Iranian Journal of Virology
Volume:12 Issue: 2, 2018

Infectious bursal disease (IBD) is an acute, very contagious disease of juvenile chickens. High mortality following its acute clinical form on the one hand, and immunosuppressive effects resulting from subclinical infections, on the other hand, made IBD an economically important disease. In Iran, despite regular vaccination, cases of IBD are still diagnosed clinically, with limited information on their molecular epidemiology. The present study was conducted to characterize IBD viruses responsible for a recent outbreak.

Samples of the bursa of Fabricius were collected from IBD suspected pullets having up to 40% mortality. The viral RNA was isolated and an RT-PCR targeting hypervariable region within the VP2 gene was carried out. One positive sample was sequenced and phylogenetically analyzed.

The virus detected in this study had the highest homology to a very virulent IBD virus (vvIBDV) identified in 2018 in Iran. It also shared a high level of homologies to vvIBDVs isolated from Kuwait, Iraq, and Turkey.

Despite using vaccines, very virulent IBD viruses are circulating in Iran. The close relationships of the detected virus with vvIBD viruses circulating in neighboring countries is an alarming issue announcing the necessity of imposing strict rules on importation and exportation of birds.

Determination of genotype of JC virus in northeastern Iran to finding any different genotype in different tissues. Background Data is lacking about genotypes in Iran and Due to the association of some genotypes of JC virus with PML (Progressive multifocal leukoencephalopathy) And Due to the fact that some genotypes are more likely to be associated with certain diseases, such as cancer, the importance of this research is highlighted.

 Twenty two colorectal tissue samples collected from Colorectal cancer patients and 19 urine samples collected from healthy individuals and after genomic extraction, PCR was applied to amplify the desired gene region for genotyping. Sequences reported with sequences recorded in the NCBI database were compared. The 100% match was observed in most samples.

Conclusion According to statistical analysis, there is no correlation between urinary tract genotypes and tissue samples. Although genotype 2 was observed only in urine specimens and was not observed in tissue samples. The most common genotype in this study was Type-1 and then Type-3. We did not see other genotypes in this study.

Infectious bronchitis is an economically important disease, especially in chickens. It causes disorders in the respiratory tract, kidney and reproductive tract of affected birds. The annual losses imposed by the disease are significant in the Iranian poultry industry. The Infectious bronchitis virus has many different serotypes and mutations in its RNA results in the virus variation which makes the control of IB more difficult. The control strategy of IB is based on vaccination and it has been used live and inactivated vaccines. Vaccines against different strains of the virus have been used. Vaccines should be against specific strains in each area. The application of an appropriate ELISA kit which can detect the level of antibody response leads to choosing an effective vaccine. The current study compared antibody response after four vaccination approach and then compared 3 ELISA kits in the detection of antibody rising. A total of 100 SPF chickens were divided into 5 groups. The first group considered as the control and H120-H120, H120-1/96, H120-4/91, and H120-IB88 protocols were conducted for the 2nd</sup>, 3rd</sup>, 4th,</sup> and 5th</sup> groups respectively. The validation of the Proflok, BioChek and IDEXX ELISA kits were evaluated after vaccination. Significant titers differences between four vaccination approaches were shown better by Biochek, Idexx and Proflok kit respectively. Also, the highest antibody titration belonged to the 4th</sup> group and the highest titration detected by the Proflok kit which had the most sensitivity. According to our results, it is important to use endemic strains of the IBV for vaccination to have better cross-protection. In this study, as the 3 studied kits had different sensitivity and specificity, different antibody rising was detected.

Infectious bronchitis (IB) is one of the major economically critical poultry diseases distributed worldwide including Iran. Different IB virus (IBV) genotypes are circulating in different geographical regions. Typing of IBV strains is useful for implementation of control measures and for understanding the epidemiology and evolution of IBV. S1 gene sequencing is used for IBV genotyping. Massachusetts, 793/B, QX, and   IS-14194 IBV genotypes currently exist in Iranian poultry farms.

This study aims to design an RFLP-based method to do genotyping and confirm of mentioned IBV genotypes. After amplification of parts of the S1 gene (RT-PCR), the PCR products treated with four enzymes (SfoI: Massachusetts, BtsCI: 793/B, MspI: IS-1494, and NruI: QX) and finally visualized on agarose gel electrophoresis.

  Results showed 100 percent of the specificity of the newly designed method (in compare with Sequencing).

 This method can be used to do primary confirmation and fast screening of   Massachusetts, 793/B, QX, and   IS-14194   IBV genotypes and even in local laboratories without the need for sequencing.

Turnip mosaic virus (TuMV) has a wide host range and no resistant commercial canola variety to this virus has been reported in Iran. Thus, RNA silencing mechanism was applied to consider the possibility of improvement in resistance to TuMV in spring canola, RGS003 variety.

To obtain an effective construct for silencing, based on the bioinformatics analysis, a fragment containing 130 conserved nucleotide sequences of the TuMV coat protein gene was gained as targeting candidate to produce sense, antisense and hairpin constructs and assessed for resistance efficiency in a transient expression system in Nicotiana benthamiana by agroinfiltration. The development of symptoms after virus inoculation revealed that the highest efficiency can be obtained by hairpin construct. Therefore, the hairpin construct was applied for the transformation of canola RGS003 via cotyledonary explants using Agrobacterium tumefaciens LBA4404. In transgenic and non-transgenic canola plants, the infection and virus titer were assessed by ratio of detection via ELISA and real-time PCR. In addition, severity of disease symptoms was scored four weeks after inoculation with a TuMV isolate.

Results indicated 5-12 days delay in appearance of symptoms in transgenic plants and there was a decrease in severity of symptoms in contrast to non-transgenic plants. The increased virus concentration ratio in non-transgenic compared to transgenic plants was confirmed by qRT-PCR. The ELISA results confirmed absence of infection on five out of six transformed plants 15 dpi.

These preliminary results proved that transgenic canola plants containing hairpin of 130 nucleotide sequences of TuMV CP gene could resist against TuMV.

Bacteriophages are prokaryotic viruses, which multiply in bacteria and archaea. These viruses are important in transferring mobile genetic elements such as virulence and antimicrobial resistance genes to bacteria under a process called transduction. Although bacteriophages have long been addressed with their various medical applications, an exciting application of these viruses is linked to their infection treatment potential. Since antimicrobial resistance is rapidly extending in bacterial populations and no novel antibiotics have been introduced to the market in decades, alternative treatment protocols such as phage therapy must be further supported to secure the future of infection treatments. The present review molecularly introduces bacteriophages and their major applications.