Aim:This work was conducted to study the phenotypic and genotypic characterization of locally isolated Salmonella strains (Salmonella Pullorum, Salmonella Enteritidis, and Salmonella Typhimurium) from poultry used in the preparation of Salmonella antigens in Egypt.Materials and Methods:The phenotypic characterization of Salmonella strains was done using standard microbiological, biochemical, and serological techniques. Molecular identification was done using different sets of primers on different genes using different polymerase chain reaction (PCR) techniques.Results:The phenotypic characterization of Salmonella strains was confirmed. Molecular identification revealed detection of 284 bp fragment of InvA gene in all studied Salmonella strains. Furthermore, multiplex PCR was used for more confirmation of being Salmonella spp., generally at 429 bp as well as genotyping of Salmonella Typhimurium and Salmonella Enteritidis at 559 and 312 bp, respectively, in one reaction.Conclusion:The locally isolated field Salmonella strains were confirmed phenotypically and genotypically to be Salmonella Enteritidis, and Salmonella Typhimurium and could be used for the preparation of Salmonella antigens.

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The immune response of turkeys to live attenuated vaccine for avian pathogenic Escherichia coli (APEC) constructed from O78 strain was evaluated, where ninety-one-day old turkeys were vaccinated twice with 3 weeks intervals. Other thirty turkeys were kept as non-vaccinated control. Birds were challenged against homologous O78 and heterologous O1 and O2 pathogenic strains of E. coli using 10 7 CFU/0.2 ml/ turkey. Clinical and necropsy examinations revealed that vaccinated birds showed 96.7% protection after homologous challenge while vaccinated birds were unable to withstand the heterologous challenge. E. coli was recovered from vaccinated challenged turkeys at ratio ranged from13.3%-20% from the heart blood, liver, spleen and bone marrow on the 8 th day post homologous challenge while these ratios were ranged from 53.3%-66.7% from vaccinated birds post heterologous challenge. So, the vaccination studies performed here showed that live attenuated E. coli vaccine was protective against homologous challenge with O78 strain but con not protect turkeys against heterologous challenge.

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