摘要
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。
Nowadays antibiotic efflux pumps are believed to contribute significantly to acquired bacterial resistance because of the very broad variety of substrates they recognize, their expression in important pathogens, and their cooperation with other mechanisms of resistance. Diverse molecules, from small antibacterial drugs to large protein toxins, are exported directly across cell membranes of Gram-negative bacteria. This export is brought about by the reversible interaction of substrate-specific inner-membrane proteins with an outer-membrane protein of the TolC family, thus bypassing the intervening periplasm. Bacteria that adhere to implanted medical devices or damaged tissue can encase themselves in a hydrated matrix of polysaccharide and protein, and form a slimy layer known as a biofilm. The mechanisms of resistance in biofilms are different from the now familiar plasmids, transposons, and mutations that confer innate resistance to individual bacterial cells. The possible mechanisms of resistance in efflux pumps, TolC family and biofilms are reviewed in this article.
出处
《中国兽药杂志》
2005年第7期41-45,37,共6页
Chinese Journal of Veterinary Drug
