Tiwari Ananda, Hokajärvi Anna-Maria, Santo Domingo Jorge W, Kauppinen Ari, Elk Michael, Ryu Hodon, Jayaprakash Balamuralikrishna, Pitkänen Tarja
The National Institute for Health and Welfare, Expert Microbiology Unit, P.O Box 95, 70701 Kuopio, Finland E-mail:
Office of Research and Development, United States Environmental Protection Agency, 26 West Martin Luther King Drive, Cincinnati, Ohio, USA.
J Water Health. 2018 Oct;16(5):711-723. doi: 10.2166/wh.2018.293.
Intestinal enterococci indicate the fecal contamination of bathing waters. This study defines the performance characteristics of the reference method ISO 7899-2:2000 with water samples collected from inland and coastal bathing areas in Finland. From a total of 341 bacterial isolates grown on Slanetz and Bartley medium, 63.6% were confirmed as intestinal enterococci on bile aesculin agar. The partial 16S rRNA gene sequences showed that Enterococcus faecium and Enterococcus faecalis clades accounted for 93.1% of the confirmed isolates. The range of the false positive and false negative rate of the ISO 7899-2 was 0.0-18.5% and 5.6-57.1%, respectively, being affected by the presumptive colony count on the membrane. The analysis of multiple sample volumes is proposed to reach 10-100 colonies per membrane when 47 mm diameter membranes are used to prevent overestimation of low counts and underestimation of the high counts.
肠道肠球菌表明浴场水域受到粪便污染。本研究利用从芬兰内陆和沿海浴场采集的水样，确定了参考方法ISO 7899-2:2000的性能特征。在Slanetz和Bartley培养基上生长的341株细菌分离物中，63.6%在胆汁七叶苷琼脂上被确认为肠道肠球菌。部分16S rRNA基因序列显示，屎肠球菌和粪肠球菌分支占已确认分离物的93.1%。ISO 7899-2的假阳性率和假阴性率范围分别为0.0-18.5%和5.6-57.1%，受膜上推测菌落数的影响。建议分析多个样本体积，以便在使用直径47 mm的膜时，每个膜上达到10-100个菌落，以防止低计数被高估和高计数被低估。
