Presence and growth of naturalized Escherichia coli in temperate soils from lake superior watersheds
Presence and growth of naturalized Escherichia coli in temperate soils from lake superior watersheds
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DOI：
10.1128/aem.72.1.612-621.2006
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发表时间：
2006-01-01
影响因子：
4.4
通讯作者：
Sadowsky, MJ
中科院分区：
文献类型：
--
作者：
Ishii, S;Ksoll, WB;Sadowsky, MJ
水中大肠杆菌的存在被用作粪便污染的指标，但最近的报告表明，在热带、亚热带和一些温带环境中也可以检测到土壤种群。本研究报告了2003年10月至2004年10月在苏必利尔湖三个流域的北温带土壤中反复分离到活的大肠杆菌种群。观察了土壤传播大肠杆菌种群密度的季节变化；在夏季至秋季（6月至10月），细胞密度最高，达到3 × 10(3) CFU/g土壤；在冻土中越冬，细胞密度最低，相似值为92%。土壤传播的大肠杆菌菌株具有特定土壤和地点特有的HFERP DNA指纹图谱，表明这些大肠杆菌菌株成为土壤微生物群落的归化、本土成员。在实验室研究中，归化的大肠杆菌菌株能够在30或37℃的非无菌土壤中生长和复制到高细胞密度，高达4.2 X 10(5) CFU/g土壤，并且在土壤温度为1℃时存活时间超过1个月
The presence of Escherichia coli in water is used as an indicator of fecal contamination, but recent reports indicate that soil populations can also be detected in tropical, subtropical, and some temperate environments. In this study, we report that viable E. coli populations were repeatedly isolated from northern temperate soils in three Lake Superior watersheds from October 2003 to October 2004. Seasonal variation in the population density of soilborne E. coli was observed; the greatest cell densities, up to 3 X 10(3) CFU/g soil, were found in the summer to fall (June to October), and the lowest numbers, = 92% similarity values, overwintered in frozen soil and were present over time. Soilborne E. coli strains had HFERP DNA fingerprints that were unique to specific soils and locations, suggesting that these E. coli strains became naturalized, autochthonous members of the soil microbial community. In laboratory studies, naturalized E. coli strains had the ability to grow and replicate to high cell densities, up to 4.2 X 10(5) CFU/g soil, in nonsterile soils when incubated at 30 or 37 degrees C and survived longer than 1 month when soil temperatures were