Scope and objectives

1. Scope & Objectives of
Medical Microbiology
Dr. (NM) Shehla Unmbreen

2. What is Microbiology?
• Microbiology is the study of all living organisms that are too small to
be visible with the naked eye. This includes bacteria, archaea, viruses,
fungi, prions, protozoa and algae, collectively known as 'microbes'.

3. • Microbes are everywhere and affect almost all aspects of our lives. We cannot see
them, but our world would not function without them.
• Bacteria, viruses, fungi, protists, archaea, algae and other microscopic life forms are
on us and in us, in the air, soil and water, and in our food.
• They are in and on the surfaces of everything in our homes, workplaces and other
environments.
• Most do not harm us and many are essential for the good health of humans, animals
and the planet.
• Microbes help keep the planet healthy by recycling waste and supplying nutrients.
• Agricultural systems would not function without some while others are harmful pests.
• Industry uses microbial processes to produce foodstuffs and drugs, benefiting society
and creating wealth.

4. History
• Microbiologist # 1. Antony Van Leeuwenhoek:
• Antony van Leeuwenhoek (pronounced Lay-wen-hook) (1632-1723), a
citizen of Delft, Holland, was not a man of great learning, but he was very
ingenious. He became expert in the grinding of simple magnifying lenses.
• He made these lenses of small bits of glass, polished them very carefully,
and mounted each separately between two brass, copper, silver, or gold
plates, to which he fastened an adjustable holder for the object to be-
examined.
• He constructed many of these ‘microscopes’ each containing a single lens
ground by himself. The best of lenses magnified about 200 times. His
microscopes were superior to any of that time.

5. • Microbiologist # 2. Louis Pasteur:
• Pasteur’s contributions are many and great. The diversity of the fields in which he used
his talents is astounding. The credit of a sound and scientific beginning of microbiology
goes to him, and hence he is rightly called the Founder of Microbiology.
• The term ‘microbiology’, as the study of living organisms of microscopic size, was coined
by Pasteur.
• 2. He also coined the term ‘vaccine’.
• 3. He concluded during the period between 1844-57.
• a) That optically active compounds, such as the stereo-isomeric forms of tartaric acid and
amyl alcohol, never arose from the purely chemical decomposition of sugars but were
formed from them by the action of
• microorganisms. These were always present in fermenting liquors and increased in
number as the process continued.
• Sterilization and media preparation

6. • Microbiologist # 3. Robert Koch:
• A bacteriologist second only to Louis Pasteur and popularly called the
‘Founder of Microbial Techniques’ was Robert Koch (1843-1910). He
was born on December 11, 1843 in Germany. In 1866, he took his
degree in Medicine and began a general practice in a small country
town. In 1872, he took a diploma in Public Health and became
interested in microscopical studies
• Slide preparation,

7. The Scope of Microbiology
• Microbiology is one of the largest and most complex of the biological
sciences because it integrates subject matter from many diverse
disciplines.
• Microbiologists study every aspect of microbes—their genetics, their
physiology, characteristics that may be harmful or benefi cial, the ways
they interact with the environment, the ways they interact with other
organisms, and their uses in industry and agriculture.
• Each major discipline in microbiology contains numerous subdivisions or
specialties that deal with a specifi c subject area or field
• In fact, many areas of this science have become so specialized that it is
not uncommon for a microbiologist to spend an entire career
concentrating on a single group or type of microbe , biochemical
process, or disease.

8. Among the specialty professions of microbiology are:
• geo-microbiologists,
• who focus on the roles of microbes in the development of
earth’s crust;
• marine microbiologists,
• who study the oceans and its smallest inhabitants;
• medical technologists,
• who do the tests that help diagnose pathogenic microbes
and their diseases;
• nurse epidemiologists,
• who analyze the occurrence of infectious diseases in
hospitals; and
• astro biologists,
• who study the possibilities of organisms in Space

9. • Studies in microbiology have led to greater understanding of many
general biological principles.
• For example, the study of microorganisms established universal
concepts concerning the chemistry of life systems of inheritance and
the global cycles of nutrients, minerals, and gases

10. Medical microbiology
• Medical microbiology
• is a branch of medicine concerned with the prevention, diagnosis and
treatment of infectious diseases. In addition, this field of science studies
various clinical applications of microbes for the improvement of health.
• There are four kinds of microorganisms that cause infectious disease:
• bacteria,
• fungi,
• parasites and
• viruses and
• one type of infectious protein called a prion.

11. Scope of microbiology in Eastern medicines
• Eastern medicine microbiologist studies the
• characteristics of pathogens,
• their modes of transmission,
• mechanisms of infection
• growth.
Using this information a treatment can be devised.
• E.M. microbiologists often serve
• as herbal consultants for physicians,
• providing identification of pathogens
• and suggesting herbal treatment options.

12. Other tasks
• may include the identification of potential health risks to the
community or monitoring the evolution of potentially virulent or
resistant strains of microbes,
• educating the community and assisting in the design of health
practices.
• They may also assist in preventing or controlling epidemics and
outbreaks of disease.
• Some E.M . microbiologists study microbial pathology; some study
common, non-pathogenic species to determine whether their
properties can be used to develop herbal antibiotics or other
treatment method

13. Safety in herbal preparation
• The microbiological safety of herbal medicines and food preparations
can b possible after study of microbiology
• strict Good Manufacturing Practices should be considered in the
production and sale of these herbal preprations.

14. The Main
Themes of
Microbiology
Dr. (NM) Shehla Unmbreen

15. • As we observe the natural world, teeming with life, we cannot help but be struck by its
beauty and complexity. But for every feature that is visible to the naked eye, there are
millions of other features that are concealed beyond our sight because of their small
size.
• This alternate microscopic universe is populated by a vast microbial menagerie that is
equally beautiful and complex. To sum up the presence of microbes in one word, they
are ubiquitous. * {* ubiquitous (yoo-bik9-wih-tis) L. ubique, everywhere and ous,
having. Being,
• or seeming to be, everywhere at the same time.}
• They are found in all natural habitats and most of those that have been created by
humans.
• As scientists continue to explore remote and unusual environments, the one entity
they always find is microbes.
• They exist deep beneath the polar icecaps, in the ocean to a depth of 7 miles, in hot

16. • Microbiology is a science defined by smallness. Its creation was made possible by
the invention of the microscope (Gr. micro, small skop, to look, see), which
allowed visualization of structures too small to see with the naked eye.
• This definition of microbiology as the study of microscopic living forms still holds if
one can accept that
1) Some organisms can live only in other cells (eg, all viruses, some bacteria) and
2) Others have macroscopic forms (eg, fungal molds, parasitic worms).
• * microscopic (my0-kroh-skaw9-pik) Gr. mikros, small, and scopein, to see.
• * microbe (my9-krohb) Gr. mikros, small, and bios, life.

17. • Some people call them “germs” or “bugs” in
reference to their role in infection and disease,
but those terms have other biological meanings
and perhaps place undue emphasis on the
disagreeable reputation of microorganisms.

18. MAJOR GROUPS OF MICROORGANISMS
1. Bacteria,
2. Viruses,
3. Fungi (yeast and molds)
4. Protozoa,
5. Algae, and
6. Helminths (parasitic worms)
• Each group exhibits a distinct collection of biological characteristics. The nature of
microorganisms makes them both easy and difficult to study. Easy, because they
reproduce so rapidly and can usually be grown in large numbers in the laboratory.
Difficult, because we can’t observe or analyze them without special techniques,
especially the use of microscopes.

19. Microbiologists study every aspect of microbes
1. Their genetics,
2. Their physiology,
3. Characteristics that may be harmful or beneficial,
4. The ways they interact with the environment,
5. The ways they interact with other organisms, and
6. Their uses in industry and agriculture.

20. MOST PLAY BENIGN ROLES IN THE ENVIRONMENT
• Microorganisms are responsible for much of the breakdown and natural recycling of
organic material in the environment. Some synthesize nitrogen-containing
compounds that contribute to the nutrition of living things that lack this ability;
others (oceanic algae) contribute to the atmosphere by producing oxygen through
photosynthesis.
• Because microorganisms have an astounding range of metabolic and energy-
yielding abilities, some can exist under conditions that are lethal to other life forms.
• For example, some bacteria can oxidize inorganic compounds such as sulfur and
ammonium ions to generate energy, and some can survive and multiply in hot
springs at temperatures above 75°C.

21. PRODUCTS OF MICROBES CONTRIBUTE TO THE ATMOSPHERE
• Some microbial species have adapted to a symbiotic relationship with
higher forms of life.
• For example, bacteria that can fix atmospheric nitrogen colonize root
systems of legumes and of a few trees such as alders and provide the
plants with their nitrogen requirements.
• When these plants die or are plowed under, the fertility of the soil is
enhanced by nitrogenous compounds originally derived from the
metabolism of the bacteria.

22. THE ORIGINS OF MICROORGANISMS
• For billions of years, microbes have extensively shaped the
development of the earth’s habitats and the evolution of other life
forms.
• It is understandable that scientists searching for life on other planets
first look for signs of microorganisms.
• The fossil record dating from ancient rocks and sediments points to
bacteria like cells that existed at least 3.5 billion years ago.
• These simple cells were the dominant cells on earth for about 2 billion
years. They were very small and lacked complex internal structures.

24. The Cellular Organization of Microorganisms
• As a general rule, prokaryotic cells are smaller than eukaryotic cells, and in addition to
lacking a nucleus, they lack other complex internal compartments called organelles.
• Organelles are structures in cells that are bound by one or more membranes. Examples
such as mitochondria and Golgi complex perform specific functions in eukaryotic cells.
• Prokaryotes also perform specific functions, but they lack the dedicated organelles to
carry them out.

27. Microbial Involvement in Energy and Nutrient Flow
• The microbes in all natural environments have lived and evolved there for billions
of years. We do not yet know everything they do, but it is likely they are vital
components of the structure and function of these ecosystems and critical to the
operations of the earth.
• Microbes are deeply involved in the flow of energy and food through the earth’s
ecosystems. 1 Most people are aware that plants carry out photosynthesis,
which is the light-fueled conversion of carbon dioxide to organic material,
accompanied by the formation of oxygen.
• But microorganisms were photosynthesizing long before the first plants appeared.

28. • In fact, they were responsible for
changing the atmosphere of the earth
from one without oxygen to one with
oxygen.
• Today photosynthetic microorganisms
(including algae) account for more
than 50% of the earth’s
photosynthesis, contributing the
majority of the oxygen to the

29. • Another process that helps keep the
earth in balance is the process of
biological decomposition and
nutrient recycling.
• Decomposition involves the
breakdown of dead matter and
wastes into simple compounds that
can be directed back into the natural
cycles of living things.
• If it were not for multitudes of
bacteria and fungi, many chemical
elements would become locked up

30. • In the long-term scheme of things, microorganisms are the main forces that drive
the structure and content of the soil, water, and atmosphere.
• For example:
• Earth’s temperature is regulated by “greenhouse gases,” such as carbon dioxide
and methane, that create an insulation layer in the atmosphere and help retain
heat. A significant proportion of these gases is produced by microbes living in the
environment and the digestive tracts of animals.

31. (c) Even a dry lake in Antarctica, one
of the coldest places on earth
(235°C), can harbor microbes under
its icy sheet. Here we see a red
cyanobacterium, Nostoc (3,0003),
that has probably been frozen in
suspended animation there for 3,000
years. This is one kind of habitat on
earth that may well be a model for
conditions on Mars.

33. • The body plan of most microorganisms consists of a single cell
or clusters of cells . All prokaryotes are microorganisms and
include the bacteria and archaeons.
• Only some of the eukaryotes are microorganisms: primarily
algae, protozoa, molds and yeasts (types of fungi), and certain
animals such as arthropods and worms.
• These last two groups may not be microscopic, but they are still
included in the study because worms can be involved in
infections and may require a microscope to identify them.

34. Human Use of Microorganisms
• The incredible diversity and versatility seen in microbes make them
• excellent candidates for solving human problems. By accident or
• choice, humans have been using microorganisms for thousands of years to improve life and even to
further human progress. Yeasts, a
• type of microscopic fungi, cause bread to rise and ferment sugar to
• make alcoholic beverages. Historical records show that households
• in ancient Egypt kept moldy loaves of bread to apply directly to
• wounds and lesions, which was probably the fi rst use of penicillin!
• When humans manipulate microorganisms to make products in an
• industrial setting, it is called biotechnology. One newer application
• farms algae to extract a form of oil (biodiesel) to be used in place of
• petroleum products.

36. • Genetic engineering is a newer area of biotechnology that manipulates
• the genetics of microbes, plants, and animals for the purpose
• of creating new products and genetically modifi ed organisms.

37. • One powerful technique for designing new organisms is termed
• recombinant DNA. This technology makes it possible to deliberately
• alter DNA 2 and to switch genetic material from one organism
• to another. Bacteria and fungi were some of the fi rst organisms to
• be genetically engineered, because their relatively simple genetic
• material is readily manipulated in the laboratory. Recombinant
• DNA technology has unlimited potential in terms of medical, industrial,
• and agricultural uses. Microbes can be engineered to synthesize
• desirable proteins such as drugs, hormones, and enzymes

39. • Among the genetically unique organisms that have been designed
• by bioengineers are bacteria that contain a natural pesticide,
• yeasts that produce human hormones, pigs that produce hemoglobin,
• and plants that are resistant to disease (see table 1.1 d ). The
• techniques have also paved the way for characterizing human
• genetic material and diseases.

40. • Another way of tapping into the unlimited potential of microorganisms
• is the relatively new science of bioremediation. * This
• process introduces microbes into the environment to restore stability
• or to clean up toxic pollutants. Bioremediation is required to
• control the massive levels of pollution that result from human
• activities. Microbes have a surprising capacity to break down
• chemicals that would be harmful to other organisms. Agencies and
• companies have developed microbes to handle oil spills and detoxify
• sites contaminated with heavy metals, pesticides, and even
• radioactive wastes (fi gure 1.6 b ).

42. • The solid waste disposal industry
• is focusing on methods for degrading the tons of garbage in landfi
• lls, especially plastics and paper products. One form of bioremediation
• that has been in use for some time is the treatment of water
• and sewage. With dwindling clean freshwater supplies worldwide,
• it will become even more important to fi nd ways to reclaim polluted
• water.