In recent years , for the irrational use of antibiotics produces resistant strains and other reasons , bacterial resistance is more and more serious . human are trying to solve the problem from different ways , including the study of antimicrobial peptides . defensin is one of the most important of antimicrobial peptides 防御素( defensin )是抗菌肽中较为重要的一种，是一种生物体产生的具有强大的抗菌功能的阳离子小分子多肽，主要来源于皮肤、呼吸道等的上皮组织，是正常机体抵抗外界病原微生物入侵的重要防线。
In conclusion , the compact engineered peptide can form lethal ion channel in the membrane of staphylococcus aureus guided by staphylococcal agrd pheromone , therefore the engineered peptide had bactericidal activity against staphylococcus aureus , especially against the drug - resistant strains . because of the properties mentioned above , the engineered peptide showed great potential in the future . the engineered peptide was an example of bactericidal protein machine combining two minidomains with different bioactivities and different protein origins 该工程多肤能在人工脂质膜上形成电压依赖性离子通道，即当电压由omv变为+ somv时通道立刻开放，电导骤然上升到某一数值，其后电导发生丫系列谐振式变化;而当电压由+ somv变为一50mv时电导并不立即减小至o ，而出现正电压状态下类似的表现。
The pcr products of gyra of a resistant strain ( sll - 3 ) was sequenced and analysed . when compared to the corresponding sequence of the gyra of salmonella typhimurium from the nucleotide sequences data of the gyra reported by griggs , 5 mutants sites were found in the qrdr . dma sequencing identified in the strain sll - 3 ser to phe change at codon 83 of gyra gene 对所试菌株染色体的pcr产物行hinfi酶切后电泳检测表明， cip高敏菌株( 6株)得到预期大小为363bp 、 206bp 、 99bp的3个条带；而耐药菌株和中敏菌株( 10株)电泳检测到大小为363bp和305bp的2个条带。
4 . the decrease of cu2 + in bg11 medium was observed to mainly took place before 24h . the resistant strain accumulated the maximal cu2 + at 24h . the removal ratio of cu2 + at 24h in bg11 medium was 48 . 87 % , and it was 80 . 77 % at 96h . but as to the non - resistant strain , the respective biodegradation ratio of 24h and 96h are 20 . 88 % and 34 . 29 % 抗性株在24h之前对cll ’ “富积较快， 24h的去除率为48 87 ，而96h的去除率为80 77 ；而非抗性株在24h之前对cuy富积相对较慢， 24h去除率为20
The results obtained were as follows : the mic of engineered peptide against staphylococcus aureus atcc 25923 ( penicillin sensitive strain ) , atcc 29213 ( penicillinase - producing strain ) and atcc baa - 42 ( methicillin resistant strain ) were 1g / ml , 2g / ml , 4g / nil respectively . pi staining showed the staphylococcus aureus treated with the engineered peptide were dead 实验结果表明:该工程多肤对三种atcc标准菌株atcc25923 (青霉素敏感菌株) 、 atcc29213 (产青霉素酶菌株) 、 atccbaa一42 (耐甲氧西林菌株)的mlc分别为1林留血l 、 2林留ml 、 4林创ml 。
Leading the list of current problems are drug - resistant strains of p . falciparum ( which first developed in south america and asia and then spread to the african continent ) , followed by insecticide resistance among mosquitoes , crumbling public health infrastructures , and profound poverty that hobbles efforts to prevent infections in the first place 目前有许多问题，最严重的是疟原虫已经出现了抗药性（具抗药性的疟原虫最早出现在南美与亚洲，然后才蔓延到非洲） ，其次是许多种蚊子已经不怕杀虫剂，接下来还有公共卫生基础建设的崩溃，以及普遍的贫穷，一开始就让防止感染措施窒碍难行。
