|
Introcution: Background (continued)
The same drugs prescribed for human therapy are widely exploited in animal husbandry and agriculture. Large amounts of these drugs are given to animals to promote growth. These amounts are too small
to combat infection but perfect for producing more disease resistant bacteria. When humans consume this food, bacterial strains are transmitted to the people who are eating as well as cooking this food
is possible.
Antibiotics are applied as aerosols to acres of fruit trees to control infections. High concentrations may kill the bacteria on the targeted trees, but the trees at the edge of the target receive low doses
which can encourage the growth of disease resistant bacteria. These resistant bacteria can be inhaled by animals--including humans--at the site. They are also being packaged and shipped with the
fruit from sprayed fruit trees all over the world. Each country is now producing their own antibiotic resistant bacteria as well as sharing this resistance with countries half a world away.
The above misuses of antibiotics are responsible for many different strains of drug resistant bacteria. Following are some examples of these strains of disease resistant bacteria. An often
deadly bacterium, Staphylococcus aureus, is responding poorly to a once reliable antidote, the antibiotic vancomycin. It was not long ago when vancomycin was the drug of choice in killing highly resistant bacterial strains. Tuberculosis, once
considered to be nearly eradicated in the 1940’s, is now the world’s leading cause of death from a single infectious disease according to the World Health Organization. A particularly dangerous strain of
Mycobacterium tuberculosis is spreading rapidly in Russia and other hot spots around the world. Widespread use of antibiotics have promoted the proliferation of the once benign intestinal bacterium
Enterococcus faecalis, which is naturally resistant to those drugs. This bacterium can be fatal to persons with compromised immune systems.
Ever since antibiotics became widely available in the 1940s, they have been hailed as miracle drugs or the magic bullets able to eliminate bacteria. Yet with each passing decade, bacteria that defy not
only single but multiple antibiotics are becoming increasingly common. However, this picture is not totally bleak. Through education, research and some rather simple changes in human behavior, the
production of disease resistant can be controlled or at least slowed down. Treating physicians will need to be educated in the proper use of antibiotics. The agriculture world will need to rethink
the doses of antibiotic that they are using in their treatment of animals and orchards. Research will need to focus on the development of new alternatives to our current arsenal of antibiotic
weapons. This research and education will need to be conducted and applied worldwide.
Justification:
Why is the study of antibiotic resistance an especially relevant subject to today’s student?
First, it reinforces previously learned material about the Monera Kingdom (eubacteria). Second, it ties in
the theory of evolution by natural selection. This lesson underscores the basic elements of the theory of evolution: (1) there is variation among the individuals in a population; (2) some of these
differences can be inherited; (3) some individuals will be better adapted to their environment than others; (4) the better adapted individuals will reproduce more successfully, and; (5) thus, the heritable
characteristics that make individuals better adapted will increase in frequency in the population. Third, this subject is relevant to the daily health and medical practices of each student. The
information that the students acquire by completing this program will provide them with a firm foundation from which to make future health and political decisions. Finally, this program will directly address
the following National Science Education Content Standards:
CONTENT STANDARD A
As a result of activities in grades 9 - 12, all students should develop:
- Abilities to do scientific inquiry
- Understandings about scientific inquiry
CONTENT STANDARD C
As a result of their activities in grades 9-12, all students should develop understanding of:
- The cell
- Molecular basis of heredity
- Biological evolution
- Interdependence of organisms
- Matter, energy, and organization in living systems
- Behavior of organisms
|
