thumbnail

Population structure, persistence, and seasonality of autochthonous Escherichia coli in temperate, coastal forest soil from a Great Lakes watershed

Environmental Microbiology

By:
, , , , and
DOI: 10.1111/j.1462-2920.2005.00916.x

Links

Abstract

The common occurrence of Escherichia coli in temperate soils has previously been reported, however, there are few studies to date to characterize its source, distribution, persistent capability and genetic diversity. In this study, undisturbed, forest soils within six randomly selected 0.5 m2 exclosure plots (covered by netting of 2.3 mm2 mesh size) were monitored from March to October 2003 for E. coli in order to describe its numerical and population characteristics. Culturable E. coli occurred in 88% of the samples collected, with overall mean counts of 16 MPN g-1, ranging from <1 to 1657 (n = 66). Escherichia coli counts did not correlate with substrate moisture content, air, or soil temperatures, suggesting that seasonality were not a strong factor in population density control. Mean E. coli counts in soil samples (n = 60) were significantly higher inside than immediately outside the exclosures; E. coli distribution within the exclosures was patchy. Repetitive extragenic palindromic polymerase chain reaction (Rep-PCR) demonstrated genetic heterogeneity of E. coli within and among exclosure sites, and the soil strains were genetically distinct from animal (E. coli) strains tested (i.e. gulls, terns, deer and most geese). These results suggest that E. coli can occur and persist for extended periods in undisturbed temperate forest soils independent of recent allochthonous input and season, and that the soil E. coli populations formed a cohesive phylogenetic group in comparison to the set of fecal strains with which they were compared. Thus, in assessing E. coli sources within a stream, it is important to differentiate background soil loadings from inputs derived from animal and human fecal contamination. ?? 2005 Society for Applied Microbiology and Blackwell Publishing Ltd.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Population structure, persistence, and seasonality of autochthonous Escherichia coli in temperate, coastal forest soil from a Great Lakes watershed
Series title:
Environmental Microbiology
DOI:
10.1111/j.1462-2920.2005.00916.x
Volume
8
Issue:
3
Year Published:
2006
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Environmental Microbiology
First page:
504
Last page:
513
Number of Pages:
10