重庆市河水中粪源微生物污染特征及源解析

以重庆主要河流水体作为研究对象，使用传统培养技术评估了细菌总数、粪链球菌、肠球菌、脆弱拟杆菌、总大肠菌群及粪大肠菌群的污染水平；同时以拟杆菌作为特异性指示菌，选取人源性粪便专一指示菌引物（HF183）和猪源性粪便专一指示菌引物（Pig-2-Bac）进行源追踪.微生物培养结果表明：重庆市主要河流在春季有15.4%的研究断面未达到Ⅲ类水质，秋季有61.5%的研究断面未达到Ⅲ类水质.在春季，主城区河流主要受人类粪便污染，区县河流主要受动物粪便污染；在秋季，主城区和区县河流都主要受人类粪便污染.指示微生物指标间Pearson相关性分析结果表明粪链球菌、粪大肠菌群、肠球菌两两之间有显著相关性，肠球菌与脆弱拟杆菌有显著相关性.猪源性拟杆菌特异性生物标记Pig-2-Bac和人源拟杆菌特异性生物标记HF183对人和动物粪便污染区分成功率达100%；用这两种特异性引物对春季水样DNA进行扩增，发现13个采样点均未受到猪源粪便污染，唐家沱、朝天门、鸡冠石、合川受到人源粪便污染.

Pollution characteristics and source track of fecal microorganism in the rivers across Chongqing city

In this study, 13 water samples were collected from the main stem rivers in Chongqing city. The numbers of total bacteria, Streptococcus faecalis, enterococci, Bacteroides fragillis, total coliforms and Fecal coliforms were counted using traditional culturing techniques. The bacteroides were selected as specific indicator bacteria to identify the specific fecal pollution sources by using human-specific bacteroides maker (HF183) and pig-specific bacteroides maker (Pig-2-Bac). The results showed that 15.4% of the main stem river reaches in Chongqing did not reach category Ⅲ water quality in spring, and 61.5% did not reach category Ⅲ water quality in autumn. In spring, the rivers in the main urban areas were mainly polluted by human excrement, and those in the rural areas were mainly polluted by animal manure. In autumn, the main stem river reaches and the rivers in the rural areaswere polluted by human excrement. Pearson correlation analysis of indicator microorganisms showed that there were strong correlation between any two indicator of fecal streptococcus, fecal coliform and enterococci, and there was a significant correlation between enterococci and Bacteroides fragilis. The verification tests showed that pig source-specific biomarkers, pig-2-bac and human-specific markers, HF183, showed good specificity to pig manure and human feces samples, respectively. Using these two specific biomarkers to amplify DNA in water samples, it was found that in the spring all the 13 sampling sites were not contaminated by pig feces; four samples including Tangjiatuo, Chaotianmen, Jiguanshi and Hechuan were polluted by human feces.