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.

可以转移对克林霉素（CC-R）和四环素（TC-R）的抗性 通过在杀菌剂中结合。 某些CC-R菌株含有共轭 CC-R质粒。 共轭TC-R元素和共轭TC-R-CC-R 在质粒上找不到元素，但似乎已集成在 细菌染色体。 克林霉素是治疗的首选药物 厌氧感染以及CC-R在细菌中的传播是 临床关注。 TC-R结合系统有时会共同传输CC-R EN 集体并可以动员至少一个CC-R质粒和几个神秘 细菌质粒。 三个共轭CC-R质粒包含一个 Transposon，TN4351，携带CC-R决定因素和A *TC-R 仅在有氧大肠杆菌中表达的决定因素。 TN4351 在大肠杆菌和杆菌中转置。 TN4351将用于研究 CC-R向杀菌剂染色体和细菌质粒的扩散， 特别是对任何一个神秘的质粒。 TC-R系统将是 使用TN4351来表征以下方法：i）使用TN4351 插入细菌中的TC-R元素以允许克隆大肠杆菌的克隆 确定整个TC-R元素的大小和位置和到 亚克隆和隔离TC-R决定因素本身。 ii）使用TN4351 转座子诱变，以定位TC-R系统的转移基因和 引起杆菌中的合并营养，以确定染色体DNA是否为 与TC-R共同转移。 iii）使用类似于曾经的方法 分离TN4351，以确定TC-R是否也在转座子上。 iv）使用 TN4351，包含转移的克隆起源，由 TC-R系统，插入杀菌剂染色体的各个部位 查看TC-R系统是否会在其中启动染色体的转移 站点。