不同地表水体中四种典型肠道病原细菌的分布特性研究

Distribution of four kinds of typical enteric pathogens in different surface waters

利用实时荧光定量PCR方法,对西安市区洁净水体、轻度污染水体以及重度污染水体中的大肠杆菌、沙门氏菌、志贺氏痢疾杆菌以及霍乱弧菌进行4个月的连续检测,结果表明:霍乱弧菌在各种地表水体,甚至城市污水中均未检出,而埃希氏大肠菌从各种水体检出的频度最高,且在水体受到轻微污染后即持续检出。在污染严重的水体中,埃希氏大肠菌检出的强度在10~4~10~5 copies·(100 mL)^(-1),沙门氏菌和志贺氏痢疾杆菌检出强度分布在10~1~10~2 copies·(100 mL)^(-1),且能够持续检出;在轻度污染水体和清洁水体中,3种病原细菌的强度都在10 copies·(100 mL)^(-1)左右,并且不能够连续检出。这些结果说明,对于污染严重的水体,埃希氏大肠菌是水中肠道感染细菌的主体,沙门氏菌和志贺氏痢疾杆菌强度尽管远低于埃希氏大肠菌,但可以认为是水体病原污染的标志之一。

The cell densities of Escherichia coli, Salmonella typhrmurium, Shigella dysenteriae and Vibrio cholerae in clean waters, slightly polluted waters and seriously polluted waters located in urban area of Xi＇an were detected continuously for four months by using real-time quantitative PCR（QPCR） method. The results showed that the Vibrio cholerae was not existed in any kinds of surface waters, even not found in municipal wastewater. However, E. coli is the one that can be most frequently found out in all kinds of waters. When the water was polluted slightly, it could be detected continually. In seriously polluted waters, the cell densities of E. coli is 10^4-10^5 copies.（100 mL）^-1, the cell densities of Salmonella typhrmurium and Shigellaflexneri are 10^1-10^2 copies.（100 mL）^-1, and can be detected continually. In clean waters and slightly polluted waters, the cell densities of three enteric pathogens above are 10 copies.（100 mL）^-1, and can not be detected continually. These results indicated that the E. coli is the main pathogenic bacteria in the seriously polluted waters, although the cell densities of Salmonella typhrmurium and Shigella flexneri are far lower than that orE. coli, it still can be considered as one of the marks of water pathogenic pollution.