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目的探讨纳米氧化铝(Al2O3)对细菌抗氧化系统和接合基因转录活性的影响,阐明纳米Al2O3促进多重耐药质粒RP4接合转移的机制。方法接合供体菌为E.coli HB101(RP4),受体菌为沙门菌50312(Salmonella aberdeen Kauffmann 50312 strR),供、受体菌液均为109 cfu/ml(浓度比为1∶3),25℃条件下静止接合8 h,检测纳米Al2O3对细菌抗氧化系统和接合基因转录活性的影响。结果纳米Al2O3干预后,细菌产生的游离羟自由基(OH.)随着纳米Al2O3浓度的升高而上升,5和50 mmol/L组与对照组相比较,细菌的抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽还原酶(GR)的活力都明显增加;TrbBp和TrfAp转录活性也升高,差异均具有统计学意义(P<0.05)。结论纳米Al2O3促进RP4结合转移的机制可能是,纳米Al2O3作用后,促进了接合基因表达;同时也对细菌产生损伤,影响细菌抗氧化系统。
Objective To investigate the effect of nano-alumina (Al2O3) on the bacterial anti-oxidative system and the transcriptional activity of the junction gene, and elucidate the mechanism by which nano-Al2O3 promotes the RP4 conjugation and metastasis of multi-drug resistant plasmids. Methods The donor bacteria were E.coli HB101 (RP4) and the recipient bacteria were Salmonella aberdeen Kauffmann 50312 strR. The amount of donor and recipient bacteria was 109 cfu / ml (concentration ratio was 1: 3) The cells were incubated at 25 ° C for 8 h to determine the effect of nano-Al2O3 on the transcriptional activity of the antioxidant system and the binding gene. Results After the intervention of nano-Al2O3, the free hydroxyl radical (OH) produced by bacteria increased with the increase of nano-Al2O3 concentration. Compared with the control group, the antioxidant capacity (T-AOC ), Superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR) activity were significantly increased; TrbBp and TrfAp transcription activity also increased, the differences were statistically significant ( P <0.05). CONCLUSION: The mechanism of nano-Al2O3 in promoting RP4 binding and metastasis may be that the nano-Al2O3 can promote the expression of the splicing gene after the action of nano-Al2O3, and also damage the bacteria and affect the bacterial anti-oxidative system.