Iranian Journal of Virology
Volume:13 Issue: 2, 2019

Foot and Mouth Disease is one of the important live stocks contagious viral diseases caused by Aphtovirus genus, belonging to the family of Picornaviride. The important characteristic of FMD virus is high mutation that gives rise to diversity of antigen on the surface of neutralizing proteins. For this reason FMD virus has 7 distinct serotype and many subtypes. Vaccination is one of the methods to control the disease caused by different type and subtype of FMD virus, the effective vaccine should have virus with close relationship with field virus and also many passage on cell culture may cause mutation on viral genome. The rate of genetic changes of FMD virus type O2016 during of 70 passages in BHK monolayer cell is the main reason of this paper. 

After determining the type of virus in epithelium sample by ELISA, the virus inoculated in BHK monolayer cell for 70 consequence passage. Harvested viruses in 10 selected passage (P1,P10 , P20,P30,P40,P50,P60,P70) were subjected to RT-PCR, ELISA, titration, real time PCR, Double dimension virus neutralization test for  immunological relationship value (r value) and Nucleotide sequencing of 1D segment of viral genome.

Harvested FMD virus type O2016 from passage 1 until 70 were constant. No significant change was detected neither in sequencing nor in r values.

The virus has displayed very little change over the course of repeated passages, which can even be claimed to stay unchanged.

One of the main causes of severe respiratory infection in infants and young children is respiratory syncytial virus (RSV). The disease can also occur in adults and elderly individuals and clinically not to be differentiated from other viral respiratory infection. The disease causes bronchiolitis, and sometimes pneumonia in new born and young children which requires hospital care. To differentiate the disease from other respiratory infection and rapid treatment accurate laboratory diagnosis of the disease is necessary.

specimen taken from the sick children suffering from respiratory infection were processed and fixed on the slides. They were stained with fluorescein conjugated RSV specific antibody and examined by a UV microscope.

From 141 patients attending the Kasra hospital laboratories 62 of them were positive, most of the infection occurred in children with in 6 month of birth. The rate of infection was higher in the month of January and February.

It seems that RSV infection is common in infants and young children which occur mostly during the cold season.

Newcastle disease (ND) is one of the most serious diseases among many species of birds and causes devastating effects on the poultry industry. This disease is endemic in Iran and ND outbreaks occur unexpectedly and with high mortality and severe clinical signs. The sequence of the F protein cleavage site is that the major virulence determinant of Newcastle disease virus (NDV). This study aimed to understand the molecular characterization of three NDVs isolates from commercial broilers from Qazvin province during 2019-2020. Thus, we can design appropriate control programs by obtaining useful data.

The partial open reading frame sequences of the F gene and haemagglutinin-neuraminidase (HN) genes of three isolates were amplified and sequenced. All sequences were edited using BioEdit Package and phylogenic trees were created based on the partial F gene sequences of isolates attained in this study and other NDV sequences available in GenBank with MEGA 7 software.

The phylogenetic analysis displayed that the viruses belonged to genotype VII and further clustered into sub-genotype VII.1.1. Analysis of the F protein showed polybasic amino acid motif and a phenylalanine at position 117 at the cleavage site.

The similarity of these strains could indicate the entry of migratory birds from neighboring countries into Iran. Also, the role of backyard poultry is very important in the epidemiology of ND.  This study proclaims the urgency of effective control strategies.

Avian encephalomyelitis is caused by a Tremovirus and primarily affects chickens. The virus can infect young chicks and cause nervous symptoms. Vaccines are used to control the disease in breeders. Recently, the occurrence of the disease is causing concern in the poultry industry.

In the present study, we report a case of avian encephalomyelitis in one broiler farm in Kashan (center of Iran). The chickens showed nervous symptoms like depression, head trembling, ataxia, dull eyes, as well as drowsiness, lack of coordination, and unsteady gait in chickens. In this study, we detected avian encephalomyelitis with the molecular procedure like reverse transcriptase-polymerase chain reaction (RT-PCR). Also, the histopathological diagnosis was made.  

The disease was confirmed based on the clinical, molecular and histopathological findings.

Due to the increase in vaccine prices and the difficulties of vaccine providing in the breeders’ farms, the probability of disease has increased. Stringently monitoring of breeders farms before the beginning of egg production and using a suitable protocol with vaccination is recommended.

Serological assay is considered as one of the best choices for conducting large number of infection tests. Recombinant DNA technology has been used for expression of virus coat protein (CP) gene in prokaryotic bacterial cells such as Escherichia coli and the recombinant CP (rCP) is used as immunogen in antibody production. Heterologous CP protein expression and purification of the full length Prunus necrotic ringspot virus-PNRSV, Ilarvirus genus, from an Iranian isolate as an antigen was the aim of the study.

A predominant Iranian PNRSV isolate (PK5) was selected and its CP gene was amplified using specific primers and the nucleotide sequence has been determined. The amplicon was cloned into pET28a(+) expression vector. The amplified CP gene and linearized pET-28a(+) were purified from gel, ligated and transformed into BL21 strain of E. coli. Expression of rCP in transformed BL21 competent cells was tested using SDS-PAGE and Western Blot assays.

RT-PCR on total RNA extracted from the infected leaves resulted in a DNA fragment of approximately 688 bp corresponding to full PNRSV/CP. BLAST analysis of the obtained nucleotide sequence for PNRSV/CP revealed 97% identity to JW isolate (accession no. DQ983491). The size of pET-PNRSV/CP was about 6000 bp. The E. coli BL21 cells harboring recombinant pET-PNRSV/CP successfully expressed the recombinant CP after IPTG induction.

In this study, the recombinant CP gene of a predominant Iranian PNRSV isolates expressed in E. coli. The recombinant CP can be used for producing high quality antibodies against PNRSV.

The novel coronavirus (2019-nCoV), one of the most important infectious diseases of the current decade causes a severe respiratory global pandemic. It was first reported on December 8, 2019 in Wuhan City, Hubei Province, China and spread all over the world. It can cause severe respiratory, enteric, hepatic, and neurologic diseases. This study aimed to report the symptoms and lab identification of a patient confirmed with COVID-19 infection with no respiratory symptoms compared to few other cases.

Viral Nervous Necrosis (VNN) causes viral encephalopathy and retinopathy (VER), a hazardous and devastating disease of many species of cultured and marine fish worldwide. It caused by betanodaviruses a serious concern especially in the fry and young fish. This virus infects most of the cultured fishes causing severe mortality. Our current review focuses chiefly on recent studies performed on VNN disease. Recent outbreaks have been reported in China, Indonesia, Singapore and India, affecting the mariculture and aquaculture industry. It also decreased dramatically Mullet stocks in the Caspian Sea. The four main genotypes of VNN were found in all continentals’ except South America. The economic loss due to the virus is mainly due to mortality and spread of infection both vertically and horizontally. Our investigation in recent years suggest that more research and epidemiological surveys should be conducted, especially in critical areas were mariculture farms are planned to be established. Therefore, finding new rapid diagnosis tools, Monitoring and Surveillance program, and effective vaccines, Control, Prevention and Eradication in the comprehensive program should be considered globally.