The present study was conducted to identify new target immunogenic molecules from the larval stage of the cattle tick, Boophilus annulatus (Acari: Ixodidae). Two specific larval glycoproteins (GLPs) were isolated by two-step affinity chromatography. The larval immunogens were first purified with CNBr-Sepharose coupled to rabbit anti-larval immunoglobulins, and the glycoproteins were then purified with Con-A Sepharose. These glycoproteins have molecular weights of approximately 32 and 15 kDa with isoelectric points between 6.8 and 7.2. Antibodies against the two GLPs, labeled I and II, were detected in the anti-whole tick, -whole larval, and -gut antigens through immunoblot analysis. These results suggest that these GLPs are good immunogens and can be useful in the vaccination of cattle against tick infestation.

C RYPTOSPORIDIOSIS is a significant disease that causes diarrhea in humans and animals with relatively high morbidity and mortality. The present study aimed to adopt a purified and potent antigen for the accurate diagnosis of cryptosporidiosis. A total of 278 animal hosts (60 newborn calves and 218 buffaloes) were used in the current study. Sixty fecal samples were collected from new-born calves aged less than one month raised in the Beni-Suef and Qalyubia governorates. The samples were examined under a microscope after modified Ziehl-Neelsen staining, and Cryptosporidium oocysts were isolated from naturally infected calves. These oocysts were used in mice experimental infection. The oocyst antigen and coproantigen were prepared from the mice feces. The diagnostic efficacy of the two prepared antigens was evaluated using an Enzyme Linked Immunosorbent Assay (ELISA) with experimentally infected mice sera. The crude oocyst antigen proved to have higher diagnostic potential than coproantigen, so, it was chosen for purification using Cyanogen Bromide-activated Sepharose-4B affinity chromatography coupled with rabbit hyperimmune serum raised against oocyst antigen. The affinity purified fraction and its crude Cryptosporidium antigen were evaluated using the ELISA. The resulting purified fraction was 6733 fold increase in binding activity compared with its crude antigen. Characterization of the isolated fraction was performed using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), western blot, and amino acid analysis. SDS-PAGE clarified that the fraction contained three polypeptides of 94.7, 65, and 50 kDa, which were identified as immune-reactive components using a western blot analysis. The isolated fraction exhibited 17 amino acids and was rich in tyrosine, alanine, and phenylalanine. The affinity purified Cryptosporidium oocyst antigen effectively detected Cryptosporidium antibodies in experimentally infected mice sera and naturally infected buffalo sera with a sensitivity of 94.4% and 95.24 %, and a specificity of 100% and 93.33%, respectively. The purified fraction succeeded in diagnosis of cryptosporidiosis in 182 random serum samples collected from buffaloes with an incidence of 57.14 %. In conclusion, the affinity purified fraction of the Cryptosporidium oocyst antigen might be a good diagnostic candidate for cryptosporidiosis diagnosis and seroepidemiological surveillance.

Four PLA 2 isoenzymes (N. nigricollis CM-PLA 2 I-IV) were purified from Naja nigricollis (N. nigricollis) venom using Sephadex G-50 gel filtration, and ion exchange chromatography on CM-Sephadex C-25. The characterization of the isolated PLA 2 isoenzymes revealed similarities in molecular weights, and differences in the isoelectric points, the optimum temperature, optimum pH, optimum Ca +2 concentration and metal ion requirements. A good correlation (r > 0.7) for the in vitro neutralization of enzymatic PLA 2 s activity and the ELISA titers was found for sera collected at one week from each boosting of the rabbits. The found correlations were particularly high (r>0.9) when the purified Seph-PLA 2 and CM-PLA 2 II were used rather than the whole venom. The established correlations show the importance of the purified PLA 2 enzymes as immunogens for raising therapeutic antisera and as diagnostic reagents for in vitro determination of the potency of the therapeutic antisera.

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