Department of Civil Engineering, University of British Columbia, Vancouver, BC V5l 3B6, Canada.
Civil and Environmental Engineering, University of Strathclyde, Glasgow G1 1XJ, UK.
Sci Total Environ. 2018 Jul 1;628-629:490-498. doi: 10.1016/j.scitotenv.2018.01.278. Epub 2018 Feb 13.
Environmental transport of contaminants that can influence the development of antibiotic resistance in bacteria is an important concern in the management of ecological and human health risks. Agricultural regions are locales where practices linked to food crop and livestock production can introduce contaminants that could alter the selective pressures for the development of antibiotic resistance in microbiota. This is important in regions where the use of animal manure or municipal biosolids as waste and/or fertilizer could influence selection for antibiotic resistance in pathogenic bacterial species. To investigate the environmental transport of contaminants that could lead to the development of antibiotic resistance in bacteria, a watershed with one of the highest levels of intensity of agricultural activity in Canada was studied; the Sumas River located 60 km east of Vancouver, British Columbia. This two-year assessment monitored four selected tetracycline resistance genes (tet(O), tet(M), tet(Q), tet(W)) and water quality parameters (temperature, specific conductivity, turbidity, suspended solids, nitrate, phosphate and chloride) at eight locations across the watershed. The tetracycline resistance genes (Tc) abundances in the Sumas River network ranged between 1.47 × 10 and 3.49 × 10 copies/mL and ranged between 2.3 and 6.9 copies/mL in a control stream (located far from agricultural activities) for the duration of the study. Further, Tc abundances that were detected in the wet season months ranged between 1.3 × 10 and 2.29 × 10 copies/mL compared with dry season months (ranging between 0.6 and 31.2 copies/mL). Highest transport rates between 1.67 × 10 and 1.16 × 10 copies/s were observed in November 2005 during periods of high rainfall. The study showed that elevated concentrations of antibiotic resistance genes in the order of 10-10 copies/mL can move through stream networks in an agricultural watershed but seasonal variations strongly influenced specific transport patterns of these genes.
污染物在环境中的迁移会影响细菌对抗生素耐药性的发展，这是管理生态和人类健康风险的一个重要关注点。农业区是与粮食作物和牲畜生产相关的做法可能引入污染物的地方，这些污染物可能改变微生物群落中抗生素耐药性发展的选择压力。在那些将动物粪便或城市生物固体作为废物和/或肥料使用的地区，这一点尤为重要，因为这可能会影响病原菌对抗生素耐药性的选择。为了研究可能导致细菌对抗生素产生耐药性的污染物在环境中的迁移，研究了加拿大一个农业活动强度最高的流域；该流域位于不列颠哥伦比亚省温哥华以东 60 公里处的萨默斯河。这项为期两年的评估监测了流域内八个地点的四个选定的四环素耐药基因（tet(O)、tet(M)、tet(Q)、tet(W)）和水质参数（温度、比导率、浊度、悬浮物、硝酸盐、磷酸盐和氯化物）。在研究期间，萨默斯河流域网络中的四环素耐药基因（Tc）丰度在 1.47×10 和 3.49×10 拷贝/毫升之间，而在远离农业活动的对照溪流中丰度在 2.3 和 6.9 拷贝/毫升之间。此外，在雨季检测到的 Tc 丰度在 1.3×10 和 2.29×10 拷贝/毫升之间，而在旱季则在 0.6 和 31.2 拷贝/毫升之间。在 2005 年 11 月降雨量较高的时期，观察到的最高传输率在 1.67×10 和 1.16×10 拷贝/秒之间。该研究表明，浓度高达 10-10 拷贝/毫升的抗生素耐药基因可以通过农业流域的溪流网络迁移，但季节性变化强烈影响这些基因的特定传输模式。
