Attenuation of pathogenesis of Eimeria stiedae sporulated oocysts using Egyptian alginate propolis nanoparticles

BACKGROUND

Coccidiosis is a costly and widespread infectious disease that affects mammals and causes huge losses for the global rabbit meat industry. This study evaluated the potency of Egyptian alginate propolis nanoparticles (NPs) in attenuating the infectivity of Eimeria stiedae sporulated oocysts. The gelification method was used to prepare alginate propolis NPs, which were then characterized using a transmission electron microscope and zeta potential analysis.

RESULTS

The results revealed that the zeta potential of the prepared alginate propolis NPs increased from - 60.60 ± 9.10 mV to -72.26 ± 6.04 mV. The sporulated oocysts were treated with 50 mg/mL of the alginate propolis NPs. Thereafter, the treated oocysts were tested for their ability to infect rabbits. The rabbits were divided into three groups: the healthy control (G1) group, the infected control (G2) group, and the treated oocyst-infected (G3) group. The rabbits were sacrificed 43 days post-infection (dpi). The infectivity of the oocysts was assessed. The treated oocyst-infected rabbits exhibited slight abdominal distension and dullness symptoms. The G3 group had no oocyst output, with a 100% reduction from 41 dpi until the end of the experiment. Immunologically, the IgG level of the G2 group gradually increased (p ≤ 0.05) much more than that of the G3 group. The IL-12 level in the G3 group significantly increased from 16 dpi until the end of the experiment, nearly reaching the level in healthy animals. Decreased CD4+ and CD8+ immunolabelling was observed in the liver sections of the group infected with the alginate propolis NP-treated oocysts, and there was a remarkable improvement in the histopathological parameters.

CONCLUSIONS

These data indicate that Alg propolis NPs are sufficient to reduce the infectivity of E. stiedae oocysts.

Molecular Epidemiological Investigation of Piroplasms and Anaplasmataceae Bacteria in Egyptian Domestic Animals and Associated Ticks

Piroplasmosis and anaplasmosis are serious tick-borne diseases (TBDs) that are concerning for the public and animal health. This study aimed to detect the molecular prevalence and epidemiological risk factors of Piroplasma and Anaplasma species in animal hosts and their associated ticks in Egypt. A total of 234 blood samples and 95 adult ticks were collected from animal hosts (112 cattle, 38 sheep, 28 goats, 26 buffaloes, 22 donkeys, and 8 horses) from six provinces of Egypt (AL-Faiyum, AL-Giza, Beni-Suef, Al-Minufia, Al-Beheira, and Matruh). Blood and tick samples were investigated by polymerase chain reaction coupled with sequencing targeting 18S and 16S RNA genes for Piroplasma and anaplasmataceae, respectively. Statistical analysis was conducted on the potential epidemiological factors. Of the 234 animals examined, 54 (23.08%) were positive for pathogens DNA distributed among the six provinces, where 10 (4.27%) were positive for Piroplasma, 44 (18.80%) for anaplasmataceae, and 5 (2.14%) were co-infected. Co-infections were observed only in cattle as Theileria annulata and Anaplasma marginale plus Babesia bigemina, A. marginale plus B. bigemina, and T. annulata plus B. bigemina. Piroplasmosis was recorded in cattle, with significant differences between their prevalence in their tick infestation factors. Animal species, age, and tick infestation were the potential risk factors for anaplasmosis. All ticks were free from piroplasms, but they revealed high prevalence rates of 72.63% (69/95) with anaplasmataceae. We identified T. annulata, B. bigemina, and A. marginale in cattle; A. platys in buffaloes; A. marginale and A. ovis in sheep; for the first time, A. ovis in goats; and Ehrlichia sp. in Rhipicephalus annulatus ticks. Our findings confirm the significant prevalence of piroplasmosis and anaplasmosis among subclinical and carrier animals in Egypt, highlighting the importance of the government developing policies to improve animal and public health security.

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.

Molecular characterization of the 2018 outbreak of lumpy skin disease in cattle in Upper Egypt

Background and Aim

Lumpy skin disease (LSD), an infectious disease of cattle, is characterized by raised nodules on the skin. Although the morbidity rate of LSD is low, it has a considerable fatality rate. Despite the annual mass vaccination of livestock with sheep pox vaccine (Veterinary Serum and Vaccine Research Institute, Egypt) enforced by Egyptian authorities, the LSD virus (LSDV) continues to circulate almost every summer. The present study aimed to discover the cause of cows naturally infected with LSDV circulating in Upper Egypt during the summer of 2018 using polymerase chain reaction (PCR) assay and to analyze their phylogenetics against reference genome sequences.

Materials and Methods

We cultured LSDV in specific pathogen-free embryonated chicken eggs (SPF-ECE) and used conventional PCR to identify fusion and P32 genes, previously deposited in GenBank (MN694826, MN694827, and MN954664). Sequencing and phylogenetic analyses were performed on these two highly conserved viral genes.

Results

LSDV infection of SPF-ECE resulted in characteristic white pock lesions. PCR products were identified on 1.5% agarose gel after electrophoresis at the expected positions for the fusion and P32 genes at 472 and 587 bp, respectively.

Conclusion

The present study revealed that the two viral genes were identified from the Beni Suef and Sohag Governorates in all clinical cases and confirmed the circulation of LSDV in this outbreak. After sequencing, these genes were identical to those of the LSDV that had been identified and recorded in GenBank for the past 3 years.

A simple and efficient purification method of native immunoreactive antigen for diagnosis of camel hydatidosis

BACKGROUND

Cystic echinococcosis (CE), a zoonotic disease that affects animal and human health, is of increasing economic importance due to high morbidity rates and high economic losses in the livestock industry.

AIM

The present study was conducted to purify the antigen from hydatid cyst fluid (HCF) with high diagnostic efficacy of camel hydatidosis using indirect enzyme-linked immunosorbent assay (ELISA).

MATERIALS AND METHODS

The HCF antigen was purified using Sephacryl S-300 column chromatography. Characterization of fractions was performed using reducing and non-reducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis. Further, antibodies against Echinococcus granulosus cysts in camel serum were detected using indirect ELISA.

RESULTS

The purification process resulted in three fractions of antigens: FI, FII, and FIII. Indirect ELISA showed that higher diagnostic efficacy was observed in FI than in FII and FIII. Indirect ELISA, in which FI was utilized, showed 88% sensitivity and 91.7% specificity. Non-reducing SDS-PAGE showed that FI had two bands of molecular weights 120 and 60 kDa. Western blot analysis of FI demonstrated that 60, 38, and 22 kDa were antigenic bands when reacted with naturally infected camel sera with E. granulosus cysts. Using indirect ELISA, F1 recorded an infection percentage of 81.7% in randomly collected camel serum samples.

CONCLUSION

FI is a promising antigen for accurate diagnosis of camel CE using indirect ELISA.

Evaluation of vaccine candidates purified from the adult ticks of Ornithodoros savignyi (Acari: Argasidae) and Hyalomma dromedarii (Acari: Ixodidae) against tick infestations

Ticks cause anemia, toxicosis, growth delay, and transmit infectious diseases in animals and humans. The current study aimed to evaluate the immunoprophylactic properties of two vaccine candidates to develop vaccine against tick infestations. These two vaccine candidates were specific fraction from the adults of the soft tick Ornithodoros savignyi and cross-reactive fraction from the adults of the hard tick Hyalomma dromedarii. Both specific and cross-reactive fractions were isolated by Cyanogen Bromide-activated Sepharose-4B affinity column chromatography. Both candidates proved their cross-reactivity by enzyme linked immunosorbent assay and Western blot. Characterization of the two vaccines by SDS-PAGE showed that the O. savignyi specific fraction consists of four bands; 97, 85, 66 and 11.5 kDa compared with nine bands associated with its crude antigen (196-11.5 kDa). The H. dromedarii cross-reactive vaccine candidate consists of three bands; 97, 66 and 45 kDa compared to eight bands of its crude antigen (196-21 kDa). Two common bands of 97 and 66 kDa between two candidates showed immunogenic cross-reactivity with the developed antisera of both infestations by Western blot. Immunization of rabbits intramuscularly with two doses of the fractions separately (40 µg/kg) led to immunological and parasitological changes. Immunologically; the level of immunoglobulins in vaccinated rabbits increased significantly compared with control infested non-vaccinated rabbits. These immunoglobulins are probably responsible for the protective effect of both candidates. Parasitologically, immunized rabbits showed protection against infestation by adult ticks as proved by significant feeding rejection percentage and significant reduction in egg and engorgement weights of H. dromedarii. While insignificant protection was observed against O. savignyi ticks infestation in feeding rejection and reduction in engorgement weight. In conclusion, this study suggests promising immunoprophylactic potentials of the purified fractions against tick infestations in rabbits through induction of IgG responses. The protective effect of both vaccine candidates deserves further evaluation in other hosts and against other tick infestations.

Toxocara vitulorum cuticle glycoproteins in the diagnosis of calves' toxocariasis

Aim:

The current study was designed to isolate and characterize Toxocara vitulorum glycoprotein antigens and then to evaluate its potency in accurate diagnosis of toxocariasis.

Materials and Methods:

T. vitulorum glycoprotein fractions were isolated using Con-A affinity chromatography. The fractions characterized using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and immunoblot assay. Mass spectrometric analysis was used for identification of proposed structure of the N-acetylglucosamine (GlcNAc) fraction. Enzyme-linked immunosorbent assay (ELISA) was used to assess the diagnostic potential of the isolated fractions.

Results:

Surface of T. vitulorum adult worm revealed two glycoprotein fractions rich in glucose (Glc) and GlcNAc. Three bands of molecular weight 212kDa, 107 kDa, and 93 kDa were detected in Glc fraction by SDS-PAGE. These bands were also detected in GlcNAc fraction with an additional band of 49 kDa. GlcNAc fraction showed more diagnostic potency of calves’ toxocariasis; 79% than Glc fraction; 46.9% by indirect ELISA. The additional band of 49 kDa in GlcNAc fraction is probably responsible for its higher diagnostic potentials. Western blotting verified the immunoreactivity of the Glc and GlcNAc isolated fraction as they reacted with calves sera infected with toxocariasis. The proposed structure of GlcNAc fraction was Ser-Meth-Arg-O-methylated GlcNAc.

Conclusion:

GlcNAc-rich fraction of T. vitulorum can be successfully utilized in the diagnosis of calves’ toxocariasis.

Molecular and immunological characterization of Hyalomma dromedarii and Hyalomma excavatum (Acari: Ixodidae) vectors of Q fever in camels

BACKGROUND AND AIM

Q fever Coxiella burnetii is a worldwide zoonotic disease, and C. burnetii was detected in mammals and ticks. Ticks play an important role in the spread of C. burnetii in the environment. Therefore, the aims of this study were to detect Q fever C. burnetii in camels and ixodid ticks by molecular tools and identification of Hyalomma dromedarii and Hyalomma excavatum using molecular and immunological assays.

MATERIALS AND METHODS

A total of 113 blood samples from camels and 190 adult ticks were investigated for the infection with C. burnetii by polymerase chain reaction (PCR) and sequencing the targeting IS30A spacer. The two tick species H. dromedarii and H. excavatum were characterized molecularly by PCR and sequencing of 16S ribosomal RNA (16S rRNA) and cytochrome oxidase subunit-1 (CO1) genes and immunologically by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and western blot.

RESULTS

A total of 52 camels (46%) were positive for Q fever infection. Only 10 adult ticks of H. dromedarii were infected with C. burnetii. The IS30A sequence was around 200 bp in length for C. burnetii in H. dromedarii ticks with a similarity of 99% when compared with reference data in GenBank records. The length of 16S rDNA and CO1 was 440 and 850 bp, respectively, for both H. dromedarii and H. excavatum. The phylogenetic status of H. dromedarii was distant from that of H. excavatum. SDS-PAGE revealed seven different bands in the adult antigens of either H. dromedarii or H. excavatum with molecular weights ranged from 132.9 to 17.7 KDa. In western blot analyses, the sera obtained from either infested camel by H. dromedarii or infested cattle by H. excavatum recognized four immunogenic bands (100.7, 49.7, 43.9, and 39.6 kDa) in H. dromedarii antigen. However, the infested camel sera identified two immunogenic bands (117 and 61.4 kDa) in H. excavatum antigen. Furthermore, the sera collected from cattle infested by H. excavatum recognized three immunogenic bands (61.4, 47.3, and 35 kDa) in H. excavatum antigen.

CONCLUSION

Molecular analyses indicated that both camels and ticks could be sources for infection of animals and humans with Q fever. Furthermore, the molecular analyses are more accurate tools for discriminating H. dromedarii and H. excavatum than immunological tools.

The role of Ser-(Arg-Ser-Arg-Ser-GlucNAc)19-GlucNAc Fasciola gigantica glycoprotein in the diagnosis of prepatent fasciolosis in rabbits

In the present study, the carbohydrate structures associated with Fasciola gigantica adult worm were identified by indirect hemagglutination inhibition test. Glucose was found to be the main monosaccharide associated with the fluke. According to indirect hemagglutination inhibition results, purification of glycoprotein fractions from worm crude extract was carried out by affinity chromatography immobilized glucose agarose gel and Con-A lectin columns. The isolated glycoprotein fractions, FI and FII, were characterized by SDS-PAGE which revealed one band in FI of 26 kDa and another one band of 19.5 kDa in FII compared with 12 bands associated with whole worm extract. Both fractions were also characterized by isoelectric focusing technique which proved that both bands were acidic in nature with pIs 6.4 and 6.5 respectively. The comparative diagnostic evaluation of the two isolated glycoprotein fractions and crude extract of experimental fasciolosis in rabbits by ELISA revealed that FII was more potent in the diagnosis during prepatent (first week post infection) and patent periods (10 weeks post infection) than FI and crude extract. Moreover, infected rabbit sera at ten weeks post infection identified both bands; 26 and 19.5 kDa in western blot analysis confirming its immunodiagnostic activities which was proved previously by ELISA. FII proved potency in diagnosis of fasciolosis in 200 buffalo serum samples of different ages and sexes using ELISA which recorded 95 % positive and 5 % negative samples. Moreover, the detailed structural analyses of the most potent fraction, F11, using mass spectrum was made and elucidated chemical structure; O-glycan [Ser-(Arg-Ser-Arg-Ser-GlucNAc)19-GlucNAc]. The present result introduces GlucNAc rich fraction of F .gigantica that can be used successfully in the diagnosis of acute and chronic fasciolosis.

Induction of cytochrome P450 1A1 as a biomarker of Benzo-a-pyrene pollution in Egyptian fresh water fish

The activity of Ethoxyresorufin-o-dealkylase (EROD) in the liver of Oreochromis niloticus and Clarias gariepinus was evaluated as a response to experimental and natural contamination of water with Benzo-a-pyrene and/or cadmium. The activity was measured fluorimetrically in the hepatic S9 fraction while the content of the enzyme was measured by ELISA. The response appeared as early as six hours post exposure. This study also reveled that Oreochromis niloticus exhibits higher values of EROD activity than that of Clarias gariepinus. CYP450 1A1 content showed lower responsiveness when compared to EROD activity measurements. The present study also estimated the inhibitory effect of cadmium on CYP450 1A1 induction. The current results demonstrate that EROD activity reflects contamination of water with benzo-a-pyrene as a polycyclic aromatic hydrocarbon compound. Consequently it is a useful biomarker for monitoring this type of pollution.

Comparative serological diagnosis of toxoplasmosis in horses using locally isolated Toxoplasma gondii

A total of 420 serum samples collected from horses of different ages, sexes and breeds, located at some horse farms in Egypt, were used for serological studies. A crude antigen of the locally isolated Toxoplasma gondii tachyzoites from horse tissues (LA) was used for the detection of T. gondii antibodies in horses. It showed good diagnostic efficiency (38.1%) by Enzyme Linked Immunosorbent Assay (ELISA). To increase this efficiency, an affinity purification process was performed. Two fractions were obtained from LA by CNBr-Sepharose 4B affinity column chromatography named; unbound (LAunb) and bound (LAb). LAb showed the highest diagnostic potency (51.7%), while LAunb showed the lowest value (31.7%) using ELISA. The electrophoretic profile of LA (12 bands), LAb (6 bands) and LAunb (6 bands) showed molecular weights ranged from 25.1 to 184.3kDa. The immunoreactive bands of each of the three antigens were identified with infected horse sera by immunoblot assay. Four immunogenic bands of 155.8, 115.1, 83.2 and 66.2kDa were identified in LAb and probably were responsible for the highest diagnostic potency. Examination of horse sera by Indirect Fluorescence Antibody Test (IFAT) at a dilution of 1: 64 and Modified Agglutination Test (MAT) at a dilution of 1: 25 revealed that 170 (40.5%) and 202 (48.1%) had antibodies against T. gondii, respectively. The current research introduces crude and purified fractions (bound and unbound) obtained from the locally isolated tachyzoites (equine origin), which are utilized globally for the first time in detection of T. gondii antibodies in horses. Furthermore, this study recommended utilization of the bound fraction in diagnosis of toxoplasmosis using indirect ELISA which proved better diagnostic potency compared with IFAT and MAT.

Protective effect of Eimeria stiedae coproantigen against hepatic coccidiosis in rabbits

Immunization of rabbits against hepatic coccidiosis was tried. The animals were immunized twice with Eimeria stiedae coproantigen in freund's adjuvant with two week intervals. The rabbits were challenged orally with sporulated E. stiedae oocysts one week post last injection. The protection was assessed by number of oocysts output, number of focal liver lesions, clinical sings and antibody response. The immunization resulted in 70% protection from infection and decline in oocysts count. High level of IgG response in immunized rabbits than control infected ones was occurred and being responsible for the recorded protection. The electrophoretic make up of the coproantigen and oocyst antigen showed different patterns of separation. Common as well as specific bands to each antigen were identified. Using the rabbit sera after 3 weeks post vaccination in immunoblot assay, immunogenic components were detected of molecular weight 155, 103, 74, 66, 44, 22KD with coproantigen and 155, 115, 57, 26 KD with oocyst antigen. While, the rabbit sera after 2 and 4 weeks post challenge reacted with oocyts antigen, in immunoblot assay, revealing immunogenic bands of molecular weight 155, 115, 57, 26, 22KD and 155, 115, 57, 25 KD respectively. Bands of 22KD and 155KD are partially responsible for eliciting host protective immune response where they were recognized by immunized sera in coproantigen and by immunized infected sera in oocyst antigen.

Induction of protective antibody response in rabbits against fascioliasis with Toxocara/Fasciola cross- reactive defined antigen

A method of affinity chromatography purification of Toxocara vitulorum antigen cross- reacts with Fasciola gigantica antiserum is described. Characterization of the isolated cross- reactive fraction by SDS-polyacrylamide gel electrophoresis, isoelectric focusing and amino acid analysis resulted in a fraction consists of five polypeptides of 137.7KDa, 81KDa, 75KDa, 48KDa and 21.6KDa with isoelectric points of 8, 7.5, 7.2, 6.7 and 6.6. Seventeen amino acids were identified in the fraction with high proportions of only two of them (tyrosine and glutamic). Rabbits immunization with this identified T. vitulorum cross- reactive antigen in Freund's adjuvant followed by challenge with F. gigantica metacercariae resulted in 60% reduction in worm burden over control infected rabbits. Higher IgG level was detected in vaccinated rabbits four weeks post first immunization than control infected ones and remained high up to the end of the trial.

Fasciola gigantica: immunization of rabbits with proteins isolated from coproantigen

Two fractions were isolated from coproantigen by ion-exchange chromatography in which DEAE cellulose was utilized. Both fractions and crude antigen were characterized by SDS-polyacrylamide gel electrophoresis which revealed 13 bands of molecular weight ranged from 205-31 in crude coproantigen. While fraction I resolved into six bands of molecular weight 198, 178, 148, 111, 101 & 45. Fraction II showed seven bands of 191 KDa, 178KDa, 166KDa, 118KDa, 98.5KDa, 72KDa & 32KDa. Fraction 1I was higher immunoreactivity than fraction by ELISA. Three immunoreactive bands of 191KDa, 118KDa & 98.5KDa were identified in fraction II using immunoblot assay. Five bands of 178KDa, 148KDa, 111KDa, 101KDa & 45KDa were detected in fraction I. Immunization of rabbits twice with fraction II in Freund's adjuvant with two weeks interval followed by challenge with F. gigantica metacercariae resulted in 66.6% protection from infection. The protection was assessed by detect-ion of hepatic damage, worm recoveries and antibody response. High level of IgG response in vaccinated rabbits than control infected ones occurred and being responsible for the recorded protection.

Comparative immunodiagnostic approach of toxocariasis in buffalo calves

Five Toxocara vitulorum antigens were utilized to diagnose natural toxocariasis in buffalo calves by ELISA. Adult antigen was proved to be the most potent one. The second potent antigen was egg antigen followed by excretory secretory antigen of male worms then female worms. The coproantigen was the least potent one. The electrophoretic make-up of the antigens, examined by SDS-PAGE, revealed different patterns of separation. Common as well as specific component(s) to each antigen were identified. Employing naturally infected buffalo calf sera in immunoblot assay, five immunogenic components were detected in adult antigen of molecular weight 191 KD, 166 KD, 102 KD, 65 KD and 54 KD. The reactive polypeptides in egg antigen were 191 KD, 105 KD, 99 KD and 79 KD. In coproantigen, six bands were identified. These components were of molecular weight 191 KD, 178 KD, 166 KD, 124 KD, 96 KD and 65 KD. Five components of molecular weight 191 KD, 166 KD, 102 KD, 96 KD and 65 KD were immunogenic in excretory/secretory antigen of male worms. Only four polypeptide of 191 KD, 166 KD, 102 KD and 66 KD were identified in excretory/secretory female antigen. Of interest is the immunogenic component of 54 KD expressed only by adult extract in immunoblot assay. This component could be responsible for the immunodiagnostic advantage of adult worm antigen and it deserves further studies to evaluate its diagnostic value.

Cross-reaction: a common trait among helminthes

Cross-reaction between three important zoonotic helminths, Fasciola gigantica, Trichinella spiralis and Echinococcus granulosus, was proved by ELISA. Cross-binding activities in the prepared antisera were strongly directed towards protoscolices and hydatid fluid antigens of E. granulosus rather than to F. gigantica and T. spiralis antigens. Two sets of polypeptides were identified in each antigen by immunoblot; species-specific and cross-reactive. Cross-reactive components in F. gigantica antigen were 205 KD, 178 KD, 166 KD, 106 KD, 100 KD, 65 KD, 45 KD and 32 KD. While, cross-reactive molecules in T. spiralis antigen were 205 KD, 191 KD, 166 KD, 148 KD, 132 KD, and 32 KD. In protoscolices antigen six cross-reactive components were identified, 205 KD, 191 KD, 149 KD, 106 KD, 45 and 32 KD. Moreover, 205 KD, 190 KD, 177 KD, 149 KD, 103 KD and 33 KD were detected in hydatid fluid antigen by heterologous antisera. Interestingly, three polypeptides of 205 KD, 149 KD and 32 KD showed broad immunogenicity with the developed antisera raising the prospect of being putative common immunoprophylactic components.

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.