Seroprevalence and genotyping of avian infectious bronchitis virus detected from Iranian unvaccinated backyard chickens
Background and Objectives: Different epidemiological studies have found that backyard chickens are a reservoir for poultry diseases. Most backyard chicken flocks have a poor level of biosecurity, which increases the risk of spread of diseases. In recent years, the number of backyard chickens has been on the rise in Iran. However, the health status of backyard flocks is still poorly documented. Thus, this study aimed at examining the seroprevalence of antibodies against infectious bronchitis virus (IBV) and molecular surveillance and genotyping of IBV among backyard chickens (without vaccination history) in Mazandaran province, North of Iran, 2014. Materials and Methods: A total of 460 blood samples of unvaccinated backyard chickens in the mentioned area were tested for antibodies against IBV using commercial ELISA. Also, cecal tonsils were collected from 75 chickens in the same area. Real time RT-PCR (for detection) and RT-PCR and sequencing spike gene were performed. Results: The seropositivity rate was 54.5%. In addition, we detected 793/B, Variant 2, and QX in the backyard flocks and performed phylogenetic studies on them. The phylogenetic study revealed that the detected genotypes had high homology with IBV strains that were infected broilers, pullets, and layers in Iran. Conclusion: There is a need for continuous monitoring of IBV among avian species to complete the epidemiological map and work on the pathogenesis of Iranian IBV strains in Iranian backyard chickens.
Pathogenicity of a QX-like avian infectious bronchitis virus isolated in China

 ABSTRACT
 
 Avian infectious bronchitis is a serious and highly contagious disease caused by infectious bronchitis virus (IBV). We isolated a highly virulent IBV strain (CK/CH/JS/TAHY) from kidneys of diseased chickens. Phylogenetic analysis based on the S1 gene revealed that CK/CH/JS/TAHY clustered with the QX-like type. The S1 gene has 1,620 nucleotides and encoded a polypeptide of 540 amino acids with typical coronavirus cleavage recognition sites of HRRR. About 1-day-old specific pathogen-free White Leghorn chickens inoculated with CK/CH/JS/TAHY at 105.5 EID50 exhibited clinical signs including coughing, sneezing, nasal discharge, and tracheal vocalization accompanied by depression with 84% mortality and 100% morbidity. The kidneys of dead birds were swollen and pale and exhibited severe urate deposition. Histopathological examination revealed kidney hemorrhages, multifocal necrosis of the renal tubules and trachea with cilia loss, sloughing of epithelial cells, and edema of the lamina propria. IBV-specific antibodies appeared at 10 D post-infection. Chickens vaccinated with a CK/CH/JS/TAHY oil-emulsion vaccine showed 26.7% morbidity and 3% mortality indicating a protective effect. In conclusion, the IBV strain is a virulent avian IBV and that exhibited severe pathogenicity in chickens and is a vaccine candidate to prevent infection by Chinese QX-like nephropathogenic IBV strains.
 

Thermal properties of the Florida Current as related to Ocean Thermal Energy Conversion (OTEC)
The thermal properties of the Florida Current are presented and analyzed for the available ocean thermal energy. For a cold water intake depth equal to or greater than 600 m, potential sites for Ocean Thermal Energy Conversion (OTEC) power plants appear to exist in the Straits of Florida and, to a lesser extent, off the coasts of Georgia and South Carolina. The maximum thermal differences occur on the continental shelf because of the geostrophic motion of the Gulf Stream. An estimate of the total available ocean thermal energy from the Florida Current, delivered in the form of electricity, is 3.5 × 1012 kWh yr−1. For a cold water suction depth of 600 m or more, seasonal variability in the ocean thermal resource is approx. ±35 per cent of average annual output.