3. What is Microbiology?
micron = small
biologia = studying life
How small is “small”?
Study of too small organisms to be
not seen with the naked eye (< 0.1
mm)
4. Introduction to Microbiology
Microbiology:
In the broadest sense, microbiology is the study of all organisms
that are invisible to the naked eye-that is the study of
microorganisms.
These organisms include viruses, bacteria, fungi, and protozoa.
Microbiologists are concerned with characteristics and functions
such as morphology, cytology, physiology, genetics, and
molecular biology.
5.
6.
7.
8.
9. • When you hear the word bacteria, what comes to
your mind?
Not all bacteria cause disease
Most bacterial species cannot cause disease
• Many species play beneficial roles
Production of antibiotics and foodstuffs
Decompose organic waste
Produce industrial chemicals such as ethyl alcohol and acetone
Produce fermented foods such as vinegar, cheese, and bread
10. History of Microbiology
Discovering organisms
First microbes were observed in 1673
Robert Hooke- In 1665 reported that living things were composed
of little boxes or cells
devised the compound microscope and illumination system
https://ucmp.berkeley.edu/history/hooke.html
Antoni van Leeuwenhoek- (1673-1723)
He is considered the father of bacteriology
Made simple microscopes and began observing with them
(1674) Discovered bacteria (he called them animalcules).
11.
12. Golden Age of Microbiology
1857- 1914
• Beginning with Pasteur’s work, discoveries
included the relationship between microbes and
disease, immunity and antimicrobial medicine
• Germ Theory of Disease
Germ theory states that specific microscopic
organisms are the cause of specific diseases.
13. Prokaryote & Eukaryotes
Prokaryote is a unicellular organism, that lacks a membrane-bound
organelles such as nucleus, mitochondria, etc
The word prokaryote comes from the Greek (pro) "before" and (karyo)
refers to nucleus
Eukaryotes are organisms whose cells have a nucleus enclosed within
membranes. The word Eukaryotes comes from the Greek (eu, "well" or
"true") and (karyon) refers to nucleus
Eukaryotic cells also contain other membrane-bound organelles such as
mitochondria and the Golgi apparatus, and in addition, some cells of
plants and algae contain chloroplasts.
16. INTRODUCTION TO CLINICAL BACTERIOLOGY
• The study of bacteria and their relation to medicine and
to other areas.
• The main function of all diagnostic bacteriology
laboratories is the detection and identification of
microorganisms in a variety of samples of human,
animal, food, industrial, or environmental origin.
• Also drug susceptibility testing of the isolates to allow
correct treatment decisions is of major importance
17. Bacteria
A member of a large group of unicellular microorganisms which have cell
walls but lack organelles and an organized nucleus.
Size:
0.2–2.0 µm
Important Characteristics:
•Prokaryotic ,Unicellular
•Simple internal structure
•Grow on artificial laboratory media
•Reproduction asexual (mostly simple cell division)
Practical significance:
•Some cause diseases
•Some perform role in natural cycling of elements and increase soil
fertility
•Manufacture of valuable compounds in Industry
18.
19. The discipline of bacteriology evolved from the need of physicians
to test and apply the germ theory of disease and from economic
concerns relating to the spoilage of foods and wine.
The initial advances in pathogenic bacteriology were derived from
the identification and characterization of bacteria associated with
specific diseases.
During this period, great emphasis was placed on applying
Koch's postulates to test proposed cause-and-effect relationships
between bacteria and specific diseases.
20. 1. The causative (etiological) agent must be present in all affected
organisms but absent in healthy individuals
2. The agent must be capable of being isolated and cultured in pure
form
3. When the cultured agent is introduced to a healthy organism, the
same disease must occur
4. The same causative agent must be isolated again from the affected
host
Koch’s Postulates
21. In developed countries, 90 percent of documented infections in
hospitalized patients are caused by bacteria.
These cases probably reflect only a small percentage of the actual
number of bacterial infections occurring in the general population, and
usually represent the most severe cases.
The World Health Organization has estimated that each year, 3 million
people die of tuberculosis, 0.5 million die of pertussis, and 25,000 die
of typhoid.
Diarrheal diseases, many of which are bacterial, are the second
leading cause of death in the world (after cardiovascular diseases),
killing 5 million people annually.
Antonie van Leeuwenhoek (1632–1723) was one of the first people to observe microorganisms, using a microscope of his own design, and made one of the most important contributions to biology. Robert Hooke was the first to use a microscope to observe living things. Hooke’s 1665 book, Micrographia, contained descriptions of plant cells. Before Van Leeuwenhoek’s discovery of microorganisms in 1675, it had been a mystery why grapes could be turned into wine, milk into cheese, or why food would spoil. Van Leeuwenhoek did not make the connection between these processes and microorganisms, but using a microscope, he did establish that there were forms of life that were not visible to the naked eye. Van Leeuwenhoek’s discovery, along with subsequent observations by Spallanzani and Pasteur, ended the long-held belief that life spontaneously appeared from non-living substances during the process of spoilage.
Hooke presented the first published depiction of a microrganism, the microfungus Mucor. Later, Leeuwenhoek observed and described microscopic protozoa and bacteria.
