Background: Avian hepatitis E virus (HEV) is the pathogenic agent of big liver and spleen disease (BLS) and of hepatitis-splenomegaly syndrome (HSS) in chickens, which have caused economic losses to the poultry industry in China. In this study, 18 samples of BLS chickens were collected to reveal the molecular epidemiological characteristics of avian HEV in the province of Shandong, China. Results: Gross and microscopic lesions of clinical samples were observed; then, virology detection and genetic analysis of avian HEV were performed. The results showed that there was significant swelling and rupture in the liver and that the spleen was enlarged. Microscopic lesions demonstrated obvious hemorrhage in the liver, with infiltration of heterophilic granulocytes, lymphocytes, and macrophages, as well as the reduction of lymphocytes in the spleen. Eleven of the 18 samples were positive for avian HEV, with a positive rate of 61.11%. More importantly, all avian HEV-positive samples were mixed infections: among these, the mixed infections of avian HEV and chicken infectious anemia virus (CIAV) and avian HEV and fowl adenovirus (FAdV) were the most common. Furthermore, the genetic evolution analysis showed that all avian HEV strains obtained here did not belong to the reported 4 genotypes, thus constituting a potential novel genotype. Conclusions: These results of this study further enrich the epidemiological data on avian HEV in Shandong, prove the genetic diversity of avian HEV in China, and uncover the complex mixed infections of avian HEV clinical samples.

The particulate matter (PM) generated during poultry farming is characterized by its complex composition and substantial emission levels. However, researches on the respiratory damage caused by poultry house PM and the underlying mechanisms remain limited. In this study, inhalable PM collected from duck houses was administered to experimental mice through inhalation exposure. After 10 days of short-term exposure and 30 days of long-term exposure, mice samples were collected for lung histopathological analysis and inflammatory cytokines detection. The results showed that inhalation of duck house PM induced pulmonary and systemic inflammatory responses in both groups of mice, with significant upregulation of IL-6 and CXCL2. Compared to short-term exposure, long-term exposure resulted in more severe microscopic lesions in the lungs. In addition, the concentrations of malondialdehyde (MDA) and glutathione (GSH) increased in mice, indicating that duck house PM could trigger oxidative stress in lungs, we also found duck house PM induced ferroptosis in mice. Furthermore, it was confirmed that duck house PM caused cell damage and increased intracellular iron levels in MLE-12 cells, and PM reduced GSH in a dose-dependent manner. Notably, ferroptosis inhibitor treatment effectively alleviated PM-induced cell damage. These findings indicated that duck house PM can induce ferroptosis in both mice and cells, and ferroptosis plays a critical role in duck house PM-induced lung damage. These results laid a solid foundation for further exploring the mechanism of PM-induced lung injury, and providing a new insight for targeting ferroptosis to treat such damage.