唐门六道小说百度云:细菌耐药性竟然会搭便车旅行（图）

 Vans and cars loaded down with people, goods, and maybe chickens weave out of the delta town of Borbón in northwest Ecuador, zipping onto the region's new two-lane highway. Soon, many veer off onto narrower roadways, heading to villages on the Santiago and Cayapas rivers. But canned beans, people, and poultry aren't the only cargo, a new study suggests—antibiotic resistance could travel those same routes, too.  货车和轿车装载着人们、货物、或许还有小鸡，在迂回的路线上穿行，驶出厄瓜多尔西北部的三角镇——波旁，快速地跑上该地区新建的双车道公路。很多车很快转向开到较窄的路面上，朝着圣地亚哥河和卡亚帕斯河沿岸的村庄驶去。但是一项新研究表明，车上装载的不仅仅是罐装菜豆、人们以及家禽，细菌的耐药性可能也沿着同样的路线出游了！ For centuries, getting to the more than 100 Afro-Ecuadorian villages dotting the dense forests in the Ecuadorian province of Esmeraldas was an adventure: Travelers had to go by ocean, then continue down miles of winding rivers. Then in 1996, the new highway joined Borbón to much of coastal Ecuador, says study co-author Joseph Eisenberg, an epidemiologist at the University of Michigan, Ann Arbor. Once-isolated communities became much more open to the flow of people and goods—not to mention foreign microbes, potentially including antibiotic-resistant bacteria on the run from hospitals in Quito and other city centers.  多个世纪以来，前去厄瓜多尔埃斯梅拉达斯省密林中分布的100多个非洲裔厄瓜多尔人居住的村庄是一种冒险：旅行者不得不走海路，然后不得不继续在蜿蜒的河流上漂游数英里。研究论文的作者之一、密歇根大学安娜堡分校的流行病专家约瑟夫·艾森伯格说：后来于1996年，一条新公路将波旁跟厄瓜多尔的多数海滨地区连接起来。一度被隔离的社区对流动人口和流动货物突然变得开放起来，更不用说外来细菌了，其中可能包括从基多医院里和其他城市中心逃出来的对抗生素耐药的细菌。 To test the theory, Eisenberg and colleagues conducted a 5-year census: They visited 21 communities, both short and long drives from Borbón and with nearly identical rates of antibiotic usage, collecting more than 2000 stool samples. The group then cultured the samples, looking for Escherichia coli bacteria resistant to common antibiotics, particularly ampicillin and sulfamethoxazole drugs. Genes that protect microbes against these two frequently prescribed cell killers typically sit together on plasmids, small circlets of DNA that, similar to children trading baseball cards, pass easily between bacterial species. The shorter the drive time to Borbón, the more antibiotic-resistant bacteria villagers had in their guts, Eisenberg and colleagues report online today in the Journal of the Royal Society Interface.  为了检验这个理论，艾森伯格及同事进行了为期五年的普查：他们走访了21个社区，既包括距离波旁近的社区，也包括距离波旁远的社区，而且社区抗生素的使用率几乎相同。研究小组收集了2000多份粪便样品，然后对样品进行了培养，同时观察了大肠杆菌对普通抗生素的耐药性，特别是对氨苄西林和磺胺甲恶唑的耐药性。保护细菌的基因对抗这两种经常作为药方开出的号称“细胞杀手”的抗生素，这些保护基因通常位于质粒（微型环状DNA）上，而质粒类似于孩子们交换的棒球卡，很容易在不同的菌种之间穿梭。今天，艾森伯格及同事在《皇家学会交界杂志》在线版上报道说：到波旁的距离越近，村民们肠道中的耐药菌越多。 The team drew up a mathematical simulation based on its data to estimate how antibiotic usage might influence the flow of resistant bacteria. The more antibiotics villagers in this study took, Eisenberg and colleagues calculated, the more likely they were to transfer the resistant E. coli to their close neighbors. When people take antibiotics, the resistant bacteria become the dominant strains in their guts and the ones they transmit, Eisenberg says. So, in communities in which the antibiotics flow freely, villagers tend to swap resistant gut frequently, especially because sanitation tends to be poor—latrines are few and far between, and community members usually draw their drinking water directly from freshwater streams. But that intravillage swapping likely becomes rarer when ampicillin and similar drugs are more restricted, in which case the majority of new antibiotic-resistant bacteria presumably flood in from the outside.  研究小组根据获得的数据编制了数学模型，评估了抗生素的使用对耐药菌的流传可能造成的影响。艾森伯格及同事经计算得出，接受研究的村民服用的抗生素越多，就越有可能将具有耐药性的大肠杆菌传播给近围的邻居。艾森伯格说，当人们服用抗生素之后，耐药菌便成为他们肠道中占支配地位的菌株，同样成为他们所传播的菌株。因此，特别是由于卫生条件差——公共厕所稀少，而且相距遥远，再加上社区成员通常从淡水溪里直接打来饮用水，结果，在自由使用抗生素的社区，村民们经常交叉感染耐药性肠炎。但是，当氨苄西林和类似药物得到较为严格的控制时，村内的那种交叉感染很可能会较为罕见，在这种情况下，新型耐药菌可能是从村外涌入的。 The team's results fall in line with a number of studies that warn against excessive antibiotic use, says Stuart Levy, a physician scientist at Tufts University School of Medicine in Boston and a member of the advocacy group Alliance for the Prudent Use of Antibiotics. Even if some individuals are responsible about how much antibiotics they take, they're still vulnerable to catching antibiotic-resistant strains from their neighbors who take too many antibiotics, Levy says.  波士顿市塔夫茨大学医学院的医务科学家兼抗生素慎用联盟倡导组成员斯图尔特·利维说，该小组的研究结果跟一些告诫过度使用抗生素的研究结果是一致的。利维说：尽管一些个人以负责任的态度把握自己的抗生素服用剂量，但是他们仍然易于感染来自邻居的耐药菌株，因为邻居们服用了太多的抗生素。 Such widespread studies are a major undertaking in rural settings like these, says Randall Singer, an epidemiologist at the University of Minnesota, Twin Cities. But he's not convinced that the authors have nailed the argument that roads were a major culprit in the spread of antibiotic resistance. Some resistance genes are very old, he says, often because they protect bacteria against toxins. So the defensive microbes the team spotted may have been in the villages all along.  明尼苏达大学双城分校的流行病学家兰德尔·辛格说，如此大范围的研究在这样的农村环境中是一项主要任务。但是，这些研究人员抓住了这一论点——道路是传播细菌耐药性的主要因素，辛格对此表示怀疑。他说，有些耐药基因是非常古老的，原因通常是它们需要保护细菌不受毒素的侵袭。因此，研究小组发现的防御性细菌可能一直都存在于村子里。