Livestock such as poultry is consumed as food worldwide and it constitutes one of the main protein sources for diners, as well as an important source of revenue generation for farmers. Poultry meat production chain id...Livestock such as poultry is consumed as food worldwide and it constitutes one of the main protein sources for diners, as well as an important source of revenue generation for farmers. Poultry meat production chain identifies a significant role of the farm to folk. Most often, the systems used in poultry production can result in a higher prevalence of <i>Campylobacter, Salmonella, and Escherichia coli</i> contamination, leading to adverse health effects with detrimental consequences. The method of poultry keeping plays a significant role in the poultry meats’ outcome and its food safety standards. Farmers attempt to develop new poultry operations, however, there are two main possibilities;to operate within the present vertically integrated system which is incredibly good for disease prevention and to develop independently, or a smaller operation that is more animal friendly. This article reviews the available research on the impact of free-range poultry production systems on food safety, most importantly the prevalence and control of <i>Campylobacter, Salmonella</i> and <i>Escherichia coli</i> in free-range production systems. The results suggest a conflicting view when bacterial loads of poultry meat from conventional and free-range systems are compared. Studies have shown increased bacterial loads in a free-range production system.展开更多
[目的]调查鸡肠道内大肠杆菌分泌肠菌素的水平,以及其对空肠弯曲菌的促生长作用。[方法]利用间接竞争ELISA(ic-ELISA)方法检测临床分离的30株鸡肠道大肠杆菌分离株的肠菌素产量;利用λRed同源重组系统构建大肠杆菌entB基因缺失突变株,并...[目的]调查鸡肠道内大肠杆菌分泌肠菌素的水平,以及其对空肠弯曲菌的促生长作用。[方法]利用间接竞争ELISA(ic-ELISA)方法检测临床分离的30株鸡肠道大肠杆菌分离株的肠菌素产量;利用λRed同源重组系统构建大肠杆菌entB基因缺失突变株,并用ic-ELISA方法测定大肠杆菌亲本株和突变株的肠菌素产量;检测亲本株和突变株在不同限铁培养基中的生长曲线;将大肠杆菌亲本株和突变株培养上清接种空肠弯曲菌,探究大肠杆菌肠菌素对空肠弯曲菌生长的影响。[结果]30株鸡肠道大肠杆菌分离株分泌肠菌素水平介于11~126μmol/L之间。利用λRed同源重组系统成功构建2株大肠杆菌entB基因缺失突变株。定性结果显示,大肠杆菌亲本株在CAS培养基中产生黄色晕圈,而entB基因缺失株不产生晕圈。ic-ELISA检测结果显示,亲本株分泌肠菌素浓度为100~150μmol/L,而基因缺失株未检测出肠菌素。大肠杆菌亲本株和entB基因缺失株在富铁培养基中生长无显著差异(P>0.05),在限铁培养基中达到平台期的D 600 nm值分别为0.6和0.3。促生长试验结果显示,大肠杆菌亲本株培养上清接种空肠弯曲菌24和36 h,菌落数分别为7.8和8.2 lg CFU/mL,而entB基因缺失株培养上清接种后菌落数分别为7.0和7.3 lg CFU/mL。[结论]大肠杆菌具有分泌肠菌素的能力,且其在限铁环境下能促进空肠弯曲菌的生长,试验结果为深入研究肠菌素介导的肠道细菌之间的相互作用奠定基础。展开更多
目的建立结肠弯曲菌实时PCR检测方法并评价该方法的可行性。方法BLAST与Vector NTI Suite 6.0筛选出结肠弯曲菌的特异基因ceuE作为检测靶基因,Primer 5.0和Oligo6.0设计引物和探针,优化实时PCR反应体系并评价其最低检测限、特异性、可...目的建立结肠弯曲菌实时PCR检测方法并评价该方法的可行性。方法BLAST与Vector NTI Suite 6.0筛选出结肠弯曲菌的特异基因ceuE作为检测靶基因,Primer 5.0和Oligo6.0设计引物和探针,优化实时PCR反应体系并评价其最低检测限、特异性、可重复性。结果与结论在结肠弯曲菌的ceuE特异基因上设计引物和探针,经优化了的实时PCR反应体系最低检测限为5.62CFU,特异度为100%,变异系数为0.15%～1.30%,本研究为结肠弯曲菌的快速检测提供了一种参考方法。展开更多
文摘Livestock such as poultry is consumed as food worldwide and it constitutes one of the main protein sources for diners, as well as an important source of revenue generation for farmers. Poultry meat production chain identifies a significant role of the farm to folk. Most often, the systems used in poultry production can result in a higher prevalence of <i>Campylobacter, Salmonella, and Escherichia coli</i> contamination, leading to adverse health effects with detrimental consequences. The method of poultry keeping plays a significant role in the poultry meats’ outcome and its food safety standards. Farmers attempt to develop new poultry operations, however, there are two main possibilities;to operate within the present vertically integrated system which is incredibly good for disease prevention and to develop independently, or a smaller operation that is more animal friendly. This article reviews the available research on the impact of free-range poultry production systems on food safety, most importantly the prevalence and control of <i>Campylobacter, Salmonella</i> and <i>Escherichia coli</i> in free-range production systems. The results suggest a conflicting view when bacterial loads of poultry meat from conventional and free-range systems are compared. Studies have shown increased bacterial loads in a free-range production system.
文摘[目的]调查鸡肠道内大肠杆菌分泌肠菌素的水平,以及其对空肠弯曲菌的促生长作用。[方法]利用间接竞争ELISA(ic-ELISA)方法检测临床分离的30株鸡肠道大肠杆菌分离株的肠菌素产量;利用λRed同源重组系统构建大肠杆菌entB基因缺失突变株,并用ic-ELISA方法测定大肠杆菌亲本株和突变株的肠菌素产量;检测亲本株和突变株在不同限铁培养基中的生长曲线;将大肠杆菌亲本株和突变株培养上清接种空肠弯曲菌,探究大肠杆菌肠菌素对空肠弯曲菌生长的影响。[结果]30株鸡肠道大肠杆菌分离株分泌肠菌素水平介于11~126μmol/L之间。利用λRed同源重组系统成功构建2株大肠杆菌entB基因缺失突变株。定性结果显示,大肠杆菌亲本株在CAS培养基中产生黄色晕圈,而entB基因缺失株不产生晕圈。ic-ELISA检测结果显示,亲本株分泌肠菌素浓度为100~150μmol/L,而基因缺失株未检测出肠菌素。大肠杆菌亲本株和entB基因缺失株在富铁培养基中生长无显著差异(P>0.05),在限铁培养基中达到平台期的D 600 nm值分别为0.6和0.3。促生长试验结果显示,大肠杆菌亲本株培养上清接种空肠弯曲菌24和36 h,菌落数分别为7.8和8.2 lg CFU/mL,而entB基因缺失株培养上清接种后菌落数分别为7.0和7.3 lg CFU/mL。[结论]大肠杆菌具有分泌肠菌素的能力,且其在限铁环境下能促进空肠弯曲菌的生长,试验结果为深入研究肠菌素介导的肠道细菌之间的相互作用奠定基础。
基金Supported by the National Natural Science Foundation（No.81071314）~~
文摘目的建立结肠弯曲菌实时PCR检测方法并评价该方法的可行性。方法BLAST与Vector NTI Suite 6.0筛选出结肠弯曲菌的特异基因ceuE作为检测靶基因,Primer 5.0和Oligo6.0设计引物和探针,优化实时PCR反应体系并评价其最低检测限、特异性、可重复性。结果与结论在结肠弯曲菌的ceuE特异基因上设计引物和探针,经优化了的实时PCR反应体系最低检测限为5.62CFU,特异度为100%,变异系数为0.15%～1.30%,本研究为结肠弯曲菌的快速检测提供了一种参考方法。
