Penicillin and Alexander Fleming

Introduction

The name given by Sir Alexander Fleming, in 1929, to an antibacterial substance produced by the mould Penicillium notatum. The two great advantages of penicillin are that it is active against a large range of bacteria and that, even in large doses, it is non-toxic. Penicillin diffuses well into body tissues and fluids and is excreted in the urine, but it penetrates poorly into the cerebrospinal fluid.

Discussion

The discovery of penicillin in 1928 and sulfanilamide drugs in the 1930s played a major role in treating bacterial diseases and in the creation of today's pharmaceutical industry. These chemical agents, called antibiotics, saved many lives during World War II. Though they were initially remarkable in their treatment of disease, it was soon learned that they could be harmful to humans and that the diseases they treated could become resistant to their action.

Background

Diseases have plagued human beings from the beginning of their appearance on Earth. Causes were unknown, so early humans often blamed these frightening visitations on devils or the will of the gods and frequently thought their appearance was caused by wrong behavior or portended some chaos in the future. Thousands of years later, when man had advanced enough to try to understand disease, visionary doctors suggested that disease was caused by "seeds" that were invisible. That invisibility was overcome beginning in the seventeenth century, when the microscope was invented and curious men began to look at objects through it. A man named Malpighi, an Italian, saw the movement of blood in capillaries. In the 1680s Englishman Robert Hooke (1635-1703) looked through a microscope and drew the first pictures of a cell. Anton van Leeuwenhoek (1632-1723) of Holland discovered microscopic life forms in 1676 that he called animal-cules. He described them so clearly that they can easily be identified today as bacteria, sperm, and blood corpuscles. The structure and understanding of cells was on the verge of being discovered, but nothing more could be done until microscopes were refined two centuries later. (Clark, 25)

Bacteria were among the first living things on Earth, but their existence was not known until the sixteenth century, and their role in the cycle of life was obscure until the nineteenth century. At the time it was believed that life sprang from non-living matter, a notion called spontaneous generation, and no one knew what a cell was. It was known that diseases came from unseen agents, but doctors did not know what they were. They did know from observation that some diseases spread easily between people with no obvious outside agent. That was the state of affairs in the middle of the nineteenth century.

Louis Pasteur (1822-1895), a French chemist and theoretical scientist, worked on many aspects of matter that had not been understood before the microscope was improved. In 1848 he began working on bacteria and soon was able to show that they were living units. He proved that living things came only from living things. Among his other activities, Pasteur proved that many ...