小型景观水体中病原微生物的分布特性

为了研究病原微生物在景观水体中的分布特性,采用定量PCR方法,监测了校园景观湖水中指示微生物(粪大肠菌群和大肠杆菌),病原性细菌(沙门氏菌和志贺氏菌)和病毒(肠道病毒、轮状病毒和诺如病毒)等典型肠道微生物的分布及变化情况.结果显示,粪大肠菌群未在景观水体中检出,而其他微生物均可检出,表明该水体未受到来自粪便源的污染,其他病原微生物来源于非粪便来源的面源污染.大肠杆菌、沙门氏菌和肠道病毒的检出率(>50%)比其他病原微生物的高;细菌和病毒的浓度分别分布在10-2~101 copies/mL和100~102 copies/mL.统计学分析结果表明,各病原微生物的浓度均服从对数正态分布,大肠杆菌与沙门氏菌和志贺氏菌无显著相关性.而肠道病毒与轮状病毒和诺如病毒在0.05置信水平上显著相关,相关系数分别为0.744和0.609.进一步分析病原微生物在景观水体中一年的变化,结果表明,随着降雨的汇入病原微生物的浓度明显增大,在高温和日光照射可致使病原微生物检出率和浓度明显降低.

Distribution of pathogenic microorganisms in midget landscape water by real-time PCR methods

To determine the distribution of pathogenic microorganisms in recreational waters, pathogenic bacteria (Salmonella and Shigella) and viruses (enterovirus, rotavirus and norovirus) in a landscape lake located in a university were investigated using the real-time PCR methods, as well as the biological indicators (fecal coliform and E. coli). The results show that all target pathogens except for fecal coliform could be detected, indicating that the recreational water was not contaminated with fecal pollution and pathogens derived from non-point pollution. E. coli, Salmonella and enterovirus were presented in a higher occurrence (>50%). The concentration of bacteria and viruses were in the ranges of 10-2 to 101 and 100 to 102 copies/mL, respectively. Statistical analysis demonstrated that the concentration of pathogens followed the logarithmic normal distribution. According to results of correlation test, E. coli were not apparently related with Salmonella or Shigella, while the correlation of enterovirus and rotavirus were significant at the 0.05 confidence level, as well as that of enterovirus and norovirus. With further study on the influence of environmental factors on the distribution of pathogenic microorganisms for one year, the prevalence and concentration of pathogenic microorganisms could be reduced under high temperature and radiation of sunlight, and pathogens would be intruded into water environment though particulate and rain.