快速评估近岸海洋水体与沉积物中E.coli与S.aureus抗生素抗性水平的新方法

随着抗生素抗性污染日益严重,快速评估环境中典型病原菌与条件性致病菌的抗生素抗性水平,对掌握区域环境抗生素抗性污染状况、揭示抗性污染传播规律至关重要。通过以最低抑菌浓度浸入抗生素改进MI、VJ培养基,并结合滤膜法,建立了针对近岸海洋环境中指示性病原微生物大肠杆菌(Escherichia coli,E.coli)与金黄色葡萄球菌(Staphylococcus aureus,S.aureus)的抗生素抗性监测方法。水体和沉积物样品抗生素抗性水平评估实验结果显示,该方法具有较好重现性(水体和沉积物中E.coli和S.aureus抗生素抗性水平的相对标准偏差分别为11%、8%)与准确度(水体和沉积物中E.coli和S.aureus的平均回收率分别为83.5%、68.4%;相对于CLSI药敏试验的偏离度为±0.1)。且与CLSI药敏实验相比,该方法过程简便、耗时短(36 h/84 h),能最大限度节约经济和人员成本提高抗性评价效率。应用该方法评估辽河口与莱州湾环境中2种病原微生物磺胺类抗生素抗性水平,结果显示辽河口水体中E.coli和S.aureus磺胺二甲嘧啶的平均抗性率分别为27.0%、28.4%,沉积物中分别为35.5%、34.6%;莱州湾水体中E.coli和S.aureus磺胺二甲嘧啶的平均抗性率分别为26.0%、14.5%,沉积物中分别为12.0%、32.9%。该方法适用于河口、近岸海洋及入海排污口水体与沉积物样品中E.coli与S.aureus的快速分析及抗生素抗性水平评估。

A Novel Method for Rapid Assessment of Antibiotic Resistance E. coli and S. aureusin in Waters and Sediments

With the exacerbation of antibiotic resistance pollution, a rapid assessment method of antibiotic resistance in pathogen and opportunistic pathogen isolating from environment is becoming vital to reveal the contamination status by antibiotic resistant and to explore the dissemination discipline of it. In present study, a novel method for rapidly assessing the antibiotic resistance in typical pathogen E.coli and S.aureus in marine waters and sediments was established by combining the modified MI chromogenic agar and VJ chromogenic agar with the membrane filtration. Water and sediment antibiotic resistance experiments results showed that this method was highly precise and accurate. The relative standard deviation (RSD) of antibiotic resistance level in E.coli and S.aureus isolates from water sand sediments were 11% and 8%, respectively. The average recoveries of E.coli and S.aureus isolates from waters and sediments were 83.5% and 68.4%, respectively. The deviation rate to the CLSI disk susceptibility test was ± 0.1. Comparing with the CLSI disk susceptibility test, this method is simpler and time-saving (36 h/84 h). Due to the great reduction of expense and human energy, this method is highly efficient and economic. This method was applied to assess the sulfonamides antibiotic resistance levels of E.coli and S.aureus in Liaohe Estuary and Laizhou Bay. The results showed that the sulfonamides antibiotic average resistance levels of E.coli and S.aureus in the water of Liao river estuary were 27.0% and 28.4%, respectively, which in the sediment were 35.5% and 34.6%, respectively. The sulfonamides antibiotic average resistance levels of E.coli and S.aureus in the water of Laizhou Bay were 26.0% and 14.5%, respectively, which in the sediment were 12.0% and 32.9%, respectively. The method is applicable to rapid assessment of antibiotic resistance in E.coli and S.aureus isolating from the waters and sediments in estuary, coastal area and sewage outlet.