Slides Of basic Microbiology

1. Mb-202 3(2-1)
Basic Microbiology
BSc.(Hons.) Agriculture

2. Course Contents
• Introduction to Microbiology
( microoranisms,types,classification,their
benificial and detrimental aspects)
• History of Microbiology
– Contribution of scientists, Golden age of
microbiology
• Branches of microbiology

3. Course Contents
• Differences between Prokaryotic and
Eukaryotic cell
• A single Bacterial cell
– cell types, their classification
– Cell wall
– Different structures which are external and
internal to cell wall e.g. Glycocalyx, flagella,
cell membrane, ribosomes, ER, chromosomes
etc.

4. Course Contents
• Bacterial growth, requirements, curves and
measurements
• Bacterial endospore formation
---------------Mid Term----------------
• Bacterial Genetics
– Genes, genotype, phenotype, nuclear material
– Nucleotides, genetic code, DNA & RNA
structure

5. Course Contents
• DNA Replication process
• Transcription
• Translation
• Introduction to viruses, their Classification
and Replication
• Introduction to Fungi, Classification and
Importance

6. Course Contents
• Introduction to immune system and
immunity
---------------Final---------------

7. Materials required for this class.
• Textbooks
Prescott's Principles of Microbiology
by J Willey, Sherwood and Woolverton
Foundations in Microbiology
by Talaro and Chess
Microbiology: An Introduction.
by Totora, Funke and Case

8. M I C R O B I O L O G Y
WITH DISEASES BY BODY SYSTEM SECOND EDITION
An Introduction toAn Introduction to
MicrobiologyMicrobiology

9. What is a Microbe
• Smaller than 0.1mm
• Includes bugs, things, germs, viruses,
protozoan, bacteria, animalcules, small
parasites

10. Why study Microbiology
• Microbes are related to all life.
– In all environments
– Many beneficial aspects
– Related to life processes (food web, nutrient
cycling)
– Only a minority are pathogenic.
– Most of our problems are caused by microbes

11. • Emerging infectious diseases (EID’s)
– Weapons of mass destruction
– New evolutionary features
– Response to man encroaching on the
environment
• Can you name an example?

12. Microbes in research
• 10 trillion human cells
10x this number
microbes
• Easy to grow
• Biochemistry is
essentially the same
• Simple and easy to
study

13. Bacteriology
Mycology
Parasitology
Immunology
Epidemiology
Biotechnology
Virology
Environmental Microbiology
Bioremediation
Various disciplines of study within microbiology:

14. Diversity of Microbes
• Bacteria-single celled prokaryotes
• Protozoa-eukaryotic, single celled, colonial,
many ways of nutrition
• Fungi- absorb nutrients, single celled
filamentous
• Viruses-acellular entities
• Others- worms, insects

16. • Prokaryotes
• Peptidoglycan cell
walls
• Binary fission
• For energy, use
organic chemicals,
inorganic chemicals,
or photosynthesis
Bacteria
Figure 1.1a

17. • Prokaryotic
• Lack peptidoglycan
• Live in extreme
environments
• Include:
– Methanogens
– Extreme halophiles
– Extreme thermophiles
Archaea:
Halobacteria not
from book

18. • Eukaryotes
• Chitin cell walls
• Use organic
chemicals for energy
• Molds and
mushrooms are
multicellular
consisting of masses
of mycelia, which are
composed of
filaments called
hyphae
• Yeasts are unicellular
Fungi
Figure 1.1b

19. • Eukaryotes
• Absorb or ingest
organic chemicals
• May be motile via
pseudopods, cilia, or
flagella
• Most free some
parasites
Protozoa
Figure 1.1c

20. • Eukaryotes
• Cellulose cell walls
• Use photosynthesis for
energy (primary
producers)
• Produce molecular
oxygen and organic
compounds
• Metabolically diverse
Algae
Figure 1.1d

21. • Acellular
• Consist of DNA or
RNA core
• Core is surrounded by
a protein coat
• Coat may be enclosed
in a lipid envelope
• Viruses are replicated
only when they are in
a living host cell
Viruses
Figure 1.1e

22. • Eukaryote
• Multicellular
animals
• Parasitic
flatworms and
round worms are
called helminths.
• Microscopic
stages in life
cycles.
Multicellular Animal Parasites
Figure fluke

23. The Scientific Method
• Make an observation
• Make a hypothesis
• Test the hypothesis
• Draw your conclusions
• Repeat
• Theory/Law

24. Scientific Method
 Hypothesis
 Laboratory experimentation or field Studies
 Data collection and analysis
 Conclusion, either reject or accept hypothesis
 Theory or Law

25. Abiogenesis vs Biogenesis
 “Spontaneous Generation” was an early belief that
living things can arise from vital forces present in
nonliving and decaying matter.
(Ex: maggots from meat or mushrooms from
rotting wood
 The alternative hypothesis that living organisms
can arise only from preexisting life forms is called
“Biogenesis”

26. • The hypothesis that living organisms arise from
nonliving matter is called spontaneous generation.
According to spontaneous generation, a “vital
force’ forms life.
• The Alternative hypothesis, that the living
organisms arise from preexisting life, is called
biogenesis.
The Debate Over Spontaneous
Generation

27. • 1668: Francisco Redi filled six jars with
decaying meat.
Evidence Pros and Cons
Conditions Results
3 jars covered with fine
net
No maggots
3 open jars Maggots appeared
From where did the maggots come?
What was the purpose of the sealed jars?
Spontaneous generation or biogenesis?

28. • 1765: Lazzaro Spallanzani boiled nutrient
solutions in flasks.
Evidence Pro and Con
Conditions Results
Nutrient broth placed in
flask, heated, then sealed
No microbial growth
Spontaneous generation or biogenesis?

29. • Pasteur’s S-shaped flask kept microbes out
but let air in.
The Theory of Biogenesis
Figure 1.3

30. A timeline of Microbiology
• Some highlights
– 1665 Hooke
– 1673 van Leeuwenhoek’s microscopes
– 1735 Linnaeus Nomenclature
– 1798 Jenner vaccine
– 1857 Pasteur Fermentation
– 1876 Koch germ theory of disease

31. Historical review of the Science of
Microbiology
Robert Hook – 1665 – Englishman, used a
primitive compound (two magnifying lenses)
microscope, reported that life’s smallest units
were little boxes – Cells, his work
started the process of the development of the
Cell theory of life

32. Hook’s microscope

33. Antoni Van Leeuwenhoek –1673 - probably the
first person to observe living cells with a simple
microscope, ground his own lenses and
described what we know today as bacteria – rod
shaped , spiral shaped , etc. “animalcules”

34. Antoni Van Leeuwenhoek

35. Francesco Redi – 1668 – opposed the prevailing
theory of Spontaneous Generation, maggots in
meat , He used covered jars to show that
maggots came from flies –strong evidence
against spontaneous generation
Now we teach the theory of Biogenesis – Life
comes from Life But issue of Spontaneous
Generation was actively believed for many more
years

36. Francesco Redi

37. Edward Jenner is credited with first vaccine – in
epidemics of smallpox during the late 1700’s he
observed that milk maids didn’t get the disease, cattle
had a similar disease – cowpox, milk maids had cow
pox lesions, but not small pox, he purposefully took
scrapings from cowpox blister and scraped a 8 year old
volunteer. With the material – child got mild illness but
not small pox,
Vaccination comes from Latin word “vacca” meaning
cow. Jenner laid the foundation for Pasteur’s later work
with other vaccinations.

38. Jenner and vaccination

39. Pasteur – French sceintist that dealt the death
blow to the spontaneous generation theory.
He devised the ingenious curved necked flasks
that prevented contaminated air from reaching
boiled beef broth – the broth remained
uncontaminated even though exposed to the air
He was very lucky – no endopores present, or it
would have failed
(resitant to boiling)

40. 1. He developed process we call Pasteuriztion –
he heated wine to kill contaminating microbes –
cured sick wine (today we heat treatment to kill
pathogens in milk also)
2. He proved that fermentation was caused by a
microbe – yeast
3. He developed vaccines for rabies and anthrax.
Vaccines led to immunity to diseases that
routinely killed many people, used to help
people long before they understood how they
even worked (science of Immunology)
4. He began the revolution in science that led to
the Golden Age of Microbiology (from 1857-
1914)

42. Robert Koch - Developed Koch’s postulates –
important technique for determining the
actual microbial cause agent of a disease – more later,
German, contemporary of Pasteur, several very
important contributions
1. He discovered the tuberculosis bug (tubercle
bacillus, Mycobacterium tuberculosis)
2. He discovered the cause of anthrax (Bacillus
anthracis) – from blood of dead cattle, cultured
bacteria in pure culture, injected bacteria in live
cattle and they died, then again cultured the bacteria
in pure culture. This led to the
Establishment of a procedure for determining
microbial cause of disease

43. Koch’s postulates

44. Koch’s and Pasteur’s work helped establish
the “Germ Theory of Disease” - that
microorganisms cause disease (in people,
animals, and even plants)

45. Iwanowski 1892 - Discovered that plant disease
can be caused by small organisms that were so
small they passed through filters , Tobacco
mosaic virus (TMV) was later
identified as the cause - beginning of virology
(Today we have discovered new and weird
things like viroids, prions)

46. Microbiology – Chapter 1

47. Paul Ehrlich, German doctor, wanted to find a “magic
bullet” an agent that would kill the disease agent
without hurting the patient.
Developed Salvarsan, “salvation from syphilis”agent
2. This was an arsenical – arsenic compound, that was
effective against syphilis
Antimicrobial agent, medicine to treat a
microbial disease, it was chemical – chemotherapy

48. • Syphilis spirochete: T. pallidum Paul Ehrlich

49. Joseph Lister – 1860’s, English surgeon that applied
ideas of the germ theory to surgery, remembered the
work of Semmelweis in Hungary in the 1840’s, if a Dr.
would wash their hands childbed fever was prevented.
He knew that phenol would kill bacteria; (phenol is the
basic agent of today’s – Lysol)
1. First antiseptic use in surgery, chemicals used as
agents on tissue before surgery
(tissue treated with an antimicrobial agent –
antiseptic, betadine) disinfectants are chemicals, used
on a surface
2. Also proved that microbes cause surgical infections

50. Semmelweis

51. Lister
• Antisepsis in surgery

52. Alexander Fleming - Scottish physician and bacteriologist -
1928
Observed mold growing on a bacteria culture, there was a
ring of clearing around the mold where the bacteria didn’t
grow, the mold was later found to be a Penicillium species
and the naturally secreted chemical was called penicillin, an
antibiotic
1. Antibiotics are natural agents
2. Synthetic drugs are chemicals produced in labs (sulfas)
3. Problems with them - toxicity, resistance, allergic reactions
4. Fleming’s work - shelved until early WWII, sulfas were
failing, needed penicillin to cure battle field wounds
5. Now have thousands of antibiotics and synthetics (and a
significant problem – resistance)

53. Flemming and Penicillium

54. Salk - Polio vaccine, 1950’s polio was a scary
epidemic, Salk developed a vaccine by treating the virus
with formalin (IPV) inactivated polio virus
Sabin 1963 live Polio virus vaccine, attenuated –altered
virus, OPV-oral polio vaccine
The work done on polio revolutionized the science of
virology and we are seeing the results today in advances
with Hepatitis and HIV viral infections - tissue
culture and other techniques

55. Watson and Crick, DNA, 1953

56. DNA Double helix
• Double Helix

57. Jacob and Monod – 1965 Did research on RNA
and protein synthesis in bacteria – last necessary
step in understanding how genetics works on a
cellular level (Replication, Transcription,
Translation – protein synthesis – expression of
traits)

58. The Golden Age of
Microbiology
• 1857-1914
• Beginning with Pasteur’s work,
discoveries included the relationship
between microbes and disease,
immunity, and antimicrobial drugs

59. •Classification

60. Microbiology
• Classification, Taxonomy,
• Binomial Nomenclature

61. The Classification of Living
Things
• Living organisms are assigned to groups
based upon their similarities.
• Systematics is the discipline of
identifying and classifying organisms.

62. Domains
• The highest – largest category, recent addition
• 3 domains
– 1. Archaea – ancient “bacteria”, unicellular like
bacteria, also simple cell structure (prokaryote – no
nucleus) but have distinct metabolism (chemistry)
allowing them to exist in “extreme” environments
– 2. Bacteria – unicellular, prokaryote, found
everywhere (Old kingdom name – Monera)
– 3. Eukarya – unicellular to multicellular, complex and
organized cells with nuclei and organelles
(mitochondria)

63. Domain Archaea
• Archaea are single-
celled organisms that
lack a membrane-bound
nucleus. - Prokaryote
• Archaea can be found in
environments that are
too hostile for other life
forms.

64. Domain Bacteria
• Bacteria are single-
celled organisms that
lack a membrane-bound
nucleus. (Prokaryote
also)
• Bacteria are found
almost everywhere on
the planet Earth.

65. Domain Eukarya
• The cells of all eukaryotes have a membrane-bound
nucleus. Members of the Domain Eukarya are
further categorized into one of four Kingdoms.
(know these kingdoms)

66. Microbiology
• Check your notes; Older 5 kingdom
scheme is still widely used
• Monera – bacteria (Prokaryotic)
• Protista – Protozoans (Eukaryotic)
• Fungi - yeast, molds, etc. (Eukaryotic)
• Plant – photosynthetic producers
(Eukaryotic)
• Animals – heterotrophic consumers
(Eukaryotic)

67. Categories of Classification
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

68. Categories of Classification
Domain - Dumb
Kingdom - King
Phylum - Philip
Class – Came
Order - Over
Family - For
Genus - Good
Species -
__

69. Categories of Classification
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species Least inclusive
Most inclusive

70. Scientific Names
• Binomial (two name) Genus first and first letter
capitalized, then species not capitalized. If
written or typed – either underline or italicize
– Genus name, species name
– Homo sapiens - italicized
– Escherichia coli (Bacterial spp.) – underlined
– Or
– Escherichia coli (italicized)