Yolk Antibodies Research Articles

Oral antibody to interleukin-10 receptor 2, but not interleukin-10 receptor 1, as an effective Eimeria species immunotherapy in broiler chickens.

Coccidiosis is a major gastrointestinal disease caused by several Eimeria species in floor raised chickens. Feeding an antibody to interleukin 10 (aIL-10) ameliorates the negative symptoms of coccidiosis in broilers, i.e., lack of weight gain, decreased feed conversion, and mortality. IL-10 signals by forming a ligand-receptor complex with IL-10 Receptor 1 (IL-10 R1) and IL-10 Receptor 2 (IL-10 R2). In this study, we hypothesize oral antibodies to the IL-10 receptors will neutralize the IL-10 signaling pathway equal to or better than aIL-10 to act as an oral anti-coccidiosis immunotherapy. A total of 5 sequential feed trials, set up as a 4 (diet antibody) × 2 (Eimeria challenge) factorial design, tested oral egg yolk antibodies to a total of 6 IL-10 R1 epitopes and 3 IL-10 R2 epitopes compared to a control antibody diet. A total of 10 pens of 5 chicks/pen/diet antibody/Eimeria challenge were housed for 21 d. On day 3 of age, chicks were either infected or not infected with a 10× dose of an Eimeria vaccine containing Eimeria acervulina, Eimeria tenella, and Eimeria maxima. Pen feed consumption and mean body weights were assessed weekly (d1, d7, d14, and d21); fecal oocyst shedding was assessed on day 10. Data were analyzed using a 2-way ANOVA. No significant interaction on chick weight was observed in chicks fed IL-10 R1 antibodies compared to chicks fed the control antibody was observed. In studies evaluating aIL-10 R2 oral antibodies, infected chicks fed aIL-10 R2: epitope 1 overcame the negative effects of Eimeria infection and had similar 21-d body weight to uninfected chicks (P4 = 0.07). We hypothesized that feeding oral antibodies to the IL-10 receptors would result in equivalent anti-coccidial benefits to aIL-10. However, none of the 6 antibodies to IL-10 R1 epitopes yielded any benefits during Eimeria infection compared to controls. A total of 2 oral antibodies to IL-10 R2 showed promising results equivalent to the aIL-10 immunotherapeutic. Immunofluorescence staining shows that the IL-10R2 significantly increases in abundance in response to Eimeria infection, whereas IL-10R1 does not.

Rainbow trout fillet biopreservation by edible chitosan-based coating containing egg yolk antibody (IgY) and lycopene.

The aim of the study was to investigate the effect of the extracted egg yolk antibody along with lycopene on the chemical quality of the rainbow trout fillet during 16days of refrigeration storage. Chickens were immunized against Pseudomonas fluorescens (P. fluorescens), Shewanella putrefaciens (S. putrefaciens) and total spoilage bacteria and their eggs were collected for the isolation of egg yolk antibodies. Then fish fillets were immersed in chitosan-based coating solutions, containing lycopene and extracted antibodies, and analyzed for lipid oxidation changes (peroxide, thiobarbituric acid, free fatty acid and fatty acid profile), physico-chemical properties (pH and water holding capacity), and sensory evaluation, during 16days of refrigeration storage. Results showed that chitosan solutions with lycopene or IgY could significantly (p < 0.05) increase the oxidative stability of lipids in fish fillets; although, combinational use of lycopene and IgY showed a higher effect on delaying the rate of lipid oxidation. Significant differences were also observed between treatments contained combination of chitosan, antibody and lycopene with the control group, regarding pH and WHC. Saturated fatty acids increased in all treatments, although the changes in the treatments containing lycopene and antibody were significantly (p < 0.05) lower than the control group. Hence the addition of egg yolk antibody and lycopene in coating solution are good bio-preservatives for seafood products as it improves sensory attributes and prevents lipid oxidation.

Evaluation of efficacy of chicken egg yolk (IgY) antibodies and aloe vera extract against Candida albicans in vitro and In vivo with respect to oral candidiasis

Evaluation of efficacy of chicken egg yolk (IgY) antibodies and aloe vera extract against Candida albicans in vitro and In vivo with respect to oral candidiasis

Reducing Campylobacter jejuni colonization in broiler chickens by in-feed supplementation with hyperimmune egg yolk antibodies

Campylobacter infections sourced mainly to poultry products, are the most important bacterial foodborne zoonoses worldwide. No effective measures to control these infections in broiler production exist to date. Here, we used passive immunization with hyperimmune egg yolks to confer broad protection of broilers against Campylobacter infection. Two novel vaccines, a bacterin of thirteen Campylobacter jejuni (C. jejuni) and C. coli strains and a subunit vaccine of six immunodominant Campylobacter antigens, were used for the immunization of layers, resulting in high and prolonged levels of specific immunoglobulin Y (IgY) in the hens’ yolks. In the first in vivo trial, yolks (sham, bacterin or subunit vaccine derived) were administered prophylactically in the broiler feed. Both the bacterin- and subunit vaccine-induced IgY significantly reduced the number of Campylobacter-colonized broilers. In the second in vivo trial, the yolks were administered therapeutically during three days before euthanasia. The bacterin IgY resulted in a significant decrease in C. jejuni counts per infected bird. The hyperimmune yolks showed strong reactivity to a broad representation of C. jejuni and C. coli clonal complexes. These results indicate that passive immunization with hyperimmune yolks, especially bacterin derived, offers possibilities to control Campylobacter colonization in poultry.

Antigenic epitopes on the outer membrane protein A of Escherichia coli identified with single-chain variable fragment (scFv) antibodies.

Bacterial meningitis is a severe disease that is fatal to one-third of patients. The major cause of meningitis in neonates is Escherichia coli (E. coli) K1. This bacterium synthesizes an outer membrane protein A (OmpA) that is responsible for the adhesion to (and invasion of) endothelial cells. Thus, the OmpA protein represents a potential target for developing diagnostic and therapeutic agents for meningitis. In this study, we expressed recombinant OmpA proteins with various molecular weights in E. coli. The sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was performed to check the molecular size of OmpA's full length (FL) and truncated proteins. OmpA-FL protein was purified for immunizing chickens to produce immunoglobulin yolk (IgY) antibodies. We applied phage display technology to construct antibody libraries (OmpA-FL scFv-S 1.1 × 107 and OmpA-FL scFv-L 5.01 × 106) to select specific anti-OmpA-FL scFv antibodies; these were characterized by their binding ability to recombinant or endogenous OmpA using ELISA, immunofluorescent staining, and confirmed with immunoblotting. We found 12 monoclonal antibodies that react to OmpA fragments; seven scFvs recognize fragments spanning amino acid (aa) residues 1-346, aa 1-287, aa 1-167, and aa 60-192, while five scFvs recognize fragments spanning aa 1-346 and aa 1-287 only. Two fragments (aa 246-346 and aa 287-346) were not recognized with any of the 12 scFvs. Together, the data suggest three antigenic epitopes (60 aa-160 aa, 161 aa-167 aa, 193 aa-245 aa) recognized by monoclonal antibodies. These scFv antibodies show strong reactivity against OmpA proteins. We believe that antibodies show promising diagnostic agents for E. coli K1 meningitis.

Assessment on reticuloendotheliosis virus infection in specific-pathogen-free chickens based on detection of yolk antibody.

Reticuloendotheliosis virus (REV) is the most frequent exogenous virus that contaminates attenuated vaccines. Therefore, it is extremely important to select REV-free specific-pathogen-free (SPF) chicken embryos. Generally, REV infection is assessed by detecting REV antibodies in SPF chickens. This present study seeks to evaluate REV infection by replacing serum antibody detection with yolk antibody detection. A cohort of 40 nineteen-week-old SPF chickens were artificially inoculated with REV, with 32 SPF chickens raised in another isolation environment served as a blank control. Eggs and serum from 23-week-old chickens were sampled, and yolks were diluted separately to ratios of 1:150, 1:200, 1:300 and 1:400, which were detected together with serum. We found that the yolk antibody detection findings at a dilution of 1:300 had the highest coincidence rate compared with that based on serum antibody measurements. At a dilution ratio of 1:300 for yolk antibody, 72 chickens were continuously observed for 10 weeks from 25- to 34-weeks-old. Our findings were based on serum antibody or yolk antibody detection, and the evaluation results were completely consistent. Therefore, all serum antibody-positive chickens were yolk antibody-positive, and vice versa. Accordingly, vaccine producers can estimate REV cleanliness in a poultry farm by sampling yolk antibody titers.

IgY-based antivenom against Bothrops alternatus: Production and neutralization efficacy

Antivenom for the treatment of bothropic snakebite is a priority for public health institutions from Latin America. An alternative to the conventional antivenom production is based on the use of egg yolk antibodies – IgY-technology – by immunizing laying hens. In this study, we produced, characterized and assessed the efficacy of IgY-based antivenoms against B. alternatus venom. Immunochemical studies (reactivity, avidity and antigen recognition pattern) as well as antivenom efficacy assays were performed. After the 3rd immunization, levels of specific IgY reached a maximum that was maintained throughout the observation period, while avidity indexes of the extracts increased after the successive immunizations. Furthermore, IgY against B. alternatus recognized protein complexes of the venom with high (>40 kDa), medium (20–40 kDa) and low (<20 kDa) molecular weights. IgY antivenoms obtained after 8 immunizations neutralized 35.65 μg of B. alternatus venom per mg of antivenom, while specific activities values ranged from 0.28 to 0.42. In conclusion, we produced and characterized IgY antivenoms capable of neutralizing the lethal activity of B. alternatus venom at a preclinical level. Thus, IgY-technology may allow the production of effective and affordable antivenoms fulfilling the urgent needs of many countries where conventional manufacture is unable to provide enough availability of antivenoms.

Production and Purification of Specific IgY Against InvG Protein of Salmonella typhimurium

Background: Salmonella infections are one of the most important causes of human and animal diseases, worldwide. InvG gene is one of the main genes of type III secretion system and leads to initial binding of the bacteria to the host cells. In the recent decades IgY technology has been detected as an efficient alternative procedure to generate antibody for applying in immunotherapy. Objectives: This research attempted to produce and detect IgY against the recombinant InvG protein of Salmonella typhimurium and evaluate specificity of anti-InvG IgY against the recombinant InvG antigen. Methods: Polymerase chain reaction was carried out to amplify InvG gene with InvG one pair of specific primer of Salmonella typhimurium. pTZ57R/T and pET32a vectors were used to clone and sub-clone InvG gene. Recombinant pET32a-InvG plasmid was transferred to E. coli BL21 (DE3). Expression induction was carried out using 1.5 mM isopropyl β-D-1-thiogalactopyranoside. Next, the recombinant InvG protein was injected to laying hens. Western-blotting and Dot-blotting analysis and iELISA were carried out to determine the specify of anti-InvG IgY. Results: This research produced specific InvG egg yolk antibodies by injecting InvG protein to the hens. The anti-InvG IgY corroborated to bind specifically with the InvG protein of Salmonella typhimurium. Conclusions: The finding of the present research confirmed that anti-InvG IgY could be suggested as a candidate for passive immunization and protection against Salmonella typhimurium.

Specific Chicken Egg Yolk Antibody Improves the Protective Response against Gallibacterium anatis Infection.

Gallibacterium anatis is a pathogen associated with peritonitis and salpingitis in chickens and other avian species. Novel safety prevention strategies are urgently needed because of widespread multidrug resistance and antigenic diversity. The objective of this study was to produce a specific chicken egg yolk antibody and evaluate its protective response against a G. anatis infection model in 4-week-old chicks. Enzyme-linked immunosorbent assays showed that hens immunized with the recombinant N terminus of Gallibacterium toxin A (GtxA-N) had significantly increased antibody titers against GtxA-N in serum and egg yolk IgY. Western blotting showed that IgY antibody had specificity against GtxA-N in the egg yolks of immunized hens. The growth of G. anatis in brain heart infusion (BHI) broth and agar was significantly inhibited by the GtxA-N-specific IgY antibody. The protective effects of the specific IgY antibody were evaluated in G. anatis-infected chicks after intramuscular injection (10 mg/ml). The anti-GtxA-N antibody titers in the sera of G. anatis-challenged chicks following an injection of specific IgY antibody were significantly higher than those of the control and the nonspecific IgY groups, but lower lesion scores for the peritoneum, liver, and duodenum were found after specific IgY antibody treatment. The results from this study suggest that the GtxA-N-specific IgY antibody could potentially improve the protective response against G. anatis infection in chicks.

Intact anti-LPS IgY is found in the blood after intragastric administration in mice.

Severe burn injury and cirrhosis often cause the translocation of bacterial endotoxins into blood, leading to systemic damage and even death. Our previous studies have shown that anti‐lipopolysaccharide egg yolk antibody (anti‐LPS IgY) can neutralize bacterial endotoxins in vitro and in vivo effectively, thereby reducing endotoxin damage. Whether anti‐LPS IgY can be absorbed into the blood through the intestinal barrier and neutralize endotoxins in circulation remains unclear. In this study, we used in vivo small animal imaging techniques, protein purification, molecular biology, and mass spectrometry to show that intragastrically administered anti‐LPS IgY is detected in the blood of mice as an intact molecule and has the capacity to bind to LPS. Immunohistochemical analysis confirmed that anti‐LPS IgY is associated with the intestinal mucosa of mice. However, the route of absorption of this large protein molecule was not determined. This study suggests that anti‐LPS IgY can be absorbed into the circulation, with the same molecular mass as purified anti‐LPS IgY as a macromolecular protein, suggesting a new strategy for the prevention of damage caused by endotoxins.

Poliovirus-binding inhibition ELISA based on specific chicken egg yolk antibodies as an alternative to the neutralization test

The first application results of enzyme immunoassay system (ELISA) – binding inhibition ELISA (BI ELISA) for the detection of antibodies to polioviruses of three types based on the use of specific antibodies from chicken yolk (IgY) are presented. This variant of ELISA is a “surrogate” neutralization test (NT). When comparing the results of the detection of antibodies in 90 sera of children who were vaccinated with oral and inactivated poliovirus vaccines, good correlation (r = 0.67, 0.61, 0.76 for types 1, 2, 3 respectively) between the BI ELISA and the NT results was shown. The presented variant of ELISA is the further stage of the development of “IgY-technology” for laboratory diagnostics of viral infections, namely poliovirus infection, which can be used for seroepidemiological studies as an analogue of the NT which requires the use of life poliovirus with the required standard of biosafety containment facilities.

Exposure of yellow-legged gulls to Toxoplasma gondii along the Western Mediterranean coasts: Tales from a sentinel.

Efficiently tracking and anticipating the dynamics of infectious agents in wild populations requires the gathering of large numbers of samples, if possible at several locations and points in time, which can be a challenge for some species. Testing for the presence of specific maternal antibodies in egg yolks sampled on the colonies could represent an efficient way to quantify the exposure of breeding females to infectious agents, particularly when using an abundant and widespread species, such as the yellow-legged gull (Larus michahellis). We used such an approach to explore spatio-temporal patterns of exposure to Toxoplasma gondii, a pathogenic protozoan responsible of toxoplasmosis in humans and other warm-blooded vertebrates. First, we tested the validity of this approach by exploring the repeatability of the detection of specific antibodies at the egg level using two different immunoassays and at the clutch level using an occupancy model. Then, samples gathered in 15 colonies from France, Spain and Tunisia were analysed using an immunoassay detecting antibodies specifically directed against T. gondii. Prevalence of specific antibodies in eggs was overall high while varying significantly among colonies. These results revealed that T. gondii circulated at a large spatial scale in the western Mediterranean yellow-legged gull population, highlighting its potential role in the maintenance community of this parasite. Additionally, this study illustrates how species commensal to human populations like large gulls can be used as wildlife sentinels for the tracking of infectious agents at the human-wildlife interface, notably by sampling eggs.

Effect of IgY on Periodontitis and Halitosis Induced by Fusobacterium nucleatum.

Fusobacterium nucleatum is a morbific agent in periodontitis and halitosis. Egg yolk antibody (IgY) was obtained from egg yolks from chickens stimulated with F. nucleatum. This study was to assess the effectiveness of IgY on periodontitis and halitosis caused by F. nucleatum in vitro and in vivo. The growth of F. nucleatum was inhibited (p <0. 05) by different concentrations of IgY in vitro and the results of a Halimeter show volatile sulfur compounds (VSCs) were reduced to 904 ± 57 ppb at a concentration 40 mg/ml of IgY. The changes of fatty acids of F. nucleatum were determined using GC-MS. The scores for odor index of rat saliva were decreased. The major constituent of volatile organic compounds (VOCs) including short-chain acids decreased 46.2% in 10 mg/ml IgY, ammonia decreased 70% in 40 mg/ml IgY, while aldehydes and olefine ketones were almost unchanged. The ELISA assay revealed that IL-6 and TNF-α were decreased after 4 weeks' IgY treatment. Morphometric (X-ray) and histological analyses (HE) showed that IgY reduced alveolar bone loss and collagen fibers became orderly in rat models. As a result, IgY may have the potential to treat periodontitis and halitosis.

Analysis of antibody levels in egg yolk for detection of exposure to Ascaridia galli parasites in commercial laying hens

Ascaridia galli is one of the most abundant nematode parasites in poultry. A. galli infections can significantly impact the profitability of egg farms and have negative implications for bird health and welfare. The main objectives of this study were to determine whether A. galli specific antibodies in egg yolks can be used to detect prior or current exposure to A. galli in laying hens, and to distinguish between eggs obtained from caged and free-range hens. Twenty-two laying hen flocks from different production systems (10 free-range, 2 barn-housed, and 9 caged flocks) were enrolled in the study. An in-house enzyme-linked immunosorbent assay was used to analyze levels of A. galli specific antibodies in yolk. The numbers of A. galli eggs in hen excreta were also determined in a subset of farms. Free-range flocks had higher and also more variable levels of anti-A. galli antibodies in the egg yolk compared to those of the cage flocks (0.50 ± 0.39 vs. 0.16 ± 0.13 OD units) (P < 0.001). Results also confirmed that excreta from free-range and barn-housed flocks contained higher numbers of A. galli eggs than did excreta from caged flocks in which no A. galli eggs were detected. In conclusion, analysis of anti-A. galli antibodies in the egg yolk can be used to detect worm exposure in commercial layer flocks. However, the method used in this study cannot be used in isolation to distinguish between eggs from cage and free-range production systems as anti-A galli antibodies were detected in egg yolk samples from all production systems, and the range of antibody levels overlapped between production systems.

Awareness and antibody detection of Newcastle disease virus in a neglected society in Nigeria

Aims:This study aimed to assess the level of awareness of rural poultry farmers on vaccination and to detect Newcastle disease virus (NDV) antibody in local birds (LB) and eggs in Kwara State, Nigeria.Materials and Methods:Data on farmers’ attitude, knowledge, practices, and experiences on ND mortality were obtained through an interview using a structured cross-sectional checklist. NDV antibodies were detected in sera and egg yolks of local chickens (LC) and guinea fowls (GF) using hemagglutination inhibition test.Results:A total of 83 interviewees, 287 sera and 121 egg yolk extracts, were examined. The study revealed that 98.8% (82/83) of the interviewee had never vaccinated their flock before. 90% of the interviewee had reported high mortality in birds within 1-6 months old, while the major clinical signs were cold (40.4%) and torticollis (30.8%). Evidences of LB exposure to wild-type NDV were confirmed by the detection of NDV antibodies in 20.8% and 0% of LC and GF, respectively. The mortality differences experiencedin <1 and 1-6 months old LB could be explained by the presence of maternally-derived NDV antibody (49.6%) in egg yolk.Conclusion:The study showed that LB suffers from NDV as a result of LB keepers’ ignorance and neglect by the government. This has limited local investment and subsequent contribution to gross domestic product. This study suggests that the key factors to the prevention of ND remain awareness creation about poultry vaccination, production of affordable vaccines, and availability/accessibility to veterinarian (or trained personnel).

Enterobacter cloacae associated with mass mortality in zoea of giant freshwater prawns Macrobrachium rosenbergii and control with specific chicken egg yolk immunoglobulins (IgY)

Outbreaks of mass mortality among cultured zoea of M. rosenbergii occurred in different hatcheries of Gaoyou country of China in April 2017. Of the isolates obtained from the diseased zoea, XL3–1 was pathogenic to the zoea and postlarva of M. rosenbergii in the virulence test, with a LD50 value 3.2 × 106 CFU/mL and 3.5 × 106 CFU/mL, respectively. XL3–1 was identified as Enterobacter cloacae by biochemical characteristics and molecular tools. Detection of virulence-associated genes by PCR indicated that XL3–1 was positive for irp2, fhuA, sodB, sltA, flaD and OmpX. According to the antibiotic resistant assay, the isolate was sensitive to quinolones, while they were resistant to cephalosporins and penicillins. This study also investigated the protection of specific chicken egg yolk antibodies (IgY) in E. cloacae-infected M. rosenbergii. The highest titer against E. cloacae of the obtained specific IgY by ELISA was 1: 213. M. rosenbergii treated with specific egg yolk powder could achieve the survival rate of 67% after E. cloacae infection, while M. rosenbergii treated with non-specific egg yolk powder or no egg yolk powder could achieve survival rates of 20% and 17%, respectively. As well, the bacterial burden in hepatopancreas was significantly lower in M. rosenbergii treated with specific egg yolk powder than those treated with non-specific egg yolk powder. This study clarified the virulence characteristics and antibiotic resistance of E. cloacae, and provided a strategy to control the disease by using specific IgY.

Specific egg yolk antibodies (IgY) confer protection against Acinetobacter baumannii in a murine pneumonia model.

Acinetobacter baumannii, an increasingly serious health threat, is considered as one of the six most dangerous microbes of high mortality rate. However, treatment of its infections is difficult because of the lack of efficient antibiotic or commercial vaccines. Passive immunization through administration of specific antibodies such as IgY, could be an attractive practical solution. In the current study, antigenicity of two recombinant outer membrane proteins (OmpA and Omp34) as well as inactivated whole cell of A. baumannii was assessed by ELISA. Moreover, prophylactic effects of specific IgY antibodies (avian antibody) raised against these antigens were evaluated in a murine pneumonia model. The specific IgY antibodies had various prophylactic effects in the pneumonia model. OmpA was the most potent antigen in terms of triggering antibody and conferring protection. While a synergic effect was observed in ELISA for antibodies raised against a combination of OmpA and Omp34 (which are known as Omp33-36 and Omp34kDa), an antagonistic effect was unexpectedly seen in challenges. The reason for this phenomenon remains to be precisely addressed. All the specific IgY antibodies could protect mice against pneumonia caused by A. baumannii. The specific IgY antibodies could be employed as a pharmaceutical against pneumonia caused by A. baumannii.

An immunological determination of somatostatin in pharmaceutical by sandwich ELISA based on IgY and polyclonal antibody

A sensitive and specific enzyme-linked immunosorbent assay (ELISA) for the detection of Somatostatin based on double antibody sandwich method was studied in this paper. The Somatostatin specific Yolk antibody (IgY) and polyclonal antibody were available to Somatostatin-conjugated KLH immunized rabbits and chickens used to construct the sandwich ELISA for the measurement of Somatostatin. The limit of detection was 0.1 μg/mL and the half maximal inhibitory concentration (IC50) was 0.859 μg/mL. The method developed in the study showed no evident cross-reactivity with other similar analogs. The recoveries of Somatostatin spiked mannitols were in the range of 98.45% to 103.90% with intra- and inter-day coefficient of variants (CVs) <8.71% and 4.60% respectively. The detection standard curve of Somatostatin exhibited a good linearity (R2 = 0.9931, n = 3). Therefore, the methods could be selectively used for rapid screening of Somatostatin in pharmaceutical.

Development of IgY-Based Sandwich ELISA as a Robust Tool for Rapid Detection and Discrimination of ToxigenicVibrio cholerae

Background The conventional methods for diagnosis of Vibrio cholerae are time consuming, complicated, and expensive. Development of rapid detection tests is critical for prevention and management of cholera. This study aimed to introduce two sensitive sandwich ELISAs based on avian antibodies (IgY) targeting outer membrane protein W (OmpW) and cytotoxin B (CtxB) antigens of V. cholerae. Methods The sequences of ompW and ctxB genes were cloned into pET28a vector. Escherichia coli BL21 (DE3) was transformed with the recombinant vectors, and gene expression was induced by IPTG. The expressed proteins were purified by affinity chromatography using Ni-NTA resins. Two groups of white Leghorn chickens were immunized by recombinant proteins, and the generated antibodies were purified from egg yolks of chickens by PEG precipitation. The antibodies were used for the development of α-OmpW and α-CtxB ELISAs. Results The expression and purification yielded 59 and 38 mg of recombinant OmpW and CtxB, respectively, per one liter of bacterial culture. PEG precipitation and purification of egg yolk antibodies yielded on average (±SD) 66.5 ± 1.80 and 50.9 ± 2.23 mg of purified α-OmpW and α-CtxB per egg, respectively. The analytical sensitivity of α-OmpW ELISA was 103 cfu/mL of V. cholerae and that of α-CtxB ELISA was 33 pg/mL of recombinant cytotoxin B. The two developed ELISAs did not show any cross-reactivity to any tested bacteria grown in common conditions. Discussion The current study is the first report on using IgY for detection of V. cholerae. The developed ELISAs were shown to have considerable analytical sensitivity and specificity. Therefore, the assays can be one of the convenient methods for sensitive and specific detection of toxigenic V. cholerae strains in clinical and environmental samples.

STUDY OF MATERNAL IMMUNITY IN RELATION TO SOME PRODUCTIVE TRAITS IN CHICKENS

The present study was carried out in the Department of Poultry Production, Faculty of Agriculture at Shibin El-Kom, Menoufia University. The aim of the present study was to determine the concentration of maternal antibody (IgY) in blood serum and egg yolk of three, control, high and low IgY antibody lines of Sinai and Silver Montazah local chickens in relation to some productive traits in chicken. The results were discussed and summarized as follows: 1- Sinai strain had significantly higher IgY antibody concentration than Silver Montazah strain of chickens, being 4.68 vs 4.22 mg/ml in hen blood serum, 4.11 vs 3.46 mg/ml in egg yolk, 3.09 vs 2.66 mg/ml in hatched chicks serum and 48.00 vs 38.41 mg/egg yolk total, respectively. 2- Highly significant differences (P<0.01) among lines, the high lines harvested the highest IgY level and control lines occupied intermediate level, where the low lines had the lowest IgY level in both strains of chickens. 3- The transferred (%) of IgY were 66.24 vs 62.88 (%) from dams to newly hatched chicks in Sinai and Silver Montazah strains of chicken respectively. 4- The IgY (%) transferred from dams to newly hatched chicks were 67.21 vs 61.89 (%) for control lines, 76.47 vs 71.67 (%) for high lines and 58.17 vs 52.06 for low lines of Sinai and Silver Montazah strains of chickens respectively. 5- There were strong positive highly significant simple correlation coefficients between IgY concentration in the layers and egg yolk (r=0.994 vs 0.934), between layers and chicks (r= 0.937 vs 0.879) and between egg yolk and chicks (r= 0.930 vs 0.908) in Sinai and Silver Montazah strains of chicken respectively. 6- The birds high in IgY antibody levels had significantly higher percentages of fertility, hatchability, livability, early age at sexual maturity, and higher egg production traits as compared to low birds in IgY antibody concentrations. 7- The present results, explained that the IgY antibody can be used as genetic marker to improve some productive traits in chickens.