Download Suggested Answers for Insight Questions, Foundations in

Suggested Answers for Insight Questions, Foundations in Microbiology, 7th Edition, listed
by chapter, number, and page location.
A note to the users of these answers: These answers discuss some of the possible ways to
approach the questions. They are not meant to be exhaustive in depth, but can offer information,
suggestions, and points of view that will be helpful in understanding some of the concepts
covered in the Insight and the chapter. Furthermore, they are not the final word--you may have
thought of some other explanations that are just as valid. It is hoped they will serve to stimulate
class discussion and inspire further research.
21.1, pg. 630 – The Disease Named for a Town
In its early stages, Lyme infection may not manifest overt signs or symptoms. The bullseye rash
or other lesions can be absent, fever can be absent, and often there is no indication of a tick bite.
The silent persistence of the spirochete in the tissues over time gradually stimulates inflammatory
reactions that damage organs and cause the debilitating aspects of the disease. It may be
several weeks or even months before medical attention is sought. Often the first noticeable
symptoms involve arthritis, muscle aches, and neurological signs that are not necessarily
associated with an infection. Interestingly, the other spirochetal diseases show a similar pattern.
Syphilis, sometimes called "the great imitator" can persist for many years and through stages that
are mistaken for other diseases. The link that ties all diseases together is that, in a vast majority,
very similar inflammatory reactions are triggered. Noninfectious diseases such as arthritis,
allergies, cancer can also be mistaken for infection diseases and vice versa. (One viewpoint we
are hearing more and more is that all diseases may have an infectious component, but that is a
subject for another time!)
21.2, pg. 635 – Oral Rehydration Therapy
The minimal ingredients that are likely to be found in the kitchen are table salt, baking soda, corn
syrup (plain), and orange juice. These should be added to a quart of boiled water. The table salt
would provide sodium and chloride plus some minor salts such as potassium and magnesium.
Sea salt would also work. Add about one tablespoon to the water. The baking soda contains a
buffer with carbonate ions. Add about one tablespoon. Most homes would not have potassium
chloride salt, but fruit juices such as orange and grapefruit have relatively high levels of
potassium. Add about one-half cup to the solution. The best sugar to use is glucose, which is
found in regular (not high fructose) corn syrup. Other substitutes can be table sugar (sucrose) or
honey (a mixture of sugars). Add one-fourth cup of this. Dissolve all components and taste for
salt and sweetness. If you happen to have it in your kitchen, a sports drink such as Gatorade will
work for oral rehydration as well.
21.3, pg. 645 – Atherosclerosis and Blood Infection
Since it is increasingly evident that blood borne microbes contribute to some forms of heart and
cardiovascular disease, any personal or medical actions to curtail these infections would help.
For example, many microbes can enter through gingival damage, so tooth brushing and cleaning
to maintain oral health could cut down on this portal of entry. People with known heart disease
need to take antibiotics prior to any dental work. Prompt treatment of any type of infection,
whether skin, STD, or respiratory will lessen the possibility of bacteremia and persistence of the
microbe in the blood. Other personal actions that could prevent damage to the endothelium
would be to stop smoking, to monitor ones intake of harmful fats, taking a small dose of aspirin to
block chronic inflammation, and in the more severe cases, a drug like Plavix that slows the
adherence of platelets to the artery lining.