E. coli is an abbreviated form of the name
Escherichia Coli. It is a naturally occurring
bacterium that dwells inside a human’s
large intestine. In exchange for the
nutrients it gets, E. coli secretes
Vitamins K and
B-complex. Although an important dweller of our
alimentary canal E. Coli only makes up
0.1% of the bacteria that lines an
adult intestine. The relation between the
human and the E. Coli bacterium is a
symbiotic one. Humans provide the E. Coli with nutrients and, in turn they
secrete necessary
vitamins. The
mutant form of E. Coli,
E. Coli 0157:H7 is the strain that has given its nicer
brothers a bad name. The most
controversy seems to be surrounding uncooked
beef, which became a nationwide problem with the “
Jack in the Box” outbreak 1993. The mutant form, even though it is better known, is much rarer than normal E. coli.
The good form of E. coli could have transferred
DNA with a
virus or other sources (
transduction possibly). This source possibly altered its
make up and made the
good E.coli into the mutant form. The mutant form is lethal for it secretes a toxin called Shiga-like
toxin (SLT). A a result of the mutant E. coli releasing SLT, damage to the
epithial cells of the intestine occurs. Due to injuries there is a loss of
water and
salts,
bleeding, and
hemorrhaging. This hemorrhaging can be lethal to small
children.
The mutant E. coli (which will from here in be labeled as E. coli for reasons of
convenience) can be
transferred anytime a person comes in contact, more specifically ingests, any product that has been near
animals. Most of the public is more concerned with getting it from undercooked
hamburgers, but as in many cases it can even be transferred through
beverages. Unless there is a cut in the meat below the surface it is usually
sterile. If a
knife cuts through the meat it can carry the E. coli down with it. Although it is rare
infection can occur easily for it only takes about
10 bacterial cells for infection. The standard
cooking rule of thumb is to cook the meat until all the
juices run clear. The problem with hamburger meat is the fact that it is
ground, for the once only surface dwelling bacteria plunge into every
nook and cranny of the meat. A person who eats contaminated meat and gets infected, can spread the disease further through contaminated water. If any
vegetables were washed in such water, or it was used to make a
beverage, then it is likely to become a disease carrying
entity. A case involving contaminated water occurred in
July of
1993. Around 35,000 residents of
New York City had to
boil their water when it was discovered that somehow E. coli had made its way into the city’s
water supply, despite the
chlorination and
filtration systems employed there.
Regarding treatment, the author of
The Coming Plague , Laurie Garret, writes
“The Lederbergs [a research team] discovered tests that could identify streptomycin-resistant [E. coli] before the organisms were exposed to antibiotics. They showed that the use of antibiotics in colonies of bacteria in which even less than 1 percent of he organisms were generally resistant could have tragic results. The antibiotics would kill off the 99 percent of the bacteria that were susceptible, leaving a vast nutrient-filled petri dish free of competitor for the surviving resistant bacteria… the resistant bacteria rapidly multiplied and spread out, filling the petri dish within a matter of days with a uniformly antibiotic-resistant population of bacteria.”
Although that type of treatment was successful at first, the bacteria has grown, like others, resistant to many forms of antibiotics. What makes E. coli so resistant is that, like most bacteria roughly one out of every 10 million E. coli in a petri dish might
randomly mutate to be resistant to, say
penicillin. Then, if the drug were poured into the petri dish, 9,999,999 bacteria would die, but that one resistant E. coli would survive, and
divide and
multiply, passing its
genes for resistance on to its
progeny.
Because the
rogue form of E. coli has gotten the majority of the
press, many people don’t know that E. Coli in its natural form is actually a
necessity. The future
contamination and
outbreaks will only proceed until people take proper
precautions, and/or
legislation regarding testing is passed. The problem does entail bacteria’s sped up evolution due to human’s role. It is a
conundrum, if we try to cure it, it will evolve to break the cure.
Works Cited
“What the heck is an E. Coli?.” Bugs in the news. (7 October 2000)
Garrett, Laurie. The Coming Plague. New York: Farrar, Straus and Giroux, 1994.