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E. Coli Research Article Map - Coggle Diagram
E. Coli
Research Article Map
Discussion
Post-host
E. coli
can tolerate a wide range of stressors, but different strains specialize in certain environments.
The ability to ferment sucrose could be huge advantage in the wild.
When water has been recently polluted by human or bovine fecal matter,
E. coli
strains could not survive more than 2 days, but only ones with certain survival characteristics.
Being able to grow at lower than optimal temperature was also an advantage, even over other strains of
E. coli
M&M
PCR tested for virulence when outside the gut of host. (O157 positive)
Selective media at 37C for 24 hours
To test life span at local environmental water temperature, 88 strains were put in 10C sterile water for 14 days.
1% to 8% salt tolerance tested.
Intro
Looking to see if some of the E coli strains have adapted to have an environmental advantage over others that cannot survive the stresses of post-host life.
Studies
E. coli
from four water environments contaminated by fecal bacteria, taking into account the distance from the contamination source, land use, type of water (fresh, brackish, etc.) and water chemistry (Salinity DO, pH, etc.).
Post-host stresses in an aquatic environment can include nutrient deprivation, unexpected low or high temperature, higher salinity, sun exposure, competition with other microbes that may occur naturally in the environment, and being snacked on by protozoan
Results
From 2 days to 14 days of viability, depending on the strain and the level of contamination in the environment in which it was held. .
In water previously polluted by long ago and far away introduction of fecal bacteria from soil runoff, ranches or farms, all four
E. coli
phenotypes were found.
Viability in up to 4% NaCl concentration
Recent fecal pollution meant that most strains of
E. coli
could not live long.