Date of Award


Degree Name

Master of Arts


Biological Sciences

First Advisor

Merrill R. Wiseman

Second Advisor

Dr. Jean O. Lawrence

Third Advisor

Dr. Richard Brewer

Access Setting

Masters Thesis-Open Access



The use of antibiotics has increased the average life expectancy of mankind. They have prevented and cured infectious diseases that previously terminated in death. Consequently, recovery is often prompt and complete.

Though a benefit to mankind, the use of antibiotics in the treatment of infectious disease has also been accompanied by new problems. For example, treatment of a primary infection such as a bacterial pneumonitis with a broad spectrum antibiotic, may result in the death of some of the bacteria. More than one species of bacteria, however, are often found in the infected area. If such be the situation, a reduction of the antibiotic sensitive bacteria may result in establishment of a resistant bacterial population. Pathogens present in this resistant population may then cause secondary infection. This infection is often more serious than that caused by the primary pathogen (1). The antibacterial effects of the drug are also exerted in non-infected tissues of the body. If given orally, some of the drug is usually absorbed through the small intestine, circulated by the blood stream and excreted. Quantities of the drug, however, may not be absorbed, but discharged through the large intestine. While it remains in the large intestine, some of the antibiotic may continue to exert its antibacterial action. Normally a balanced micrfolora is present in the lower intestine of man. If the drug inhibits sensitive organisms in the large intestine, the creation of an ecologic vacuum is possible. This vacuum may be filled by other microorganisms.

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