With the continuous emergence and rapid spread of multidrug-resistant and extensively-drug-resistant Mycobacterium tuberculosis strains, it is imperative to develop novel therapies against this bacterium. The intrins...
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With the continuous emergence and rapid spread of multidrug-resistant and extensively-drug-resistant Mycobacterium tuberculosis strains, it is imperative to develop novel therapies against this bacterium. The intrinsic β-lactam resistance of M. tuberculosis is primarily due to the production of an Ambler class-A β-lactamase BlaC, which limits the application of β-lactam antibiotics in the treatment of tuberculosis. Therefore, the inhibitors of BlaC could be novel anti-tuberculosis drug synergistic agents to recover the sensibility of M. Tuberculosis to the β-lactam antibiotics. In the present study, BlaC of M. tuberculosis was expressed and purified to establish a screening model of the BlaC inhibitors. The screening conditions were determined, and the screening model was evaluated to fit for the high throughput screening. A total of 22 BlaC inhibitors were screened out from 26 400 compound samples with a positive rate of 0.083%. Taken together, our findings lay the foundation for the discovery of novel anti-tuberculosis drug synergistic agents in clinic.
Pseudomonas aeruginosa is an opportunistic pathogen that contributes to high morbidity and mortality. MexAB-OprM is the main efflux pump among the Resistance-Nodulation-Division family multi-drug effiux systems, which...
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Pseudomonas aeruginosa is an opportunistic pathogen that contributes to high morbidity and mortality. MexAB-OprM is the main efflux pump among the Resistance-Nodulation-Division family multi-drug effiux systems, which contribute greatly to the multidrug resistance of P. aeruginosa. Effiux pump inhibitors (EPIs) of MexAB-OprM could enhance the activity of the antibiotics effiuxed by MexAB-OprM, and thus they might be useful in the clinic as antibacterial synergistic agents. In this work, a new EPI of MexAB-OprM, KL-0153, was discovered by screening of a small molecular library. Its inhibition of MexAB-OprM was confirmed by assays of synergistic activity and EB accumulation. The activity of KL-0153 was shown to be synergistic with antibiotics effiuxed by MexAB-OprM when they were tested against strains expressing MexAB-OprM, especially so for the strains that express MexAB-OprM at high levels. KL-0153 showed more activity than the positive drug carbonyl cyanide m-chlorophenylhydrazone in the EB accumulation assay. It cannot be neglected that KL-0153 has significant liver and kidney toxicity. However, KL-0153 may be a lead comoound for the research and development of new tvoes of EPIs.
【目的】勘探海南东寨港真红树植物内生放线菌多样性,为发现放线菌新物种和新抗生素奠定基础。【方法】样品经表面消毒后粉碎,用10种不同培养基分离放线菌;通过PCR扩增、测定并比对16S r RNA基因序列,开展放线菌多样性分析;通过发酵、...
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【目的】勘探海南东寨港真红树植物内生放线菌多样性,为发现放线菌新物种和新抗生素奠定基础。【方法】样品经表面消毒后粉碎,用10种不同培养基分离放线菌;通过PCR扩增、测定并比对16S r RNA基因序列,开展放线菌多样性分析;通过发酵、萃取等处理方法得到四类样品,包括发酵原液、乙酸乙酯提取液及水层和菌体的丙酮浸泡提取液;采用纸片扩散法对样品进行抗菌活性筛选;基于PCR的基因筛选技术探测活性菌株可能存在的NRPS、PKS I、PKS II抗生素生物合成基因。【结果】经形态特征排重,从14种真红树植物样品中共得到放线菌146株,16S r RNA基因序列比对表明它们分布于13个科18个属,其中链霉菌属为优势菌属,菌株S3Cf-2和S3Af-1的16S r RNA基因序列分别与有效发表菌株Couchioplanes caeruleus DSM44103T(X93202)和Microlunatus terrae BS6T(JF806519)的相似率最高,分别为97.45%和97.43%,可能为新物种。对其中46株放线菌发酵样品的抗菌活性检测表明,40株具有抗菌活性,总阳性率为86.96%;活性菌株中,38株菌存在至少一种所探测的生物合成基因簇,阳性率为95%,其中14株同时具有所探测的3种抗生素生物合成基因簇。【结论】海南东寨港真红树植物中存在多样性丰富的药用放线菌资源,具有从中发现放线菌新物种及新抗生素的潜力。
目的勘探湖北利川喀斯特洞穴放线菌多样性并进行抗菌活性筛选,以期发现新的药用微生物资源,为新抗生素发现奠定基础。方法采用10种分离培养基,从来自3个洞穴内的38份样品中分离放线菌;通过基于16S r RNA基因序列的系统发育学分析,开展...
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目的勘探湖北利川喀斯特洞穴放线菌多样性并进行抗菌活性筛选,以期发现新的药用微生物资源,为新抗生素发现奠定基础。方法采用10种分离培养基,从来自3个洞穴内的38份样品中分离放线菌;通过基于16S r RNA基因序列的系统发育学分析,开展放线菌多样性研究;对67株放线菌发酵液乙酸乙酯萃取浓缩物和菌丝体丙酮浸提浓缩物进行抗菌活性筛选;阳性菌株进行次级代谢产物生物合成基因PKSⅠ、PKSⅡ和NRPS的初步筛选。结果从38份样品中共分离得到197株放线菌,它们分布于6个目13个科24个属,其中链霉菌为优势菌属,菌株T3-7-1为微杆菌科的一个潜在新分类单元;发酵67株放线菌,均在至少一个抗菌活性检测中显示为阳性;67株阳性菌株中有63株基于PKSⅠ、PKSⅡ或NRPS基因的引物PCR扩增出相应的目的条带,表明这些放线菌可能含有相应的PKSⅠ、PKSⅡ或NRPS基因。结论湖北利川喀斯特洞穴中蕴藏着丰富的放线菌资源,具有从中发现放线菌新物种及新抗生素的潜力,值得进一步研究。
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