Cu Exposure under Field Conditions Coselects for Antibiotic Resistance as Determined by a Novel Cultivation-Independent Bacterial Community Tolerance Assay
Cu Exposure under Field Conditions Coselects for Antibiotic Resistance as Determined by a Novel Cultivation-Independent Bacterial Community Tolerance Assay
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DOI：
10.1021/es101798r
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发表时间：
2010-11-15
影响因子：
11.4
通讯作者：
Brandt, Kristian K.
中科院分区：
文献类型：
--
作者：
Berg, Jeanette;Thorsen, Maja K.;Brandt, Kristian K.
抗生素耐药性的环境宿主对人类健康很重要，最近的证据表明，在抗生素时代，陆地耐药性宿主已经扩大。我们的目的是研究铜污染作为土壤中抗生素耐药性传播的选择性驱动因素的影响。从80多年前完全被CuSO4污染的土壤和相应的对照土壤中提取细菌。通过一种基于[H-3]溴脱氧尿苷（BrdU）与DNA结合的新型培养独立方法和固体培养基上土壤细菌分离株的耐药性分析，确定了污染诱导的细菌群落对Cu和一组抗生素的耐受性（PICT）。高铜暴露选择了耐铜细菌群落，但也共同选择了增加社区对四环素和万古霉素的耐受性。铜耐药菌株对7种抗生素中的5种（四环素、喹啉、萘啶酸、氯霉素和氨苄西林）的耐药率明显高于铜敏感菌株。我们的BrdU-PICT数据首次表明，土壤铜暴露在细菌群落水平上共同选择了对临床重要抗生素（如万古霉素）的耐药性。我们的研究进一步表明，Cu暴露对土壤细菌抗性组的扩展提供了强大的选择压力。
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 [H-3]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.