Characterisation of triclosan resistance in Salmonella enterica serovar Typhimurium.

消毒剂通常用于对可能存在细菌污染风险的表面和材料进行消毒，并为人类提供了感染途径。近年来，国内大量的抗菌产品被列为抗菌产品，其中许多含有三氯生，这是一种对多种细菌具有广泛活性的抗菌化合物。三氯生常见于洗手液、洗洁精、牙膏和化妆品中。它也可以浸渍在砧板和其他表面，因为它可以与塑料结合。在美国，家庭使用三氯生已经变得非常普遍，在环境中的溪流和河流中都可以检测到。虽然三氯生能有效杀灭细菌，但仍有可能筛选出对三氯生有抗药性的菌株。细菌对抗生素产生耐药性的许多机制也会对包括消毒剂在内的其他化合物产生耐药性。外排泵是一种蛋白质，它将包括抗生素和消毒剂在内的有毒分子泵出细胞，使细胞具有抵抗力。沙门氏菌是人类疾病的主要原因，2004年在英国造成了12500多例肠炎。大多数人类沙门氏菌感染与食用家禽产品（即鸡肉和鸡蛋）有关。我们的初步工作表明，暴露于三氯生后，沙门氏菌很容易产生三氯生耐药性，但耐药类型不同。在实验室中，不同的沙门氏菌菌株对三氯生产生了三种不同程度的耐药性。这是一个新的观察结果。本项目拟确定沙门氏菌中与三氯生耐药性有关的基因和蛋白质，并评估无限制使用三氯生是否可能导致作为副产物的抗生素耐药性的选择。我建议研究三种不同类型的三氯生抗性的例子，并确定每种表型涉及哪些基因。我还建议确定三氯生耐药菌株是否比它们的亲本更能产生抗生素耐药性并确定从动物和人类中分离出来的大量沙门氏菌中三氯生耐药的流行程度。

Disinfectants are routinely used to sterilize surfaces and materials which may be at risk of bacterial contamination and provide a route by which humans can become infected. Recently a large number of domestic products have been marketed as antimicrobial and many contain triclosan which is an antimicrobial compound with a wide range of activity against many bacteria. Triclosan is commonly found in handwashes, washing up liquids, toothpaste and cosmetics amongst others. It is also impregnated into chopping boards and other surfaces as it can be incorporated into plastics. In the USA domestic triclosan use has become so common it can be detected in streams and rivers in the environment. Although triclosan kills bacteria effectively it is possible to select bacterial strains which are resistant to triclosan. Many of the mechanisms of antibiotic resistance in bacteria can also give resistance to other compounds including disinfectants. Efflux pumps are proteins that pump toxic molecules including antibiotics and disinfectants out of the cell making the cell resistant. Salmonella is a major cause of human disease and were responsible for over 12,500 cases of enteritis in the U.K in 2004. Most salmonella infections in humans are associated with consumption of poultry products (i.e. chicken and eggs). Our preliminary work has demonstrated that triclosan resistance can be easily generated in salmonella after exposure to triclosan but that the type of resistance differs. Three different levels of resistance to triclosan have been produced from various strains of salmonella in the laboratory. This is a new observation. This project proposes to determine the genes and proteins involved in triclosan resistance in salmonella and to evaluate whether unrestricted use of triclosan is likely to result in selection of antibiotic resistance as a byproduct. I propose to study examples of each of the three different types of triclosan resistance and determine what genes are involved in each phenotype. I also propose to determine whether the triclosan resistant strains are more or less able to become antibiotic resistant than their parents and determine what the prevalence of triclosan resistance is amongst a large collection of various salmonella isolated from animals and humans.