Effects of nano-TiO2 on antibiotic resistance transfer mediated by RP4 plasmid
Effects of nano-TiO2 on antibiotic resistance transfer mediated by RP4 plasmid
复制标题
纳米TiO对RP4质粒介导的抗生素抗性转移的影响。
DOI：
10.3109/17435390.2014.991429
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发表时间：
2015-01-01
期刊：
影响因子：
5
通讯作者：
Li, Jun-Wen
中科院分区：
文献类型：
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作者：
Qiu, Zhigang;Shen, Zhiqiang;Li, Jun-Wen
纳米材料的潜在风险和抗生素耐药基因（ARGs）的传播已成为全球关注的两大问题。研究证实，纳米氧化铝可以促进质粒介导的ARGs的传播。纳米二氧化钛（TiO2）是一种优异的光催化纳米材料，广泛应用于水环境中。在不同纳米材料浓度、细菌密度、消光时间和消光温度下，纳米tio2均能显著促进RP4质粒在大肠杆菌中的结合。我们建立了一个数学模型来定量描述共轭过程，并利用该模型来评估纳米tio2对ARGs扩散的影响。通过质粒和染色体特有的遗传位点的丰度，我们获得了总菌和耐药菌的分析解。结果表明，该数学模型能够很好地拟合实验数据，可用于定量评价纳米tio2的效果。根据我们的模型，纳米tio2的存在将细菌的生长速率从0.0360降低到0.0323 min(-1)，并将共轭转移速率从6.69 × 10（-12）增加到3.93 × 10(-10) mL cell(-1) min（-1）。这些结果表明，纳米tio2在抑制细菌生长的同时促进了细菌的结合。形态学和mRNA表达数据也证实了这一现象。我们的研究结果证实了环境纳米tio2可能引起ARGs的传播，从而构成环境风险。此外，我们还提供了一种潜在的方法来监测由偶联引起的ARG变化，并评估抗菌物质对ARG表达的影响。
The potential risks of nano-materials and the spread of antibiotic resistance genes (ARGs) have become two major global public concerns. Studies have confirmed that nano-alumina can promote the spread of ARGs mediated by plasmids. Nano-titanium dioxide (TiO2), an excellent photocatalytic nano-material, has been widely used and is often present in aqueous environments. At various nano-material concentrations, bacterial density, matting time, and matting temperature, nano-TiO2 can significantly promote the conjugation of RP4 plasmid in Escherichia coli. We developed a mathematical model to quantitatively describe the conjugation process and used this model to evaluate the effects of nano-TiO2 on the spread of ARGs. We obtained analytical solutions for total and resistant bacteria, which were enumerated by the abundance of genetic loci unique to the plasmid and the chromosome using qPCR. Our results showed that the mathematic model was able to fit the experimental data well and can be used to quantitatively evaluate the effects of nano-TiO2. According to our model, the presence of nano-TiO2 decreased the bacterial growth rate from 0.0360 to 0.0323 min(-1) and increased the conjugative transfer rate from 6.69 x 10(-12) to 3.93 x 10(-10) mL cell(-1) min(-1). These results indicate that nano-TiO2 inhibited bacterial growth and promoted conjugation simultaneously. The data for morphology and mRNA expression also demonstrated this phenomenon. Our results confirm that environmental nano-TiO2 may cause the spread of ARGs and thus poses an environmental risk. In addition, we provide a potential method for monitoring changes in ARGs that result from conjugation and evaluating the effects of antimicrobial substances on ARG expression.