SAN FRANCISCO, Jan. 18 (Xinhua) -- Researchers with Oregon State University (OSU) have identified a molecule that neutralizes germs' resistance to antibiotic.
Known as a PPMO, short for peptide-conjugated phosphorodiamidate morpholino oligomer, the molecule has shown ability to inhibit expression of an enzyme, known as NDM-1, short for New Delhi metallo-beta-lactamase, that makes bacteria resistant to a wide range of penicillins.
The study demonstrated that in vitro the new PPMO restored the ability of an ultra-broad-spectrum drug of the carbapenem class, called meropenem, to fight three different genera of bacteria that express NDM-1, and that a combination of the PPMO and meropenem was effective in treating mice infected with a pathogenic strain of E. coli that is NDM-1 positive.
"We're targeting a resistance mechanism that's shared by a whole bunch of pathogens," Bruce Geller, professor of microbiology in OSU's College of Science and College of Agricultural Sciences, was quoted as saying in a news release. "It's the same gene in different types of bacteria, so you only have to have one PPMO that's effective for all of them, which is different than other PPMOs that are genus specific."
While the results were published in the Journal of Antimicrobial Chemotherapy, Geller said the PPMO will likely be ready for testing in humans in about three years.
"We've lost the ability to use many of our mainstream antibiotics," Geller explained. "Everything's resistant to them now. That's left us to try to develop new drugs to stay one step ahead of the bacteria, but the more we look the more we don't find anything new. So that's left us with making modifications to existing antibiotics, but as soon as you make a chemical change, the bugs mutate and now they're resistant to the new, chemically modified antibiotic."
That progression made the carbapenems, the most advanced penicillin-type antibiotic, the last line of defense against bacterial infection.
"The significance of NDM-1 is that it destroys carbapenems, so doctors have had to pull out an antibiotic, colistin, that hadn't been used in decades because it's toxic to the kidneys," Geller said. "That is literally the last antibiotic that can be used on an NDM-1-expressing organism, and we now have bacteria that are completely resistant to all known antibiotics."
Geller added: "but a PPMO can restore susceptibility to antibiotics that have already been approved, so we can get a PPMO approved and then go back and use these antibiotics that had become useless."
雅思听力高频词汇:生活类
应对雅思听力考试的十三条潜规则
雅思听力之必须知道原则
雅思听力高频词汇:证件办理
雅思听力应考需要注意的六个点
雅思听力配对题的解题技巧介绍
雅思听力观点题的难点突破方法
雅思听力备考:听写练习全方位指导
书写雅思听力考试答案的注意事项
雅思听力高频词汇:课题研究
考生分享雅思听力提高的方法
雅思听力:选择题型解题方法介绍
雅思听力备考需做好量的把握
雅思听力备考需要了解的模仿原则
雅思听力答案的正确写法总结
决胜雅思 雅思听力高分需把握的五个环节
考生备考雅思听力易进入的三大误区
雅思听力简单表格题的解题技巧
雅思听力:冷门知识总结
雅思听力考试的10条重要tips
雅思听力旅游场景必备的主题词汇
雅思听力考试之数字的考点及难点
雅思听力考试中的高频同意转换
雅思听力之听力中混淆视听的短语
雅思听力高频词汇:职业名称
雅思听力的魔鬼训练法简介
雅思听力高频词汇:动物与植物
雅思听力之备考中的误区
学好雅思听力 良好的听力习惯必不可少
雅思听力高频词汇:校园生活
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |