A study of Newcastle disease virus obtained from exotic caged birds in Tehran between 2009 and 2010.

The aim of this study was to investigate the frequency of the Newcastle disease virus (NDV) infection and its virulence in exotic cage birds over a limited area and time period. A set of 335 samples was collected from 24 different species of exotic unvaccinated cage birds kept in the zoological gardens and bird markets of the Tehran province of Iran during 1.5 years. Except for three pigeons, all of the sampled birds were healthy with no clinical signs of Newcastle disease. NDV was detected in three sick pigeons by haemagglutination assay (HA), haemagglutination inhibition (HI) and reverse transcription-polymerase chain reaction (RT-PCR) tests while two of them were identified as virulent types by RT-PCR. Although the remaining samples were negative by Newcastle-disease-specific HA and HI tests, 35 of them (10%) were identified as positive and 25 (72%) were determined as the velogenic type by RT-PCR test. Five PCR products were sequenced and all were confirmed as NDV but sequences were different from each other and from other sequences from Iran. In total, 14 species (58%) were infected and 10 species were uninfected with the velogenic type without showing any signs. Pigeons are very sensitive to NDV infection and play an important role in its epidemiology. In this study, the PCR test was found to be a more sensitive and powerful method than the HA and HI tests for detection of NDV reservoirs and carrier status in exotic birds. Also, the frequency of infection with the virulent type showed that the exotic birds should probably be considered one of the main causes of recurrent annual epidemics of Newcastle disease in endemic regions.

Evaluation of Immunogenicity of Clostridium perfringens Type B Toxoid and Inactivated FMD (O) Virus with Adjuvant (ISA70-MF59).

Foot and mouth disease (FMD) and enterotoxemia are important diseases of hoofed animals. Vaccination against livestock pathogens, especially these two diseases, plays a key role in the prevention and control of these diseases. The use of combined vaccines with the aim of creating a better immune response and producing cheaper vaccines is a great contribution to Vaccine industry. This research aimed to compare the immunogenicity of FMD (O) and Clostridium perfringens type B toxoid along with adjuvant (MF59) and Montanide (ISA70) to create the best immunogenicity. To investigate the immune responses of vaccines, it was injected into an animal model, and the antibody titer was measured by enzyme-linked immunosorbent assay (ELISA) test and VN antibody titer. The results showed that the formulation with MF59 adjuvant brought more stable immunogenicity against FMD and Clostridium perfringens type B, and the length of the immunogenicity period also increased significantly. Therefore, the combined vaccine (Clostridium perfringens + FMD) could play a major role invaccine industry as an alternative vaccine against Clostridium perfringens and FMD in livestock.

Immunity Evaluation of an Experimental Designed Nanoliposomal Vaccine Containing FMDV Immunodominant Peptides.

Foot-and-mouth disease (FMD) is a highly contagious viral disease affecting cloven-hoofed animals. The particular virus causing FMD disease is called FMD virus and is a member of the Aphthovirus genus in the Picornaviridae family. The FMD virus has an 8500 nt long single strain positive RNA genome with one open reading frame (ORF) trapped in an icosahedral capsid protein. This virus genome doesn't have proofreading property which leads to high mutagenesis. It has seven serotypes, including O, A, ASIA, SAT1, SAT2, and C serotypes, as well as many subtypes. Iran is an endemic region for foot-and-mouth disease. Vaccination of susceptible animals with an inactivated whole-virus vaccine is the only way to control the epidemic in many developing countries. Today, conventionally attenuated and killed virus vaccines are being used worldwide. In Iran, animals have been vaccinated every 105 days with an inactivated FMD vaccine. Although commercially available FMD vaccines are effective, they provide short-term immunity requiring regular boosters. A new FMD vaccine is needed to improve immunization, safety, and long-term immune responses. A synthetic peptide vaccine is one of the safe and important vaccines. Peptide vaccine has low immunogenicity, requiring strong adjuvants. Nanoliposomes can be used as new adjuvants to improve immune response. In the current study, nanoliposomal carriers were selected using Dimyristoylphosphatidylcholine (DMPC), dimyristoyl phosphoglycerol (DMPG), and Cholesterol (Chol) as an adjuvant containing two immunodominant synthetic FMDV peptides. The liposomal formulations were characterized by various physicochemical properties. The size, zeta potential, and encapsulation efficiency were optimized, and the obtained nanoliposome was suitable as a vaccine. The efficacy of vaccines has been evaluated in guinea pigs as animal models. Indirect ELISA was used to detect FMDV-specific IgG. The obtained results indicated that although antibody titer was observed, the amount was lower compared to the groups that received inactivated virus-containing liposomes. In addition, the results showed that liposome was an appropriate adjuvant, compared to other adjuvants, such as Alum and Freund, and can act as a depot and induce an immune response.