Prediction of chicken embryo lethality with the avian Escherichia coli traits complement resistance, colicin V production, and presence of the increased serum survival gene cluster (iss)
Prediction of chicken embryo lethality with the avian Escherichia coli traits complement resistance, colicin V production, and presence of the increased serum survival gene cluster (iss)
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DOI：
10.1637/0005-2086(2003)047
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发表时间：
2003-04-01
期刊：
影响因子：
1.4
通讯作者：
Wooley, RE
中科院分区：
文献类型：
--
作者：
Gibbs, PS;Maurer, JJ;Wooley, RE
区分强毒和无毒禽大肠杆菌分离株仍然是家禽诊断实验室和家禽大肠杆菌病研究的一个问题。如果实验室能够进行一项与毒力相关的简单测试，将简化这些领域的研究;然而，以前的研究还没有使研究人员能够建立这样的测试。在这项研究中，某些表型和基因型性状的发生，据称有助于禽大肠杆菌毒力在20禽大肠杆菌分离株与胚胎挑战研究的结果。进行该分析是为了确定哪种性状最好地鉴定每种禽大肠杆菌分离株为毒性或无毒力。选择的性状是补体抗性、大肠杆菌素V（ColV）的产生、运动性、F1型皮利表达、温度敏感性血凝素基因（tsh）的存在以及增加的血清存活遗传位点（iss）的存在。ColV产生、补体抗性和iss遗传元件的存在是与高胚胎致死率相关性最高的三个性状。根据最常见的分离株特征，使用逻辑回归模型来预测胚胎致死率结果。结果表明，ColV，补体抵抗，和iss是显着的预测变量的百分比胚胎致死率造成的挑战与特定的禽大肠杆菌分离。然而，没有一个单一的性状能够100%的预测致病力菌株。这样的结果表明，胚胎致死试验可能被证明是一个测试需要确定如果禽大肠杆菌分离株是有毒的可能性。
Differentiating between virulent and avirulent avian Escherichia coli isolates continues to be a problem for poultry diagnostic laboratories and the study of colibacillosis in poultry. The ability of a laboratory to conduct one simple test that correlates with virulence would simplify studies in these areas; however, previous studies have not enabled researchers to establish such a test. In this study, the occurrence of certain phenotypic and genotypic traits purported to contribute to avian E coli virulence in 20 avian E coli isolates was correlated with the results of embryo challenge studies. This analysis was undertaken in an effort to determine which trait(s) best identified each avian E coli isolate as virulent or avirulent. Traits selected were complement resistance, production of colicin V (ColV), motility, type F1 pili expression, presence of the temperature-sensitive hemagglutinin gene (tsh), and presence of the increased serum survival genetic locus (iss). ColV production, complement resistance, and presence of the iss genetic element were the three traits most highly correlated with high embryo lethality A logistic regression model was used to predict the embryo lethality results on the basis of the most frequent isolate characteristics. Results indicate that ColV, complement resistance, and iss are significant predictor variables for the percentage of embryo lethality resulting from challenge with a specific avian E coli isolate. However, no single trait has the ability to predict virulent isolates 100% of the time. Such results suggest the possibility that the embryo lethality assay may prove to be the one test needed to determine if an avian E coli isolate is virulent.