Kühn I, Allestam G, Huys G, Janssen P, Kersters K, Krovacek K, Stenström T A
Microbiology and Tumor Biology Centre, Karolinska Institute, S-171 77 Stockholm, Sweden.
Appl Environ Microbiol. 1997 Jul;63(7):2708-15. doi: 10.1128/aem.63.7.2708-2715.1997.
The Aeromonas populations in 13 Swedish drinking water distribution systems, representing different treatments, were investigated. From each system, water samples were collected four times during the period from May to September 1994 from raw water and water after treatment and at two to five sites within the distribution system. In total, 220 water samples were collected. From samples containing presumptive Aeromonas, up to 32 colonies were analyzed by the PhenePlate Aeromonas (PhP-AE) system, which is a highly discriminating biochemical fingerprinting method. Selected isolates from different phenotypes (PhP types) were further identified by the API 20 NE system and by gas-liquid chromatography analysis of fatty acid methyl esters (FAMEs). Selected isolates were also assayed for their potential to produce hemolysin and cytotoxin and for their ability to adhere to human intestinal cells. In total, 117 water samples (53%) contained presumptive Aeromonas which numbered up to 10(6) CFU/100 ml in raw water and up to 750 CFU/100 ml in tap water. Among the 2,117 isolates that were subjected to typing by the PhP-AE system, more than 300 distinct PhP types were found, of which the majority occurred only sporadically. Raw (surface) water samples usually contained many different PhP types, showing high diversity indices (Di) (median Di = 0.95). The Aeromonas populations in samples collected from within the distribution systems were less diverse (median Di = 0.58) and were often dominated by one major PhP type that was found on several sampling occasions. Seventeen such major PhP types could be found and were represented in 1,037 isolates (49%). Identification by API 20 NE and FAME analysis revealed that most of the major PhP types were Aeromonas hydrophila or belonged to unidentified Aeromonas species. Hemolysin and cytotoxin production was observed in most major PhP types (representing 87 and 54% of the assayed isolates, respectively), and adherence was found in 89% of the isolates that produced cytotoxin. Thus, the data presented here show that although raw water may contain very diverse Aeromonas populations, the populations seemed to be remarkably stable within the studied water distribution systems, and that some potentially pathogenic Aeromonas strains could persist for several months in drinking water.
对瑞典13个代表不同处理方式的饮用水分配系统中的气单胞菌种群进行了调查。1994年5月至9月期间，从每个系统的原水、处理后的水以及分配系统内的两到五个地点，共采集了四次水样。总共采集了220份水样。对于含有疑似气单胞菌的样本，使用PhenePlate气单胞菌（PhP-AE）系统分析多达32个菌落，这是一种高度区分性的生化指纹识别方法。通过API 20 NE系统以及脂肪酸甲酯（FAME）的气-液色谱分析，对来自不同表型（PhP类型）的选定分离株进行进一步鉴定。还对选定的分离株进行溶血素和细胞毒素产生潜力以及粘附于人类肠道细胞能力的检测。总共117份水样（53%）含有疑似气单胞菌，原水中气单胞菌数量高达10(6) CFU/100 ml，自来水中高达750 CFU/100 ml。在通过PhP-AE系统进行分型的2117株分离株中，发现了300多种不同的PhP类型，其中大多数只是偶尔出现。原（地表）水样通常含有许多不同的PhP类型，显示出高多样性指数（Di）（中位数Di = 0.95）。从分配系统内采集的样本中的气单胞菌种群多样性较低（中位数Di = 0.58），并且通常由在多个采样场合发现的一种主要PhP类型主导。可以发现17种这样的主要PhP类型，它们在1037株分离株（49%）中出现。通过API 20 NE和FAME分析鉴定表明，大多数主要PhP类型是嗜水气单胞菌或属于未鉴定的气单胞菌物种。在大多数主要PhP类型中观察到溶血素和细胞毒素的产生（分别占检测分离株的87%和54%），并且在产生细胞毒素的分离株中，89%发现有粘附能力。因此，此处呈现的数据表明，尽管原水可能含有非常多样的气单胞菌种群，但在所研究的水分配系统中，这些种群似乎非常稳定，并且一些潜在致病的气单胞菌菌株可能在饮用水中持续存在数月。
