作者机构：
[Dong, Yuhao; Geng, Jinzhu; Nie, Meng; Huang, Hao; Zhao, Dan; Liu, Yongjie; Lu, Chengping] Nanjing Agr Univ, Coll Vet Med, Joint Int Res Lab Anim Hlth & Food Safety, Nanjing, Peoples R China.;[Liu, Jin] Wuhan Polytech Univ, Hubei Key Lab Anim Nutr & Feed Sci, Wuhan, Peoples R China.;[Wan, Xihe] Inst Oceanol & Marine Fisheries, Nantong, Peoples R China.
通讯机构：
[Yongjie Liu] J;Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
摘要：
Protozoan predation has been demonstrated to be a strong driving force for bacterial defence strategies in the environment. Our previous study demonstrated that <i>Aeromonas hydrophila</i> NJ-35, which evolved small-colony variants (SCVs), displayed various adaptive traits in response to <i>Tetrahymena thermophila</i> predation, such as enhanced phage resistance. However, the evolutionary mechanisms are largely unknown. In this study, we performed a genome- and transcriptome-wide analysis of the SCV1, representing one strain of the SCVs, for identification of the genes of mutation and altered expression underlying this phage resistance phenotype. Our study demonstrated that phage resistance caused by <i>T. thermophila</i> predation was due to the downregulation of a flagellar biosynthesis regulator, <i>flhF</i>, in SCV1. Interestingly, we confirmed that phage resistance in SCV1 was not straightforwardly attributable to the absence of flagella but to FlhF-mediated secretion of extracellular protein that hinders phage adsorption. This finding improves our understanding of the mechanisms by which <i>A. hydrophila</i> lowers the susceptibility to phage infection under predation pressure, and highlights an important contribution of bacterium-protozoan interactions in driving the adaptive evolution of pathogens in complex environments.
摘要：
As a quorum sensing signal molecule, N-(3-oxododecanoyl)-homoserine lactone (3OC12) regulate the population behavior of microorganisms. Many studies have proved that 3OC12 harm the physiological function of host intestinal epithelial cells. However, the detrimental effects of 3OC12 on intestinal health need verification in animals. Besides, the role of gut microbiome in 3OC12-induced intestinal damage also needs further understanding. In our study, 3OC12 was first administered to specific pathogen-free (SPF) mice, then the fecal microbiome of SPF mice was transplanted into germ-free (GF) mice to reveal the effects of 3OC12 on intestinal health and regulatory mechanisms of the intestinal microbiome. 3OC12 treatment significantly decreased body weight, shortened colonic length, disrupted the morphology of the colonic epithelium and increased the histopathological score of the colon in SPF mice. The levels of diamine peroxidase, D-lactate, TNF-alpha, IL-1 beta, and IL-8 were found to be significantly elevated in the serum of 3OC12 mice, while the levels of IL-10 were significantly reduced. Besides, the fecal microbial community of mice was also altered in the 3OC12-treated SPF mice. The results of fecal microbial transplantation (FMT) experiment showed that the phenotypes in SPF mice were almost reproduced in GF mice, manifested by body weight loss, colon damage and changed in serum chemical markers. More importantly, a joint analysis of fecal microbes in SPF and GF mice revealed Feature14_Elizabethkingia spp. was common differential bacteria in the feces of two kinds of mice treated with and without FMT. Our results demonstrated that 3OC12 challenge led to systemic inflammation and body weight loss in mice by disrupting in-testinal barrier function, in which gut microbiome played a key role. These findings increased our understanding of the mechanism of intestinal injury caused by 3CO12, providing new ideas for the prevention and therapy of diseases caused by bacterial infection from the perspective of intestinal microbiome. (c) 2021 Elsevier B.V. All rights reserved.
摘要：
For birds, the uterus is an important part for eggshell mineralization, and the establishment of the endometrial epithelial cell (EEC) model was beneficial to the study of uterine function. This study was conducted to establish a culture model of primary EECs of laying hens and explore the effects of zinc on primary EEC proliferation, zinc transport, and calcium deposition in vitro. The EECs were isolated and cultured via type I collagenase digestion, and in the logarithmic phase during 2–5days, and then reached the plateau phase on the 7th day of inoculation. Results showed that the proliferation of EECs treated by 50μM ZnSO4 or zinc-methionine (Zn-Met) were markedly promoted at 24-h or 48-h treating time (P < 0.05). In later experiments, the EECs were divided into three groups, involving a control group (no zinc treated), ZnSO4 group (50μM zinc treated) and a Zn-Met group (50μM zinc treated). Results showed the relative fluorescence intensity of Ca2+ in the Zn-Met group was significantly higher than that in the control group (P < 0.05). As for zinc transporters, it was only observed that mRNA levels of metallothionein (MT) in EECs showed a significant difference (P < 0.05) between the Zn-Met group and the control. In conclusion, the EECs of laying hens isolated by scraping and digested collagenase I were with better adherent growth. Moreover, Zn-Met can increase intracellular Ca2+ concentration and upregulate expressions of MT mRNA in the EECs of laying hens.
摘要：
The purpose of this study was to compare the pharmacokinetics and relative bioavailability of tilmicosin enteric granules and premix after oral administration at a dose of 40 mg/kg in pigs. Three kinds of different respiratory pathogens were selected for determination of minimal inhibitory concentration (MIC) to tilmicosin. Eight healthy pigs were assigned to a two-period, randomized crossover design. A modified rapid, sensitive HPLC method was used for determining the concentrations of tilmicosin in plasma. Pharmacokinetic parameters were calculated by using WinNonlin 5.2 software. The MIC90 of tilmicosin against Haemophilus parasuis, Actinbacillus pleuropneumoniae, and Pasteurella multocida were all 8 mug/ml. These results indicated that these common pig respiratory bacteria are sensitive to tilmicosin. The main parameters of time to reach maximum plasma concentration (Tmax ), elimination half-life (t1/2beta ), mean residence time (MRT), and apparent volume of distribution (VF ) were 2.03 +/- 0.37 hr, 29.31 +/- 5.56 hr, 25.22 +/- 2.57 hr, 4.06 +/- 1.04 L/kg, and 3.05 +/- 0.08 hr, 17.06 +/- 1.77 hr, 15.55 +/- 1.37 hr, 2.95 +/- 0.62 L/kg after the orally administrated tilmicosin enteric granules and premix. The relative bioavailability of tilmicosin enteric granules to premix was 114.97 +/- 7.19%, according to the AUC0-t values. These results demonstrated that tilmicosin enteric granules produced faster tilmicosin absorption, slower elimination, larger tissue distribution, and higher bioavailability compared to the tilmicosin premix. The present study results manifest that tilmicosin enteric granules can be used as a therapeutic alternative to premix in clinical treatment.
摘要：
The effect of dietary supplementation with fermented cassava bioethanol waste (FCBW) on the growth performance and meat quality was evaluated in 80 15-day-old male Cherry Valley meat ducks with an initial body weight (BW) of 250.67 +/- 7.50 g. The experiment has 5 replications and 4 treatments and 4 ducks per treatment. Four groups (groups I, II, III, IV) supplemented with 0%, 5%, 10%, and 15% FCBW substituted for part of maize, soybean meal, and bran in basal diet and were fed for 29 days; the metabolizable energy and content of lysine in the four groups were equal. The results indicated that there were no significant differences in average daily weight gain and average daily feed intake among the four groups (P > 0.05). The digestibility rate of dry matter, ash, and phosphorus in group IV was significantly lower than that in group I by 5.23%, 6.25%, and 6.40% respectively (P < 0.05), but the digestibility rate of crude fat was significantly higher than that in group I by 8.30% (P < 0.05). No significant differences were presented among different levels of FCBW supplementation in carcass yield, eviscerated carcass yield, and semi-eviscerated carcass yield (P > 0.05), but 5% FCBW can improve the carcass yield relatively. In conclusion, with dietary supplementation of 5% FCBW, a better growth performance in meat ducks could be achieved.
摘要：
l-Glutamate (Glu) has traditionally not been considered as a nutrient needed in diets for humans and other animals (including swine) due to the unsubstantiated assumption that animals can synthesize sufficient amounts of Glu to meet their needs. The lack of knowledge about Glu nutrition has contributed to suboptimal efficiency of global livestock production. Over the past 25 years, there has been growing interest in Glu metabolism in the pig, which is an agriculturally important species and also a useful model for studying human biology. Because of analytical advances in its analysis, Glu is now known to be a highly abundant free amino acid in milk and intracellular fluid, a major constituent of food and tissue proteins, and a key regulator of gene expression, cell signaling, and anti-oxidative reactions. Emerging evidence shows that dietary supplementation with 2% Glu maintains gut health and prevents intestinal dysfunction in weanling piglets, while enhancing their growth performance and survival. In addition, the inclusion of 2% Glu is required for dietary arginine to maximize the growth performance and feed efficiency in growing pigs, whereas dietary supplementation with 2% Glu reduces the loss of skeletal muscle mass in endotoxin-challenged pigs. Furthermore, supplementing 2% Glu to a corn- and soybean-meal-based diet promotes milk production by lactating sows. Thus, an adequate amount of dietary Glu as a quantitatively major nutrient is necessary to support maximum growth, development, and production performance of swine. These results also have important implications for improving the nutrition and health of humans and other animals.
摘要：
Scope Flaxseed oil is a rich source of α‐linolenic acid (ALA), which is the precursor of the long‐chain n‐3 polyunsaturated fatty acids (PUFAs), including docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). This study investigates the protective effect of flaxseed oil against intestinal injury induced by lipopolysaccharide (LPS). Materials and results Twenty‐four weaned pigs were used in a 2 × 2 factorial experiment with dietary treatment (5% corn oil vs 5% flaxseed oil) and LPS challenge (saline vs LPS). On day 21 of the experiment, pigs were administrated with LPS or saline. At 2 h and 4 h post‐administration, blood samples were collected. After the blood harvest at 4 h, all piglets were slaughtered and intestinal samples were collected. Flaxseed oil supplementation led to the enrichment of ALA, EPA, and total n‐3 PUFAs in intestine. Flaxseed oil improved intestinal morphology, jejunal lactase activity, and claudin‐1 protein expression. Flaxseed oil downregulated the mRNA expression of intestinal necroptotic signals. Flaxseed oil also downregulated the mRNA expression of intestinal toll‐like receptors 4 (TLR4) and its downstream signals myeloid differentiation factor 88 (MyD88), nuclear factor kappa B (NF−κB), and nucleotide‐binding oligomerization domain proteins 1, 2 (NOD1, NOD2) and its adapter molecule, receptor‐interacting protein kinase 2 (RIPK2). Conclusion These results suggest that dietary addition of flaxseed oil enhances intestinal integrity and barrier function, which is involved in modulating necroptosis and TLR4/NOD signaling pathways. The protective effect of flaxseed oil against intestinal injury induced by lipopolysaccharide (LPS) is investigated. The results indicate that flaxseed oil supplementation improves intestinal integrity and barrier function, which is involved in modulating the necroptosis and TLR4/NOD signaling pathway.
期刊：
Methods in Molecular Biology,2018年1694:105-115 ISSN：1064-3745
通讯作者：
Wu, G.
作者机构：
[Hou, Yongqing] Hubei Key Laboratory of Animal Nutrition and Feed Science, Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Wuhan Polytechnic University, Wuhan, 430023, China;[Li, Xilong] Institute of Feed Science, The Chinese Academy of Agricultural Sciences, Beijing, 100081, China;[Dai, Zhaolai; Wu, Zhenlong] State Key Laboratory of Animal Nutrition, China Agricultural University, Beijing, 100193, China;[Bazer, Fuller W] Department of Animal Science, Texas A&M University, 2471 TAMU, RM 133 Kleberg, College Station, TX, 77843-2471, USA;[Wu, Guoyao] Hubei Key Laboratory of Animal Nutrition and Feed Science, Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Wuhan Polytechnic University, Wuhan, 430023, China. g-wu@tamu.edu
通讯机构：
Hubei Key Laboratory of Animal Nutrition and Feed Science, Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Wuhan Polytechnic University, Wuhan, China
摘要：
Haemophilus parasuis (H. parasuis) can cause vascular inflammatory injury, but the molecular basis of this effect remains unclear. In this study, we investigated the effect of the anti-inflammatory, antimicrobial and anti-oxidant agent, baicalin, on the nuclear factor (NF)-kappa B and NLRP3 inflammasome signaling pathway in pig primary aortic vascular endothelial cells. Activation of the NF-kappa B and NLRP3 inflammasome signaling pathway was induced in H. parasuis-infected cells. However, baicalin reduced the production of reactive oxygen species, apoptosis, and activation of the NF-kappa B and NLRP3 inflammasome signaling pathway in infected cells. These results revealed that baicalin can inhibit H. parasuis-induced inflammatory responses in porcine aortic vascular endothelial cells, and may thus offer a novel strategy for controlling and treating H. parasuis infection. Furthermore, the results suggest that piglet primary aortic vascular endothelial cells may provide an experimental model for future studies of H. parasuis infection.
关键词：
probiotic yeasts;identification and characterization;duck digestive tract
摘要：
The objective of this study was to isolate and identify yeast strains from the digestive tract of ducks, and evaluate in vitro their potential as probiotics in poultry. The yeast strains were isolated using malt extract agar medium, and identified through morphological, physiological, and biochemical tests as well as sequence homology analyses of 26S rDNA D1/D2 region. A total of 35 yeast strains were isolated from the guts of Cherry Valley meat ducks, including seven strains of Saccharomyces cerevisiae (S. cerevisiae). These seven strains of S. cerevisiae were further screened for their use as alternative yeast probiotics strains for poultry feed. The yeast strains were characterized for their cell surface hydrophobicity, autoaggregation ability, and resistance to high temperature (30°C, 37°C, and 42°C), low pH (2.0, 3.0, and 4.0), bile salts (0.3% and 0.6%), and nutrition starvation (2, 4, 6, 8, 10, and 12 days). The isolates of WHY-2 and WHY-7 had a higher survival percentage at 37°C, pH 2.0, 0.60% poultry bile salts, and 10 days of nutrition starvation, with higher cell surface hydrophobicity and autoaggregation, when compared with the other isolates, suggesting that the isolates WHY-2 and WHY-7, could be used as probiotic candidates. The data obtained in this study could help in selecting probiotic yeast candidates for use in poultry industry.
关键词：
Clevelandellida;Endocommensal;Phylogenetic analysis;Protargol;Scanning electron microscopy;SSU-rRNA
摘要：
Morphological studies of Sicuophora (Syn. Wichtermania) multigranularis Xiao et al., 2002, from the rectum of the frog, Quasipaa spinosa, performed using silver impregnation and scanning electron microscopy, confirmed the following newly recognized features: (1) only one apical suture on the right surface; (2) two naked regions at the posterior end of both the left and the right side of the body. Phylogenetic analysis based on the SSU-rRNA gene showed that S. multigranularis is a sister to a clade comprising all other Clevelandellida, strongly supporting the validity of the genus Sicuophora. This is also the first molecular data obtained for the genus Sicuophora. Because of the lack of molecular data, it will be necessary to obtain more genetic data from the family Sicuophoridae to discuss the question of the taxonomic status of the genus Sicuophora.
