紫外线消毒前后大肠埃希菌光复活及影响因素研究  

Study on photoreactivation of Escherichia coli before and after ultraviolet disinfection and its influencing factors

作　　者：查碧晴 彭紫怡 令狐晨曦 张翔凌 王国庆 ZHA Bi-qing;PENG Zi-yi;LINGHU Chen-xi;ZHANG Xiang-ling;WANG Guo-qing(West China School of Public Health,Sichuan University/West China Fourth Hospital,Chengdu,Sichuan 610041,China;不详)

机构地区：[1]四川大学华西公共卫生学院/华西第四医院,四川成都610041 [2]中国医学科学院医学信息研究所,北京100020

出　　处：《现代预防医学》2023年第21期3985-3990,共6页Modern Preventive Medicine

摘　　要：目的以水体中大肠埃希菌为研究对象,了解紫外线消毒后细菌复活情况及紫外线剂量、复活光强度、低温、避光时间等因素对水体中大肠埃希菌光复活的影响。方法将大肠埃希菌人工污染至灭菌自来水中,调整紫外线灯照射距离和时间,改变紫外线消毒前后的试验条件,然后取样采用营养琼脂倾注法培养计数复活菌落数,计算并比较不同复活条件下大肠埃希菌0~8 h的复活率。结果复活光照强度一定时,大肠埃希菌光复活率随紫外线剂量的增加而降低,且8 h光复活率与紫外线剂量呈负相关(R2=0.954,P<0.001);紫外线剂量一定时,大肠埃希菌光复活率随着复活光照强度的增加而升高,在光照强度为288、386和504 Lux条件下大肠埃希菌8 h光复活率为分别为(0.009±0.001)%、(0.020±0.002)%、(0.075±0.008)%,且三组之间存在显著差异;低温处理的水样中大肠埃希菌经紫外线消毒后没有明显光复活现象,其8 h光复活率(0.012±0.003)%显著低于未经低温处理的水样(0.113±0.004)%;大肠埃希菌的暗修复能力较弱,复活现象不明显,经不同时间避光处理的大肠埃希菌从初始见光至8 h光复活率期间的平均复活速率基本一致,且8 h光复活率接近。结论增加紫外线剂量、降低复活光强度及低温处理可有效减弱大肠埃希菌的光复活程度,而避光处理并不能有效保证抑制大肠埃希菌的光复活现象。Objective To investigate the reactivation of Escherichia coli in water after ultraviolet disinfection and the effects of ultraviolet dose,reactivation light intensity,low temperature,and dark time on the photoreactivation of Escherichia coli in water.Methods Escherichia coli was artificially contaminated into sterilized tap water,the irradiation distance and time of ultraviolet lamp were adjusted,and the test conditions before and after ultraviolet disinfection were changed,and then the number of reactivated bacteria was counted by nutrient agar pouring method.The reactivation rate of Escherichia coli was calculated and compared under different resurrection conditions.Results When the reactivation light intensity was constant,the photoreactivation rate of Escherichia coli decreased with the increase of ultraviolet dose,and there was a negative correlation between 8 h photoreactivation rate and ultraviolet dose(R2=0.954,P<0.001).When the ultraviolet dose was constant,the photoreactivation rate of Escherichia coli increased with the increase of reactivation light intensity.Under the light intensity of 288,386,and 504 Lux,the photoreactivation rates of Escherichia coli for 8 hours were(0.009±0.001)%,(0.020±0.002)%,and(0.075±0.008)%,respectively.There was no obvious photoreactivation of Escherichia coli after ultraviolet disinfection in water samples treated with low temperature,and the photoreactivation rate of Escherichia coli in 8 hours was(0.012±0.003)%,which was significantly lower than that in water samples without low temperature treatment(0.113±0.004)%.The dark repair ability of Escherichia coli was weak and the reactivation phenomenon was not obvious.The average reactivation rate of Escherichia coli treated by avoiding light for different time was basically the same from initial light to 8 h light reactivation rate,and the 8 h light reactivation rate was similar.Conclusion Increasing ultraviolet dose,reducing reactivation light intensity and low temperature treatment can effectively reduce the degree of

关 键 词：光复活 紫外线消毒 大肠埃希菌 

分 类 号：R187.4[医药卫生—流行病学]