珠江水域微生物的分布特征

Investigation and analysis on microbial indicators in Pearl River

目的了解珠江水域指示菌和常见致病菌的时空分布规律以及相关性。方法分别于2010年7月(丰水期)和2011年3月(枯水期)采集珠江水域上游、中游和下游5个断面的岸边和中心共20个水样,分别对水样中5种卫生指示菌(菌落总数、总大肠菌群、粪大肠菌群、大肠埃希菌和肠球菌)和4种常见致病菌(沙门菌、志贺菌、弧菌和大肠杆菌O157∶H7)进行检测和分析。结果珠江水域中除菌落总数和肠球菌外,各项指示微生物指标均呈现下游>中游>上游的规律。水体上、中和下游总大肠菌群(4.20×103～9.49×104cfu/ml)、粪大肠菌群(1.84×103～3.09×104cfu/ml)和大肠埃希菌(6.45×102～1.30×104cfu/ml)均存在统计学差异(P<0.05)。珠江岸边指示菌和致病菌均高于中心,丰水期的指示菌和致病菌均不低于枯水期,但差异均无统计学意义(P>0.05)。除菌落总数外,总大肠菌(P<0.05)、粪大肠菌群(P<0.01)、大肠埃希菌(P<0.01)和肠球菌(P<0.01)均与致病菌总数呈正相关。结论珠江水域从上游至下游其微生物污染逐渐加重,指示菌与致病菌呈一定的相关性。

Objective To investigate the spatial and temporal distribution of indicator bacteria and common pathogens, and the correlation of them in the Pearl River. Methods The water samples were collected from the shore and the middle of the five river cross sections in the upper reach, middle reach and lower reach of the Pearl River in July, 2010（high flow period） and March, 2011 （low flow period）. The five indicator bacteria（total bacteria count, total coliforms, fecal coliforms, Escherichia coli and Enterococcus） and the four common pathogens （Salmonella, Shigella, Vibrio and Escherichia coli 0157：H7） were detected. Results The data of the microbial indicator tended to increase from upper to lower reaches except the total bacteria count and Enterococcus in the Pearl River. There were significant differences in the upper reach, middle reach and lower reach through the ANOVA analysis, and the difference lied in total coliforms （4.20×103-9.49×104 cfi/ml）, fecal coliforms （1.84×103-3.09×104 cfu/ml） and Escherichia eoli （6.45×102-1.30×104 cfu/ml）. The indicator bacteria and total pathogens of the shore were higher than the middle, the indicator bacteria and pathogens of the high flow period were no less than the low flow period, but there were no significant differences. Total coliforms （P〈0.05）, fecal coliforms （P〈0.01）, Escherichia coli （P〈 0.01 ） and Enterococcus （P〈0.01） and total pathogens respectively presented positive correlation. Conclusion The spatial and temporal distribution of the microbial indicators in the Pearl River demonstrates that the microbial contamination tends to increase from the upper to the lower reaches.