抗生素的替代品--多肽

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An Alternative To Antibiotics
抗生素的替代品--多肽
Antibiotics are among the greatest achievements of medical science. But lately the former multi-purpose weapon fails in the battle against infectious diseases. Bacteria are increasingly developing resistance to antibiotics. Researchers have now found a therapeutic equivalent which could replace penicillin and related phamaceuticals.

More and more pathogens are becoming immune to antibiotics. Some bacteria can no longer be combated. The World Health Organization WHO is warning about resistance to drugs which were once so potent. The WHO's director-general Margaret Chan has pointed out that if measures are not taken quickly, it may soon not be possible to treat many frequently occurring infections. Figures released by the WHO show that in 2010 nearly half-a-million people were infected with a strain of tuberculosis which is resistant to many antibiotics one third of those infected died. The Organization states that the growing spread of resistant pathogens is attributable to the indiscriminate use of penicillin and other antibiotics.

Research scientists at the Fraunhofer Institute for Cell Therapy and Immunology IZI in Leipzig have found an alternative to the established antibiotics. In the future, antimicrobial peptides will take up the battle against pathogens. "We have already identified 20 of these short chains of amino acids which kill numerous microbes, including enterococci, yeasts and molds, as well as human pathogenic bacteria such as Streptococcus mutans, which is found in the human oral cavity and causes tooth decay. Even the multi-resistant hospital bug Staphylococcus aureus is not immune, and in our tests its growth was considerably inhibited," says Dr. Andreas Schubert, group manager at Fraunhofer IZI.

From familiar fungicidal and bactericidal peptides the research scientists produced sequence variations and tested them in vitro on various microbes. Putrefactive bacteria, for example, were incubated for an hour with the artificially produced antimicrobial peptides. As the new peptides contain cationic amino acid residues, they can bond with the negatively charged bacterial membrane and penetrate it. In their tests the research scientists compared the survivability of the pathogens with an untreated control. The experts focused on peptides with a length of less than 20 amino acids. "Antibiotic peptides unlock their microbicidal effect within a few minutes. They also work at a concentration of less than 1 µM, compared with conventional antibiotics which require a concentration of 10 µM," states Schubert, summarizing the test results. "The spectrum of efficacy of the tested peptides includes not only bacteria and molds but also lipid-enveloped viruses. Another key factor is that the peptides identified in our tests do not harm healthy body cells," the scientist explains.

The food sector could also benefit from the antimicrobial peptides given that the bacterial contamination of food products costs the industry billions every year. Fresh lettuce and other salad greens, for example, are badly contaminated by yeasts and molds. The shelf-life of foodstuffs could be improved by adding antimicrobial peptides during the production process. "This is a definite possibility because the short-chain peptides tested during the project do not exhibit any allergological risk on being added to foodstuffs," says Schubert. Magdeburg-based company HMI Analytic GmbH is the project partner in the development of peptides for salad greens. The research scientist is convinced that many possible applications exist, including in machinery manufacture for instance to keep hydraulic fluids free of microbes. As a next step the expert and his team are going to test the antimicrobial peptides in vivo on infection models.
http://www.medicalnewstoday.com/releases/228103.php

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抗生素的替代品--多肽

      抗生素是医学界里最大的成就。但是最近这些多功能武器在对抗感染性疾病的战斗中失败了。细菌对抗生素的耐药性越来越强。目前，研究者们发现可以替代盘尼西林和其相关药品治疗的药物。
      越来越多的病原体对抗生素产生免疫。一些细菌不再能被杀死。WHO 对那些曾经很有效的抗生素的耐药性发出了警告。世卫组织总干事陈冯富珍指出如果不尽快对这些药进行检测评估，它们将很快对经常发生的感染无效。WHO 公布的数据显示2010年将近50万人感染了一种对大多数抗生素耐药的肺结核菌株，导致1/3 感染者死亡。WHO称耐药病原体的增多是由于盘尼西林和其他抗生素的滥用。
      莱比锡的细胞治疗和免疫学IZI弗劳恩霍夫研究所的科学家发现了可以替代抗生素的药物。将来，抗微生物肽将占据对抗病原体的市场。“我们已经鉴别了20多种可以杀死大多数微生物的氨基酸的短链，包括肠球菌，酵母和霉菌，还有人的病原性细菌，比如在人口腔中发现并可以导致龋齿的变异链球菌。即使是多重耐药的医院的金黄色葡萄球菌也不能幸免，并在我们的测试大大抑制其生长。”弗劳恩霍夫IZI组经理安德烈亚斯舒伯特博士说。
      科学家生产了序列变异的抑菌和杀菌肽，并在体外的各种微生物上做了检测。比如，腐败细菌与人工合成的抗菌肽共同作用一个小时。由于新的多肽中含有阳离子氨基酸残基，所以他们可以渗透到带负电的细菌膜中去。在这些实验中，研究者比较了处理后的病原体和原病原体的存活率。专家们关注的焦点集中在长度小于20的肽段。“抗菌肽在几分钟内释放器抗菌效应，而且它们的有效作用浓度低于1个国际单位，而传统抗生素的作用浓度则要求10个国际单位以上，”Schubert 总结说。“这些肽段的有效谱不仅包括细菌，霉菌还包括脂质体包裹的病毒。更重要的是这些肽段在这些实验中显示对正常身体细胞无害。”科学家们解释道。
      粮食部门还可以从抗微生物肽中受益的是，食物生产过程中的细菌污染每年都花费十亿美元。比如，新鲜的生菜和沙拉，被酵母菌和霉菌严重污染。
     食品的保质期可以通过在生产过程中添加抗菌肽而延长。“这个可能性是可以肯定的，因为通过检测的短链肽段被添加到食品中不会出现任何变质的危险，”Schubert说。
     马格德堡的公司HMI分析有限责任公司是在沙拉肽的发展项目的合作伙伴。
     研究者们确信抗菌肽有很多可能的应用，包括机械制造商制造无微生物的液压油。下一步，专家和他的研究团队将要检测在体内的感染模式下检测这些抗菌肽。

cl1961

好消息,在抗生素耐药越来越严重的今天,抗生素的替代品--多肽的出现,无凝将给人类带来福音。谢谢提供！

宝瓶

好消息，期待早日应用于临床。

王周

是个好消息，期盼尽早应用于临床，以解决人类疾病的痛苦。