1. Fundamentals of Microbiology

Microbiology:
Microbiology is the study of microscopic organisms and their activities
It considers the microscopic forms of life and deals about their
Reproduction and physiology
participation in the process of nature
helpful and harmful relationship with other living things
significance in science and industry

1. 1. Fundamentals of Microbiology Outlines Development of Microbiology Significance of Studying Microbiology Prokaryotic and Eukaryotic cell structure Bacterial Taxonomy Bacterial cell Structure Bacterial Nutrition and Growth Bacterial Genetic 6/28/2019 1

2. Objectives Upon completion of this unit of instruction, the student will be able to: Discuss the historical background of Microbiology Discuss the significance of studying Microbiology Classify medically-significant bacteria according to their phenotype and genotype Identify external and internal structural components of bacteria Discuss bacterial genetics 6/28/2019 2

3. Objectives…. Discuss bacterial metabolism and growth Describe types of disinfection, decontamination and sterilization Prepare and apply disinfectants and antiseptics 6/28/2019 3

4. Chapter I : Introduction To Microbiology Microbiology: Microbiology is the study of microscopic organisms and their activities It considers the microscopic forms of life and deals about their Reproduction and physiology participation in the process of nature helpful and harmful relationship with other living things significance in science and industry 6/28/2019 4

5. Subdivisions of Microbiology Sub divisions of microbiology Bacteriology – which deals with bacteria Mycology- which deals with fungi Phycology - Which deals with Algae. Protozoology – which deals with Protozoa . Helminthology –which deals with worms Virology -studies about viruses 6/28/2019 5

6. Division of Microbiology 6/28/2019 6

7. Medical Bacteriology It involves the study of pathogens , the disease caused by them, and the body’s defenses against disease. It is also concerned with Epidemiology, transmission of pathogens Disease prevention measures, and Aseptic techniques and treatment of infectious diseases Immunology and production of vaccines . 6/28/2019 7

8. HISTORICAL BACKGROUND Man kind has always been affected by diseases which were originally believed to be visitations by the gods and meant to punish evil doers . 6/28/2019 8

9. History… Hippocrates: father of medicine observed that ill health resulted due to changes in air, winds, water, climate, food, nature of soil and habits of people. Varro (117-26 BC) : formulated a theory that diseases were caused by animated particles invisible to naked eye which were carried in the air and acquired via the mouth and nose into the body. 6/28/2019 9

10. Background … Fracastoro (1478–1553 G.c): proposed that the agent of communicable diseases were living things. Could be transmitted by direct contact with humans and animals. Indirectly by objects But no proofs due to lack of experimental evidence. 6/28/2019 10

11. Background … Antony van Leeuwenhoek ( 1632-1723 G.c) Father of microbiology, observed “animalcules” using simple microscope with one lenses. He was the first who properly described the different shapes of bacteria. 6/28/2019 11

12. Question raised - where did they originate? Leeuwenhoek was not concerned about the origin of Mos. Many other scientists were searching for an explanation for spontaneous appearance of living things from decaying meat stagnating ponds fermenting grains and infected wounds 12 6/28/2019 Background…

13. History… On the bases of this observation, two major theories were formulated. 1. Theory of Abiogenesis 2. Theory of Biogenesis 6/28/2019 13

14. Theory of Abiogenesis: Theory of Abiogenesis: deals with the theory of spontaneous generation stating that living things originated “spontaneously” from non-living things . Aristotle (384-322 BC): The founder of a theory spontaneous generation. He observed spontaneous existence of fishes from dried ponds, when the pond was filled with rain. 6/28/2019 14

15. Theory of Biogenesis: Theory of Biogenesis: States that life comes from pre-existing life. Francesco Redi (1626-1697): He is the scientist who first tried to set an experiment to disprove spontaneous generation. Utilized jars containing meat. Some were covered, some were not. 6/28/2019 15

16. Theory of Biogenesis… He observed that the flies laid eggs on uncovered jar from which the maggots developed but not from covered jars. He said maggots did not developed from meat but from flies egg. Results not accepted for microscopic organisms. Introduced experimental procedure to disproof spontaneous generation. The controversy on spontaneous generation took 200 years. 6/28/2019 16

17. F . Redi ‘s experiment 6/28/2019 17 Figure 1 Redi experiment jars

18. Theories of … John Needham (1749 )- Utilized infusion broth prepared by boiling meat, grain, etc. to extract nutrients. Lazzaro Spallanzani (1776 )- used boiled broth Turbidity indicated growth. Louis pasture (1822- 1895) : He was the scientist who disproved the theory of abiogenesis once and for all . In his experiment he filtered air through cotton plug. 6/28/2019 18

19. Theory of… He placed plug in infusion broth, broth became cloudy - organisms present in the air. He designed a large curved flask or swan-necked or pasture goose neck flask and placed a sterile infusion broths. Flasks remained sterile unless tilted or neck broken. 6/28/2019 19

20. Luis Pasteur’s experiment 6/28/2019 20 In ‘A’ air freely moved through the tube, but dust particles were trapped in the curved portion of the flask. And no microbial growth was observed

21. Therefore, Pasteur proved that microorganisms entered to the broth with the air and micro organisms did not evolve spontaneously . 6/28/2019 21

22. Other major contribution of Louis Pasteur Microbial theory of fermentation Principles and practices of sterilization and pasteurization Control of disease of silk worm Development of vaccines against anthrax and rabies Discovery of streptococci. 6/28/2019 22

23. The Germ Theory of diseases Robert Koch He established an experimental procedure to prove the germ theory of disease in 1876. The theory states that specific disease is caused by specific pathogen. The scientific procedure is known as Koch’s Postulate . 6/28/2019 23

24. Koch’s Postulate : proof of germ theory of disease. A Mo can be accepted as a causative agent of an infectious disease only if the following conditions are satisfied. 1. The specific causative agent must be found in every case of the disease but absent from health organism. 2. The suspected micro-organism must be isolated and grown in pure culture. 3. Inoculation of a sample of the culture into a healthy organism, susceptible animal must produce the same disease . 6/28/2019 24

25. Koch’s Postulate : 4 . The disease organism must be isolated from the inoculated animal. E.g. 6/28/2019 25

26. Fig 2. Koch’s postulate 6/28/2019 26

27. Exceptions to Koch’s postulate Many healthy people carry pathogens but do not exhibit symptoms of the disease. Some microbes are very difficult or impossible to grow in vitro (in the laboratory) in artificial media. E.g . Treponema pallidum . Many pathogens are species specific. E.g . Brucella abortus cause abortion in animals but not in humans. Certain diseases develop only when an opportunistic pathogen invades imuno-compromised host. 6/28/2019 27

28. Major achievements of Robert Koch use of solid medium in bacteriology Discovery of causative agents of tuberculosis and cholera Koch’s postulate Luis Pasture has also developed the germ theory of diseases. 6/28/2019 28

29. 6/28/2019 29 Currently infectious agents could be Acellular Viruses Viroids Prions Cellular Bacteria Fungi Protozoa Helminths Arthropods

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31. Significance of Studying Microbiology WHY STUDY MICROBIOLOGY ? MOs have a tremendous impact on all life They are physical and chemical makeup of our planet. Microorganisms have a close association with humans. They are in us, on us, and nearly everywhere around us. One reason for studying microbiology is that MOs are part of the human environment and are therefore important to human health. MOs are essential to the web of life in every environment. 6/28/2019 31

32. Significance… Microorganisms: capture energy from sunlight decompose dead organisms, waste material, and even some kinds of industrial wastes . make nitrogen available to plants maintain the balance of nature synthesize antibiotics, vaccines are the major tools of genetic engineering 6/28/2019 32

33. Significance… certain microbes cause disease. S tudying microbiology is provides insight into life processes in all life-forms . In general, Microorganisms are part of the human environment and are therefore important to human health and activities. The study of microorganisms provides insight into life processes in all forms of life . 6/28/2019 33

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