Department of Agriculture and Ecology and Department of Basic Sciences and Environment, Faculty of Life Sciences, University of Copenhagen, Frederiksberg C, Denmark.
Environ Sci Technol. 2010 Nov 15;44(22):8724-8. doi: 10.1021/es101798r. Epub 2010 Oct 22.
Environmental reservoirs of antibiotic resistance are important to human health, and recent evidence indicates that terrestrial resistance reservoirs have expanded during the antibiotic era. Our aim was to study the impact of Cu pollution as a selective driver for the spread of antibiotic resistance in soil. Bacteria were extracted from a well-characterized soil site solely contaminated with CuSO₄ more than 80 years ago and from a corresponding control soil. Pollution-induced bacterial community tolerance (PICT) to Cu and a panel of antibiotics was determined by a novel cultivation-independent approach based on [³H]bromodeoxyuridine (BrdU) incorporation into DNA and by resistance profiling of soil bacterial isolates on solid media. High Cu exposure selected for Cu-tolerant bacterial communities but also coselected for increased community-level tolerance to tetracycline and vancomycin. Cu-resistant isolates showed significantly higher incidence of resistance to five out of seven tested antibiotics (tetracycline, olaquindox, nalidixic acid, chloramphenicol, and ampicillin) than Cu-sensitive isolates. Our BrdU-PICT data demonstrate for the first time that soil Cu exposure coselects for resistance to clinically important antibiotics (e.g., vancomycin) at the bacterial community-level. Our study further indicates that Cu exposure provides a strong selection pressure for the expansion of the soil bacterial resistome.
环境抗生素耐药性库对人类健康很重要，最近的证据表明，在抗生素时代，陆地耐药性库已经扩大。我们的目的是研究 Cu 污染作为土壤中抗生素耐药性传播的选择驱动因素的影响。从一个 80 多年前仅被 CuSO₄污染的特征明确的土壤点和相应的对照土壤中提取细菌。采用一种新的基于[³H]溴脱氧尿苷（BrdU）掺入 DNA 的培养独立方法和对土壤细菌分离物在固体培养基上的耐药性分析，确定了污染诱导的细菌群落耐 Cu 性（PICT）和一组抗生素。高 Cu 暴露选择了 Cu 耐受细菌群落，但也共同选择了对四环素和万古霉素的群落水平耐受力增加。Cu 抗性分离株对七种测试抗生素中的五种（四环素、喹乙醇、萘啶酸、氯霉素和氨苄西林）的耐药性发生率明显高于 Cu 敏感分离株。我们的 BrdU-PICT 数据首次表明，土壤 Cu 暴露在细菌群落水平上共同选择了对临床重要抗生素（例如万古霉素）的耐药性。我们的研究进一步表明，Cu 暴露为土壤细菌抗药性库的扩展提供了强大的选择压力。
