Up-regulated expression of PD-1 and its ligands during acute Classical Swine Fever virus infection in swine

In order to investigate the relationship between the PD-1 pathway and impairment of immune responses with the CSFV infection, the mRNA expression of PD-1 and its ligands were evaluated by quantitative polymerase chain reaction (qPCR) during artificial CSFV infection. Simultaneously, expression of IL-2 and IL-10 mRNA were detected. The T cell proliferation and CSFV load in plasma were also measured. Results showed that the expression of PD-1 and its ligands mRNA were significantly increased (p < 0.01) in PBMC from 3 to 7 days post infection (dpi). Meanwhile the level of IL-10 was up-regulated (p < 0.01). The IL-2 mRNA was not obviously changed but it is significantly increased from 14 dpi. The T cell proliferation was notably decreased at 7 dpi. The CSFV load was also increased in plasma. Overall, our results suggest that the expression of PD-1 and its ligands were up-regulated and probably correlated with immune inhibition during acute CSFV infection.     

Tembusu virus infection in Cherry Valley ducks: The effect of age at infection

Three groups of Cherry Valley ducks at 5 day, 2 week and 5 week of age were intranasally infected with the WFCL strain of Tembusu virus (TMUV) to investigate the effect of host age on the outcome of TMUV infection. For each age group, clinical signs, gross and microscopic lesions, viral copy numbers in tissues and serum neutralizing antibody titers were recorded. Age-related differences in the resistance to TMUV infection were observed with younger ducks being more susceptible. Some ducks infected at 5 day and 2 week of age developed severe clinical signs, including severe neurological dysfunction and death. However, subclinical signs and no mortality were observed in ducks infected at 5 week of age. A decline in the severity of gross and microscopic lesions was observed as ducks mature. Systemic infections were established in the three age groups post challenge. Higher viral copy numbers in the tissues, especially in vital organs such as the brain and the heart, were developed in the ducks infected at 5 day of age than older ducks, correlating with the severity of clinical signs and lesions in the tissues. Furthermore, ducks infected at 5 week of age developed significantly higher serum neutralizing antibody titers than ducks infected at 5 day of age as determined by serum neutralization test. Therefore, age-related differences in the resistance to TMUV infection should be considered when studying the pathogenicity, pathogenesis, formulation of the vaccination and therapy strategies of TMUV infection in ducks.     

Adiponectin‐impaired adipocyte differentiation negatively regulates fat deposition in chicken

Adiponectin is a protein hormone secreted exclusively by adipocytes that plays an important role in the modulation of glucose and lipid metabolism. To investigate the effect of adiponectin on lipid metabolism in chicken, rosiglitazone (agonist of adiponectin) and dexamethasone (inhibitor of adiponectin) were used to treat 23‐day‐old broilers in vivo. To verify the functionality of adiponectin on fat deposition, chicken pre‐adipocytes were cultured in the medium containing 10 μg/ml adiponectin. Serum adiponectin and lipids and fat distribution were analysed. Oil Red O staining was used to determine lipid deposition in adipocytes. The expression levels of adiponectin, adiponectin receptors (AdipoR) and lipid metabolism–related genes in different tissues and pre‐adipocytes were measured using real‐time PCR, and the abundance of lipid metabolism–related proteins was measured by Western blot. Rosiglitazone increased serum adiponectin concentration and the expression levels of adiponectin and adiponectin receptor 1 (AdipoR1) in tissues and significantly decreased levels of serum lipids and fat deposition. Rosiglitazone significantly increased the expression levels of adipose triglyceride lipase (ATGL) and AdipoR1 and decreased the expression levels of fatty acid synthase (FAS). Dexamethasone had the converse effects compared with rosiglitazone. Oil red O staining results showed a marked decrease in fat deposition in cells treated with adiponectin. In adipocytes, adiponectin could decrease the expression levels of CCAAT/enhancer‐binding protein α (C/EBPα) and FAS and increased the expression levels of ATGL and AdipoR1. These results indicate that adiponectin has a remarkable effect on impairment of adipocyte differentiation, which contributes to the negative regulation of fat deposition in chicken.     

Apoptosis‐Like Events and In Vitro Fertilization Capacity of Sex‐Sorted Bovine Sperm

This study utilized three staining assays (Annexin V, mitochondrial membrane potential (JC‐1) and TUNEL) for flow cytometric analysis of apoptosis in sex‐sorted sperm from four different bulls (A, B, C and D). Correlations between sperm quality and IVF efficiency were then assessed to determine which assay provided the best prediction of IVF efficiency. The results of the Annexin V assays, as well as measures of viable sperm, early apoptosis, necrotic sperm and mitochondrial membrane potential (?ψm) showed that the sex‐sorted sperm collected from bull A significantly differed from those of the other three bulls (p < 0.05). In addition, the levels of DNA fragmentation in sex‐sorted sperm from bull A were significantly lower than those from bulls B and C (p < 0.05). The percentage of cells reaching the cleavage and blastocyst stages in sex‐sorted sperm from bull A were significantly greater than those from the other bulls (p < 0.05). A significant positive correlation was observed between viable sperm and the percentage of cells at the cleavage or blastocyst stages (p < 0.05). In contrast, a negative correlation was found between early apoptotic sperm and the percentage of cells at the cleavage or blastocyst stages (p < 0.05). In conclusion, these results indicated that the Annexin V assay was the most reliable technique for the prediction of the IVF success of sex‐sorted bovine sperm.     

Experimental study on the effect of horizontal waves on netting panels

The effect of horizontal waves on flexible netting panels is examined in this study, to evaluate the testing method of pretensioned mooring, radial systems, and flexible netting structures. The netting was suspended at a specific hanging ratio for six polyethylene panels with different characteristics. The aim was to evaluate the calculation method for horizontal wave forces on flexible netting panels. A regular wave was used in the experiment, with wave period 0.8–2.0 s and wave height 50–250 mm. The force on the netting structure was recorded by a tension transducer and digital signal recorder, and was simulated by a cubic spline in terms of the wave experiment under different wave conditions. The horizontal wave force on the netting panel changed periodically and asymmetrically, which was similar to the surface wave elevation. The horizontal wave force was related to the netting panel height and width (l), wave height (H) and wave length (L), twine diameter (d) and bar length (a) of the mesh. Using dual series relations, least-squares approximation, and multiple stepwise regression analysis, the following formula was obtained for the horizontal wave average apex value (F) on the netting panel: F=0.13ρgl(H/2)²(d/a)(H ^0.64 L ^0.77/0.9a ^0.44).     

基于16srDNA序列分析冬樱花花期蜜囊细菌多样性

对昆明冬樱花花期东、西方蜜蜂蜜囊细菌进行分离、纯培养;并对分离菌株的16srDNA基因片段进行扩增和测序,序列比对后进行系统发育分析。结果表明:东方蜜蜂蜜囊细菌包括3个纲中的10个种,西方蜜蜂蜜囊细菌包括3个纲中的13个种,花蜜细菌包括4个纲中的6个种,所采集样品除Bacillus subtili相似以外,其余菌种差异较大。     

对2014年春季上海市某猪场猪伪狂犬病暴发调查

2014年初,上海市闵行区某猪场妊娠母猪暴发妊娠障碍性疫病,疫病期间共发生34个流产病例,袭击率为11.8%。经现场流行病学暴发调查和实验室检测验证,判定该场暴发猪伪狂犬病疫情,建议立即实施猪伪狂犬病的紧急免疫、加强猪场内部管理并修改免疫程序,最终疫情得到有效控制。     

江苏徐州市鸡白痢沙门氏菌的分离鉴定与耐药性分析

[目的]调查徐州地区鸡白痢沙门氏菌的耐药性。[方法]从徐州不同地区分离鉴定了19株鸡白痢沙门氏菌,并对19株鸡白痢沙门氏菌分离株进行了药敏试验。[结果]该地区鸡白痢沙门氏菌的多重耐药率为94.7%,多重耐药谱为PG-MY-DOX-TET-AMP的菌株百分比为42.1%,对青霉素和林可霉素耐药率为100%,而对氨苄西林、四环素和新霉素耐药率在50%以上,对头孢唑啉和强力霉素耐药率为40%~50%,对头孢氨苄和复方新诺明耐药率为20%~30%,对氟苯尼考、阿米卡星和环丙沙星未出现耐药菌株,对氟苯尼考和头孢曲松高敏菌株在80%以上。[结论]徐州地区鸡白痢沙门氏菌的多重耐药情况比较严重。