A total number of 27 vaccine vials including 3 batches of 3 different types of live attenuated poultry viral vaccines (tissue culture Gumboro vaccine, egg adapted colored ILT vaccine and egg adapted non colored ILT vaccine) were experimentally contaminated with 1,5,10 CFU of Salmonella typhimurium reference strain/dose then subjected for sterility testing as referenced in OIE. Further dilution was carried out of vaccines showing negative results. The results of statical analysis showed that there is a significant difference between direct inoculation of the vaccines and their dilutions. It could be concluded that the applied testing method is appropriate for testing sterility of living attenuated poultry viral vaccines but testing of some of such vaccines need further dilutions to obtain accurate results.

Rift Valley Fever (RVF) is an endemic disease in Egypt causing disease in animals and humans since the 1977. Full molecular description of the national vaccine strain is a strategic concern to ensure the antigenic makeup of local vaccine is adequate to provide the required protective immunity for the vaccinated animal species and as a tool of final product quality control. Molecular characterization and phylogenetic analysis of Gc gene of M segment of RVF-ZH501 strain which used in local vaccine production in veterinary serum and vaccine research institute (VSVRI) were carried out in this study. RVF-ZH501 strain was propagated by passages on BHK cell line and then purified my plaque purification technique. RT-PCR for amplification of the Gc gene of M segment. Sequence analysis of the obtained PCR product carried out by MEGA7 program. The result of the study revealed that RVF strain ZH501 Gc genomic content has 99.5 % molecular identity to the strains firstly isolated in Egypt in 1977, so still suitable for vaccine production.

Samples of internal organs (liver, heart, spleen, kidney and intestinal contents) were aseptically collected from 120 freshly died newly weanling rabbits and subjected to isolation and identification of the causative bacterial pathogens. The causative pathogens were isolated and identified biochemically. E.coli and Salmonella (the major associated pathogens) were typed serologically and tested for antimicrobial agents. The bacterial infection prevalence rate was Escherichia coli (56.6%), Salmonella spp. (27.5%), Enterobacter spp. (7.5%), Citrobacter spp. (5%) and Proteus spp. (3.3%). Out of the 68 infections with E.coli, 30 were serotyped as O125 (ten), O127 (six), O128 (five), O86 (five) and untyped (four). Out of the 33 Salmonella infections, seven were serotyped as serovar S. goldcoast (four) and serovars S. magherafelt (three). E.coli serogroups were resistant to the majority of used antimicrobial and were sensitive only to Sulphamethazole. Both Salmonella serovars were sensitive to most antimicrobial used in this study but they were resistant to amoxicillin. Both infected rabbit groups with E.coli and Salmonella demonstrated obvious histopathological alterations in the intestine, liver and spleen. Both E.coli (O86) and Salmonella goldcoast were used for experimental infection of weanling rabbits (6-8 weeks). Five days post-infection and after observation of the clinical symptoms, animals were sacrificed and tissue samples from the intestine, liver, kidney and spleen were examined histopathologically. Utmost care must be taken around the time of weaning in rabbits.

Mycoplasma contamination remains a major concern in the biopharmaceutical industry especially in tissue culture based viral vaccine and its presence and/or its endotoxin-like metabolites in the final products can result in pyrogenic responses ranging from fever and chills, to irreversible and fatal septic shock. This study was conducted by in vitro screening of mycoplasma in the different ingredients used in production of Foot and mouth Disease (FMD) vaccine using Polymerase Chain Reaction (PCR) using universal primers that are specific to the 16S rRNA region. Tested items include growth media, cell lines, trypsin, seed virus and working virus. Also the study evaluates the inhibitory effect of different concentrations of neomycin, kanamycin, gentamycin, polymyxin B and ciprofloxacin on mycoplasma contaminated cell lines. Our results showed that the prepared growth media, trypsin, seed virus as well as working virus were mycoplasma free and three tested cell lines were also free while another two lines were mycoplasma positive. The mycoplasma positive cell line are poorly grown in comparison with the free line using the same growth media and the virus yield from the apparently normal contaminated line was very low. Ciprofloxacin can be used for treating valuable cell line after 12 days in 25mg/L and after 18 days in 10mg/L. Ciprofloxacin plus regular antibiotic may keep the line sterile for prolonged time but treatment of contaminated cell line is not advisable. So, prophylactic control by strict personal hygiene and personal protective equipment (PPE) and adopt appropriate aseptic techniques is the core solution.

The present study was undertaken to development of BHK-21 cell adapted inactivated vaccine of Newcastle disease virus (NDVgenotype VII) from the field isolate from broiler chicken in Egypt during 2015-2016. The isolatesof El-Giza/2015were classified by sequencing as velogenic NDV genotype VII d contains F protein cleavage site motifs (112RRQKRF117). Such virus was propagated in the BHK-21 cell line. and cell adapted virus was confirmed as NDV by reverse transcription-polymerase chain reaction (RT-PCR) using fusion gene-specific primers and used to develop inactivated vaccine adjuvanted with Montanide IMS 1313.Potency test revealed that Vaccinated chicks with 0.5ml of prepared NDV vaccine exhibited HI antibody titer of 8.6 log2 three weeks post vaccination with the highest titer (10.6 log2/ml) at the 6th-week post vaccination, and 3rd weeks post challenge test. Protective antibodies values were persisting till 12th weeks post vaccination. All chicken groups vaccinated with both prepared inactivated tissue culture vaccine using ISA 1313 and VSVRI inactivated ISA70 adjuvant vaccines were passed challenge test (97.5%,97%,96% protective efficiency to SPF chickens) against the isolated virulent NDV, while the control group could not provide any protective efficiency. The present study indicated that, BHK-21 cell adapted recent isolated NDV inactivated vaccine produced a satisfactory antibodies titre that efficient in control of the disease in Egypt.