Salmonella under the conditions of this study in comparison with other forms of IgY antibody.

Production and evaluation of egg derived hot start antibodies

Abstract Background Hot start can greatly improve specificity, sensitivity and yield of PCR. Non-specific amplification can occur in PCR when reaction mixture is prepared at room temperature, because Taq DNA polymerase is active and the primers can hybridize non-specifically. Hot start Taq DNA polymerases remain inactive at room temperature and are activated after heating at 95°C preventing non-specific amplification. Monoclonal antibodies against Taq DNA polymerase is the first line of reagents used for turn on regular Taq DNA polymerase into Hot start one. The goal of this research was to produce and evaluate Hot Start antibodies derived from chicken eggs. Results We performed affinity purification of yolk immunoglobulin (IgY) and obtained polyclonal Hot Start antibodies. The yield of specific antibodies was 0.36 mg per egg or 0.2% of total yolk antibodies. The protocol for real time measurement and Hot start IgY activity assessment was developed. We found that Hot start IgY can reversibly block Taq DNA polymerase activity at 50°C and have no negative impact neither on the Taq DNA polymerase activity after denaturation nor on the reverse transcriptase. We estimated that 1.0 μg of Hot start IgY effectively blocks 5 U activity of Taq DNA polymerase. Conclusions Egg derived Hot Start polyclonal antibodies are the cheapest source of Hot start antibodies, from one immune egg we can isolate 0.36 mg IgY, this quantity is enough for producing 1800 U activity of Hot start Taq DNA Polymerase. How to cite: Spyrydonov V, Pihida D, Sereda A, et al. Production and evaluation of egg derived hot start antibodies. Electron J Biotechnol 2020;44. https://doi.org/10.1016/j.ejbt.2020.01.005 .

Expression, Purification, and Characterization of Anti-Zika virus Envelope Protein: Polyclonal and Chicken-Derived Single Chain Variable Fragment Antibodies.

Zika virus (ZIKV) is a new and emerging virus that has caused outbreaks worldwide. The virus has been linked to congenital neurological malformations in neonates and Guillain–Barré syndrome in adults. Currently there are no effective vaccines available. As a result, there is a great need for ZIKV treatment. In this study, we developed single chain variable fragment (scFv) antibodies that target the ZIKV envelope protein using phage display technology. We first induced an immune response in white leghorn laying hens against the ZIKV envelope (E) protein. Chickens were immunized and polyclonal immunoglobulin yolk (IgY) antibodies were extracted from egg yolks. A high-level titer of anti-ZIKV_E IgY antibodies was detected using enzyme-linked immunosorbent assay (ELISA) after the third immunization. The titer persisted for at least 9 weeks. We constructed two antibody libraries that contained 5.3 × 106 and 4.5 × 106 transformants. After biopanning, an ELISA phage assay confirmed the enrichment of specific clones. We randomly selected 26 clones that expressed ZIKV scFv antibodies and classified them into two groups, short-linker and long-linker. Of these, four showed specific binding activities toward ZIKV_E proteins. These data suggest that the polyclonal and monoclonal scFv antibodies have the diagnostic or therapeutic potential for ZIKV.

Storage stability of anti-Salmonella Typhimurium immunoglobulin Y in immunized quail eggs stored at 4°C

Chicken egg yolk antibodies (IgYs) are extensively used for immunotherapy and immunodiagnostic purposes. Oral immunotherapy with specific IgYs is established as an efficient alternative to traditional antibiotic therapy in human and animals. Storing immunized eggs in refrigerator for a period of time could provide an inexpensive and convenient source of large volumes of specific antibodies. This study investigated the storage stability of anti- Salmonella Typhimurium IgYs in immunized quail egg yolks at 4°C over a period of more than 6 months. Salmonella spp.-free female Japanese quails (Coturnix coturnix japonica) were intramuscularly immunized whit Salmonella Typhimurium whole bacterial suspension (1.0×109 CFU/ml) emulsified with Freund adjuvants. During a period of 10 days after final immunization, eggs from each group were collected, randomized and stored at 4°C over a period of 200 days. Egg yolk IgY titer and specificity were determined using ELISA technique. S. Typhimurium specific IgY antibodies were detected in immunized quails and were significantly higher than the control group which confirmed the immunization procedure. Eggs from immunized quails can be collected and stored in 4°C refrigerator over a period of 2 months without any concern about the antibody degradation. After 80 days of storage at 4°C, although lower antibody titer was obtained in comparison to the first of study, anti-S. Typhimurium IgY level remained stable up to the 6 months without more significant declining. This trend will provide economical sources of polyclonal antibodies through reducing the number of immunized animals, management expenses and housing costs.

The impacts of Ascaridia galli on performance, health, and immune responses of laying hens: new insights into an old problem

Gastrointestinal nematodes are re-emerging in countries where the popularity of free-range poultry production systems is increasing. Amongst all gastrointestinal nematodes, Ascaridia galli is of significant concern due to the parasite's direct life cycle and ability to survive extreme environmental conditions. In laying hens, A. galli parasites have been associated with reduced health, welfare, immunity, and egg production. Direct losses are caused by obstruction and damage of the intestinal tract in hens when high worm burdens are present. These result in reduction in egg production and body weight of infected laying hens, consequently leading to significant economic losses for farmers. Furthermore, heavy infections with A. galli may lead to increased mortality within the flock. Indirect losses are due to suppression of immune system function which can increase susceptibility to secondary infections. Infection with A. galli can also alter nutrient utilization and absorption. Levels of anti- A. galli serum and egg yolk antibodies increase following A. galli infection. Elevated antibodies can be used as an indicator of current or previous infections and therefore can be used as a diagnostic tool. The impact of A. galli on hen health and welfare manifests through the depletion of liver lipid reserves and increased use of energy reserves to mount immune responses against the parasite. This review highlights the variable effects of A. galli infection on the performance, health, egg quality, and emphasizes especially on immune responses of free-range laying hens as well as it evaluates various potential detection methods and preventive and control measures of this parasitic disease.

Anti-PcrV IgY antibodies protect against Pseudomonas aeruginosa infection in both acute pneumonia and burn wound models

Pseudomonas aeruginosa is a common nosocomial pathogen in burn patients, and rapidly acquires antibiotic resistance; thus, developing an effective therapeutic approach is the most promising strategy for combating infection. Type III secretion system (T3SS) translocates bacterial toxins into the cytosol of the targeted eukaryotic cells, which plays important roles in the virulence of P. aeruginosa infections in both acute pneumonia and burn wound models. The PcrV protein, a T3SS translocating protein, is required for T3SS function and is a well-validated target in animal models of immunoprophylactic strategies targeting P. aeruginosa. In the present study, we evaluated the protective efficacy of chicken egg yolk antibodies (IgY) raised against recombinant PcrV (r-PcrV) in both acute pneumonia and burn wound models. R-PcrV protein was generated by expressing the pcrV gene (cloned in pET-28a vector) in E. coli BL-21. Anti-PcrV IgY was obtained by immunization of hen. Anti-PcrV IgY induced greater protection in P. aeruginosamurine acute pneumonia and burn wound models than control IgY (C-IgY) and PBS groups. Anti-PcrV IgY improved opsonophagocytic killing and inhibition of bacterial invasion of host cells. Taken together, our data provide evidence that anti-PcrV IgY can be a promising therapeutic candidate for combating P. aeruginosa infections.

Simple Label-Free Electrochemical Immunosensor in a Microchamber for Detecting Newcastle Disease Virus

In this study, a simple, label-free, electrochemical immunosensor system, including a three-electrode transducer and a microchamber, was designed, fabricated, and integrated with focus toward the detection of Newcastle disease virus (NDV). The chicken egg yolk antibodies (IgY) against NDV were used as the biological recognition element, replacing purified IgG antibodies that require a complex extraction process and time-consuming. The IgY against NDV was immobilized on the sensor surface using PrA/GA and SAM/NHS approaches. The immunosensor showed high sensitivity with NDV concentrations ranging from 106 to 102 EID50/mL with good specificity, repeatability, and small standard deviations. Compared to traditional methods, the immunosensor with advantages such as simple fabrication, quick response, direct detection, and possibility for miniaturization by integrating the immunosensor with the microchamber is potential for applications in contamination studies and field measurements.

Reduction in Oviposition of Poultry Red Mite (Dermanyssus gallinae) in Hens Vaccinated with Recombinant Akirin.

The poultry red mite (PRM), Dermanyssus gallinae, is a hematophagous ectoparasite of birds with worldwide distribution that causes economic losses in the egg-production sector of the poultry industry. Traditional control methods, mainly based on acaricides, have been only partially successful, and new vaccine-based interventions are required for the control of PRM. Vaccination with insect Akirin (AKR) and its homolog in ticks, Subolesin (SUB), have shown protective efficacy for the control of ectoparasite infestations and pathogen infection/transmission. The aim of this study was the identification of the akr gene from D. gallinae (Deg-akr), the production of the recombinant Deg-AKR protein, and evaluation of its efficacy as a vaccine candidate for the control of PRM. The anti-Deg-AKR serum IgY antibodies in hen sera and egg yolk were higher in vaccinated than control animals throughout the experiment. The results demonstrated the efficacy of the vaccination with Deg-AKR for the control of PRM by reducing mite oviposition by 42% following feeding on vaccinated hens. A negative correlation between the levels of serum anti-Deg-AKR IgY and mite oviposition was obtained. These results support Deg-AKR as a candidate protective antigen for the control of PRM population growth.