CONJUGAL TRANSFER OF BACTEROIDES ANTIBIOTIC RESISTANCES

拟杆菌抗生素耐药性的夫妻传播

• 批准号: 3133381
• 负责人: Abigail A Salyers
• 金额: $ 12.57万
• 依托单位: UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-09-30 至 1988-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3133381
• 关键词: Bacteroides; Escherichia coli; bacterial genetics; drug resistance; gene conversion; genetic manipulation; genetic transcription; molecular cloning; plasmids; tetracyclines

Resistance to clindamycin (Cc-r) and tetracycline (Tc-r) can be transferred by conjugation in bacteroides. Certain Cc-r strains contain conjugative Cc-r plasmids. The conjugative Tc-r elements and conjugative Tc-r-Cc-r elements are not found on plasmids but appear to be integrated in the Bacteroides chromosome. Clindamycin is the drug of choice for treating anaerobic infections, and the spread of Cc-r among Bacteroides is of clinical concern. The Tc-r conjugal system sometimes co-transfers Cc-r en bloc and can mobilize at least one Cc-r plasmid and several cryptic Bacteroides plasmids. Three of the conjugative Cc-r plasmids contain a transposon, Tn4351, which carries the Cc-r determinant and a *Tc-r determinant that expresses only in aerobically grown E. coli. Tn4351 transposes in both E. coli and Bacteroides. Tn4351 will be used to study the spread of Cc-r to Bacteroides chromosome and to Bacteroides plasmids, especially to any of the cryptic plasmids. The Tc-r system will be characterized, using Tn4351, by the following methods: i) Use Tn4351 insertions into the Tc-r element in Bacteroides to allow cloning in E. coli to determine the size and location of the entire Tc-r element and to subclone and isolate the Tc-r determinant itself. ii) Use Tn4351 transposon mutagenesis to locate the transfer genes of the Tc-r system and to cause auxotrophs in Bacteroides to determine if chromosomal DNA is co-transferred with Tc-r. iii) Use methods similar to those used to isolate Tn4351 to determine if the Tc-r is also on a transposon. iv) Use Tn4351, containing cloned origins of transfer that are recognized by the Tc-r system, inserted into various sites of the Bacteroides chromosome to see if the Tc-r system will initiate transfer of the chromosome at those sites.

对克林霉素（Cc-r）和四环素（Tc-r）的耐药性可转移 通过类杆菌中的接合。 某些Cc-r菌株含有接合性 Cc-r质粒。 共轭Tc-r元和共轭Tc-r-Cc-r 元件不在质粒上，但似乎整合在 拟杆菌染色体。 克林霉素是治疗 厌氧感染，Cc-r在拟杆菌中的传播是 临床关注 Tc-r共轭系统有时会将Cc-r en 阻断并可动员至少一个Cc-r质粒和几个隐蔽的 拟杆菌质粒。 接合性Cc-r质粒中的三个含有 转座子Tn 4351携带Cc-r决定簇和a *Tc-r 一个仅在需氧生长的大肠杆菌中表达的决定子。杆菌 Tn4351 在E. coli和Bacteroides。 Tn 4351将用于研究 Cc-r向拟杆菌染色体和拟杆菌质粒的传播， 尤其是对任何隐藏质粒的反应。 TC-R系统将在 使用Tn 4351，通过以下方法表征： 插入拟杆菌中的Tc-r元件，以允许在E.杆菌 以确定整个Tc-r元件的大小和位置， 亚克隆并分离Tc-r决定簇本身。 ii）使用Tn 4351 转座子诱变以定位Tc-r系统的转移基因， 在拟杆菌中引起营养缺陷型，以确定染色体DNA是否 与Tc-r共转移。 （三）使用与过去类似的方法， 分离Tn 4351以确定Tc-r是否也在转座子上。 （四）用途 Tn 4351，包含被识别的克隆转移起点， Tc-r系统，插入拟杆菌染色体的各个位点， 看看Tc-r系统是否会在那些 网站.