xiii
When you hear the words “germ,” “bacteria,” and “virus” you might cringe, run-
ning for the nearest sink to wash your hands. These words may bring back mem-
ories of when you caught a cold or the flu—never a pleasant experience. Germs,
bacteria, viruses and other microscopic organisms are called microorganisms, or
microbes for short. And as you’ll learn throughout this book, some microbes
cause disease while others help fight it.
Think for a moment. Right now there are thousands of tiny microbes living
on the tip of your finger in a world that is so small that it can only be visited by
using a microscope. In this book we’ll show you how to visit this world and how
to interact with these tiny creatures that call the tip of your finger home.
The microscopic world was first visited in the late 1600s by the Dutch mer-
chant and amateur scientist Antoni van Leeuwenhoek. He was able to see living
microorganisms by using a single-lens microscope. We’ve come a long way
since Van Leeuwenhoek’s first visit. Today scientists are able to see through
some microbes and study the organelles that bring them to life.
It wasn’t until the Golden Age of Microbiology between 1857 and 1914 when
scientists such as Louis Pasteur and Robert Koch made a series of discoveries
that rocked the scientific community. During this period scientists identified
microbes that caused diseases, learned how to cure those diseases, and then pre-
vented them from occurring through the use of immunization.
Scientists were able to achieve these remarkable discoveries by using cultur-
ing techniques to grow colonies of microbes in the laboratory. Once microbes
could be grown at will, scientists focused their experiments on ways to slow that
growth and stop microbes in their tracks—killing the microbe and curing the dis-
ease caused by the microbe.
Culturing microbes is central to the study of microbiology. You’ll be using
many of the same culturing techniques described in this book to colonize
microbes in your college laboratory. We provide step-by-step instructions on
how to do this.xiii
INTRODUCTION
00 Betsy FM 5/11/05 2:20 PM Page xiii