65 research outputs found
Survival of Escherichia coli in the environment: fundamental and public health aspects
In this review, our current understanding of the species Escherichia coli and its persistence in the open environment is examined. E. coli consists of six different subgroups, which are separable by genomic analyses. Strains within each subgroup occupy various ecological niches, and can be broadly characterized by either commensalistic or different pathogenic behaviour. In relevant cases, genomic islands can be pinpointed that underpin the behaviour. Thus, genomic islands of, on the one hand, broad environmental significance, and, on the other hand, virulence, are highlighted in the context of E. coli survival in its niches. A focus is further placed on experimental studies on the survival of the different types of E. coli in soil, manure and water. Overall, the data suggest that E. coli can persist, for varying periods of time, in such terrestrial and aquatic habitats. In particular, the considerable persistence of the pathogenic E. coli O157:H7 is of importance, as its acid tolerance may be expected to confer a fitness asset in the more acidic environments. In this context, the extent to which E. coli interacts with its human/animal host and the organism's survivability in natural environments are compared. In addition, the effect of the diversity and community structure of the indigenous microbiota on the fate of invading E. coli populations in the open environment is discussed. Such a relationship is of importance to our knowledge of both public and environmental health. The ISME Journal (2011) 5, 173-183; doi:10.1038/ismej.2010.80; published online 24 June 2010NATO [ESP.EAP.CLG 981785]; The Soil Biotechnology Foundationinfo:eu-repo/semantics/publishedVersio
Registered Ship Notes
https://digitalmaine.com/blue_hill_documents/1179/thumbnail.jp
Letter from Samuel J. Tilden, The Tilden Company, St. Louis, Missouri, to John Little Jr., Tuscaloosa, Alabama, July 25, 1898
An item in the Little family papers collection
The overwintering of Antarctic krill, Euphausia superba, from an ecophysiological perspective
A major aim of this review is to determine
which physiological functions are adopted by adults and
larvae to survive the winter season with low food supply
and their relative importance. A second aim is to clarify the
extent to which seasonal variation in larval and adult krill
physiology is mediated by environmental factors with a
strong seasonality, such as food supply or day light. Experimental
studies on adult krill have demonstrated that speciWc
physiological adaptations during autumn and winter,
such as reduced metabolic rates and feeding activity, are
not caused simply by the scarcity of food, as was previously
assumed. These adaptations appear to be inXuenced
by the local light regime. The physiological functions that
larval krill adopt during winter (reduced metabolism,
delayed development, lipid utilisation, and variable growth
rates) are, in contrast to the adults, under direct control by
the available food supply. During winter, the adults often
seem to have little association with sea ice (at least until
early spring). The larvae, however, feed within sea ice but
mainly on the grazers of the ice algal community rather
than on the algae themselves. In this respect, a miss-match
in timing of the occurrence of the last phytoplankton
blooms in autumn and the start of the sea ice formation, as
has been increasingly observed in the west Antarctic Peninsula
(WAP) region, will impact larval krill development
during winter in terms of food supply and consequently the
krill stock in this region
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