Immunology and Medical Microbiology

Abstract

We are continuously exposed to many pathogens through inhalation, ingestion, and touch. The immune system protects us from the majority of these pathogens as flatworms, bacteria, fungi, and viruses. We have also witnessed tremendous progress in the prevention and treatment of infectious diseases; still, they remain a major challenge and are responsible for major cause of death and disability worldwide. The immune system’s memory response and vaccination have resulted in complete eradication of many diseases. Our immune system is very adaptive and consists of a variety of cells and molecules, which play an active role in protecting us. It not only protects us from the outside pathogenic agents but also is also capable of recognizing the body’s own components. It recognizes them as self and does not induce response against them. It is known as self-/non-self-discrimination. Sometimes due to certain defects or other reasons when the immune system is not able to differentiate self, then it mounts an attack on self-components leading to autoimmunity. The importance of the immune system was recognized by early work of Dr. Edward Jenner and Louis Pasteur; they recognized the abilities of the immune system, and since then the system was gradually being explored and it laid the foundation of immunology.However, day-by-day microbes are also posing health risks as new strains are continuously being evolved. Many chemotherapeutic agents have been developed to control the spread and infections. However, microbes are also continuously developing the ability of their survival with emergence of new strains and properties. Antibiotic resistance is occurring with all classes of microbes posing a serious clinical problem in managing infections. The diseases like tuberculosis, cholera, and rheumatic fever, which were believed to be eradicated, have ferociously reemerged. The reemergence and new pathogenic agents might be the result of mutations in their genome and changes occurring in the environment. In this chapter, basic concept of the immune system and some of the diseases of the skin, gastrointestinal tract, nervous system, and respiratory system caused by microorganisms are discussed along with sexually transmitted diseases and characterization of pathogens.