Robenidine is a synthetic coccidiostat that is excreted from animals in its prototype form, leading to soil contamination. Despite its widespread use, comprehensive environmental risk assessments remain limited. Consequently, we initially constructed a manure-soil microcosm and investigated the degradation pattern of robenidine using a highly efficient HPLC-dSPE method. The degradation half-lives of robenidine in soil were 14.74 days at 0.8 mg/kg and 21.26 days at 8 mg/kg. Exposure to 8 mg/kg of robenidine significantly altered the soil microbial community, leading to a 140.0 % increase in the abundance of Proteobacteria. However, the Shannon index indicated that soil microbial diversity decreased by 32.4 % from 1 d to 60 d. Compared to the control check group, 8 mg/kg of robenidine significantly increased the abundance of harmful bacteria (e.g., unclassified_Intrasporangiaceae increased by 33.5 %) in the soil at 60 d, while simultaneously reducing the populations of beneficial bacteria such as Bacillaceae (decreased by 23.8 %), Pseudograilibacillus (decreased by 39.6 %), and Massilia (decreased by 31.7 %). Network correlation and FAPROTAX analyses indicated that long-term exposure to robenidine inhibited chitinolysis and aromatic compound degradation pathways. Furthermore, low-dose robenidine increased the activities of dehydrogenase, acid phosphatase, and β-glucosidase by 34.0 %, 24.7 %, and 21.6 % at 1 d, respectively, while these enzymes returned to control levels over time. These findings provide critical insights into the biological and metabolic impacts of robenidine exposure on soil microbial communities, which is crucial for clarifying the ecological concerns associated with robenidine.

Intensive farming practices have necessitated the extensive use of veterinary drugs, raising significant concerns regarding residue contamination. Consequently, long-term monitoring of residues and the evaluation of dietary exposure risks are essential. In this study, 326 pork samples were collected from local supermarkets between October 2024 and April 2025. Methods were developed for the analysis of 25 veterinary drugs (including sulfonamides, tetracyclines, fluoroquinolones, β-agonists, amphenicols, macrolides, and roxarsone) using high-performance liquid chromatography-tandem mass spectrometry. Roxarsone was extracted using a methanol/water solution (6:4, v/v), and amphenicols were extracted with a 2% ammonia in ethyl acetate solution. Other analytes were extracted with acetonitrile containing 2% acetic acid, followed by cleanup via dispersive solid-phase extraction. Chromatographic separation and detection were performed under multiple reaction monitoring conditions in both positive and negative ionization modes. The method exhibited good linearity (r2 > 0.99) for all target analytes. Recoveries ranged from 70% to 110% with relative standard deviations below 13%, and limits of quantitation ranged from 0.02 to 5.0 µg/kg. Tetracyclines were the most frequently detected class (detection rate of 63.6%), whereas prohibited substances (β-agonists and roxarsone) were not detected. Residue levels exhibited seasonal fluctuations, with tetracyclines peaking in October and fluoroquinolones and amphenicols in November. Hazard quotient values for dietary intake were consistently below 1, indicating a low health risk to consumers. The dynamic monitoring of drug residue levels offers a more comprehensive approach compared to static methods, which provides valuable insights to guide the rational use of veterinary drugs.

Monensin is a polyether ionophore antibiotic widely used to prevent coccidiosis and inhibit Gram-positive bacteria. Composting is widely regarded as an effective strategy for reducing the abundance of antibiotic resistance genes (ARGs) in manure. However, the long half-life of monensin may impose selective pressure on ARG attenuation, while its potential ecological risk remains unclear. In this study, metagenomics was used to analyze the effect of monensin residues on microbial communities during chicken manure composting (1, 15, and 45 days). Results showed that monensin significantly changed the structure of microbial communities during composting. It suppressed functional groups within Firmicutes and Actinobacteria, particularly the genera Bacillus and Streptomyces. Simultaneously, it promoted tolerant taxa, including Proteobacteria and the genus Halomonas. The results of qPCR for six representative ARGs (aadD, ant2-I, sul1, sul2, tetZ, and tetL) revealed that monensin could reduce the attenuation of some ARGs. Furthermore, monensin increased the abundance of several mobile genetic elements (MGEs) during the middle composting phase, especially the integron intI1 and transposase tnpA. Co-occurrence network analysis suggested stronger associations among specific ARGs, MGEs, and tolerant bacteria under monensin exposure, indicating a potential increase risk of ARG dissemination. Monensin may suppress ARGs attenuation during manure composting by changing microbial communities and increasing the potential risk of ARG dissemination via MGEs. This study will provide a theoretical basis for the treatment of livestock waste and ecological risk assessment of monensin.

Abstract Background Porcine Epidemic Diarrhea Virus (PEDV) frequently outbreaks across China, posing a significant economic threat to the swine industry. PEDV exhibits a high degree of variability and is associated with a high mortality rate in piglets. Currently, vaccines show limited efficacy against variant strains, making it critical to explore alternative treatments, particularly the potential of traditional Chinese medicine (TCM) in combating PEDV infection. Results This study aims to elucidate the antiviral mechanisms of Codonopsis pilosula (Dangshen) aqueous extract and its bioactive components, with a particular focus on the relationship between autophagy and antiviral effects, thereby providing theoretical support for the clinical application of TCM in treating PEDV infection. In this study, different concentrations of Codonopsis aqueous extract (1.25 mg/mL, 2.5 mg/mL, and 5 mg/mL) were applied to PEDV-infected IPEC-J2 cells. The results demonstrated that cells treated with the high-dose group exhibited well-preserved cellular structure, with minimal organelle damage. Furthermore, the high-dose treatment significantly reduced the expression of PEDV N, LC3, AMPK, and p-AMPK proteins in the infected cells. Additionally, it modulated the expression of key regulators in the AMPK/mTOR pathway, including mTOR, while upregulating the expression of AMPK and ATG13 mRNA. Moreover, five bioactive components of Codonopsis including β-sitosterol (SITO), quercetin (Que), 5-hydroxymethylfurfural (HMF), apigenin (APG), and nicotinic acid (NA), significantly decreased both the mRNA and protein expression of PEDV N and LC3. APG exhibits the strongest combined antiviral and anti-autophagic effects. SITO, QUE, APG, and NA reduced AMPK expression. QUE increased ATG13 levels, whereas the other four bioactive components significantly decreased ATG13 expression. Conclusions Therefore, Codonopsis aqueous extract and its bioactive components can alleviate pathological damage in IPEC-J2 cells, inhibit PEDV replication, and modulate the expression of genes and proteins associated with the AMPK/mTOR pathway. This study provides new theoretical evidence for the potential clinical application of Codonopsis in the treatment of PEDV infection.

The widespread of colistin resistance gens has aroused great public concern, and many efforts have been made to re-evaluate the application of colistin in veterinary medicines. Most of colistin is excreted with feces, while no literature has reported the determination of colistin in plants and its accumulation on the potential toxicity to plant life. In this study, a rapid and eco-friendly method using liquid chromatography tandem mass spectrometry (LC-MS/MS) based on dispersive solid-phase extraction was developed for detecting colistin in lettuce and was successfully applied to real samples. Furthermore, the toxic effects of colistin exposure on the growth, oxidative stress, and metabolism of lettuce were investigated. The LC-MS/MS results showed that the developed method had good linear correlation. Average recoveries of colistin at four spiked concentrations (10, 30, 100, and 300 µg/kg) ranged from 73.3

Isoflavone components extracted from red clover have anti-inflammatory, antioxidant and immune boosting effects. We hypothesize that red clover isoflavones (RCIs) achieve health-promoting effects via altering the gut microbiota. A total of 48 mice (20 ± 2 g) were randomly divided into a control group, low-dose group (0.05% RCIs in feed), middle-dose group (0.1% RCIs in feed), and high-dose group (0.2% RCIs in feed) with 12 mice per group. The feeding period was 20 d. The results showed that RCIs can increase the daily gain and decrease the ratio of feed to gain in mice. The organ indexes and blood biochemical indexes of the mice in each RCI group were in the normal range, indicating that RCIs do not damage liver or kidney function. RCI supplementation increased serum immunity and altered the microbial community structure in the cecum of the mice. RCIs can increase the diversity of beneficial bacteria such as Bacteroidaceae, Muribaculaceae, and Akkermansiaceae, and reduced the pathogenic Staphylococcaceae. Therefore, supplementing the diet with RCIs results in improved growth performance and notable alterations in the cecal microbiota in mice, and has potential applications as a feed additive to improve livestock production.

The emergence and worldwide dissemination of mobile tigecycline resistance genes tet (X3)/ tet (X4) posed an enormous threat to the public health. Urgently, feasible strategies must be implemented to restore the clinical efficacy of tetracyclines and prolong the lifespan of existing drugs to address the emerging global antimicrobial resistance threat. Herein, versatile structural scaffolds of quinones for antibiotic adjuvants discovery enlightened a promising and underappreciated reservoir to circumvent the antibiotic resistance. 2-methoxy-1,4-naphthoquinone (MNQ) exhibited the potent potentiation (4 to 32-fold) with tetracyclines, along with effective inhibition on biofilm formation. Mechanistic studies revealed that MNQ synergistically operates with tetracyclines by inhibiting the enzymatic activity of Tet(X3)/Tet(X4) proteins through interaction with their active residues. Furthermore, exposure to MNQ significantly dissipate the proton motive force, leading to a cascade of membrane structural damage and metabolic homeostasis imbalance. Encouragingly, the MNQ-tetracyclines combination showcased substantial therapeutic benefits in two in vivo infection models, as evidenced by the reduced bacterial burden and mitigated pathological injury. Our findings propose a potential therapeutic option and a novel tetracyclines' adjuvant against drug-resistant pathogens carrying Tet(X3)/Tet(X4).

Infections caused by multidrug-resistant (MDR) bacteria have become a major challenge for global healthcare systems. The search for antibacterial compounds from plants has received increasing attention in the fight against MDR bacteria. As a medicinal and edible plant, Lophatherum gracile Brongn. (L. gracile) has favorable antibacterial effect. However, the main antibacterial active compound and its antimicrobial mechanism are not clear. Here, our study first identified the key active compound from L. gracile as luteolin. Meanwhile, the antibacterial effect of luteolin was detected by using the broth microdilution method and time-kill curve analysis. Luteolin can also cause morphological structure degeneration and content leakage, cell wall/membrane damage, ATP synthesis reduction, and downregulation of mRNA expression levels of sulfonamide and quinolones resistance genes in multidrug-resistant Escherichia coli (MDR E. coli). Furthermore, untargeted UPLC/Q-TOF-MS-based metabolomics analysis of the bacterial metabolites revealed that luteolin significantly changed riboflavin energy metabolism, bacterial chemotaxis cell process and glycerophospholipid metabolism of MDR E. coli. This study suggests that luteolin could be a potential new food additive or preservative for controlling MDR E. coli infection and spread.

In the present study, we investigated whether baicalin could reduce the damage caused to RAW264.7 cells following infection with H6N6 avian influenza virus. In addition, we studied the expression of autophagy-related genes. The morphological changes in cells were observed by hematoxylin and eosin (H&E) staining, and the inflammatory factors in the cell supernatant were detected by enzyme-linked immunosorbent assay (ELISA). Transmission electron microscopy (TEM) was used to detect the levels of RAW264.7 autophagosomes, and western blotting and immunofluorescence were used to detect the protein expression of autophagy marker LC3. Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) was used to detect the mRNA transcription levels of autophagy key factors. The results showed that different doses of baicalin significantly reduced the H6N6 virus-induced damage of RAW264.7 cells. The contents of interleukin (IL)-1β, IL-2, IL-6, and tumor necrosis factor (TNF)-α in the cell supernatant significantly decreased. In addition, the protein expression of LC3 and Beclin-1, ATG12, ATG5 the mRNA levels were significantly decreased. This study showed that baicalin can reduce cell damage and affect the H6N6-induced autophagy level of RAW264.7 cells.

Arsenic trioxide (ATO) is a classic first-line treatment for acute promyelocytic leukemia (APL). An increasing number of studies regarding the use of ATO in tumor treatment have shown consistently remarkable results. In this study, subgroup J avian leukosis virus (ALV-J) was used as a model virus, and different doses of ATO were used to treat ALV-J-positive chickens. Sexually mature green-shelled laying hens from the same ALV-J-positive offspring were grouped and treated with one of 3 different doses of ATO. The anti-inflammatory effects of different doses of ATO in ALV-J-positive chickens and their mechanisms were investigated by analyzing levels of inflammatory cytokines, antioxidant parameters and apoptosis-related genes. The results showed that ATO administration mitigated ALV-induced lymphoid leukosis in the liver. ATO inhibited the activation of the TLR4/MyD88/NF-κB signaling pathway and downregulated the expression levels of the inflammatory cytokines IL-1β, IL-6 and TNF-α. The SOD and GSH-Px activities were also increased, and the MDA content was decreased in the serum of ALV-J-positive chickens treated with different doses of ATO, so the antioxidant capacity of ALV-J-positive chickens was improved. The mRNA expression levels of p53, p21 and Bcl-2 in the livers of ALV-J-positive chickens treated with different doses of ATO were significantly downregulated, which induced the apoptosis of tumor cells and slowed the inflammatory response. The combined analysis revealed that the therapeutic effect of 2 mg/kg/dose ATO was superior to that of the other 2 treatments (0.5 and 1 mg/kg/dose ATO). In conclusion, the anti-inflammatory effect of ATO can effectively alleviate the ALV-J pathogenic process. ALV-J serves as a model virus for antiviral tumor research, while ATO provides references for the treatment of such tumors.

IntroductionThe pharmacokinetic profile and residue depletion of eugenol in carp (Cyprinus carpio) tissues and plasma were performed by a convenient and reliable high-performance liquid chromatography (HPLC) method.MethodsThe eugenol in carp tissues and plasma was extracted with a mixed solution of acetonitrile and methanol. N-hexane was used to remove lipid impurities. The method was successfully applied to the pharmacokinetic and residue elimination of eugenol in carp after the carp was administered a medicated bath.ResultsThe average recoveries of eugenol in tissues and plasma fortified with four concentration levels were 69.0–106.6% and 80.0–86.7%, respectively. The relative standard deviations were < 8.9%. The limit of detection (LOD) was 0.01 μg/g in tissue and 0.008 μg/ml in plasma, respectively. The pharmacokinetic parameter of Cmax for eugenol in plasma at the concentrations of 20, 35, and 75 mg/L were 10.86, 17.21, and 37.32 mg/L, respectively. The t1/2 values were 3.68, 4.22, and 9.31 h. After the investigation of the anesthetic effect, 35 mg/L of eugenol was the optimal concentration for anesthesia. The highest accumulation concentration of eugenol in carp is in the liver and the lowest is in the muscle. In addition, the eugenol in tissue was eliminated rapidly and at a lower level than the LOD at 48 h. According to the residue elimination, the withdrawal time of eugenol was suggested at 5.2 days.DiscussionThese results indicate that the developed method had good linearity and accuracy, and is sensitive enough for the monitoring of eugenol residue in carp. The half-life of eugenol decreased with the increase in drug concentration and the eugenol was eliminated rapidly in carp tissues. 35 mg/L eugenol was recommended as an anesthetic in carp due to its favorable anesthetic effect and no mortality. This study will contribute to the establishment of MRL regulation and setting a withdrawal period.

Introduction Duck enteritis virus (DEV) mainly causes infectious diseases characterized by intestinal haemorrhage, inflammation and parenchymal organ degeneration in ducks and other poultry. However, the mechanism by which it causes intestinal damage in ducks is not well understood. Metabolomics can provide an in-depth understanding of the full complexity of the disease. Methods In this study, 24 clinically healthy green-shell ducks (weight 1.5 kg ± 20 g) were randomly divided into 2 groups (experimental group, 18; control group, 6). The experimental group was intramuscularly injected with 0.2 mL of DEV virus in solution (TCID 50 3.16 × 10 8 PFU/mL), and the control group was injected with 0.2 mL of sterile normal saline. Duck duodenum and ileum tissue samples were collected at 66 h, 90 h and 114 h post-injection (12 h of fasting before killing), and metabolomics analysis of duck duodenum and ileum tissues at the three time points (66, 90, 114 h) was performed by liquid chromatography–mass spectrometry (LC–MS) to screen for and analyse the potential differentiated metabolites and related signalling pathways. Results Screening was performed in the positive/negative mode (Pos: Positive ion mode; the ionization of substances at the ion source with positive ions such as H + , NH 4 + , Na + and K + ; Neg: Negative ion mode; the ionization of substances at the ion source with negative ions such as Cl − , OAc − ), and compound abundance was compared to that in the control group. The total number of differentially abundant compounds in the duodenum at 66 h, 90 h and 114 h of DEV infection gradually increased, and metabolites such as cytidine, 2′-deoxyriboside and 4-guanidinobutyric acid were differentially abundant metabolites common to all three time periods. The metabolic pathways related to inflammatory response and immune response were tryptophan acid metabolism, cysteine-methionine metabolism, histidine metabolism and other amino acid metabolism and fat metabolism. Among them, the metabolic pathways with more differentially abundant metabolites were amino acid biosynthesis, cysteine and methionine metabolism, tryptophan metabolism, unsaturated fatty acid biosynthesis and purine metabolism, and the metabolic pathways with more enrichment factors were the IgA-related intestinal immune network pathway and lysosome pathway. Compared with the control group, there were 16 differentially abundant metabolites in the ileum tissue of DEV-infected ducks at 66 h of infection, 52 at 90 h of infection, and 40 at 14 h of infection with TD114. The metabolic pathways with more enriched differentially abundant metabolites were pyrimidine metabolism, tyrosine metabolism, phenylalanine metabolism and tryptophan biosynthesis. The metabolic pathways with the most enrichment factors were the mTOR signalling pathway, ferroptosis pathway, tryptophan metabolism pathway and caffeine metabolism pathway. Conclusion Comparative analysis showed that the number of differentially abundant metabolites in the duodenum and ileum differed to some extent after DEV infection, with significantly more differentially abundant metabolites in duodenal tissues and fewer in ileal tissues; after DEV infection, the highest number of differentially abundant metabolites was obtained at 114 h of DEV infection, followed by the second highest at 90 h of infection and the lowest at 66 h of infection. The common differentially abundant metabolites in duodenal and ileal tissues were prostaglandins, arachidonic acid, and arachidonic ethanolamine. The main metabolic pathways in the duodenum were the IgA-associated intestinal immune network pathway and the lysosomal pathway, and the metabolic pathways with more enriched factors in the ileum were the mTOR signalling pathway, the ferroptosis pathway, and the tryptophan metabolism pathway.

为探讨由枯草芽孢杆菌发酵的辣椒秸秆粉在肉鸡饲粮中的作用,试验选择30日龄雄性麻黄肉鸡240羽,随机分为2个组,对照组(A组)饲喂基础日粮,试验组(B组)饲喂基础日粮中添加2％发酵辣椒秸秆粉的日粮,每组6个重复,每个重复20羽.结果表明:(1)同对照组相比,试验组肉鸡的日增重显著增加(P<0.05),生长性能其他指标差异不显著(P>0.05).(2)B组肉鸡法氏囊指数、胸腺指数和脾脏指数较A组均显著提高(P<0.05).(3)B组血清中免疫球蛋白IgG、谷胱甘肽过氧化物酶(GSH-PX)活性含量较A组显著提高(P<0.05),丙二醛(MDA)含量较A组显著降低(P<0.05),其余血清指标A、B组差异均不显著(P>0.05).(4)A组和B组样本的微生物丰度和均匀度相似,且物种多样性差异不显著(P>0.05).盲肠内微生物的优势菌门分别为拟杆菌门(Bacteroidetes)和厚壁菌门(Firmicutes);优势菌属为厚壁菌属(Firmicutes)、另枝菌属(Alistipes);与A组相比,日粮添加发酵辣椒可显著降低肉鸡盲肠拟杆菌门(Bacteroidetes)和迷踪菌门(Elusimicrobia)的相对丰度(P<0.05),以及降低拟杆菌属相对丰度(P<0.05),显著提高柔嫩梭菌属(Faecalibacterium)相对丰度(P<0.05).综合以上结果可知,在日粮中添加以枯草芽孢杆菌发酵辣椒秸秆粉,能够提高肉鸡生长性能,改善机体免疫机能,维持盲肠微生物的稳定.

IntroductionTrifolium pratense L. has anti-inflammatory, antioxidant, cardiovascular disease prevention, and estrogen-like effects. The existing method for the assay of effective components is commonly based on a spectrophotometer, which could not meet the requirement of quality control. Furthermore, although there have been many studies on the anti-inflammation effect of red clover, a few have been reported on the regulatory effect of red clover isoflavones (RCI) on lipopolysaccharide (LPS)-induced inflammatory response in porcine alveolar macrophages (3D4/2 cells), and its mechanism of action is still unclear.MethodsThe main components of RCI including daidzein, genistein, and biochanin A were accurately quantified by high-performance liquid chromatography coupled with diode array detection (HPLC-DAD) after optimizing the extraction process through response surface methodology. The anti-inflammatory potential of RCI was carried out by detecting the level of inflammatory cytokines and mRNA expression of related genes. Furthermore, its anti-inflammatory mechanism was explored by investigating two signaling pathways (NF-κB and MAPK).ResultsThe optimal extraction conditions of RCI were as follows: the concentration of ethanol is 86% and the solid–liquid ratio is 1:29, with the herb particle size of 40 mesh sieve. Under the optimal conditions, the total extraction of target components of RCI was 2,641.469 μg/g. The RCI could significantly suppress the production and expression of many pro-inflammatory cytokines. The results of the Western blot revealed that RCI dramatically reduced the expression of p65, p-p65, IκB-α, p38, and p-p38. These results are associated with the suppression of the signal pathway of p38 MAPK, and on the contrary, activating the NF-κB pathway. Collectively, our data demonstrated that RCI reversed the transcription of inflammatory factors and inhibited the expression of p65, p-p65, IκB-α, and p38, indicating that RCI had excellent anti-inflammatory properties through disturbing the activation of p38 MAPK and NF-κB pathways.ConclusionThe extraction conditions of RCI were optimized by HPLC-DAD combined with response surface methodology, which will contribute to the quality control of RCI. RCI had anti-inflammatory effects on the LPS-induced 3D4/2 cells. Its mechanism is to control the activation of NF-κB and p38 MAPK pathways, thereby reducing the expression of inflammatory-related genes and suppressing the release of cytokines.

Ethnopharmacological relevance: As a medicinal and edible plant, Lophatherum gracile Brongn. (L. gracile) has favorable antibacterial effect, is used to clear heat and purge fire, relieve irritability and thirst, diuresis and catharsis. It is reported that ethanol extract from the dried stems and leaves of L. gracile has an obvious inhibitory effect on Escherichia coli (E. coli), while the main antibacterial component and its mechanism are not clear.Aim of study: As multidrug-resistant (MDR) bacteria become a challenge for the global healthcare system, the search for antibacterial compounds from plants has received attention. To find natural active compounds against MDR E. coli (MDREC) and improve the utilization rate of L. gracile. This study aims to further isolate the main antibacterial active part and compounds of the ethanol extract from L. gracile. and to explore the anti-MDREC mechanism of the main active compound luteolin.Materials and methods: The ethanol extract of L. gracile was obtained by rotary evaporation method. This study examined the anti-MDREC activity of different polar extraction parts in the ethanol extract and screened the part with the best activity. Then, the compounds of the best part were isolated and screened the best compound by LC-MS/MS. The dynamic antibacterial and bactericidal effects of the best compound on MDREC were observed by time-kill curve. The mechanism of the best compound against MDREC was explored by determination of extracellular alkaline phosphatase (AKP) content, crystal violet staining, scanning and transmission electron microscopy, and bacterial viability assay. The effect of luteolin on the expression of multiple drug-resistance genes in MDREC was studied by qRT-PCR. and its possible targets were discussed. Finally, 1/4 × MIC luteolin was selected to treat MDREC for untargeted metabolomics analysis by UPLC/Q-TOF-MS.Results: The results showed that luteolin with the highest content showed excellent anti-MDREC (GZGY201912) activity. The MIC of luteolin was 1.0～4.0 mg/mL The mechanisms of luteolin against MDREC include the damage of cell wall and membrane, inhibiting the formation of biofilm, destroying the morphological structure and down-regulated the expression levels of sulfonamide and quinolone resistance genes. Furthermore, untargeted UPLC/Q-TOF-MS-based metabolomics analysis of the bacterial metabolites revealed that luteolin significantly changed energy metabolism (such as riboflavin metabolism) of MDREC.Conclusion: Experimental studies have shown that the ethyl acetate extract has good anti-MDREC biological activity, and the luteolin has multiple targets rather than a specific mechanism to eliminate drug resistance. This work suggests luteolin as a new food additive or preservative to control MDREC infection and spread.

《兽医病理学》是动物医学专业的专业基础课,也是基础兽医学与临床兽医学之间的桥梁学科.实验教学是《兽医病理学》教学的重要内容,是培养学生专业素养、动手能力和创新性思维的重要途径.通过实验教学内容及环节的改革有效提高了学生的动手能力和对兽医病理学理论知识的理解.该文针对《兽医病理学》实验教学中存在的问题,进行了实验性改革和分析.

Abstract Introduction Duck enteritis virus (DEV) mainly causes infectious diseases characterized by intestinal hemorrhage, inflammation and parenchymal organ degeneration in ducks and other poultry. However, its mechanism of intestinal damage in ducks is not well understood. Metabolomics can provide an in-depth understanding of the full complexity of the disease. Methods In this study, 24 clinically healthy green-shell ducks (weight 1.5kg ± 20g) were randomly divided them into 2 groups (experimental group of 18 rats and control group of 6 rats). The experimental group was intramuscularly injected with 0.2 mL of DEV virus liquid (TCID50 is 3.16×10 -9 /0.1 mL), and the control group was injected with 0.2 sterilized normal saline. mL; at 66 h, 90 h and 114 h after injection (fasting for 12 h before killing), tissue samples from the duodenum and ileum were collected and analyzed by LC-MS. Results Compared with the control group, in the positive/negative mode, the metabolic pathways involved in the differential metabolites in the duodenum of DEV-infected ducks at 66h, 90h and 114h were basically the same; the metabolic pathways related to inflammatory response and immune response were tryptophan Acid metabolism, cysteine-methionine metabolism, histidine metabolism and other amino acid metabolism and fat metabolism. Among them, the metabolic pathways with more differential metabolites are amino acid biosynthesis, cysteine and methionine metabolism, tryptophan metabolism, Unsaturated fatty acid biosynthesis and purine metabolism, the metabolic pathways with more enrichment factors were IgA-related intestinal immune network pathway and lysosome pathway. Compared with the control group, there were 16 differential metabolites in the ileum tissue of DEV-infected ducks at 66 hours of infection, 52 at 90 hours of infection, and 40 at 14 hours of infection with TD114, among which the metabolic pathways with more enriched differential metabolites were Pyrimidine metabolism, tyrosine metabolism, phenylalanine metabolism and tryptophan biosynthesis, the metabolic pathways with more enrichment factors are mTOR signaling pathway, ferroptosis pathway, tryptophan metabolism pathway and caffeine metabolism pathway Conclusion The differential metabolites of DEV-infected ducks are enriched in metabolic pathways such as tryptophan metabolism, amino acid biosynthesis, cysteine-methionine metabolism, unsaturated fatty acid biosynthesis and purine metabolism, among which tryptophan metabolism pathway The enrichment is the most obvious and can be used as a follow-up study;

MG-132, an aldehyde-based peptide proteasome inhibitor (PI) that binds to the proteasome and reversibly inhibits proteasome activity, has been widely used in experimental research. However, it is not clear whether MG-132 has anti-inflammatory effects on liver injury. The molecular mechanism of the anti-inflammatory effect of the PI MG-132 on Con A-induced acute liver injury (ALI) mice was investigated by ELISA, HE, q RT-PCR, and IHC. The results showed that the serum activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and TNF-α and IL-6 contents of mice in the high and medium dose groups were reduced compared with those in the ALI group. The superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels in liver tissues were significantly increased, and the malondialdehyde (MDA) content was decreased. The pathological sections of mice in the ALI group showed typical ALI manifestations such as significant central venous stasis of liver tissues, cell swelling, and inflammatory cell infiltration. The pathological damage of liver tissues was relieved significantly in the three dose groups, especially in the high-dose group. The transcriptional level of TLR4/NF-κB pathway key factors mRNA was significantly reduced, and the expression of TLR4 and NF-κB P65 protein in liver tissues was significantly and positively correlated with the contents of TNF-α and IL-1β (p < 0.01). Our findings suggest that MG-132 can alleviate the inflammatory response to Con A-induced ALI and exert a hepatoprotective effect, and its anti-inflammatory effect is related to the inhibition of TLR4/NF-κB signaling pathway activation.

探究黄芩苷对H6N6亚型禽流感病毒诱导小鼠肺脏致病损伤的作用.选用40只昆明小鼠随机分为4组,即对照组、模型组、黄芩苷治疗组、3-MA抑制剂组.通过HE染色观察肺组织病理形态学变化,ELISA法检测血清中IL-1β、IL-2、IL-6及TNF-a的含量,透射电镜检测小鼠肺脏中 自噬体的水平,Western blot检测肺组织LC3、Beclin-1及ATG7蛋白表达水平,免疫荧光法检测肺组织LC3蛋白表达水平,免疫组化法检测肺组织LC3、Beclin-1及ATG5蛋白表达水平,RT-qPCR检测肺组织自噬关键基因LC3、Beclin-1、ATG3、ATG5、ATG7及ATG12 mRNA转录水平.结果显示,经黄芩苷治疗后能显著缓解H6N6亚型禽流感病毒对小鼠肺组织的损伤,血清中IL-1β、IL-2、IL-6及TNF-a含量显著下降(P＜0.01),肺组织中 自噬体数量减少,LC3、Beclin-1、ATG5及ATG7蛋白表达水平显著下降(P＜0.01),肺组织中LC3、Beclin-1、ATG3、ATG5、ATG7及ATG12 mRNA转录水平显著下降(P＜0.01).结果表明,黄芩苷能减轻H6N6亚型禽流感病毒诱导小鼠肺脏炎症损伤,同时下调自噬关键因子及自噬体的水平,提示其抗小鼠肺损伤机制可能与调控细胞自噬有关.

A simple, sensitive, and efficient method based on ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the determination of 8 coccidiostats in chicken feces and environmental water (including sewage, pond water, and lake water) surrounding the farm. Target analytes in chicken feces were extracted with 2% acetic acid in acetonitrile solution, followed by a dispersive solid-phase extraction (DSPE) cleanup step using the mixture of PSA and C18 adsorbents. Environmental water samples were pretreated using a lyophilization approach. Analysis was carried out on a UPLC-MS/MS with the combination of methanol and 0.1% formic acid aqueous solution as the mobile phase under multiple reaction monitoring in positive and negative ionization modes. Results showed that 8 coccidiostats were linear with correlation coefficients higher than 0.99. Method validation was performed using fortified samples, reaching satisfactory recoveries of 75.9%-97.8% in chicken feces and 71.9%-108.2% in environmental water. Limits of detection for 8 analytes in chicken feces and environmental water were 0.03-2 mu g/kg and 0.005-1 mu g/L, respectively. Matrix effects were calculated and strong signal suppression (>50%) for some coccidiostats was observed. The developed method was successfully applied to analyze coccidiostats in chicken feces and environmental water collected from local chicken farms.