1. An Introduction to Microbiology

2. The Scope of Microbiology
The study of living things too small to be seen without magnification
Microorganisms or microbes
germs: cause diseases
useful or essential for human life
Microorganisms or microbes- e

3. Introduction to Microbiology
How Can Microbes Be Classified? Carolus Linnaeus (Swedish; li- nee-uh s) developed taxonomic system for naming plants and animals and grouping similar organisms together
Leeuwenhoek’s (ley-vuh n-hoo k) microorganims group into 6 categories
Fungi
Protozoa
Algae
Bacteria
Archaea
small animals

4. Nomenclature
Linnaeus introduced the binomial system of scientific nomenclature
Each organism has two names: the genus and species epithet
Italicized or underline
Genus name is capitalized and species in lower case.

5. Scientific Names Staphylococcus aureus
describes clustered arrangement of cells and golden yellow color of colonies
Escherichia coli
Honors the discoverer, Theodor Escherich and describes its habitat, the colon.
After the first use, scientific names may be abbreviated with the first letter of the genus and full species epithet. (Ex: E. coli)

6. General Characteristics
Prokaryotes no nucleus and organelles
Eukaryotes membrane bound nucleus and organelles
Acellular agents genomes contain either DNA or RNA; newer agent is proteinaceous

7. Comparative cellular structures of microbes
Cell Types
Comparative cellular structures of microbes

8. The Microbes viruses protozoa bacteria bacteriophage algae
cyanobacteria
spirochaetes
fungi

10. Size of Microbes
Microbes vary in size ranging from 10 nm (nanometers) to 100 µm (micrometers) to the macroscopic.
Viruses in nm = m
Bacteria in µm = 10-6 m
Helminths in mm = 10-3 m

11. Branches of Studies Bacteriology study of bacteria
Mycology study of fungi and yeast
Virology study of viruses
Parasitology study of parasitic protozoans and helminths
Immunology study of the humoral 體液 and cellular immune response to disease agents and allergens

12. Specializations in Microbiology
Epidemiology and Public Health Microbiology
distribution and spread of diseases and their control and prevention
Food Microbiology
use of microbes in the production of food products and drinks
Agricultural and Veterinary Microbiology
use of microbes to increase crop and livestock yield and control of plant pests and animal diseases
Environmental Microbiology
study of the beneficial and harmful effects of microbes on the environment

13. Modern Uses of Microbes
Biotechnology, the use of microbes as miniature biochemical factories to produce food (cheese, wine etc) and chemicals is centuries old.
Genetic engineering makes use of molecular biology and recombinant DNA techniques as new tools for biotechnology.
Gene therapy replaces missing or defective genes in human cells through genetic engineering.
Genetically modified bacteria are used to protect crops from pests and freezing.

14. Woese-Fox 3 Domain System
Microbial Taxonomy
Woese-Fox 3 Domain System

15. Fungi (fuhn-jahy, fuhng- gahy)
Eukaryotic (have membrane-bound nucleus)
Obtain food from other organisms
Possess cell walls
Macro and microfungi

16. microfungi Microfungi Molds multicellular; have hyphae;
reproduce by sexual and asexual spores
Yeasts
unicellular
reproduce asexually by budding
some produce sexual spores

17. Macrofungi and Microfungi

18. Protozoa (kingdom Protista)
Single-celled eukaryotes
Similar to animals in nutrient needs and cellular structure
Live freely in water; some live in animal hosts
Asexual (most) and sexual reproduction

19. Protozoans Most are capable of locomotion by
Pseudopodia – cell extensions that flow in direction of travel
Cilia – numerous, short, hair-like protrusions that propel organisms through environment
Flagella – extensions of a cell that are fewer, longer, and more whiplike than cilia

20. Protozoa Eukaryotes Mostly saprobes and commensals
May be motile by means of pseudopod, cilia or flagella

22. Algae
Unicellular or multicellular
Photosynthetic
Simple reproductive structures
Categorized on the basis of pigmentation, storage products, and composition of cell wall

24. Unicellular and lack nuclei Much smaller than eukaryotes
Bacteria and Archaea
Unicellular and lack nuclei
Much smaller than eukaryotes
Found everywhere there is sufficient moisture;
some found in extreme environments
Reproduce asexually
Two kinds
Bacteria – cell walls contain peptidoglycan; some lack cell walls; most do not cause disease and some are beneficial
Archaea – cell walls composed of polymers other than peptidoglycan

25. Bacteria (eubacteria)
Two kinds (formerly classified under kingdom Monera)
Bacteria (eubacteria)
cell walls contain peptidoglycan (pĕp′tĭ-dō- glī′kən);
some lack cell walls;
most do not cause disease and some are beneficial
Archaea (ahr-kee-uh) (archaebacteria)
cell walls composed of polymers other than peptidoglycan
Live in extremely environments such as hot- springs, salt lakes,

26. Helminths Eukaryotes Multicellular animals
Parasitic flatworms and roundworms called helminths
Microscopic stages in life cycles

27. Viruses Acellular Obligate intracellular parasites
Genome consist of DNA or RNA called Core
Core surrounded by protein coat called Capsid
Virion may be enclosed in lipid envelope

28. Redi’s Experiments
When decaying meat was kept isolated from flies, maggots never developed
Meat exposed to flies was soon infested
As a result, scientists began to doubt Aristotle’s theory
Spontaneous generation

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

30. Louis Jablot

31. Franz Schultze and Theodor Schwann

32. The Golden Age of Microbiology
Pasteur’s Experiments
When the “swan-necked flasks” remained upright, no microbial growth appeared
When the flask was tilted, dust from the bend in the neck seeped back into the flask and made the infusion cloudy with microbes within a day

33. Louis Pasteur put an end to Abiogenesis debate with his
Goose Neck Flask Expt
“father of microbiology”

34. Louis Pasteur Showed microbes caused fermentation
Studied spoilage and introduced “Pasteurization” to prevent it
Used cotton plugs in his cultures to prevent air borne contamination, devised Aseptic Technique.

35. Antiseptics and Hand Washing
1860s - Joseph Lister used, carbolic acid, a chemical antiseptic to prevent surgical wound infections
Ignaz Semmelweis, a Hungarian physician introduced hand washing as a means of preventing transfer of puerpueral sepsis 產褥期敗血症 in obstetrical patients

36. Germ Theory of Disease
Robert Koch provided proof that a bacterium causes anthrax using experimental steps now called the Koch’s Postulates
He was the first to use agar as solid culture medium in bacteriology.

37. Koch’s Postulates
The microbe must always be present in every case of the disease
It must be isolated in pure culture on artificial media
When inoculated into healthy animal host it should produce the same disease
It must be isolated from the diseased animal again

38. Infection and Disease Infection the entry of a microbe into the host.
Disease infection followed by the appearance of signs and symptoms.
Pathogen an infectious or disease agent.
Saprobe a microbe that lives on dead or decaying organic matter.
Opportunistic pathogen
is a microbe that cause disease in immunocompromised hosts or when the normal microbiota is altered.

43. What Causes Disease?
Pasteur developed germ theory of disease
Robert Koch studied causative agents of disease
Anthrax
Examined colonies of microorganisms

44. Koch’s Experiments Simple staining techniques
First photomicrograph of bacteria
First photomicrograph of bacteria in diseased tissue
Techniques for estimating CFU/ml
Use of steam to sterilize media
Use of Petri dishes
Aseptic techniques
Bacteria as distinct species
Koch’s Postulates

47. How Can We Prevent Infection and Disease?
Semmelweis and handwashing
Lister’s antiseptic technique
Nightingale and nursing
Snow – infection control and epidemiology
Jenner’s vaccine – field of immunology
Ehrlich’s “magic bullets” – field of chemotherapy

49. The Modern Age of Microbiology

50. What Are the Basic Chemical Reactions of Life?
Biochemistry
Began with Pasteur’s work on fermentation and Buchner’s discovery of enzymes in yeast extract
Kluyver and van Niel – microbes used as model systems for biochemical rxns
Practical applications
Design of herbicides and pesticides
Diagnosis of illnesses and monitoring of patients’ responses to treatment
Treatment of metabolic diseases
Drug design

51. How Do Genes Work?
Microbial genetics
Molecular biology
Recombinant 重組 DNA technology
Gene therapy

52. Recombinant DNA Technology
Genes in microbes, plants, and animals manipulated for practical applications
Production of human blood- clotting factor by E. coli to aid hemophiliacs
Gene Therapy
Inserting a missing gene or repairing a defective one in humans by inserting desired gene into host cells

53. What Role Do Microorganisms Play in the Environment?
Bioremediation 整治 uses living bacteria, fungi, and algae to detoxify polluted environments
Recycling of chemicals such as carbon, nitrogen, and sulfur

54. How Do We Defend Against Disease?
Serology
The study of blood serum
Von Behring and Kitasato – existence in the blood of chemicals and cells that fight infection
Immunology
The study of the body’s defense against specific pathogens
Chemotherapy
Fleming discovered penicillin
Domagk discovered sulfa drugs

55. What Will the Future Hold?
Microbiology is built on asking and answering questions
The more questions we answer, the more questions we have

56. Worldwide Infectious Diseases Affecting Health Sciences
Increasing number of drug resistant strains including Nosocomial and Community Acquired microorganisms
MRSA Methicillin Resistant Staphylococcus aureus
VRE Vancomycin Resistant Enterococcus
VRSA Vancomycin Resistant Staphylococcus aureus
MDR-TB Multidrug Resistant Tuberculosis

57. Worldwide Infectious Diseases Affecting Health Sciences
Increasing # of emerging diseases (SARS, AIDS, hepatitis C, viral encephalitis)
Other diseases previously not linked to microorganisms now are (gastric ulcers, certain cancers, multiple sclerosis)

58. Cellular Organization
Prokaryotic Eukaryotic

59. Definition of Life
What characteristics must an organism have in order to considered alive?
Metabolism: Transformation of energy by converting chemicals and energy into cellular components (anabolism) and decomposing organic matter (catabolism). Living things require energy to maintain internal organization (homeostasis) and to produce the other phenomena associated with life.
Reproduction: The ability to produce new individual organisms either asexually, from a single parent organism, or sexually, from at least two parent organisms.

60. Types of Microorganisms Based on Acquiring Nutrition
Autotrophic
Heterotrophic
Saprophytic or Saprobic 腐生

61. Viruses Not independently living cellular organisms
Much simpler than cells- basically a small amt of DNA or RNA wrapped in protein and sometimes by a lipid membrane
Individuals are called a virus particle or virion (vahy-ree-on)
Depend on the infected cell’s machinery to multiply and disperse

62. Taxonomy: Naming, Classifying, and Identifying Microorganisms
Microbial nomenclature-- (noh-muhn-kley-cher) naming microorganisms
Taxonomy-- classifying living things
Identification-- discovering and recording the traits of organisms so they can be named and classified

63. Traditional Whittaker Classification
Five Kingdoms
Prokaryotae (Monera)
Protista
Fungae
Plantae
Animalia
Based on:
Morphology
Metabolism (Biochemical Activity)
Molecular Techniques
Fatty Acid Profiles
Protein Differentiation
DNA Finger Printing

64. Classification Woese-Fox Classification 3 Super Kingdoms Eubacteria
Archaeabacteria
Eukarya
System is based on rRNA

65. Assigning Specific Names
The binomial system of nomenclature
The generic (genus) name followed by the species name
Generic part is capitalized, species is lowercase
Both are italicized or underlined if italics aren’t available
Staphylococcus aureus

66. The Origin and Evolution of Microorganisms
Phylogeny (fahy-loj-uh-nee) 發展史 -- the degree of relatedness between groups of living things
Based on the process of evolution-- hereditary information in living things changes gradually through time; these changes result in structural and functional changes through many generations
Two preconceptions:
All new species originate from preexisting species
Closely related organisms have similar features because they evolved from a common ancestor
Phylogeny usually represented by a tree- showing the divergent nature of evolution

67. The Origin and Evolution of Microorganisms
Based on the process of evolution----
Two preconceptions:
All new species originate from preexisting species
Closely related organisms have similar features because they evolved from a common ancestor
Phylogeny usually represented by a tree- showing the divergent nature of evolution

68. The First Microscope
Microbes were first observed by Antonie van Leeuwenhoek using a simple microscope (ca. 1673)
Reported his “animalcules” to the Royal Society of London

69. Spores and Sterilization
John Tyndall showed that some microbes in dust and air were resistant to heat.
Ferdinand Cohn discovered and described endospores
Term “sterile” was introduced to mean the complete removal of all life forms including endospores