Detection of immune effects of the Mannheimia haemolytica gamma irradiated vaccine in sheep

Exposure to gamma rays from cobalt 60 (Co60) can induce a complete inactivation of Mannheimia haemolytica. The inactivated bacterial pathogen is a potential vaccine candidate for immunization of ruminants such as sheep. The subcutaneous administration of irradiated vaccine in a two-dose regimen (4.0 × 109 colony forming unit (CFU) per dose) results in no mortality in any of the vaccinated sheep during immunization and after subsequent challenge of the live bacteria of the same strain of M. haemolytica. A significant rise in serum IgG titer, detected through ELISA, is observed after the passage of two weeks from the inoculation of the first dose whereas, the peak of the mean serum antibody titer occurred after two weeks of booster dose. The vaccination does not bring significant change to the IFN-γ levels in serum. The bacterial challenge of the vaccinated sheep does not induce a further seroconversion relative to serum antibody titer. In conclusion, the vaccinated sheep are protected by the elevated IgG titer and increased levels of IL-4 (Th-2 response) compared to the non-vaccinated sheep. Radiation technology can provide the opportunity for mass production of immunologically safe vaccines against animal and zoonotic diseases. Ethics Approval by the National Research Center Ethics Committee (Trial Registration Number (TRN) no 13,602,023, 13/5/2023) was obtained.

Evaluation of the therapeutic effect of propolis on Fasciola gigantica and Clostridium novyi type B infections in sheep

The use of natural products for disease control is a promising approach to solving the problem of drug resistance. The aim of the research reported here was to evaluate the fasciolicidal and anti-Clostridium novyi type B activities of propolis administered orally to sheep infected with Fasciola gigantica and C. novyi type B. Sheep infected with both pathogens were divided into two groups: an infected treated group and an infected non-treated group. The treatment was oral administration of 50 mg propolis extract/kg daily for 15 days. The body weight of the sheep, fecal egg counts of F. gigantica, serum levels of F. gigantica IgG, concentrations of cytokines (IL-2, IL-10, and IL-17), and bacterial counts of C. novyi were evaluated. Following treatment, the sheep had increased body weight and a significant decrease in the egg count, which was reduced by 54.54% at 15 days post treatment. The level of anti- Fasciola IgG increased, whereas levels of IL-2, IL-10, and IL-17 decreased in propolistreated sheep. Treatment of sheep with propolis produced a significant reduction in fecal count of C. novyi, from 8 × 10⁹ to 3 × 10³ colony units per gram at 15 days post treatment. This research highlights the therapeutic potential of Egyptian propolis extract as a treatment against F. gigantica and C. novyi type B infections, and investigated its mode of action through its effect on some cellular and humoral responses in sheep with both infections.

Preparation of goat and rabbit anti-camel immunoglobulin G whole molecule labeled with horseradish peroxidase

Aim:

As the labeled anti-camel immunoglobulins (Igs) with enzymes for enzyme-linked immunosorbent assay (ELISA) are unavailable in the Egyptian market, the present investigation was directed for developing local labeled anti-camel IgG with horseradish peroxidase (HRP) to save hard curacy.

Materials and Methods:

For purification of camel IgG whole molecule, camel sera was preliminary precipitated with 50% saturated ammonium sulfate and dialyzed against 15 mM phosphate-buffered saline pH 7.2 then concentrated. This preparation was further purified by protein A sepharose affinity column chromatography. The purity of the eluted camel IgG was tested by sodium dodecyl sulfate polyacrylamide gel electrophoresi. Anti-camel IgG was prepared by immunization of goats and rabbits separately, with purified camel IgG. The anti-camel IgG was purified by protein A sepharose affinity column chromatography. Whole molecule anti-camel IgG was conjugated with HRP using glutraldehyde based assay. Sensitivity and specificity of prepared conjugated secondary antibodies were detected using positive and negative camel serum samples reacted with different antigens in ELISA, respectively. The potency of prepared conjugated antibodies was evaluated compared with protein A HRP. The stability of the conjugate at −20°C during 1 year was assessed by ELISA.

Results:

The electrophoretic profile of camel IgG showed four bands of molecular weight 63, 52, 40 and 33 kDa. The recorded sensitivity and specificity of the product are 100%. Its potency is also 100% compared to 58-75% of commercial protein A HRP. The conjugates are stable for 1 year at −20°C as proved by ELISA.

Conclusion:

Collectively, this study introduces goat and rabbit anti-camel IgG whole molecules with simple, inexpensive method, with 100% sensitivity, 100% specificity and stability up to 1 year at −20°C. The important facet of the current study is saving hard curacy. Future investigations are necessary for preparation of IgG subclasses.

Significance of a common 65 kDa antigen in the experimental fasciolosis and toxoplasmosis

In the current study, cross-reaction between two important zoonotic parasites; extracellular helminthes Fasciola gigantica and intracellular protozoa Toxoplasma gondii was proved by enzyme linked immunosorbent assay. Five antigens were used to identify and compare the cross-binding activities in the prepared antisera. Two F. gigantica antigens; adult flukes (FgA) and eggs (FgEA) were used to detect IgG in T. gondii naturally infected human sera (TgIHS) and experimentally infected sera of sheep (TgISS), mice (TgIMS) and rats (TgIRS). Three types of T. gondii antigens; RH (TgRHA), local sheep isolate (TgLA) and ME49 isolate (TgMEA) were used to detect cross binding activities in F. gigantica experimental infected rabbit sera (FgIRS) and F. gigantica naturally infected bovine sera (FgIBS). The cross-binding activities in the prepared antisera were strongly directed towards FgA and TgLA rather than the other antigens. The characterization of the five antigens using SDS-PAGE showed 4 common bands of FgA and TgLA; 165, 97, 76, and 65 kDa. While two common bands were observed between TgRHA, TgMEA and FgA; 165, and 65 kDa. Whereas, two common bands found between three types of T. gondii antigens and FgEA were identified; 165 and 65 kDa. The immunogenic cross-reactive bands between FgA and TgLA with F. gigantica infected bovine sera were identified by immunoblot. In FgA, the common immunogenic bands were 165, 65 and 14 kDa. While in TgLA, common immunogenic bands were 165 and 65 kDa. Whereas, the common immunogenic band between FgA and TgLA identified with T. gondii experimentally infected sheep sera was 65 kDa. The current research proves cross reaction between F. gigantica and T. gondii. One common band of 65 kDa showed broad immunogenic cross-reactivity with the developed antisera raising the prospect of being putative common immunodiagnostic candidate of both infections.

Isolation and structural characterization of Toxocara vitulorum specific antigen and its potency in diagnosis of toxocariasis among buffalo calves

A method of affinity chromatography purification of species-specific antigen from Toxocara vitulorum adult worm is described. The purification process resulted in a fraction with 9315 fold increase in specific activity compared to crude extract. Structural characterization of the isolated fraction by SDS polyacrylamide gel electrophoresis, isoelectric focusing and amino acid analysis showed that the fraction consists of only two polypeptides of 92 kD and 87 kD with isoelectric points of 8.8 and 8.9. Moreover, 17 amino acids were identified in the fraction with high proportions of only three of them (tyrosine, glycine and glutamic). The isolated antigen proved potency in the diagnosis of toxocariasis among buffalo claves using ELISA which recorded 100% sensitivity.

Molecular identity of major cross-reactive adult antigens in Fasciola gigantica, Toxocara vitulorum and Moniezia expansa

Cross reactivity between Fasciola gigantica, Toxocara vitulorum and Moniezia expansa whole worm extracts was proved by ELISA. Intense cross-reaction was observed between F. gigantica and M. expansa rather than between each of them and T. vitulorum. As judged by immunoblot, the cross-reactive antigens in F. gigantica which recognized by T. vitulorum antisera was 109 kD while this component in addition to another one of 52 kD were detected by M. expansa sera in the same extract. Furthermore, T. vitulorum antigen which cross-reacted with F. gigantica was 133 kD and with M. expansa was 143 kD. Antigens responsible for cross-reactivity in M. expansa were 130 kD and 210 kD to T. vitulorum and F. gigantica respectively.

Structural characterization and immunolocalization of egg antigens cross-react with Toxocara vitulorum, Fasciola gigantica and Moniezia expansa mature flukes

A structural homology between eggs of Toxocara vitulorum, Fasciola gigantica and Moniezia expansa was proved by the use of SDS-PAGE. In immunoblot, 9, 11 and 7 polypeptides were recognized in F. gigantica, M. expansa and T. vitulorum eggs respectively by their respective rabbit anti-adult antisera. Moreover, components of 240 KD and 206 KD were recognized in the three eggs by different anti-adult antisera. The anatomic localization of the crossreactive epitopes in eggs was determined by indirect immunofluorescence microscopy. The cross-reactive epitopes were mainly associated with embryonted cells of F. gigantica, egg shell, larvae and vitelline membranes of T. vitulorum and egg shall and granular layer of M. expansa.