The immune response and protective efficacy of a potential DNA vaccine against virulent Pasteurella multocida.

BACKGROUND: Pasteurella multocida is the main cause of several infections of farm animals, and the immunity gained from commercial vaccines is for the short term only and needs to be routinely administered, so work on new vaccines against virulent P. multocida is crucial. RESULTS: In this study, the OmpH gene was amplified from ten P. multocida strains, and the PCR products were sequenced and analyzed. The results of RFLP analysis of OmpH gene digested by MspI enzyme showed that all of ten strains examined possessed one restriction site and two fragments, 350 and 650 bp. The OmpH sequence of strain No. 10 was cloned into bacterial expression vector pUCP24, and the recombinant pUCP24-OmpH was expressed in E. coli DH5α. Serum samples obtained from the ELISA test from a group of vaccinated rats indicate that the antibodies were present at high titer in immunized rats and can be tested as a vaccine candidate with a challenge. CONCLUSIONS: In rats infected with the DNA vaccine and inactivated vaccine, a significant increase in serum antibody levels was observed. In addition, the DNA vaccine provided the vaccinated rats with partial protection; however, the protective efficacy was greater than that offered by the live attenuated vaccine. This successful recombinant vaccine is immunogenic and may potentially be used as a vaccine in the future.

Genetic polymorphism of growth differentiation factor 9 (GDF9) gene related to fecundity in two Egyptian sheep breeds.

PURPOSE: This study explores polymorphisms in the growth differentiation factor 9 (GDF9) gene (exon 1) with respect to fertility in Egyptian sheep. METHODS: Blood samples were collected, and genomic DNA was extracted from 24 Saidi and 13 Ossimi ewes. A 710 bp portion of the GDF9 gene, was amplified using specific primers, and the sequence was analyzed to clarify the phylogenetic relationship of Egyptian breed sheep. In addition, the PCR-RFLP method using Pst1 or Msp1 restriction enzymes was used to mask polymorphisms of partial exon 1 of GDF9 gene to establish molecular markers for twinning. RESULTS: The lambing rate percentage and litter size showed significant difference between ewes, which produce single and twin lamb for each breed individually, whereas the coefficient of variation of the Saidi breed is greater than that of the Ossimi breed. The results suggested that the GDF9 gene shared a similarity in sequence compared to six accession numbers of Ovis aries found in GenBank. Molecular phylogenetic analyses were performed based on nucleotide sequences in order to examine the position of the Egyptian breeds among many other sheep breeds. The results indicate that accession number AF078545 of O. aries is closely related with Saidi and Ossimi ewes that produce single or twin lamb using the unweighted pair group method with arithmetic mean (UPGMA) analysis. Results showed that Msp1 enzyme digestion revealed polymorphic restriction pattern consisting of one band with 710 bp for ewes producing single lamb and two bands with 710 and 600 bp for ewes producing twin lamb in Saidi sheep breed. CONCLUSION: Sequence analysis and diversity of polymorphisms in the GDF9 gene (exon 1) have a novel base substitution (A-T) for detection of FecG mutations that serve as a molecular marker for twinning.

Quality parameters and RAPD-PCR differentiation of commercial baker's yeast and hybrid strains.

Baker's yeast, Saccharomyces cerevisiae, is a key component in bread baking. Total of 12 commercial baker's yeast and 2 hybrid strains were compared using traditional quality parameters. Total of 5 strains with high leavening power and the 2 hybrid strains were selected and evaluated for their alpha-amylase, maltase, glucoamylase enzymes, and compared using random amplified polymorphic DNA (RAPD). The results revealed that all selected yeast strains have a low level of alpha-amylase and a high level of maltase and glucoamylase enzymes. Meanwhile, the Egyptian yeast strain (EY) had the highest content of alpha-amylase and maltase enzymes followed by the hybrid YH strain. The EY and YH strains have the highest content of glucoamylase enzyme almost with the same level. The RAPD banding patterns showed a wide variation among commercial yeast and hybrid strains. The closely related Egyptian yeast strains (EY and AL) demonstrated close similarity of their genotypes. The 2 hybrid strains were clustered to Turkish and European strains in 1 group. The authors conclude that the identification of strains and hybrids using RAPD technique was useful in determining their genetic relationship. These results can be useful not only for the basic research, but also for the quality control in baking factories.

Molecular phylogeny and identification of the peach fruit fly, Bactrocera zonata, established in Egypt.

The genetic structure of the Egyptian peach fruit fly (Bactrocera zonata (Saunders) (Diptera: Tephritidae)) population was analyzed using total RNA from adult females. A portion of mitochondrial cytochrome oxidase I (COI), 369 bp was amplified using RT-PCR, and was sequenced and analyzed to clarify the phylogenetic relationship of B. zonata established in Egypt. The data suggested that the gene shared a similarity in sequence compared to Bactrocera COI gene found in GenBank. Molecular phylogenetic analyses were performed based on nucleotide sequences in order to examine the position of the Egyptian population among many other species of fruit flies. The results indicate that four accession numbers of B. zonata (three from New Zealand and one from India) are closely related, while the Egyptian B. zonata are close to the 71 accession numbers of Bactrocera include one B. zonata from New Zealand. These two B. zonata from Egypt and New Zealand showed a close relationship in neighbor-joining analysis using the seven accession numbers of B. zonata. In addition, a theoretical restriction map of the homology portion of the COI gene was constructed using 212 restriction enzymes obtained from the restriction enzyme database to identify the Egyptian and New Zealand B. zonata.