Bates J
Worthing Hospital, West Sussex, UK.
J Hosp Infect. 1997 Oct;37(2):89-101. doi: 10.1016/s0195-6701(97)90179-1.
Several reports have documented the presence of vancomycin-resistant enterococci (VRE) in the stools of asymptomatic individuals from the community who have neither recently been in hospital nor received antibiotics. Such findings were contrary to the then existing perception of VRE as a strictly hospital-acquired infection of debilitated and immunocompromised patients on specialized units. Community-acquired infections with VRE are extremely rare but those that do occur may be conspicuous because of their serious nature, for example, endocarditis. If asymptomatic faecal carriage of VRE is present in the community, individuals admitted to hospital and subjected to the selective pressures of antibiotics on the normal gut flora, may act as the source of hospital outbreaks. VRE have also been found in sewage, from stools of healthy farm animals and animal products. Avoparcin, a glycopeptide showing cross-resistance to medically important glycopeptides, has been used in the European Community as a growth promoter in animal feeds. A possible link between the use of avoparcin, the selection of VRE, and humans becoming colonized via the food chain exists. To prove such a link is beset with many difficulties: it is necessary to explain the presence of VRE in the United States where avoparcin is not used, and the predominance of the VanA gene over the VanB gene. It is also proving difficult to show that animal and human strains are identical by means of molecular typing. To date, molecular typing of strains is only suggestive of a link, but epidemiological studies of farms that use avoparcin have shown a significant association with the presence of VRE in animal stools. As long ago as 1969, the Swann report declared that an antibiotic of medical importance should not be used as a growth promoter in animal feeds. The vasy array of antibiotics now being used in animal husbandry and fish-farming, and the cross-resistance of some antibiotics to their medically important counterparts is a real cause for concern. The emergence of multi-resistant enterococci causing human infections and the possibility of the transfer of the VanA gene from VRE to methicillin-resistant Staphylococcus aureus (MRSA) emphasizes the importance of this problem.
几份报告记录了在社区无症状个体的粪便中存在万古霉素耐药肠球菌（VRE），这些个体既未近期住院也未接受过抗生素治疗。此类发现与当时将VRE视为严格意义上在专科病房中虚弱且免疫功能低下患者的医院获得性感染的认知相悖。社区获得性VRE感染极为罕见，但一旦发生可能因其严重性而引人注目，例如心内膜炎。如果社区中存在无症状的VRE粪便携带情况，那么入院并受到抗生素对正常肠道菌群选择压力影响的个体，可能会成为医院感染暴发的源头。在污水、健康农场动物的粪便及动物产品中也发现了VRE。阿伏帕星是一种对医学上重要的糖肽类药物具有交叉耐药性的糖肽，在欧洲共同体曾被用作动物饲料中的生长促进剂。阿伏帕星的使用、VRE的选择以及人类通过食物链被定植之间可能存在联系。要证明这种联系存在诸多困难：有必要解释在美国（未使用阿伏帕星）VRE的存在情况，以及VanA基因相对于VanB基因的优势。通过分子分型证明动物和人类菌株相同也很困难。迄今为止，菌株的分子分型仅表明可能存在联系，但对使用阿伏帕星的农场进行的流行病学研究表明，其与动物粪便中VRE的存在存在显著关联。早在1969年，斯旺报告就宣称，具有医学重要性的抗生素不应用作动物饲料中的生长促进剂。目前在畜牧业和养鱼业中使用的大量抗生素，以及一些抗生素与其医学上重要的同类药物之间的交叉耐药性，确实令人担忧。多重耐药肠球菌导致人类感染的出现，以及VanA基因从VRE转移至耐甲氧西林金黄色葡萄球菌（MRSA）的可能性，凸显了这一问题的重要性。
