Suchergebnisse

Clostridium perfringens (CP) is the etiologic agent of necrotic enteritis (NE) in broiler chickens that is responsible for massive economic losses in the poultry industry in response to voluntary reduction and withdrawal of antibiotic growth promoters. large variations exist in the CP isolates in inducing intestinal NE lesions. However, limited information is available on CP isolate genetics in inducing NE with other predisposing factors. This study investigated the ability of five CP isolates from different sources to influence NE pathogenesis by using an Eimeria maxima (EM) coinfection NE model: Str.13 (from soil), LLY_N11 (healthy chicken intestine), SM101 (food poisoning), Del1 (net(+)tpeL(-)) and LLY_Tpel17 (netB(+)tpeL(+)) for NE-afflicted chickens. The 2-wk-old broiler chickens were preinfected with EM (5 X 10(3) oocysts) followed by CP infection (around 1 X 10(9) colony-forming units per chicken). The group of the LLY_Tpel17 isolate with EM coinfection had 25% mortality. No mortality was observed in the groups infected with EM alone, all CP alone, or dual infections of EM/other CP isolates. In this model of EM/CP coinfections, the relative percentages of body weight gain showed statistically significant decreases in all EM/CP groups except the EM/SM101 group when compared with the sham control group. Evident gut lesions were only observed in the three groups of EM/LLY_N11, EM/Del1, and EM/LLY_Tpel17, all of which possessed an essential NE pathogenesis locus in their genomes. Our studies indicate that LLY_Tpel17 is highly pathogenic to induce severe gut lesions and would be a good CP challenge strain for studies investigating pathogenesis and evaluating the protection efficacy for antibiotic alternative approaches. ; Agricultural Research Service, USDAUnited States Department of Agriculture (USDA)USDA Agricultural Research Service ; This work was supported by the funds from Agricultural Research Service, USDA. The authors declare that they have no competing interests. ; Public domain authored by a U.S. government employee

Abstract
The outbreak of the novel coronavirus disease 2019 (COVID-19) has posed a great impact on people's mental health, especially for undergraduate students. This study aimed to compare the mental health conditions and academic burnout between medical and non-medical undergraduates in China when the COVID-19 pandemic is mitigating. A cross-sectional online survey was conducted among 4,972 undergraduates between October 2020 and April 2021, when the pandemic was basically under control. The survey included basic demographics information and standardized scales to evaluate depression, anxiety, perceived stress, daytime sleepiness, alcohol abuse/dependence, quality of life, fatigue, and academic burnout. Compared with medical undergraduates, non-medical undergraduates had higher rates of moderate to severe depression symptoms (29.1% vs. 17.9%, P < 0.001), moderate to severe anxiety symptoms (19.7% vs. 8.9%, P < 0.001), alcohol abuse/dependence (16.3% vs.10.3%, P < 0.001), excessive daytime sleepiness (47.4% vs. 43.4%, P = 0.018), high perceived stress (34.7% vs. 22.2%, P < 0.001), high level of fatigue (51.8% vs. 42.2%, P < 0.001), low QOL (35.8% vs. 21.4%, P < 0.001), and higher academic burnout score (59.4 vs. 57.5, P < 0.001). Being non-medical undergraduates, depression, alcohol abuse/dependence, excessive daytime sleepiness, and high perceived stress were positively associated with academic burnout, while high QOL was negatively associated with the burnout (all P < 0.001). Excessive daytime sleepiness was the strongest predictor for academic burnout.