Gut microbiota has been demonstrated to be involved in intestinal nutrition, defense, and immunity, as well as participating in disease progression. This study was to investigate gut microbiota changes in chickens challenged with netB -positive Clostridium perfringens strain (CP1) and/or the predisposing Eimeria species ( Eimeria ) and fed diets with fishmeal supplementation. In addition, the effects of lauric acid, a medium-chain fatty acid (MCFA), on necrotic enteritis (NE) reduction and modulation of microbiota were evaluated. The results demonstrated that microbial communities in the jejunum were distinct from those in the cecum, and the microbial community change was more significant in jejunum. Challenge of CP1 in conjunction with Eimeria significantly reduced species diversity in jejunal microbiota, but cecal microbiota remained stable. In the jejunum, CP1 challenge increased the abundance of the genera of Clostridium sensu stricto 1 , Escherichia Shigella , and Weissella , but significantly decreased the population of Lactobacillus . Eimeria infection on its own was unable to promote NE, demonstrating decrements of Clostridium sensu stricto 1 and Lactobacillus . Co-infection with CP1 and Eimeria reproduced the majority of NE lesions with significant increment of C lostridium sensu stricto 1 and reduction in Lactobacillus . The advance of changes on these two taxa increased the severity of NE lesions. Further analyses of metagenomeSeq, STAMP, and LEfSe consistently showed significant overgrowth of Clostridium sensu stricto 1 was associated with NE. The supplementation of lauric acid did not reduce NE incidence and severity but decreased the relative abundance of Escherichia Shigella . In conclusion, significant overgrowth of C . perfringens as well as other Clostridium species in Clostridium sensu stricto 1 with the decrement of Lactobacillus in the jejunum is the featured microbiota correlated with NE. Controlling proliferation of Clostridium sensu stricto 1 and manipulation of Lactobacillus in the jejunum should be the strategy to prevent NE.

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Cell-to-cell communication by exosomes controls normal and pathogenic processes 1 , 2 . Viruses can spread in exosomes and thereby avoid immune recognition 3 . While biogenesis, binding, and uptake of exosomes are well-characterized 4 , 5 , delivery of exosome cargo into the cytoplasm is poorly understood 3 . We report that phosphatidylserine receptor HAVCR1 6 , 7 and cholesterol transporter NPC1 8 participate in cargo delivery from exosomes of hepatitis A virus (HAV)-infected cells (exo-HAV) by clathrin-mediated endocytosis. Using CRISPR/Cas9 knockouts we show that these two lipid receptors, which interact in the late endosome 9 , are necessary for membrane fusion and delivery of RNA from exo-HAVs into the cytoplasm. The HAVCR1/NPC1 pathway, which Ebola virus exploits to infect cells 9 , mediates HAV infection by exo-HAV indicating that viral infection by this exosome mimicry mechanism does not require an envelope glycoprotein. The luminal viral RNA but not endosomal uncoating of HAV particles (vpHAV) contained in the exosome is mainly responsible for exo-HAV infectivity as assessed by methylene blue-inactivation of non-encapsidated RNA. In contrast, infectivity of vpHAV is pH-independent and requires HAVCR1 or other yet unidentified receptor(s) but not NPC1. Our findings show that envelope glycoprotein-independent fusion mechanisms are shared by exosomes and viruses, and call for a reassessment of the role of envelope glycoproteins in infection.

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Future mobile services are expected to include various non-voice oriented services. One important category of non-voice oriented mobile services is non-real-time services. When a mobile user establishes a connection to access non-real-time service, the mobile user usually cares about whether the total time to complete its data transfer is within its time tolerance. In addition, different mobile users may have different bandwidth requirements and different tolerances in the total completion time. It is essential for wireless systems to provide various mobile users with different total completion times. In this paper, two quality-of-service (QoS) metrics, called stretch ratio and eligibility percentage, are employed at a connection level to present the degree of the length of the total completion time. We devise a measurement based call admission control scheme that provides multiple QoSs for various mobile users which have different requirements of stretch ratios, eligibility percentages, and bandwidths. Extensive simulation results show that the measurement based call admission control scheme not only provides various satisfactory QoSs for mobile users but also produces high throughput.