Whole-genome Sequencing and Analysis of Fowl Adenovirus Serotype 4 Strain GX2019-010 Isolated from Guangxi

To understand the genetic characteristics of fowl adenovirus serotype 4 (FAdV-4) in Guangxi region,the whole-genome sequencing were performed on a FAdV-4 strain GX2019-010 isolated from Guangxi in this study.Genome-wide nucleotide sequences were analyzed for homology alignment and genetic evolution,and the amino acid sequences of the major structural proteins Hexon,Penton and Fiber were further analyzed.The results showed that GX2019-010 had a full length of 43 719 bp and GC content of 54.9%,mainly including 43 potential protein coding regions.Genome-wide nucleotide homology comparisons revealed that GX2019-010 was 95.8% homologous to the pathogenic strain MX-SHP95,and 95.0% and 95.2% homologous to non-pathogenic strains ON1 and KR5,respectively.Genetic evolutionary analysis showed that GX2019-010 was in the same branch as the popular strains of FAdV-4 in China in recent years,but not in the same branch as the foreign strains of FAdV-4.This results indicated that there were genetic differences in FAdV-4.The main differences was at the right end of the genome and all domestic strains isolated in China were 1 966 bp missing including ORF19,ORF48 and ORF27 genes.It showed that FAdV-4 popular in China was territorial.Analysis of the amino acid sequences of the major structural proteins of Hexon,Penton and Fiber revealed that all of the three major structural proteins had mutations in amino acid sites,of which Fiber-2 had the most mutations.This study enriched the gene pool of FAdV-4 in Guangxi region and laid the foundation for future research on the prevention and control of HHS and epidemiological investigation.     

禽波氏杆菌病病原性的研究

从患眼炎、鼻窦炎的不同地点、不同时间、不同发病鸡群的病料共分离到１７株细菌，经形态学、培养特性、生化试验和动物回归试验等结果表明，该细菌能运动、无芽孢的革兰氏阴性小杆菌，即禽波氏杆菌。该菌在鲜血平板上产生β溶血，在麦康凯平板上生长良好，形成光滑中央突起的珍珠状菌落。不利用糖类，不能在６．５％ＮａＣｌ培养基中生长，尿素酶和硝酸盐还原试验均呈阳性，能凝集豚鼠和其他动物红血球。人工接种细菌均能使雏鸡发生相似于自然病例的临床症状和死亡，并且从病变部位回收到相应细菌。     

Characteristics of systemic infection and host responses in chickens experimentally infected with Salmonella enterica serovar Gallinarum biovar Gallinarum

Salmonella enterica serovar Gallinarum biovar Gallinarum (S. Gallinarum) is a host-specific pathogen causing systemic infection in poultry, which leads to significant economic losses due to high mortality. However, little is known about the dynamic process of systemic infection and pathogenic characteristics of S. Gallinarum in chickens. In the present study, we developed an oral infection model that reproduces the pathology of S. Gallinarum and clarified the host immune response of the infected chickens. Chickens at 20 days of age orally inoculated at a dose of 10⁸ colony forming unit (CFU) showed typical clinical signs of fowl typhoid and died between 6 and 10 days post infection. The inoculated S. Gallinarum rapidly disseminated to multple organs and the bacterial counts increased in the liver and spleen at 3 days post infection. Pathological changes associated wirh inflammation in the liver and spleen became apparent at 4 days post infection, and increased expression of interferon (IFN)-γ and interleuikin (IL)-12 in the liver and spleen did not observed until 3 days post infection. These results indicate that S. Gallinarum rapidly spread to entire body through intestine, and the low-level of inflammatory responses in the liver during the early stage of infection may contribute to rapid, systemic dissemination of the bacteria. Our infection model and findings will contribute to the better understanding of the pathogenic mechanism of S. Gallinarum, and provide new insights into the prevention and control of fowl typhoid.     

L-酪氨酸对泰和乌骨鸡胸腺肥大细胞数量的影响

黑色素是反映乌骨鸡肉质的重要标志,也是影响市场价格的重要因素,但乌骨鸡黑色素生成的机理仍未完全阐明.该试验在饲料中添加不同浓度的L-酪氨酸,通过甲苯胺蓝组织化学染色法检测和分析胸腺肥大细胞的数量变化,探究外源性L-酪氨酸和乌骨鸡胸腺肥大细胞之间的相关性.胸腺石蜡切片苏木精-伊红(HE)染色结果表明,在泰和乌骨鸡胸腺中有...     

氧氟沙星在乌骨鸡体内残留消除规律研究

采用高效液相色谱法分析氧氟沙星在乌骨鸡体内各组织中的残留消除规律。荧光检测器的激发波长为280nm,发射波长为450Dill。色谱柱为ttypersilODS—C18,柱温40~C,以磷酸（以三乙胺调pH至2．5）-乙腈（82：18）为流动相,流速1．0mL／min,进样量为20肛L。氧氟沙星在乌骨鸡肌肉、肝脏、。肾脏中的平均回收率分别为86．3％、83．2％、82．5％。检测限为10ng／g。当组织中氧氟沙星浓度在10～2000ug／kg范围时,线性关系良好。利用该方法对氧氟沙星在乌骨鸡体内的残留消除规律进行了研究,结果表明,氧氟沙星在鸟骨鸡体内的残留消除速度极为缓慢。40天休药期后,2日龄使用组可在肌肉、肝脏和肾脏中分别检出氧氟沙星146．8“g／kg、20．6“g／kg和437．4μg／kg;28日龄使用组分别检测出193．5ug／kg、45．0μg／kg和425．5μg／kg。2日龄使用组休药78天时（即停药71天）,肌肉和肝脏中还能分别检出氧氟沙星11．2μg／kg和12．0μg／kg。实验表明乌骨鸡使用氧氟沙星仅适用于10日龄以下给药并休药70天以上,或不给予该类药物。     

葛根粉对丝毛乌骨鸡蛋品质的影响

本试验选用35周龄的体质健康、生长良好并且均匀一致的丝毛乌骨鸡1000只,随机分成5组,每组200只,分剐接受饲喂舍0%,5%,7.5%,10%葛根粉及10%葛根粉 0.3%红辣椒粉日粮处理.每处理组设5个重复,每个重复40只.在每个重复中随机拣出10枚鸡蛋,测定蛋品质,以观察葛根粉对鸡蛋品质的影响.结果表明,在鸟骨鸡日粮中添加葛根粉乌骨鸡蛋品质及蛋黄着色效果与对照组相比差异显著(P＜0.05).说明葛根粉对乌骨鸡蛋品质及蛋黄着色效果较好.     

丝羽乌骨鸡群体遗传结构的微卫星标记分析

用 9对微卫星引物对 170只丝羽乌骨鸡的基因组DNA进行扩增 ,结果表明 ,9个微卫星标记在该品系中都表现出了丰富的多态性 ,所有扩增结果都能重复。微卫星标记平均每个座位检测到 4 .5 6个等位基因 (3～ 7个 )。 9对微卫星引物平均多态信息含量为 0 .6 0 72 ,标记平均杂合度为 0 .74 2 3。本研究的结果可以为进一步利用微卫星进行丝羽乌骨鸡种质特性等研究提供一定的参考     

Purification and Characterization of the Aetiological Agent of Hydropericardium Hepatitis Syndrome from Infected Liver Tissues of Broiler Chickens

Hydropericardium hepatitis syndrome in broiler chickens is an acute, infectious disease characterized by high mortality, excess pericardial fluid and multifocal hepatic necrosis. The aetiological agent was purified to homogeneity from infected liver tissues from field outbreaks. Electron-microscopic and serological confirmation of the virus were undertaken and the disease was reproduced experimentally in broiler chicks. The results indicated that an adenovirus, fowl adenovirus serotype 4, was alone responsible for the disease in the materials studied.     

氟甲砜霉素对实验性鸡巴氏杆菌病的药效研究

以两倍稀释法测定氟甲砜霉素及甲砜霉素对鸡巴氏杆菌的最小抑菌浓度分别为０．２５μｇ／ｍＬ和１．２５μｇ／ｍＬ。按１０,２０和３０ｍｇ／ｋｇ的氟甲砜霉素及３０ｍｇ／ｋｇ的甲砜霉素分别给实验性巴氏杆菌病患鸡肌注,每天给药一次,共５ｄ。药物对鸡巴氏杆菌病的治愈率分别为９３．３％,１００％,１００％和１００％,而感染对照组鸡全部死亡。用药组与感染对照组间疗效差异极显著