Microbiology is the study of microorganisms too small to be seen with the naked eye, including bacteria, archaea, viruses, fungi, prions, protozoa and algae. The document outlines various topics in microbiology including branches of microbiology, contributions of scientists like Van Leeuwenhoek, Redi, Pasteur and Koch, distinguishing characteristics of prokaryotic and eukaryotic cells, basic properties of viruses, nutritional requirements of microorganisms, and bacterial morphology. It also discusses the importance of microbiology in nursing practice for tasks like infection control, maintaining sterile fields, and implementing immunization schedules.

1. INTRODUCTION TO
MICROBIOLOGY

2. OBJECTIVES
1. Define microbiology.
Branches of microbiology
Types of microoganisms
2. Explain the importance of microbiology in nursing practice
3. List the contribution of the following scientists in the field of microbiology.
• A.V. Leeunvenhork
• F.Redi
• L. Pasteur
• R.Koch
4. Distinguish between eukaryotic and prokaryotic cell.
5. List some basic properties of virus
6. List basic nutritional requirements of microorganisms
7. Classify bacteria on the bases of their nutritional requirement and morphology

3. 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'.

4. Slide Title
Medical microbiology deals with the study of microorganisms
responsible for various diseases of low to high intensity and it
can be divided into:
1. Bacteriology, which deals with study of bacteria.
2. Virology, which facilitates study of viruses.
3. Parasitology, which involves unicellular to multicellular
parasites.
4. Mycology, that deals with various fungal microorganisms

5. BRANCHES OF MICROBIOLOGY
BASIC
• BACTERIOLOGY
• MYCOLOGY
• PHYCOLOGY
• VIROLOGY
• PROTOZOOLOGY
• NEMATOLOGY
APPLIED
• AGRICULTURAL
• FOOD
• DAIRY
• INDUSTRIAL
• MEDICAL
• TEXTILE
• EXO-MICROBIOLOGY
• ENVIRONMENTAL

6. Importance of Microbiology
in Nursing Practice
Role of a nurse in relation to the condition of the patient, disease stage, diagnosis, treatment
module, and hospital environment in a microbiological perspective. The role of a nurse is varied,
and it is important for a nurse to multitask intellectually with fundamental knowledge, decisive
thinking, and application. Evolving nurses with a conceptual clinical approach towards the
following:
1. Asepsis, sterilization, and disinfection
2. Recognition of infection
3. Infection control—pathogenesis and transmission
4. Nosocomial infection
5. Immune system 6. Clinical thought process.

7. Why Microbiology is Needed in
Nursing?
• Nurses are involved in managing
all aspects of patient’s health and
infection control in the hospitals.
Nurse must know microbiology to
take care of patient and to protect
oneself from pathogenic
microorganisms. Nurses utilize
concepts of microbiology while
giving patient care or doing
procedures.

8. To prevent spread of infection:
Nurses should have knowledge about the mode of
spread of infection. Some of the infections are spread
by contact (touch), air (air-borne), droplets (sneezing,
coughing), some by eating contaminated food or drink
(food borne), sexual contact (STDs), by arthropod bite
(vector born) and others by contaminated blood
transfusion, etc. the knowledge would help a nurse to
use particular measures to save community and hospital
spread of infection

9. To Maintain Sterile Field:
• A nurse must know procedures used to
create and maintain a sterile field in the
hospitals and these are based on the
knowledge of microbiology.
• The knowledge of microbiology can further
help a nurse to use sterile equipment which
are a necessary part of invasive procedures
done on patients. The principles of asepsis
are based on microbiology. The knowledge
of sterilization techniques is mandatory for
a nurse. The proper disposal of biomedical
waste is equally important.

10. To collect specimens
• Nurse must recognize the importance
of proper collection of specimens to be
sent for bacteriological examination to
obtain accurate results. For instance,
she has to be familiar with the various
infectious disease and their route of
infection so as to collect clinical
specimen from a proper site like,
pustule or blood or stool etc.

12. To Implement Immunization
Schedule in Hospitals
• A nurse also plays an important role in immunization to control threats
of various diseases like diphtheria or MMR etc. So they must have
knowledge of various antisera and vaccines used in preventing the
dreadful diseases.
• The immunization schedules and the cold chain used to deliver the
vaccines from the production to the administration should be known to
a nurse. Knowledge of immunology makes a nurse well prepared for
vaccination and protection of vaccines by using cold chain.

13. Contribution of the Following
Scientists in the Field of
Microbiology

14. Van Leeuwenhoek (24 October
1632 – 26 August 1723)
• He is commonly known as
“The Father of
Microbiology", and one of the
first microbiologists.
• Van Leeuwenhoek is best
known for his pioneering work
in microscopy.

15. • Dutch businessman and scientist in the Golden Age of Dutch science and technology.
A largely self-taught man in science.
• In the 1670s, he started to explore microbial life with his microscope. This was one of
the notable achievements of the Golden Age of Dutch exploration and discovery
(c. 1590s–1720s).
• Using single-lensed microscopes of his own design and make, van Leeuwenhoek was
the first to observe and to experiment with microbes.

16. Francesco Redi (18 February 1626 –
1 March 1697)
• Italian physician, naturalist
and biologist.
• He is referred to as the "founder
of experimental biology", and as the
“Father of Modern parasitology".
• He was the first person to challenge
the theory of spontaneous generation
by demonstrating that maggots come
from eggs of flies.

17. Spontaneous Generation
• He said simpler life forms such as worms and
maggots need no parents – they emerge alive
from the earth and from rotting organic matter.
This idea had been accepted for over 2,000
years.
• Again, Redi used experiments to research this
subject. He observed that flies laid eggs on meat.
These eggs hatched into maggots. If the meat
was protected from flies, no eggs were laid and
no maggots appeared.
• He described his work in 1668 in Experiments
on the Generation of Insects.

18. Louis Pasteur
• French chemist
and microbiologist renowned for his
discoveries of the principles
of vaccination, microbial fermentation,
and pasteurization.
• He is regarded as one of the founders
of modern bacteriology and has been
honored as the “Father of
bacteriology"

19. • Pasteur was responsible for disproving the
doctrine of spontaneous generation and his
experiment demonstrated that in sterilized
and sealed flasks, nothing ever developed.
Conversely, in sterilized but open flasks,
microorganisms could grow. For this
experiment, the academy awarded him the
Alhumbert Prize carrying 2,500 francs in
1862.

20. • German physician and microbio
logist. As the discoverer of the
specific causative agents of
deadly infectious diseases
including tuberculosis, cholera,
and anthrax.
• He is regarded as one of the
main “founders of
modern bacteriology”.
Robert Koch

21. • He was the first to use oil immersion lens, condenser and microphotography in
microscopy.
• In appreciation of his works, he was appointed as government advisor at the
Imperial Health Office in 1880, promoted to a senior executive position
(Geheimer Regierungsrath) in 1882, Director of Hygienic Institute and Chair
(Professor of hygiene) of the Faculty of Medicine at Berlin University in 1885.

22. • The methods Koch used in bacteriology led
to establishment of a medical concept
known as Koch's postulates, four
generalized medical principles to ascertain
the relationship of pathogens with specific
diseases.
• For his research on tuberculosis, he
received the Nobel Prize in Physiology or
Medicine in 1905.

24. EDWARD JENNER
• He is well known for his
innovative contribution to
immunization and the
ultimate eradication of small
pox. His work is widely
regarded as the “foundation
of immunology”.

25. LORD JOSEPH LISTER
• Antisepsis is the method of using chemicals , called
antiseptics , to destroy the germs that cause infections. It
was developed by the British surgeon joseph lister. He found
a way to prevent infection in wounds , during and after
surgery.
• He was the first to apply the science of germ theory to
surgery. His antiseptic system is the basis of modern
infection control.
• His principles made surgery safe and continue to save
countless lives.

26. PAUL EHRLICH
• In 1882 he published his
method of staining the tubercle
bacillus that Koch had
discovered and this method was
the basis of the subsequent
modifications introduced and
still used today. From it was also
derived the Gram staining
method for bacteria so much
used by modern bacteriologist.

27. ALEXANDER FLEMMING
• “I did not invent penicillin .Nature did that. I
only discovered it by accident”.
• He was a scottish physician scientist who was
recognized for discovering penicillin. The simple
discovery and use of the antibiotic agent has saved
million of lives, and earned flemming -together with
Howard Florey and Ernst chain, who devised mathods
for large scale isolation and production of penicillin,
noble prize in physiology/medicine was awarded to
him in 1945.

28. Distinguish between
eukaryotic and prokaryotic
cell.
Prokaryotic
• Nucleus Absent.
• Cell Type Usually unicellular.
• True Membrane bound
Nucleus absent.
• Example: Bacteria and
Archaea.
Eukaryotic
• Nucleus present.
• Cell Type usually multicellular
• True Membrane bound
Nucleus present
• Example: Animals and Plants.

29. List Basic Nutritional
Requirements of
Microorganism
• In order to get energy and to maintain cellular biosynthesis, every
organism must be provided with the essential substances needed for
growth from its environment.
• Most bacteria can be grown away from their natural habitats in
laboratories if suitable nutrients are provided in the form of culture
media.
• Some are obligate intracellular parasites of other cells. The host cells
must satisfy the nutritional requirements of mutualisms and parasites as
these are the residents of the host

30. Classify Bacteria on the Bases of their
Nutritional Requirement and
Morphology
• MICROBIAL NUTRITION
• In order to get energy and to maintain
cellular biosynthesis, every organism must
be provided with the essential substances
needed for growth from its environment.
These essential substances required for
bacterial growth are referred to as ‘nutrients’

31. Autotrophic Bacteria
• Based on their nutrition, the bacteria are classified into the
following:
• Autotrophic Bacteria: The bacteria that can synthesize organic
food from inorganic substances are called autotrophs. Autotrophic
bacteria are of two types, which are mentioned below.

32. Photoautotrophic Bacteria
• Photoautotrophic Bacteria: These
bacteria contain photosynthetic pigments
in thylakoids that utilize the solar energy
to synthesize food. Bacterial
photosynthesis is completely different
from that of green plants. As a result,
this process is known as an oxygenic
photosynthesis.
• CO2 + H2 S + Sunlight → Sugar +
Sulphur + Water

33. Chemoautotrophic Bacteria
• Chemoautotrophs construct organic
compounds from inorganic substances.
Here, while the oxidation of inorganic
substances occurs, energy gets liberated,
which in turn is used to construct food,
that is, organic compounds.
• Example Nitrifying Bacteria: These
bacteria derive energy by oxidizing
ammonia into nitrates (e.g., Nitrosomonas
and Nitrobacteria).
• NH4 + + 2O2 → NO2 + 2H2 O + Energy

34. Heterotrophic Bacteria
• Heterotrophic Bacteria: Heterotrophic bacteria
cannot synthesize their own food they are always
dependent on external sources. The heterotrophs are
of different forms, which are mentioned below:
• Saprophytic organisms: Bacteria that obtain their
nutritional requirements from dead and decaying
matter.
• Decomposition: During it, aerobic breakdown of
organic matter takes place
• Fermentation: Here anaerobic breakdown of
organic matter occurs. Fermentation reactions are
incomplete and always release foul gases.
• Putrefaction, which is the breakdown of protein
molecules, is also done by heterotrophs.

35. Symbiotic Bacteria
• Some bacteria can live with other
organisms in such a way that both are
not harmed by each other but rather are
benefitted by one another.
• The cellulose-digesting bacteria that
live in the alimentary canal of ruminant
mammals such as cows and goats are
another example. The relationship
observed here is the same mutual
relationship as can be seen in E. coli
residing in the human alimentary canal

36. Parasitic Bacteria
• Synthesize their own food and
always need a host for their
survival. These bacteria obtain
their food from their hosts such as
animals and plants. The majority
of parasitic bacteria are pathogens
and are responsible for several
chronic diseases in the host by
exploiting them

37. BACTERIAL MORPHOLOGY
• Bacteria are microscopic living organisms that are structurally very simple.
They are strictly unicellular and thrive solitarily. However, some bacteria are
found living in groups.
• Bacteria range from 1 mm in diameter (largest end of the scale) to 200 nm in
length (smallest end of the scale).

38. Shape of Bacterial Cell
Bacterial cells vary in shape and fundamentally are of four
groups, which are as mentioned below.
• Spherical Type: Cells are circular in shape. This type of
cells are termed as ‘cocci’ are of different forms as
mentioned below:
1. Micrococcus (if the coccus is single)
2. Diplococcus (if the coccus lives in pairs)
3. Streptococcus (if the coccus exists in chains)
4. Staphylococcus (if the coccus occurs in clusters, i.e.,
grape-like)
5. Sarcina (cubical packets of eight or more)

39. Shape of Bacterial Cell
• Bacillus Type: The cells are elongated and rod-like, and
such cells are called ‘bacilli’. Bacilli may again be of
different types. They might be single, in pairs, or in
groups to form a chain (streptobacilli).
• Spirillum Type: The cells are spirally coiled and hence
referred to as spirillum. Some of the important genera
that fall under this type are Spirillum and Microspira.
• Vibrio Type: The cells are comma-shaped. The rod-
shaped cell is curved at one end and hence appears like a
‘comma’. Vibrio cholerae is an important species of this
type.

40. Shape of Bacterial Cell
• Some bacteria tend to change their shape
according to environmental changes. Such
bacteria fall under two categories, which
are as follows:
• Monomorphic: Here, the bacterium
exhibits only a single shape.
• Polymorphic or pleomorphic: The
bacterium exhibits different shapes as the
environmental or physiological condition
gets changed. Examples of polymorphic
bacteria are Corynebacterium diphtheriae
and Mycopla

41. List Some Basic Properties of
Virus
• The size of virus ranges from
(20-300) nm in diameter.
• The overall shape of virus
varies in different groups of
virus.
• Two basic symmetry are
recognized in virus, they are
helical symmetry and
icosahedral symmetry.

42. Structure and Chemical
Composition of Virus
• Genome: Viral genome or nucleic acid contains either DNA or RNA but not
both.
• Capsid: Composed of capsomere. Capsid protects the nucleic acid and also
helps in attachments on host cell surface during infection.
• Envelope: Some virus contains phospholipid bilayer known as envelope.
• Glycoprotein spike: Envelope of some virus contains viral coded spike
projected outside the envelope called glycoprotein spike or peplomers.
• Enzymes: Some virus possess their own enzymes. Retrovirus possess reverse
transcriptase.

43. Structure and Chemical
Composition of Virus
• Viral replication: Virus only replicates inside host
cell.
• Metabolism: Viruses are metabolically inert outside
host cell. They are also called as obligate
intracellular parasite.
• Resistance:
• Temperature: Most viruses are heat labile.
• Cold: Viruses are stable and resistant to cooling.
Virus can be stored for long duration at -40°C to -
70°C by lyophilization or freeze drying.

44. Slide Title
• Radiation: Both non-ionizing and
ionizing radiation can kill virus.
• Organic solvent: Chloroform, ether
and bile salt can destroy all viruses
by lipid solution.
• Disinfectant: Most viruses are
destroyed by oxidizing agents such
as chlorine, H2O2, iodine etc.
• Antibiotics: Viruses are resistant to
antibiotics.

45. Major Elements
• The nutritional requirements of elementary level.
• The cell’s elementary composition consists of C, H, O, N,
S, P, K, Fe, and Ca and traces of Zn, Ni, Mn, Co, Cu, and
Mo.
• Some bacteria uptake these elements as water, as some
inorganic ions, microelements, and macro elements. These
elements serve as either functional or structural units of the
bacterial cell.

46. REFERENCES
• https://microbiologysociety.org/why-microbiology-
matters/what-is-microbiology.html
• https://en.wikipedia.org/wiki/Antonie_van_Leeuwenhoek
• https://www.famousscientists.org/francesco-redi/
• https://en.wikipedia.org/wiki/Louis_Pasteur
• Wikipedia:Eukaryote
• Wikipedia:Prokaryote
REFERENCES