Hazem ibrahim | Veterinary Serum and Vaccine Research Institute (original) (raw)

Papers by Hazem ibrahim

Aim: This work was conducted to study the phenotypic and genotypic characterization of locally is... more 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.

Hyperimmune serum against peste des petites ruminants virus was successfully prepared in horses w... more Hyperimmune serum against peste des petites ruminants virus was successfully prepared in horses where it was found to have specific peste des petites ruminants virus (PPRV) neutralizing antibodies titer of 1024/ml as determined by serum neutralization test (SNT). Quality control testing of such serum revealed that it was free from bacterial, fungal and mycoplasma contaminants as tested on specific media and safe when inoculated in sheep. Passive induced immunity in sheep was persisted with a protective level up to 5 weeks post inoculation as determined by SNT and ELISA. On the other side, inoculation of PPR vaccine with antisera in sheep showed similar findings with slight rise in antibody titer. Depending on the obtained results, it could be concluded that horse anti-PPR serum is of a significant importance and can help to protect and control PPR infections especially in case of outbreaks that need rapid management.

E. coli infections are responsible for great economic losses in the poultry industry worldwide, b... more E. coli infections are responsible for great economic losses in the poultry industry worldwide, bringing serious threat to the turkey industry. The present investigation aimed to prepare a potent vaccine from E. coli serogroups O1 and O78 to aid in control of colibacillosis in turkey. One hundred commercial 14 days-old turkey poults were used and divided into three groups; first group was vaccinated twice with 3 weeks interval by prepared inactivated E.coli vaccine adjuvanted with aluminum hydroxide gel, second group was vaccinated twice with 3 weeks interval by prepared inactivated E.coli vaccine adjuvanted with montanide ISA70, third group was left as unvaccinated control one. The immune response was measured by MAT (Microagglutination test), ELISA and challenge test. It was found that the protection rate for inactivated vaccine with aluminum hydroxide gel and E.coli inactivated vaccine with montanide ISA70 were 80% and 85% respectively although it was 30% among the unvaccinated group. ‫ـــــــــــــــــــــــــــــــــــــــــ‬

A B S T R A C T In the present study, efficacy of a locally prepared Salmonella Kentucky killed v... more A B S T R A C T In the present study, efficacy of a locally prepared Salmonella Kentucky killed vaccine had been studied. A total of 120, two weeks old specific pathogen free (SPF) chicks were divided into two groups; 60 chicks each. First group was vaccinated with the prepared vaccine at the age of two weeks and boostered at four weeks, the second group was kept unvaccinated as a control group. The two groups were challenged orally with 1 ml of Salmonella Kentucky (5x10 7 CFU/ml), 3 weeks post boostering of the vaccine. The degree of protection was assessed according to the severity of the clinical signs, the mortality and fecal shedding of the challenged organisms. Blood samples were collected weekly after first vaccination till fourth week after challenge and humoral immune response was measured against Salmonella strains using ELISA and microagglutination test. The prepared vaccine induced 80% protection rate in challenge test with reduced fecal shedding. (http://www.bvmj.bu.edu.eg) (BVMJ‐29(2): 153‐160, 2015)

SUMMARY Avian Salmonellosis is an inclusive term designating a large group of acute and chronic d... more SUMMARY Avian Salmonellosis is an inclusive term designating a large group of acute and chronic diseases of poultry caused by any one or more member of the genus Salmonella. Salmonellae are widely distributed all over the world. However, particular Salmonella serovars may be encountered more frequently in one country than the other. Vaccination is the best mean for controlling salmonellosis in birds. In the present study, the impact of two adjuvants on the immunizing and protective efficacy of local Salmonella strains (S. Typhimurium, S. Infantis, S. Enteritidis and S. Meleagridis) in a locally prepared polyvalent formalin inactivated vaccines had been studied. A total of 150, two weeks old broiler Ross chickens were divided into 3 groups; 50 chicks each. The 1 st group was vaccinated with the mineral oil adjuvanted vaccine, the 2 nd group was vaccinated with the gel adjuvanted vaccine and the 3 rd group was kept unvaccinated as a control group. The three groups were challenged orally with 1 ml of S. Typhimurium, S. Infantis, S. Enteritidis and S. Meleagridis strains (10 8 CFU/ml of each), 3 weeks post boostering of the vaccines. The degree of protection was assessed according to the severity of the clinical signs, the mortality and fecal shedding of the challenged organisms. Blood samples were collected weekly and humoral immune response was measured against Salmonella strains using micro-agglutination test (MAT) and ELISA. The mineral oil adjuvant vaccine induced higher protection rates in challenge test with reduced fecal shedding and higher antibody response compared with the gel adjuvant vaccine and on the other hand the gel adjuvant vaccine induced faster immune response.

Salmonellosis is one of the most important bacterial diseases affecting poultry. Its importance i... more Salmonellosis is one of the most important bacterial diseases affecting poultry. Its importance is derived from the loss in productivity in affected birds and the hazard it causes for public health. Vaccination is the best mean for controlling salmonellosis in birds. In the present study, the immunizing and protective efficacy of local strains (S. Typhimurium, S. Infantis, S. Enteritidis and S. Meleagridis) and imported ones (S. Typhimurium and S. Enteritidis) in a prepared polyvalent and bivalent formalin inactivated oil adjuvant vaccines had been studied. A total of 150, six-weeks old SPF Lohmman layer chickens were divided into 3 groups; 50 chickens each. The 1 group was vaccinated with the polyvalent locally prepared vaccine, the st 2 group was vaccinated with the imported bivalent vaccine and the 3 group was kept unvaccinated as a nd rd control group. The three groups were challenged with virulent S. Typhimurium, S. Infantis, S. Enteritidis and S. Meleagridis strains (10 CFU/ml of each) 1ml orally, 3 weeks post boostering of the vaccines. The degree of 8 protection was assessed according to the severity of the clinical signs, the mortality and fecal shedding of the challenged organisms. Blood samples were collected weekly and humoral immune response was measured against Salmonella strains using micro-agglutination test (MAT) and ELISA. In Conclusion: the locally prepared polyvalent vaccine induced higher protection rates in challenge test with reduced fecal shedding and higher antibody response compared with the imported bivalent one.

Avian salmonellosis due to Salmonella B and D serogroups has a great importance because of its pu... more Avian salmonellosis due to Salmonella B and D serogroups has a great importance because of its public health and economical impact in poultry industry. Serological diagnosis of Salmonella infection currently relies on laboratory-based ELISA for detection of antibodies against most predominant Salmonella serotypes. The present study was conducted to prepare sonicated polyvalent Salmonella antigen (group B and D) from local isolates. ELISA procedure was developed for the detection of Salmonella infection in experimentally infected chickens. For ELISA validation, the efficacy test accomplished by reaction with known positive and negative serum. The results revealed that, relative sensitivity and specificity of ELISA using the polyvalent sonicated Salmonella antigen with chicken cloacae samples compared to bacteriological diagnosis were 100 and 55.5 %, respectively. The data indicated that the polyvalent Salmonella antigen isn't suitable for clinical testing and detection of Salmonella infection among poultry by ELISA as it showed a very low level of specificity.