低强度超声对大肠埃希菌增殖的影响

Effect of low intensity pulsed ultrasound on the proliferation of Escherichia coli

目的探究低强度超声(LIPUS)对大肠埃希菌增殖的影响。方法根据是否接受超声照射将大肠埃希菌分为实验组和对照组。设置固定声强为1.00W/cm^2,对大肠埃希菌进行采用不同时长的超声照射,对照组超声时间为0.0min,实验组超声时间分别为0.5、1.0、2.0、5.0、10.0、15.0、20.0、25.0及30.0min。以对大肠埃希菌抑制效果最好的照射时间为固定时间,采用不同照射声强对大肠埃希菌进行超声照射,对照组照射声强为0.00W/cm^2,实验组照射声强分别为0.25、0.50、0.75、1.00、1.25、1.50、1.75、2.00及2.25W/cm^2。使用MTT法、CCK-8法检测细菌的OD值并计算抑制率。结果与对照组比较,实验组照射时间≤5.0min时,MTT法及CCK-8法的OD值升高(P>0.05),抑制率为负。当实验组照射时间≥10.0min时,MTT法及CCK-8法的OD值明显低于对照组,差异具有统计学意义(P<0.05),抑制率为正。当照射时间为10.0min时,OD值最低(P<0.05)。实验组不同照射声强MTT法及CCK-8法的OD值显著低于对照组(P<0.05)。当照射声强为2.00W/cm^2时OD值最低(P<0.05)。结论照射时间为10.0min,照射声强为2.00W/cm^2,LIPUS对大肠埃希菌增殖的抑制作用最优。

Objective To explore the effect of low intensity pulsed ultrasound on the proliferation of Escherichia coli.Methods Escherichia coli was divided into experimental group and control group according to whether it was irradiated by ultrasound.Setting a fixed sound intensity of 1.00 W/cm^2,Escherichia coli was irradiated for different periods of time.The control group was irradiated for 0.0 minutes,while the experimental group was irradiated for 0.5,1.0,2.0,5.0,10.0,15.0,20.0,25.0,30.0 minutes respectively.The best irradiation time for inhibiting Escherichia coli was taken as the fixed time,Escherichia coli was irradiated by different irradiation intensity.The irradiation intensity of the control group was 0.00 W/cm^2,while that of the experimental group was 0.25,0.50,0.75,1.00,1.25,1.50,1.75,2.00,2.25 W/cm^2 respectively.The OD value of bacteria was detected by MTT and CCK-8 methods,and the inhibition rate was calculated.Results Compared with the control group,the OD values of MTT and CCK-8 methods in the experimental group increased when the irradiation time≤5.0 minutes(P>0.05),and the inhibition rates were negative.When the irradiation time≥10.0 minutes,OD values of MTT and CCK-8 methods in the experimental group were significantly lower than those in the control group,the differences were statistically significant(P<0.05),and the inhibition rates were positive.The OD value was the lowest when the irradiation time was 10.0 minutes(P<0.05).The OD values of MTT and CCK-8 at different irradiation intensity in the experimental group were significantly lower than those in the control group(P<0.05).The OD value was the lowest when the irradiation intensity was 2.00 W/cm^2(P<0.05).Conclusion When the irradiation time is 10.00 minutes and the irradiation intensity is 2.00 W/cm^2,the inhibition of low intensity pulsed ultrasound on the proliferation of Escherichia coli is the greatest.