Characterization of a Series of Transconjugant Mutants of an Avian Pathogenic Escherichia coli Isolate for Resistance to Serum Complement
Characterization of a Series of Transconjugant Mutants of an Avian Pathogenic Escherichia coli Isolate for Resistance to Serum Complement
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DOI：
10.1637/0005-2086(2007)51
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发表时间：
2007-09-01
期刊：
影响因子：
1.4
通讯作者：
Nolan, Lisa K.
中科院分区：
文献类型：
--
作者：
Lynne, Aaron M.;Skyberg, Jerod A.;Nolan, Lisa K.
大肠杆菌病（Colibacillosis）是由禽致病性大肠杆菌（Avian pathogenic Escherichia coli，APEC）引起的一种严重的传染病，每年给养禽业造成巨大的损失。我们实验室和其他人以前的工作表明，增加血清存活基因（iss）是与APEC毒力相关的共同特征。该基因最早被描述为对大肠杆菌的贡献。大肠杆菌血清抗性。然而，最近发表的研究对iss对这一特征的贡献提出了质疑。在本研究中，E.对ISS法分离的大肠杆菌进行了检测。此外，还研究了λ bor基因对大肠杆菌的作用.大肠杆菌血清耐药性的研究，因为iss被认为是来自bor和bor普遍存在于大肠杆菌中。杆菌为了更好地理解iss和bor对血清抗性的贡献，产生了一系列iss和bor突变体。iss缺失突变体（iss 2）对血清的抗性显著下降。类似地，bor突变体显示血清抗性下降，但不像iss突变体观察到的那样剧烈，这表明在该E.大肠杆菌菌株。同样，当iss被重新引入iss 2突变体中时，野生型血清抗性水平恢复，证实iss的缺失是突变体中所见抗性变化的原因。
Colibacillosis, caused by avian pathogenic Escherichia coli (APEC) is a major problem for the poultry industry resulting in significant losses annually. Previous work in our lab and by others has shown that the increased serum survival gene (iss) is a common trait associated with the virulence of APEC. This gene was first described for its contributions to E. coli serum resistance. However, recently published research has called the contribution of iss to this trait into question. In the present study, the level of serum resistance conferred on an E. coli isolate by iss is examined. Additionally, the contribution of lambda bor gene to E. coli serum resistance is studied, as iss is thought to be derived from bor and bor occurs commonly among E. coli. To better understand the iss and bor contributions to serum resistance, a series of iss and bor mutants was generated. An iss deletion (iss 2) mutant showed a significant drop in its resistance to serum. Similarly, a bor mutant showed a drop in serum resistance but not as drastic as that observed with the iss mutant, suggesting that iss contributes more to serum resistance than bor in this E. coli strain. Also, when iss was reintroduced into the iss 2 mutant the wild-type level of serum resistance was restored, confirming that the deletion of iss was responsible for the change in resistance seen in the mutant.