Bacteriology is the branch and speciality of biology that studies the morphology, ecology, genetics, identification, classification and biochemistry of bacteria as well as many other aspects related to them. Bacteriology is important in medicine, public health and sanitation work, agriculture, food-processing, and industry. The importance of bacteriology is undeniable; in fact, the study of the action of bacteria in health and in disease, inside and outside the animal body, has revealed so many new facts. Major advances in bacteriology over the last century resulted in the development of many effective vaccines (e.g., pneumococcal polysaccharide vaccine, diphtheria toxoid, and tetanus toxoid). This book is a review of the medically important aspects of bacteriology and covers both the basic and clinical aspects of bacteriology, and also discusses important infectious diseases caused by pathogenic bacteria. This book presents current, medically important information in the rapidly changing fields of bacteriology.