Effects on Groundwater Microbial Communities of an Engineered 30-Day In Situ Exposure to the Antibiotic Sulfamethoxazole

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• 作者：Sheridan K. Haack ; David W. Metge ; Lisa R. Fogarty ; Michael T. Meyer ; Larry B. Barber ; Ronald W. Harvey ; Denis R. LeBlanc ; Dana W. Kolpin
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2012
• 出版时间：July 17, 2012
• 年：2012
• 卷：46
• 期：14
• 页码：7478-7486
• 全文大小：405K
• 年卷期：v.46,no.14(July 17, 2012)
• ISSN：1520-5851

文摘

Effects upon microbial communities from environmental exposure to concentrations of antibiotics in the 渭g L^鈥? range remain poorly understood. Microbial communities from an oligotrophic aquifer (estimated doubling rates of only once per week) that were previously acclimated (AC) or unacclimated (UAC) to historical sulfamethoxazole (SMX) contamination, and a laboratory-grown Pseudomonas stutzeri strain, were exposed to 240鈥?20 渭g L^鈥? SMX for 30 days in situ using filter chambers allowing exposure to ambient groundwater, but not to ambient microorganisms. SMX-exposed UAC bacterial communities displayed the greatest mortality and impairment (viable stain assays), the greatest change in sensitivity to SMX (dose鈥搑esponse assays), and the greatest change in community composition (Terminal Restriction Fragment Length Polymorphism; T-RFLP). The sul1 gene, encoding resistance to SMX at clinically relevant levels, and an element of Class I integrons, was not detected in any community. Changes in microbial community structure and SMX resistance over a short experimental period in previously nonexposed, slow-growing aquifer communities suggest concentrations of antibiotics 2鈥? orders of magnitude less than those used in clinical applications may influence ecological function through changes in community composition, and could promote antibiotic resistance through selection of naturally resistant bacteria.