Callaway T R, Edrington T S, Anderson R C, Byrd J A, Nisbet D J
Agricultural Research Service, Food and Feed Safety Research Unit, College Station, TX 77845, USA.
J Anim Sci. 2008 Apr;86(14 Suppl):E163-72. doi: 10.2527/jas.2007-0457. Epub 2007 Sep 18.
Salmonella causes an estimated 1.3 million human foodborne illnesses and more than 500 deaths each year in the United States, representing an annual estimated cost to the economy of approximately $2.4 billion. Salmonella enterica comprises more than 2,500 serotypes. With this genetic and environmental diversity, serotypes are adapted to live in a variety of hosts, which may or may not manifest with clinical illness. Thus, Salmonella presents a multifaceted threat to food production and safety. Salmonella have been isolated from all food animals and can cause morbidity and mortality in swine, cattle, sheep, and poultry. The link between human salmonellosis and host animals is most clear in poultry. During the early part of the 20th century, a successful campaign was waged to eliminate fowl typhoid caused by Salmonella Gallinarum/Pullorum. Microbial ecology is much like macroecology; environmental niches are filled by adapted and specialized species. Elimination of S. Gallinarum cleared a niche in the on-farm and intestinal microbial ecology that was quickly exploited by Salmonella Enteritidis and other serotypes that live in other hosts, such as rodents. In the years since, human salmonellosis cases linked to poultry have increased to the point that uncooked chicken and eggs are regarded as toxic in the zeitgeist. Salmonellosis caused by poultry products have increased significantly in the past 5 yr, leading to a USDA Food Safety and Inspection Service "Salmonella Attack Plan" that aims to reduce the incidence of Salmonella in chickens below the current 19%. The prevalence of Salmonella in swine and cattle is lower, but still poses a threat to food safety and production efficiency. Thus, approaches to reducing Salmonella in animals must take into consideration that the microbial ecology of the animal is a critical factor that should be accounted for when designing intervention strategies. Use of competitive exclusion, sodium chlorate, vaccination, and bacteriophage are all strategies that can reduce Salmonella in the live animal, but it is vital to understand how they function so that we do not invoke the law of unintended consequences.
在美国，沙门氏菌每年估计导致130万人感染食源性疾病，造成500多人死亡，每年给经济带来的损失估计约为24亿美元。肠炎沙门氏菌有2500多个血清型。由于这种基因和环境的多样性，各血清型适应于在多种宿主中生存，这些宿主可能表现出临床疾病，也可能不表现。因此，沙门氏菌对食品生产和安全构成多方面威胁。已从所有食用动物中分离出沙门氏菌，它可导致猪、牛、羊和家禽发病和死亡。人类沙门氏菌病与宿主动物之间的联系在家禽中最为明显。在20世纪早期，开展了一场成功的运动来消除由鸡伤寒沙门氏菌/鸡白痢沙门氏菌引起的禽伤寒。微生物生态学很像宏观生态学；环境生态位由适应的和特化的物种占据。鸡伤寒沙门氏菌的消除在农场和肠道微生物生态学中腾出了一个生态位，肠炎沙门氏菌和其他生活在其他宿主（如啮齿动物）中的血清型迅速利用了这个生态位。从那以后，与家禽相关的人类沙门氏菌病病例增加到了这样的程度，即生鸡肉和鸡蛋在公众意识中被视为有毒。过去5年中，由家禽产品引起的沙门氏菌病显著增加，导致美国农业部食品安全与检验局出台了一项“沙门氏菌攻击计划”，旨在将鸡肉中沙门氏菌的发生率降低到目前的19%以下。沙门氏菌在猪和牛中的流行率较低，但仍对食品安全和生产效率构成威胁。因此，减少动物体内沙门氏菌的方法必须考虑到动物的微生物生态学是设计干预策略时应考虑的关键因素。使用竞争排斥、氯酸钠、疫苗接种和噬菌体都是可以减少活体动物体内沙门氏菌的策略，但了解它们的作用方式至关重要，这样我们就不会引发意外后果定律。
