BACKGROUND: Ticks are one of the most important ectoparasites in animals that cause economic losses in livestock industry. So, removal or reduction of ticks on animals is necessary. Cysteine proteases are among the compounds that play an important role in the physiological action of ticks and are a good candidate for the anti-tick vaccine. Cathepsins is one of the most important cysteine proteases. OBJECTIVES: The aim of this study was cloning and expression of recombinant cathepsin L gene of Rhipicephalus annulatus in order to evaluate its immunogenicity. METHODS: After collection the ticks were cultivated. Then RNA was extracted from ticks, cDNA was synthesized by using specific primer of cathepsin and amplification by RT-PCR. The desired genes were cloned into expressional pQE30 plasmid. Further, a shorter sequence of the cathepsin gene (654 bp) was prepared as a synthetic plasmid. The expression of the protein produced by both recombinant plasmids in the E.coliBL21 prokaryotic expression system is carried out and the immunity of the recombinant proteins was evaluated by Dot Blot and Western Blot using serum of challenged rabbits with recombinant protein and calves infected with ticks were examined and compared. RESULTS: The results of this study indicate that the protein derived from recombinant plasmid No. 2 had higher expression and purity due to its solubility. Also, the challenge of rabbit serum with these proteins was able to identify both recombinant proteins. But the serum of challenged calves with ticks did not show a satisfactory response with recombinant proteins. CONCLUSIONS: Although the sera reaction of calves infested with ticks was lower than the challenged rabbits sera with cathepsin L, this result was expected, because L cathepsin protein is considered as a concealed antigen.  Overall, the recombinant cathepsin L could be an appropriate candidate for immunizing calves against Rhipicephalus annulatus, although it seems further investigations are necessary.

BACKGROUND: Diarrhea is a common disease in the neonate calf which imposes significant economic burden on cattle industry around the world. During the first week after birth, Enterotoxigenic E.coli (ETEC) strains carrying F5 fimbria are one of the most important pathogens causing calf diarrhea. F5 fimbria is involved in early stage of pathogenesis and is responsible for attachment of bacteria to enterocytes; this attachment is mediated by FanC protein of F5 fimbria. Antibodies directed against F5 fimbriae play a significant role in prevention and control of the disease. Objectives: Evaluation and expression of recombinant expression of F5 Fimbriae of Enterotoxigenic Escherichia Coli associated with calf diarrhea. Methods: In the present study,  the fanC region of F5 fimbria was cloned in a pET28a plasmid. Results: The recombinant construct was confirmed by sequencing and protein production in Escherichia coli BL21 (DE3) was evaluated by western blotting procedure. Conclusions: Based on our findings, the recombinant FanC protein or the BL21 (DE3) strain are suitable candidates to develop an effective vaccine against calf colibacillosis or use in a diagnostic kit for F5+ ETEC.

BACKGROUND: Caseous lymphadenitis, caused by Corynebacterium pseudotuberculosis, is one of the most important diseases of sheep and goats, causing considerable losses for herd owners. Phospholipase D (PLD) is a potent exotoxin produced by C. pseudotuberculosis and it has been considered as the major virulence factor for this bacterium, possibly contributing to the spread of the bacteria from the initial site of infection to secondary sites within the host. Heat shock proteins (HSPs) are important candidates for the development of vaccines because they are usually able to promote both humoral and cellular immune responses in mammals. OBJECTIVES: The aim of this study was the cloning and expression of the PLD and HSP60 genes of C. pseudotuberculosis, used subsequently to evaluate the protectivity of these recombinant proteins for vaccine development against this bacterium. METHODS: PLD and HSP60 genes were cloned into pMAL-c2X vector and recombinant plasmids construct was transformed to DH5 strain of E. coli. Expression of the proteins was shown by SDS-PAGE and accuracy of the cloned genes was confirmed by nucleotide sequence analysis. RESULTS: The transformed E. coli strain DH5 expressed PLD and HSP60 proteins effectively. The expressed fusion protein was found almost entirely in the soluble form. CONCLUSIONS: In the following studies the immunogenicity and protectivity of these recombinant proteins against C. pseudotuberculosis infections can be assessed.