Introduction of Microbiology

1. WELCOME
Dr. Hamima Hasnat
Assistant Professor
Department of Microbiology
Eastern medical college, cumilla

2. Learning Objectives
 What is microbiology?
 What are the different types of microorganisms?
 What is the history of Microbiology?
 How do we classify microorganisms?

3. What is Microbiology?
 Microbiology is the study of microorganisms, a large and
diverse group of microscopic organisms that exist as
single cells or cell clusters; it also includes viruses, which
are microscopic but not cellular.

4.  Five major groups of microorganisms :
Bacteria,
Fungi,
Protozoa,
Helminths and
Viruses.

5. What is the history of Microbiology?
 Spontaneous Generation
 The Germ Theory
 Invention of Microscope
 Louis Pasteur and Robert Koch

6. Spontaneous Generation /Abiogenesis
 It is an early belief that some forms of life could arise
from vital forces present in nonliving or decomposing
matter.
 One of the firm believers in spontaneous generation was
Aristotle, the Greek philosopher.

7.  Flies from manure, Maggot from rotting meat.
 Dead leaves falling from a tree into pond would transform
into fishes and those falling on soil would transform into
worms and insects.

8.  Two scientist disproved spontaneous generations:
Francisco Redi
Louis Pasteur

9. The Germ Theory of disease
 Many disease are caused by the growth of microbes in the
body and not by sins, bad character or poverty etc.
 Proposed by Robert Koch and Louis Pasteur.

10. Invention of Microscope
 Zacharias Janssen was a Dutch spectacle maker, first made
the microscope.

11.  Antoni Van Leeuwenhoek improved the simple
microscope to a magnification of 270x
 Described first microbes. so van Leeuwenhoek became the
first person to study bacteria.

13. Louis Pasteur (1822-1894) Father of
microbiology
 Developed the Germ Theory of disease.
 Developed pasteurization.
 Developed a method of attenuating a virulent pathogen,
the agent of chicken cholera, so it would immunize and
not cause disease.
 He is also credited with the development of vaccines for
anthrax and rabies.

14. Robert Koch (1843-1910)
 Established Koch’s postulates—a sequence of
experimental steps that verified the germ theory
 Developed pure culture techniques for handling bacteria in
lab
 Cultured bacteria on agar
 Discovered causative agent for tuberculosis
(Mycobacterium tuberculosis) and cholera (Vibrio
cholerae).

15. Classification of microorganisms
 Classification of living organisms is referred to as
taxonomy.
 Levels of classification: Domain
Kingdom
Phyla
Class
Order
Family
Genus
Species

16.  Binominal Linnean system
 Gives each microbe 2 names –
Genus –capitalized
species –lowercase.
 Both are written italicized or underlined.
 Ex. Staphylococcus aureus (S. aureus), Escherichia coli
(E. coli)

17. hamimahasnat@yahoo.com

18. Thank you all