Infectious bronchitis (IB) is a viral avian disease with economic importance in the world, including Iran. S1 gene sequencing has been used for molecular epidemiological studies and genotypic characterization of infectious bronchitis virus (IBV). A total of 118 IBV isolates were obtained from tissue samples from chickens with clinically suspected IB from Iranian broiler farms (eight provinces, 200 samples). The isolates were confirmed by real-time polymerase chain reaction (PCR) and characterized by sequencing the spike glycoprotein gene. The isolates formed six distinct phylogenetic groups (IS/1494/06 [Var2] like, 4/91-like, IS/720-like, QX-like, IR-1 and Mass-like) that were related to variants isolated in the region. The most frequently detected viruses were of the Var2-like (IS/1494/06-like) genotype, with an overall prevalence of 34 %. Twenty-one percent of the isolates formed a cluster together with the 4/91 IBV type, 10 % were of the QX genotype, and 8 % were of the IS/720 genotype. In addition, 4 % and 3 % of the isolates belonged to the Massachusetts and IR-1 genotype, respectively. For the first time, we have isolated and characterized IBV variants from broiler farms in different provinces of Iran. This study demonstrates a constant evolution of IBV in Iran, demonstrating the need for continuous monitoring and development of new vaccines based on indigenous viruses.

Newcastle disease (ND) is a contagious viral disease affecting numerous avian species, particularly domestic poultry, and causes devastating outbreaks. In spite of its endemicity and importance in Iran, data on the genetic characterization of ND virus (NDV) are scarce. An alarming issue that has just been raised is the occurrence of ND outbreaks with unexpected high mortality and severe clinical signs. The present study was conducted to characterize the emerging NDV genetically. An NDV strain, isolated in 2017 from commercial broilers showing severe nervous and enteric signs, was completely sequenced and found to be 15,192 nucleotides in length. The phylogenetic analysis demonstrated that the virus belonged to subgenotype VIIi, a subgenotype with potential panzootic features which has recently emerged in the Middle East and Asia. The supporting genetic pattern obtained from the complete genome, fusion and haemagglutinin gene analysis showed close relationship of the isolate with Pakistani VIIi NDVs. The analysis of the F protein showed a polybasic amino acid motif and a phenylalanine at position 117 at the cleavage site, which is a characteristic of virulent strains. The isolate showed significant differences from the previously characterized NDV strains from commercial and rural chickens in Iran. This may describe the importance of the illegal trade of pet birds from neighbouring countries leading to the emergence of new genotypes. This study introduces a newly emerging NDV VIIi subgenotype in Iran. This investigation emphasizes the necessity of effective control strategies.

Summary. -Avian infectious bronchitis (IB) is a major cause of economic loss to the poultry industry. IB virus primarily affects respiratory tract, but strains differ in their tropism for such other target organs as kidneys and alimentary tract. The objective of this study was to estimate the pathogenicity of an Iranian IB virus (IBV) variant (variant-2) which is one of the most prevalent isolates circulating in Iranian poultry farms. SPF chickens were intranasally inoculated with 10 4 EID 50 /0.1 ml of the virus. Sera, fecal swabs, and different tissue samples were collected on different days post infection. Clinical signs, gross pathology, and histological changes were recorded. The amount of virus genome was quantified in different tissues and feces using quantitative real-time PCR assay. The highest viral loads were detected in the feces and cecal tonsils. Real-time PCR results demonstrated variant-2 tropism for respiratory tract, digestive system and renal tissue that is due to its epitheliotropic nature. This is the first pathogenicity study of Iranian variant-2 virus. Based on histology observations and clinical signs this isolate was classified as a nephropathogenic IBV. Further knowledge of IBV pathogenesis permits to perform more effective prevention practice.

Various nanostructured particles including colloidal silica nanoparticles, mesoporous silica aerogel, silicon carbide nanoparticles, and nanowhiskers were used to modify the glass fibers surface. The influence of porosity and aspect ratio of nanoscale particles on the mechanical properties of modified glass fiber/epoxy composite samples were investigated. Fiber surfaces treated with nanoscale particles exhibited much higher coefficient of friction and roughness than unmodified fiber surfaces. Surface modified composites by silica aerogel showed the maximum increase in interfacial shear strength (IFSS) by 31%. An increase of 61% in shear punch stress was obtained by samples treated with silica aerogel and 27% for samples treated with silica nanoparticles. Improvement of 23% and 63% in tensile and flexural strength of composite samples treated with 0.5 wt% of SiC nanowhiskers and 7% and 18% for samples treated with the same content of SiC nanoparticles were observed. POLYM. COMPOS., 00:000-000, 18% for samples treated with the same content of SiC nanoparticles were observed. POLYM. COMPOS., 39:3073-3080, 2018.

Avian infectious bronchitis virus (IBV) is causing major economic losses to the poultry industry. The analysis of the S1 gene has been used to determine IBV genotype. The aim of this study was genotyping of IBVs circulating among the Iranian broiler flocks in the period between 2015 to 2017. Trachea samples from 278 broiler flocks were collected from broiler farms in eight provinces of Iran. After Real-time RT-PCR, IBV-positive samples were further characterized based on S1 gene. The results of the Real-time RT-PCR showed that 52.16% of flocks were IBV positive. Four genotypes were detected and the frequency of occurrence rates of IS-1494-like, 793/B, QX and Massachusetts IBV genotypes were 70.34%, 19.31%, 7.58% and 2.75%, respectively. Sequence analysis revealed that nucleotide identities within IS-1494-like group ranged between 98.86-100%, while each of the QX, Massachusetts and 793/B groups were 98.05-100%, 98.20-100% and 93.29-100% respectively. These results show that the IS-1494-like IBV is the dominant IBV genotype in Iran. Proper control strategies are essential to overcoming the high frequency of occurrence of IS-1494-like IBV. The phylogenetic relationship of the strains with respect to different sequences and geographical regions displayed complexity and diversity. Further studies are needed and should include the isolation and full-length molecular characterization of IBV in Iran.