除臭微生物10GD发酵工艺初探

通过单因素试验和正交优化试验方案,研究了微生物10GD发酵工艺,以满足该菌工业发酵生产的需要.试验结果表明:其最适的培养基是麸皮50 g/L,蛋白胨2.5 g/L,尿素2.5 g/L,Nau 5 g/L,K2HPO4 1 g/L,MgSO4·7H2O 0.2 g/L;最适培养环境是接种量1%、发酵温度37℃、发酵时间36 h、培养方式为摇床培养(转速为130 r/min)、pH为8.0.     

猪流行性腹泻病毒广东分离株GD/JMEP的遗传演化分析

为了解广东地区猪流行性腹泻病毒(PEDV)的流行现状,对广东地区猪场进行了PEDV流行株的分离,分离得到1株猪流行性腹泻病毒,对分离毒株的S、N、M及ORF3基因进行遗传演化分析。结果表明:检测的PEDV毒株GD/JMEP与经典的CV777毒株亲缘关系较远,与近几年广东地区流行的PEDV毒株处于一个群,亲缘关系较近;通过ORF3序列分析发现,未有核苷酸的缺失;N、M基因核苷酸和氨基酸同源性分析发现,GD/JMEP与EAS1等经典毒株的同源性相对较低,与2013—2015年中国、美国、韩国等流行毒株的同源性较高;相比于经典传统毒株CV777,GD/JMEP的N基因存在9个氨基酸的差异,M基因存在11个核苷酸位点的变异和3个氨基酸的改变S基因存在几个位点核苷酸的缺失或者插入;与目前流行毒株比较,M、N基因存在核苷酸位点的改变,S基因在406位点存在新的突变;通过氨基酸比对分析,GD/JMEP发生了6个新的氨基酸位点突变,表明本试验所检测的PEDV为目前广东流行毒株。     

GD3 cells in the intestine of broilers inoculated with intestinal homogenate

1. Reactivity of polyclonal rabbit CD3 antiserum to human T cells and density of CD3 cells in chicken intestine were studied after the inoculation of 1‐d‐old broilers with intestinal homogenate to develop the Runting and Stunting Syndrome.

2. Reactivity of CD3 antiserum in chicken intestine was very good.

3. Increased numbers of epithelial lymphocytes as well as infiltration of CD3 cells into the lamina propria were demonstrated.

4. Intestinal homogenate caused impaired growth and bad feathering in broiler chickens until 21 d of age.     

禽网状内皮组织增殖病病毒GD09株的分离与全基因组测序

从广东某鸡场送检的疑似禽网状内皮组织增殖病的病鸡中采集病料,处理后经接种DF-1细胞,经聚合酶链式反应(PCR)及特异性间接免疫荧光试验(IFA),分离并鉴定出1株禽网状内皮组织增殖病病毒(reticuloendotheliosis virus,REV),命名为GD09。依据已发表的REV前病毒全基因组序列设计并合成6对引物,采用分段扩增的方法完成了分离株的全基因组序列测定。结果显示,该分离株基因组序列全长8295 bp,符合典型的复制完全型反转录病毒的基因组结构,基因序列中不含已知致癌基因。将该分离株的亚群特异性gp90基因序列与国内外各参考株相应序列进行相似性比较分析,结果表明,GD09分离株与中国分离株HA9901亲缘关系最近,核苷酸相似性最高。     

鸭肝炎病毒GD株的全基因组序列测定与分析

为了给在分子水平上研究鸭肝炎病毒(DHV)的致病机理奠定基础,进一步丰富DHV的遗传变异和进化信息,试验采用RT-PCR方法分段克隆获得DHV-1 GD株的全基因组序列并进行序列分析。结果表明:GD株的基因组全长7 690 nt[不含Poly(A)尾],5’端和3’端非编码区长度分别为626 nt和314 nt,单一开放阅读框架(ORF)为627～7 376 nt,编码2 249个氨基酸;GD株与DHV-1参考株比较,其核苷酸和氨基酸同源性分别为94.8%～99.7%和97.7%～99.6%;与中国台湾和韩国新型DHV(DHV-N)相比同源性分别为72.7%～73.2%和81.8%～83.4%;GD株与DHV-1参考株遗传进化关系较密切,处于同一分支,而与DHV-N遗传关系较远,处于不同分支。     

Up-to-date information from the German QS salmonella monitoring and reduction programme

In the beginning, the history, objectives and basic principles of the samonella monitoring and reduction programme that has been developed and implemented since 2002 in the framework of the German cross-sectional quality management and assurance programme "QS" for the food chain are expained in detail. It is a semi-quantitative assessment of the intra-herd prevalence of animals (60 samples per slaughter pig herd and year) with antibodies against salmonella species. By means of this asessment, herds are assigned to one of three risk categories (I = low risk, II = medium risk, and III = high risk) in terms of the probability to introduce Salmonella spp. into the food chain via slaughter pigs. The assignment to the categories is the basis of salmonella-reducing intervention measures. The implementation of the programme is considerably behind the schedule by mid-2004. The reasons for the delay are explained and conclusions for the further development of the programme are drawn.