凝固酶阴性葡萄球菌生物膜形成与检测的研究进展

凝固酶阴性葡萄球菌(coagulase-negative staphylococci,CONS)是人体皮肤和黏膜上定居的正常菌群之一,因其几乎不产生对人体有毒性的酶和毒素,故一般认为是非致病菌.20世纪70年代以前,关于CoNS引起的感染仅有个别报道,20世纪80年代后,由于革兰阳性菌的抗生素广泛使用,以及介入性治疗、留置导管和组织器官移植等治疗手段的应用,CoNS成为医院感染的重要机会致病菌之一,并出现多重耐药株.本文就CoNS生物膜的形成与检测进展进行了综述.

表皮葡萄球菌生物被膜结构观察

随着生物材料被广泛应用于临床,表皮葡萄球菌已经成为医院感染的主要条件致病菌.生物材料表面细菌生物被膜(biofilm,BF)的形成是导致感染反复发作及久治不愈的根本原因,且常常引发灾难性的后果[1].本研究通过建立医用生物材料聚氯乙烯(polyvinyl chloride,PCV)表面表皮葡萄球菌BF体外模型,观察PVC材料表面细菌BF的结构,为生物材料植入感染研究提供实验模型和方法.

盐酸小檗碱对表皮葡萄球菌生物被膜形成的影响

表皮葡萄球菌(Staphylococcus epidermidis,SE)是人体皮肤和黏膜的主要共生菌之一,属于凝固酶阴性葡萄球菌,是一种常见的条件致病菌.近年来随着临床上插管、人工瓣膜、透析等医疗技术和一次性材料的使用增多,表皮葡萄球菌现已是医院感染的重要致病菌,而表皮葡萄球菌对常见抗菌药物耐药率已成为医院感染和临床治疗的棘手问题.生物被膜(biofilm,BF)可以保护细菌抵抗宿主免疫力和抗生素杀灭作用,造成感染难以治愈和反复发作.

细菌生物膜及其相关感染的研究进展

长期以来,人们对感染性疾病的认识及治疗一直建立在游离个体细菌致病的理论上,而临床上常有一些感染性疾病即使分离出致病菌,并找到敏感抗生素,经过规范的强化的抗生素联合治疗,却仍难以根除感染,这一现象无法用游离细菌致病机制解释.近20 年来,研究发现,在这些难治性的感染病灶中,细菌并不是以游离状态而是以细菌细菌生物膜(bacterial biofilm, BBF)的形式存在,这是导致抗生素治疗这些感染性疾病无效的重要原因.

细菌生物膜与细菌耐药的相关性

细菌生物膜(bacterial biofilm,BF)是细菌生长过程中为适应生存环境而吸附于惰性或活性材料表面形成的一种与浮游细胞相应的生长方式,由细菌和自身分泌的胞外基质组成.这类细菌耐药性极强,可以逃避宿主免疫作用,且感染部位难以彻底清除,是难治性感染的重要原因之一[1].

The effect of matrine against biofilm formation in Escherichia coli

Objective:To investigate the effect of matrine against biofilm formation of Escherichia coli (E.coli) in the early stage.Methods:Biofilms of E.coli (ATCC25922) was induced by using a peritoneal dialysis catheter in 96-well plates.After treatment with matrine for 24 h,the formation of biofilm on the catheters was observed by scanning electron microscope.The expressions of the flagellar gene (fliC) and motility genes (motA and motB) were determined by qPCR,and the protein expression of fliC was detected by western blotting.Results:The biofilm formation of E.coli was suppressed by different concentrations (less than the minimal inhibitory concentration) of matrine,and the mRNA levels of motA and motB as well as the mRNA and protein expression levels of fliC were decreased in a dose-dependent manner.Conclusion:Matrine could inhibit biofilm formation of E.coli via downregulating the expression of motA,motB and fliC.

白色念珠菌生物被膜及其耐药机制研究进展

近年来,随着医疗技术的发展,气管插管、支架、静脉留置管、人工瓣膜等植人性材料的运用及介入性检查的日益频繁,这些技术在给医患双方带来便利的同时也产生了许多新的问题,其中引人注意的就是生物被膜相关感染日渐增多.在关注细菌生物被膜的同时,研究也发现,近10年来白色念珠菌感染与生物医学材料的大范围使用呈平行上升趋势.尤为惊人的是,真菌(主要是白色念珠菌)感染在导管相关感染中居第三位,在条件致病菌感染中居第二位,并且有很高的病死率.

Retention wires permanently bonded to the anterior teeth are used after orthodontic treatment to prevent the teeth from relapsing to pre-treatment positions. A disadvantage of bonded retainers is biofilm accumulation on the wires, which produces a higher incidence of gingival recession, increased pocket depth and bleeding on probing. This study compares in vivo biofilm formation on single-strand and multi-strand retention wires with different oral health-care regimens. Two-centimetre wires were placed in brackets that were bonded to the buccal side of the first molars and second premolars in the upper arches of 22 volunteers. Volunteers used a selected toothpaste with or without the additional use of a mouthrinse containing essential oils. Brushing was performed manually. Regimens were maintained for 1 week, after which the wires were removed and the oral biofilm was collected to quantify the number of organisms and their viability, determine the microbial composition and visualize the bacteria by electron microscopy. A 6-week washout period was employed between regimens. Biofilm formation was reduced on single-strand wires compared with multi-strand wires;bacteria were observed to adhere between the strands. The use of antibacterial toothpastes marginally reduced the amount of biofilm on both wire types, but significantly reduced the viability of the biofilm organisms. Additional use of the mouthrinse did not result in significant changes in biofilm amount or viability. However, major shifts in biofilm composition were induced by combining a stannous fluoride-or triclosan-containing toothpaste with the mouthrinse. These shifts can be tentatively attributed to small changes in bacterial cell surface hydrophobicity after the adsorption of the toothpaste components, which stimulate bacterial adhesion to the hydrophobic oil, as illustrated for a Streptococcus mutans strain.

细菌生物膜感染及防治对策研究进展

细菌生物膜(bacterial biofilm,BF)是细菌的主要生存方式及细菌耐药性形成的重要机制之一.研究表明,BF不仅是生物材料相关感染的主要原因,也是某些反复发作、难治性感染即生物膜病的致病因素~([1]).近年来,随着对各种医疗插管相关感染的认识,人们对BF所致的感染也逐渐重视,并随之开展了大量研究工作.