Supplement Request: Investigating the role of prophage encoded gene products on mycobacterial gene expression and intrinsic antibiotic resistance

项目摘要-未对原始提交进行更新 这项拟议的研究的目标是了解前驱体是如何调控分枝杆菌的。 分枝杆菌的抗生素耐药性与基因表达改变。引起的耐药感染 临床上重要的分枝杆菌仍然是一个重大的公共卫生负担。 脓肿分枝杆菌是治疗囊性纤维化患者的一种新的病原体 成功率只有45%，而且被认为是耐药性最强的分枝杆菌之一。 耐药菌株通常表现出内在抗生素耐药性基因的表达增加， 让戒毒治疗变得具有挑战性。脓肿分支杆菌分离株通常是溶原菌，这意味着他们的 基因组携带一个或多个前噬菌体，整合的病毒基因组，具有潜在的 调节内在的抗生素耐药性。原噬菌体改变基因表达的机制 分枝杆菌对抗生素的耐药性目前还不清楚，这是这项拨款的重点。 转录调节因子WhiB7的表达随着胁迫的增加而增加，例如亚 抗生素的抑制浓度和巨噬细胞的胞内环境 在分枝杆菌固有的抗生素耐药性和巨噬细胞存活中起关键作用 (8)。我们的实验室首次证明了原噬菌体对内在抗生素的贡献。 抗性和WhiB7表达增加，进而积极调节 一组固有的抗生素耐药基因(8-10个)。我们发现了一群新奇的先知 在属于MabR(7，11)簇的脓肿分枝杆菌和龟分枝杆菌基因组中发现的 McProf确定，MabR原噬菌体增加了对龟分支杆菌的抵抗力 氨基糖苷类，治疗脓肿/龟分支杆菌感染的基石抗生素疗法(9)。我们 发现携带McProf的分枝杆菌具有增强的WhiB7反应，特别是当 被第二个噬菌体重叠感染。目前尚不清楚预言体麦克普夫是如何与 驱动WhiB7表达和内在抗性变化的第二个前驱噬菌体。我们 假设McProf基因组表达的基因检测压力并调节 分枝杆菌通过WhiB7的诱导产生抗生素耐药性。要了解 WhiB7在分枝杆菌溶原菌中的调节机制，我们建议表征 在携带Mcprof的细菌溶源中增强WhiB7反应的细胞应激 预测、鉴定和鉴定上调WhiB7的McProf基因 压力。

PROJECT SUMMARY - No updates from original submission The goal of the proposed research is to understand how prophages regulate mycobacterial antibiotic resistance and alter gene expression in mycobacteria. Drug-resistant infections caused by clinically important mycobacteria continue to be a significant public health burden. Mycobacterium abscessus is an emerging pathogen in cystic fibrosis patients with a treatment success rate of only 45%, and is considered one of the most drug-resistant mycobacteria. Resistant isolates commonly display increased expression of intrinsic antibiotic resistance genes, making drug treatment challenging. M. abscessus isolates are typically lysogens, meaning their genomes carry one or more prophages, integrated viral genomes, that have the potential to regulate intrinsic antibiotic resistance. The mechanism by which prophage alter gene expression and antibiotic resistance in mycobacteria is not yet understood and is the focus of this grant. Expression of the transcriptional regulator whiB7 increases in response to stresses, such as sub- inhibitory concentrations of antibiotics and the intracellular environment of macrophages and plays a critical role in mycobacterial intrinsic antibiotic resistance and survival in macrophages (8). Our lab showed for the first time that prophage contribute to intrinsic antibiotic resistance and increased expression of whiB7, which in turn positively regulates a large set of intrinsic antibiotic resistance genes (8-10). We identified a novel group of prophages found in the genomes of M. abscessus and M. chelonae that belong to cluster MabR (7, 11) and determined that the MabR prophage, McProf, increases M. chelonae resistance to aminoglycosides, cornerstone antibiotic treatments for M. abscessus/chelonae infections (9). We found that mycobacteria carrying McProf have an enhanced whiB7 response particularly when superinfected by a second phage. It is not understood how the prophage McProf interacts with the second prophage to drive changes in whiB7 expression and intrinsic resistance. We hypothesize that genes expressed from the McProf genome detect stress and regulate antibiotic resistance in mycobacteria through the induction of whiB7. To understand the mechanisms of whiB7 regulation in mycobacterial lysogens, we propose characterizing the cellular stresses that enhance the whiB7 response in bacterial lysogens carrying the McProf prophage and identify and characterize McProf genes that upregulate whiB7 in response to stress.