Chapter 1. The History, Progress and Importance of Microbiology I. H. Siddique

1.1Chepter Review

This introductory chapter provides definition of microbiology, the history of microbiology, the milestones of progress, and the importance of modern bacteriology. The milestones of progress describes the contributions of many scientists to this field since Anton van Leeuwenhoek first observed and discovered microbes with magnifying lenses in l673. Further, this describes the major contributions of the microorganisms to the welfare of the World's inhabitants. 

1.2 Outline

1.2.1 Introduction

Microbiology in its broadest implication (Gr., micro, small; bio, living) deals with the study of living microorganisms; it includes the study of bacteria (bacteriology), viruses (virology), yeasts and molds (mycology), protozoa (protozoology), and other forms of life that do not fit well into any of these groups. The information acquired from microbiology has made possible great advances in our ability to control many infectious diseases. In addition, microorganisms have been used to study many normal biochemical processes including metabolism that subsequently have been shown to occur in higher forms of life. For example, molecular genetics which explains explains how genes control the activities of a cell.

It is clear that the field of medical microbiology includes more than just the study of disease-producing microorganisms-it is the study of all biological activities of microbes. Although a very young science, the influence of microbiology has spread to almost every type of human endeavor. 

1.2.2 Speciality Areas of Microbiology

The science of microbiology may be subdivided into the following speciality areas:

• A. Basic microbiology

  Fundamental knowledge of cultivation, staining, growth characteristics, physiology, biochemistry and immunology.

• B. Agricultural microbiology

  The study of soil microorganisms and their role in agriculture.

• C. Dairy and Food microbiology

  The study of organisms associated with the manufacture of dairy products and elimination of pathogenic organisms in food products in order to make it safe for the consumer.

• D. Veterinary and Medical microbiology

  A focus on pathogenic microorganisms responsible for diseases in animals and man. Diagnostic microbiology, medical microbial research and immunochemical research are included in this area.

• E. Industrial microbiology

  Studies on utilization of microorganisms in the production of alcoholic beverages, antibiotics and vitamins.

• F. Sanitary microbiology

  The study of the bacteriology of water and its purification procedures, sewage control and its disposal and the examination of foods served in restaurants.

• G. Virology

  The study of viruses, their biochemistry, molecular construction and replication.

• H. Mycology

  The study of yeasts and molds. 

1.2.3 The history of microbiology

The effects of various activities of organisms have been known to man for centuries. These phenomena included occurrences of infectious diseases (which were thought to sent by gods as punishment for the sins of man); spoilage of food; degradation of proteins with the production of new and desirable flavors in certain foods, etc. The experimental evidence on the presence of microscopic organisms was provided by Van Leeuwenhoek in 1676.

1.2.4 Milestones of Progress-

The following scientists have made significant contributions to the area of Microbiology:

A. Between 1850 and 1900 many significant contributions were made to this science and hence is known as the "Golden Age" of Bacteriology. Some contributions are listed below:   Edward Jenner (1796) introduced a method of vaccination to prevent small pox. Johann Lukas Schoonlein (1839) discovered a parasitic fungus, the causative agent of favus. Casimir Joseph Davaine (1850) observed bacilli in the blood of dead sheep from anthrax and transmitted the disease by inoculating this blood into healthy animals. Louis Pasteur (1861) disproved the theory of spontaneous generation. He introduced pasteurization (1863-65) to prevent wine from souring (by exposing to 60`C for a short time). This procedure is still used for preservation of milk and certain other perishable foods. He developed an anthrax vaccine (1881) and introduced the first preventive treatment for rabies (1885). Joseph, Lord Lister (1865) applied antiseptic treatment to the prevention and cure of wound infections. He is known as the "father of antiseptic surgery." Robert Koch (1876) isolated anthrax bacillus in pure culture and provided experimental proof of its infectiousness. He introduced the use of solid culture media (1881) for isolation of bacteria in pure culture culture; discovered Mycobacterium tuberculosis and published Koch's postulates, a basis of the experimental investigation of infectious diseases. According to these, (A) the organisms causing the disease must be found in all observed cases of a given disease in pathological relationship to its symptoms and lesions. (B) The organism must be isolated from victims of the disease pure culture for study in the laboratory. (C) When the pure culture is inoculated into a susceptible animal, possibly humans, it must reproduce the disease or, as modified, engender specific antibodies in the new host. (D) The organism must be isolated again in pure culture from such experimentally-caused infection. Using these rules and techniques, Koch discovered the tubercle bacillus, the cholera bacillus and modes of transmission of other disease agents. Hans Christian Gram (1853-1938) introduced a differential staining method for bacteria. Roux and Yersin (1888) discovered diphtheria toxin and later Kitasato and Von Behring discovered tetanus antitoxin. Ziehl and Neelsen (1892) developed a method of staining Mycobacterium tuberculosis. Edmund E. Nocard (1850-1903) a French Veterinarian and mycologist discovered many pathogenic fungi. Paul Ehrlich (1896) introduced methods of standardizing toxins and antitoxins. In 1898, he exposed his "side-chain" theory of immunity, and in 1909, he introduced "salvarsan" as a treatment for syphilis. Theobald Smith (1898) differentiated the human and bovine forms of Mycobacterium tuberculosis. Karl Landsteiner (1901) discovered the basic human blood groups.  Twort and d'Herelle (1915-1017) discovered bacteriophage. Alice Woodruff (1931) grew a virus for the first time in a fertile egg. Alexander Fleming (1928) discovered penicillin; Waksman, Streptomycin in 1943; Burkholder and colleagues, Chloramphenicol (chloromycetin) in 1947; Duggar and associates, Chlortetracycline in 1948; and Finlay and associates, Oxytetracycline in 1950. Albert Coons (1941) developed the Fluorescent-Antibody technique. Sarah Stewart (1953) carried out research on tumors in animals induced by viruses. Salk (1953) tested an inactivated vaccine for poliomyelitis. Sabin (1956) developed a live (oral) virus vaccine against poliomyelitis.

1.2.5 Importance of Modern Microbiology

In medicine, the contributions of microbiology have been significant. Some contributions includes the use of aseptic and antiseptic techniques, control and eradication of infectious diseases, bioassay techniques, administration of biological products and antibiotic therapy.

The fertility of the soil is dependent on microorganisms which play a role in nitrogen fixation. Microorganisms are employed in the manufacture of certain foods, beverages, and drugs.

1.4 STUDY QUESTIONS 1. What are the contributions of the following scientists to microbiology and to medicine? a. Louis Pasteur b. Joseph Lister c. Paul Ehrlich d. Roux and Yersin e. Finlay and his associates 2. List five specialty areas of Microbiology. 3. Francis Peyton Ross received a Nobel Prize in l966. What was his contribution? 4. Discuss the importance of microbiology in the health professions. 5. How did the idea of spontaneous generation come about? 6. Match the following people to their contribution toward the advancement of microbiology. _______ Walksman (a) First to observe bacteria _______ Landsteiner (b) Discovered streptomycin _______ Pasteur (c) Introduced vaccine for rabies _______ Ziehl and Neelsen (d) Discovered blood groups in humans _______ Twort and (e) Differentiated human and bovine form of M.tuberculosis _______ Theobald Smith (f) discovered bacteriophage _______ van Leeuwenhoek d'Herelle (g) Introduced acid-fast staining