冻融循环下大肠杆菌O157:H7在长春市南湖岸边水中的存活行为研究

北方地区的初春、晚秋,水体表层的夜冻昼融过程是典型特征。冻融循环过程影响水体自身理化性质,理化性质的变化对水中微生物,尤其是潜在的致病微生物的存活也会产生一定的影响。实验在室内模拟了大肠杆菌O157:H7在冻融循环条件下,在长春南湖水中的动态存活特征;并通过线性模型和Weibull模型,计算大肠杆菌O157:H7在污染水体后衰减达到最低检测限的时间(ttd);并运用多元线性回归进行相关性分析,找出影响实验菌种存活的关键因素。研究表明,南湖水的p H和氨氮与大肠杆菌O157:H7的存活相关。研究结果可为调查大肠杆菌O157:H7在湖水中的存活趋势,评估其可能带来的环境健康风险,为制定相应的环境管控措施提供科学依据。

Suivival of Escherichia coli O157:H7 in Changchun South Lake water under freezing and thawing cycle condition

During the early spring and late autumn of northern China, the freezing and thawing process is a typical feature of water bodies. The process of freeze-thaw cycles influences the physical and chemical properties of water bodies, which in turn will affect the survival of microbes, especially the potential pathogenic microorganisms. The dynamic survival characteristics of Escherichia coli O157:H7 in Changchun the South Lake under simulated freezing-thawing cycle were simulated in this experiment. The linear regression model and the Weibull model were used to calculate the time to reach the minimum detection limit of E. coli O157:H7 in the water (ttd), and correlation analysis by using multiple linear regression to identify the key factors affecting the survival of experimental strains. Studies have shown that the pH and NH4-N of the lake water are associated with the survival of E. coli O157:H7. The results can be used to investigate the survival trend of E. coli O157:H7 in lake water, evaluate its possible environmental health risks, and provide the scientific basis for making corresponding environmental control measures.