Tropical Animal Health and Production - Avian influenza virus (AIV) H9N2 subtype is endemic in Iran and causes substantial economic loss to the growing poultry industry within the country. In this... 相似文献
In this study, a process has been proposed whereby the sulfide required for autotrophic denitrification is supplied by reducing the sulfate of influent water without the need to add an external sulfide source. The molar ratio of nitrate-to-sulfide was maintained at 1.6. The proposed system was operated continuously for 6 months, including two anoxic and anaerobic reactors with upward flow. The results indicate that the average amount of nitrate declined by 74%. The pH of 7–8 was more effective than a pH of 6 in removing the nitrate. As the hydraulic retention time was prolonged from 1.5 to 3 and was further prolonged to 5 h, the system efficiency was enhanced by removing the nitrate. An alkalinity consumption rate of 1.15 mg (as CaCO3) per mg of removed NO3?-N was achieved. In the effluent water, the increased sulfate was 6.7 mg per mg of removed NO?3-N, while the hardness was diminished by 2.85 mg (as CaCO3). 相似文献
In many countries, the Sunn pest, Eurygaster integriceps Puton (Hemiptera: Scutelleridae) is one of the most important insect pests of wheat. Chemical control of E. integriceps is not efficient making it essential to find other control methods. Plant α-amylase inhibitors expressed as transgenes have emerged as a promising way of controlling insect pests and several crop species expressing transgenic amylase inhibitors have been shown to be resistant to certain insect pest. Here we report inhibition of salivary α-amylases of E. integriceps by semi-purified proteinaceous α-amylase inhibitors from Triticale (TAI). A dose dependent trend of inhibition of the enzyme was observed using TAI with an I50 value of 0.79 μg of TAI. At the highest concentration of the inhibitor used here, we found 87% inhibition of amylase activity. The inhibitory activity was maximal at pH at 5.0, which is in accordance with the pH optimum of the salivary gland enzymes. Kinetic studies of enzyme-inhibitor interaction revealed a kind of partial mixed inhibition with an apparent inhibitory constant value (Ki[app]) of 1.1 μg of TAI against salivary α-amylase in the assay medium. In gel inhibition assays showed that all isoforms of salivary glands α-amylase were sensitive to the TAI, although to different degrees. Moreover, the effectiveness of TAI was retained in different stages of pre-oral and oral digestion of E. integriceps, although some inhibitory activity was lost, possibly by the action of the insect proteases. These findings indicate that TAI shows promise for use in the management of this pest. To the best of our knowledge, this is the first study of inhibitor-insect digestive enzymes interaction, based on the insect feeding strategy and digestion process. 相似文献
In this study, the prevalence and spatial distribution of Newcastle disease, infectious bronchitis, and avian influenza have been evaluated in commercial broiler farms in 31 provinces in Iran. In this survey, a total of 233 affected broiler chicken farms were sampled. The infectious bronchitis virus (alone) was detected with highest frequency in 60 farms, and separately or combined with other agents, in 110 farms; Newcastle disease virus, separately, was detected in 28 farms, and in 63 farms separately or combined with other infectious agents; and avian influenza H9N2 was detected in 22 farms separately and in 51 farms separately or concomitant with other infectious agents. The sample tested negative for all H5 serotypes. The results of the present study show that the most prevalent avian viral infectious disease contributing to respiratory syndromes in broiler farms in Iran was infectious bronchitis due to infectious bronchitis virus serotypes variant 2 and 793/B. On the other hand, combined with the alternation of dominant viruses and circulating strains, flocks are exposed to unremitting anamorphic viral infections. Thus, the permanent monitoring of cases that have occurred and the review of vaccination plans of affected flocks every year are some of the necessary measures needed for strategic control of respiratory syndrome in broilers. It is noteworthy that execution of epidemiologic examinations on the cogent factors of prevalence of this syndrome and defeat of vaccination strategy in the flocks is urgent and has to be fulfilled on the definite causes of time.
Based on our previous work, it was discovered that some Newcastle disease virus (NDV) isolates from backyard poultry between 2011 and 2013 in Iran formed a new separate cluster when phylogenetic analysis based on the complete F gene sequence was carried out. The novel cluster was designated subgenotype VII(L) and published.
Aim
In the current study, for further validation, we initiated a comprehensive epidemiological study to identify the dominant NDV genotype(s) circulating within the country. Collection of samples was executed between October 2017 and February 2018 from 108 commercial broiler farms which reported clinical signs of respiratory disease in their broilers.
Result
We report that 38 of the farms (> 35%) tested positive for NDV. The complete F gene sequences of seven of the isolates are shown as representative sequences in this study. According to the phylogenetic tree constructed, the recent broiler farm isolates clustered into the newly designated cluster VII(L) together with the older Iranian backyard poultry isolates in our previous work. All the sequences shared the same virulence-associated F cleavage site of 112RRQKR↓F117.
Conclusion
Our phylogenetic analysis suggested that the NDV subgenotype VII(L) may have been derived from subgenotype VIId, and contrary to popular belief, subgenotype VIId may not be the dominant subgenotype in Iran. Tracking of the subgenotype on BLAST suggested that the NDV subgenotype VII(L), although previously unidentified, may have been circulating in this region as an endemic virus for at least a decade. Other NDV genotypes, however, have also been reported in Iran in recent years. Hence, ongoing study is aimed at determining the exact dominant NDV genotypes and subgenotypes in the country. This will be crucial in effective mitigation of outbreaks in Iranian broiler farms.
Tropical Animal Health and Production - Since 1998, Iran’s poultry industry has faced several outbreaks of low pathogenic avian influenza H9N2. Tissue samples were collected from a broiler... 相似文献
The cover image is based on the Research Article Wolbachia promotes successful sex with siblings in the parasitoid Habrobracon hebetor by Zeynab Bagheri et al., https://doi.org/10.1002/ps.6649 .
