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细菌耐药性及生物被膜感染问题一直备受关注，抗生素的使用不当或滥用导致了细菌耐药性越来越严重，一些细菌出现了多重耐药甚至超级耐药的情况。为了抵抗宿主的免疫反应及抗菌药物的攻击，细菌聚集后会形成生物被膜。生物被膜的形成进一步加强细菌的耐药性，生物被膜感染是细菌性疾病迁延不愈的重要原因之一。寻找广谱、高效的抗菌和抗生物被膜的抗生素替代物是目前的研究热点。纳米银(silver nanoparticles, AgNPs)由于自身的物理、化学和生物学特性，在抗菌及抗生物被膜方面受到广泛的关注，其抗菌机制主要包括了破坏细胞壁和细胞膜、DNA损伤、氧化应激等，抗生物被膜机制主要包括抑制相关基因的表达、抑制聚集黏附、阻断群体感应等。论文综述了纳米银抗菌及抗生物被膜的研究进展，以期为开发新型抗菌药物提供参考。 相似文献
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细菌生物被膜（BBF）是指由附着于惰性或者活性实体表面的细菌细胞和包裹着细菌的由细菌自身所分泌的含水聚合性基质所组成的结构性细菌群落。生物被膜不仅是细菌存在于自然界的一种重要的生存形式，而且生物被膜的形成是细菌对抗生素广泛耐药的重要机制之一。作为细菌的一种适应性生物学特性．生物被膜菌具有与浮游菌不同的结构和生长、代谢特点．凭借其耐药屏障保护细菌不被机体免疫系统识别和清除．并且能降低抗菌药物渗入细菌体内的浓度．导致生物被膜菌较浮游菌具有更强的耐药性，不易被抗菌药物所杀灭．造成临床上生物被膜菌相关性感染的慢性、难治性特点。 相似文献
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细菌生物被膜(bacterial biofilms)是由细菌互相粘连、不可逆地固着于生物机体或物体表面并由细菌分泌的胞外基质包裹的微生物群落。生物被膜为细菌提供了一种保护性生活方式,其形成有利于微生物持续定植,抵抗宿主免疫系统清除,提高对抗生素的耐受性以及遗传物质的交换。细菌生物被膜的存在对生物医学、食品加工等方面极为不利,因此,迫切需要研发能够去除生物被膜的新技术。目前,噬菌体被认为是控制生物被膜的一种有效方法。本文综述了应用噬菌体防控生物被膜的最新进展。 相似文献
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细菌天然群体感应信号分子抑制剂研究进展 总被引：1，自引：0，他引：1
长期抗生素滥用导致了多重耐药菌株及其超级细菌的出现,由密度感应系统调控的生物被膜的形成和成熟是造成细菌感染的机制之一。自然界存在的生物活性物质能够淬灭密度感应系统,这些生物活性物质被称为群体感应信号分子抑制剂(quorum sensing inhibitor,QSI)。近年来,群体感应抑制剂成为细菌抗感染药物开发的靶点,有必要对细菌群体感应信号分子抑制剂种类、作用机制进行研究,本文综述了细菌天然群体感应信号分子抑制剂,干扰群体感应系统,从而治疗细菌感染。绝大多数原核生物能够产生群体感应抑制剂,这被认为是安全的。动物、豆类、传统的药用植物、海洋生物均能产生群体感应抑制剂。这些天然抑制剂可能替代传统抗生素,具有广阔的研究和应用前景。 相似文献
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细菌耐药机制及耐药性控制对策 总被引：15，自引：2，他引：13
细菌耐药问题日趋严重，对人类健康造成极大威胁，成为全球关注的热点。细菌耐药机制非常复杂，而且一种耐药菌株同时可具有多种耐药机制。本文对细菌耐药机制及耐药性控制对策的研究进展进行综述，并提出从产生细菌耐药性的根本原因出发、合理使用抗生素、加强基层工作人员的相关医疗知识才是控制细菌耐药性的基本原则。 相似文献
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血根碱体外抑菌作用及其对细菌生物被膜的影响 总被引：1，自引：0，他引：1
试验旨在了解血根碱的体外抑菌能力及对细菌生物被膜的作用。通过管碟法测定不同浓度的血根碱对金黄色葡萄球菌、大肠埃希氏菌、甲型副伤寒沙门氏菌、凝结芽孢杆菌、枯草芽孢杆菌的抑菌能力,并与国家允许添加的饲用抗生素盐酸金霉素比较;构建3种致病菌的细菌生物被膜;研究血根碱对其作用效果。结果表明:0.32 g/L的血根碱抑菌效果明显,并且优于盐酸金霉素;采用刚果红平板法及银染法鉴定细菌生物被膜;通过菌落计数发现,0.16 g/L血根碱可以清除细菌生物被膜。血根碱具有较强的体外抑菌能力,又能有效清除大肠杆菌、沙门氏菌、金黄色葡萄球菌形成的细菌生物被膜。 相似文献
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Biofilm formation is one of the factors responsible for antibiotic resistance. The involvement of biofilm formation in bacterial mastitis is well known. Milk composition varies during the lactation period and certain pathogens are producing more number of mastitis cases during particular periods of lactation. The present study elucidates the effects of different milk components on biofilm formation and the persistence of infection. The Plackett Burman screening design has been chosen for assessing the significance. Biofilm production of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were assessed by crystal violet assay. Dipotassium hydrogen phosphate had a significant effect on biofilm formation by S. aureus (MTCC 1430) whereas it was pH in the case of biofilm formation by P. aeruginosa (NCIM 5029). Other independent factors were found to be insignificant. 相似文献
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抗菌药仍是治疗病原菌引起的奶牛疾病的常用方法。抗菌药的不合理使用使得细菌产生耐药性已成为全球性的问题,应引起人们的足够重视。奶牛的主要病原菌金黄色葡萄球菌、链球菌、大肠杆菌等也显现出多重耐药的趋势,给奶牛疾病的临床治疗带来困难,同时也威胁人类健康。细菌产生耐药性的速度远超过人们研发抗菌药的速度,因此,保持现有抗菌药的疗效很有必要。一方面应该掌握细菌的耐药机制,如细菌分子耐药机制、抗菌药物外排机制或降低摄入机制、生物膜等,以便找到合适的治疗方法;另一方面采用不同措施减少耐药细菌的出现,如质粒消除、抗菌药替代品、开发高效安全的抗菌药物、临床合理用药（联合治疗）等。作者对奶牛主要病原菌的耐药情况、耐药机制、耐药控制技术进行综述,以期为减少耐药性、规范抗菌药的使用和提高治疗效果提供参考。 相似文献
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At present, the usual and effective method of treating the cow disease caused by pathogens is still antimicrobials. The irrational use of antimicrobials makes bacteria produce resistance, and has become a global problem. The main pathogens of dairy cows include Staphylococcus aureus, Streptococcus, Escherichia coli and so on, which show a trend of multiple drug resistance. It not only brings great challenges for the clinical treatment of dairy cow, but also gives a threat to human health. Antimicrobial resistance is far more than the speed of people developing antimicrobials. Therefore, it is necessary to maintain the efficacy of existing antimicrobials for treating infections. On the one hand, we should master the bacterial resistance mechanism, such as bacterial molecular resistance mechanism, antibiotic efflux mechanism or reducing the intake mechanism, biofilm, so as to help us find the adequate therapeutics; On the other hand, taking different measures to reduce the emergence bacterial resistance, such as plasmid elimination, antibiotic substitutes, the development of efficient and safe antimicrobials, clinical rational drug (combined treatment) and so on. This article reviews dairy cow's main pathogen resistance, drug resistance mechanism, drug resistance control technology and make a prospect for this. It would provide reference for reducing the drug resistance, regulating the use of antimicrobials and improving the therapeutic effect. 相似文献
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在多种重要病原体中存在抗生素排出泵,它与其它抗性一起构成了细菌显著的耐药性,其识别的底物非常广泛.G-菌中还存在与排出泵不同的另一种以蛋白质构成的排出系统,通过底物特异性内膜蛋白和外膜蛋白TolC家族的可逆性互作,也可以直接将包括小分子药物和大分子蛋白毒素等的多种分子从胞浆经周质区运到体外.粘附在内置医疗装置或组织中的细菌因其形成生物薄膜结构和以蛋白质、多糖为主的水性基质包裹的菌体也可以产生长期感染以及对抗生素的持久抗性,这种抗性与经典的质粒、转座子或突变产生的抗性不同.本文对细菌TolC家族和生物薄膜引起的抗性机制进行了综述. 相似文献
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Pathogenic microorganisms are commonly associated with external ocular infections in birds. Pathogen virulence factors as well as reduced host defenses resulting from poor living conditions, nutrition, genetics, physiology, hygiene, fever, and age may increase host susceptibility. Staphylococcus species are bacteria known to serve as opportunistic pathogens in eye infections. The changing profile of microorganisms involved in ocular infections and the emergence of acquired microbial resistance dictate the need for investigative studies regarding bacterial profiles and antimicrobial susceptibility patterns for external ocular infections. The aim of this study was to determine the prevalence of Staphylococcus aureus ocular infections in pigeons and to evaluate their biofilm production ability and antibiotic resistance patterns. Twenty pigeons with confirmed eye infections were included in this project. Conjunctival specimens were collected with swabs presoaked in sterile normal saline. Bacterial growth was identified by standard laboratory procedures and susceptibility testing of the isolates was performed by the Kirby-Bauer method. The ability of the isolates to form a biofilm was also assessed using the microtiter plate method. Of the 20 specimens processed, 20% of the pigeons had staphylococcal eye infections. The resistance pattern of these isolates showed that Staphylococcus spp. from pigeon samples were resistant to tetracycline (100%), erythromycin (100%), azithromycin (100%), nalidixic acid (100%), and cefazolin (50%). All of the Staphylococcus spp. isolated from the pigeons were susceptible to gentamycin and furazolidone. The results of the biofilm detection test showed that 75% of the isolates were biofilm producers. In conclusion, biofilm forming S. aureus with multidrug resistance patterns were the most prevalent bacteria isolated from the pigeons examined in this research study. 相似文献
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CpxR是细菌中Cpx双组分系统（two component system,TCS）的反应调控蛋白,通过调控靶基因的转录表达,在细菌细胞膜稳定及毒力方面发挥作用。本研究旨在探究TCS CpxR对禽致病性大肠杆菌（avian pathogenic Escherichia coli,APEC）基本生物学特性、抗血清杀菌能力及致病性的影响。利用Red同源重组系统及互补质粒构建cpxR基因缺失株、互补株,然后比较分析野生株、基因缺失株与互补株的生长曲线、运动性、生物被膜形成能力、药物敏感性、抗血清杀菌能力、动物致病性的差异。结果显示：cpxR基因缺失株与野生株、互补株的生长速度和运动性能无明显差异,且缺失cpxR基因不影响APEC的生物被膜形成能力。然而,缺失CpxR导致APEC对阿米卡星和卡那霉素耐药性降低。血清杀菌试验结果显示,CpxR有助于APEC的抗血清杀菌能力。动物感染试验结果显示,野生株、cpxR基因缺失株和互补株对雏鸭的半数致死量（LD50）分别为7.50×105、7.50×106、1.33×106 CFU,表明CpxR缺失显著降低APEC的毒力。综上表明,TCS CpxR在APEC耐药性、抗血清杀菌能力及毒力方面发挥作用,为阐明APEC的环境适应性、生存能力及致病机制提供参考。 相似文献
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Resistance to antibiotics in the normal flora of animals. 总被引：14，自引：0，他引：14
The normal bacterial flora contains antibiotic resistance genes to various degrees, even in individuals with no history of exposure to commercially prepared antibiotics. Several factors seem to increase the number of antibiotic-resistant bacteria in feces. One important factor is the exposure of the intestinal flora to antibacterial drugs. Antibiotics used as feed additives seem to play an important role in the development of antibiotic resistance in normal flora bacteria. The use of avoparcin as a feed additive has demonstrated that an antibiotic considered "safe" is responsible for increased levels of antibiotic resistance in the normal flora enterococci of animals fed with avoparcin and possibly in humans consuming products from these animals. However, other factors like stress from temperature, crowding, and management also seem to contribute to the occurrence of antibiotic resistance in normal flora bacteria. The normal flora of animals has been studied with respect to the development of antibiotic resistance over four decades, but there are few studies with the intestinal flora as the main focus. The results of earlier studies are valuable when focused against the recent understanding of mobile genetics responsible for bacterial antibiotic resistance. New studies should be undertaken to assess whether the development of antibiotic resistance in the normal flora is directly linked to the dramatic increase in antibiotic resistance of bacterial pathogens. Bacteria of the normal flora, often disregarded scientifically, should be studied with the intention of using them as active protection against infectious diseases and thereby contributing to the overall reduction of use of antibioties in both animals and humans. 相似文献