1. Introduction to microbiology
Introduction to microbiology. Classification and nomenclature of microorganisms.

3. Course Introduction Instructor: Dr Elena Romancenco
Department of Microbiology, Virology and Immunology
WEBSITE:

4. Course objectives
List major groups of microorganisms and their habitats.
Overview and history of Microbiology.
Describe the system of scientific nomenclature used to name microorganisms.

5. Definition
Microbiology (mikros bios logos – small, live, study) study microorganisms and their activities.
Microbiology is the study of microorganisms usually less than 1mm in diameter which requires some form of magnification to be seen clearly.
Microbiology - study the organisms that can exist as single cells, contain a nucleic acid genome for at least some part of their life cycle, and are capable of replicating that genome themselves or getting replicated with the help of host cells

6. Branches of Microbiology
Bacteriology: study of bacteria
Mycology: study of fungi
Virology: study of viruses
Beijerinck, NE: discovered intracellular reproduction of TMV; coined the term “virus” (1899)
Parasitology: study of protozoa and parasitic worms

7. Branches of Microbiology
Immunology: study of immunity
Edward Jenner, UK: developed vaccination (1798)
Metchnikoff, RU: discovered phagocytes (1884)
Paul Ehrlich, DE: theory of immunity (1890)
Chemotherapy
Treatment of disease by using chemical means
Antibiotics produced naturally
Synthetic drugs
Paul Ehrlich (1878) – used arsenic compounds to fight disease

8. Branches of Microbiology
Chemotherapy
Alexander Fleming, Scotland (1928) discovered penicillin
Selman Waksman, Ukraine (1944) discovered streptomycin
Problems
Toxicity of drugs => Selective toxicity
Resistance of bacteria to drugs

9. Affect our lives in many different ways.
Microorganisms are everywhere, but why is so important to learn about them?
Affect our lives in many different ways.

10. Microbes are capable of growing in a wide variety of environments.
Bacteria will grow in frigid glaciers to boiling volcanic springs, dry sands to the open ocean.

12. IMPORTANCE OF MICROORGANISMS
Microorganisms are the oldest forms of life.
Nutrient production & energy flow
Production of foods
Decomposition (bioremediation)
Without certain microorganism life could not exist; produce O2 and N2
Production of drugs & vaccines
Genetic engineering
Causing disease
Microorganisms have killed more people than have ever been killed in war.

13. Why Study Medical Microbiology?
The majority of serious diseases in humans (especially those of early childhood) are due to microbial infections.
Prior to the discovery of antibiotics and vaccines, a large proportion of children died before adulthood because of infectious disease.
Till 1900, the average life expectancy in the United States was 40 years of age.
In years, largely due to the near eradication of most serious early childhood diseases.
This trend is seen in the gap between developed and developing countries in terms of causes of death (mortality).

14. MICROBES
MICROBES includes all those living organisms that can not be viewed (seen) in any detail by the human eye.
Alternatively, a MICROBE is any living creature that must be examined with a magnifying lens in order to see its unique physical characteristics (size, shape, motility, color).

15. Microbes Pathogen or pathogenic - capable of producing disease.
Though only a minority of microorganisms are pathogenic, practical knowledge of microbes is necessary for their treatment so is highly relevant to medicine and related health sciences.
Normal flora [normal microbiota] - not typically-disease-causing
microorganisms normally found in and on healthy individuals.
on the skin,
in the eyes,
in the nose,
in the mouth,
in the upper throat,
in the lower urethra,
in the lower intestine.

16. the Bacterium Escherichia coli;
a photosynthetic cyanobacterium
a fungus
Ebola virus
the malaria parasite (a protozoan 16

17. A, Influenza virus;
B, West Nile Virus;
C, Staphylococcus aureus;
D, Streptococcus pneumoniae.

18. Microbiologists may be interested in various characteristics or activities of microbs and may study:
Microbial morphology
Microbial cytology
Microbial physiology
Microbial ecology
Microbial genetics and molecular biology
Microbial taxonomy

19. Classification of life

20. For many years, living organisms were divided into two kingdoms:
Animalia (animal) and
Plantae (vegetable).

21. Classification Schemes
Two kingdoms
Plantae
Plantae
Animalia

22. But after 1800s, scientists realized that these two kingdoms could not adequately express the diversity of life.
Since the 1960s, the most widely used scheme - five kingdoms.
Viruses are separate group of biological entities, although not organisms in the same sense as Eukaryotes, Archaea and Bacteria.

23. Classification schemes, 5 kingdoms
Plantae
Monera
Protista
Plantae
Fungi
Animalia
Prokaryotes
Domain
Bacteria
(Eubacteria)
Domain
Archaea
(Archaeabacteria)
Eukaryotes

24. Classification of Life
3 major Domains of life
Bacteria
Archaea
Eukaryota (Eukarya)
The first two are Prokaryotes (Bacteria and Archaea)- without true nucleus, while the Eukaryotes all have a true nucleus in each cell.
The 3 Domains. Source:

26. Kingdom Monera All organisms in the Kingdom Monera are prokaryotes.
lack nuclei and organelles
most of their cell walls are made of peptidoglycan (the exceptions are the archaebacteria).
The archaebacteria have cell walls that lack peptidoglycan, cell membranes that utilize different lipids, and ribosomes similar to those found in eukaryotes.
The bacteria (eubacteria-true bacteria) are characterized by how they metabolize resources, their means of motility, and their shape.
Most organisms in the Kingdom Monera reproduce through binary fission (asexual) or conjugation (sexual).

27. Bacteria Most utilize flagella for movement.
Digestion is extracellular (outside the cell) and nutrients are absorbed into the cell.
Circulation and digestion in Kingdom Monera is accomplished through diffusion.

28. Bacterial Classificationby
Metabolism
Morphology (shape)
Staining, etc

29. According the metabolism
Autotrophs manufacture their own organic compounds.
Heterotrophs obtain their energy by feeding on other organic substances.
Saprophytes, a special kind of heterotroph, obtain energy by feeding on decaying matter.

30. According the symbiotic relationships with other organisms:
In parasitism, harm is caused to the host.
In commensalism, one organism benefits while the other is unaffected.
In mutualism, both organisms benefit.

31. According the respiration:
In obligate aerobes, the prokaryotes must have oxygen to live.
In obligate anaerobes, the organisms cannot survive in the presence of oxygen.
And in facultative anaerobes they can survive with or without oxygen.

32. According the shapes: cocci (spherical), bacillus (rod shaped), and
spirillum (spirals).

33. Classification of bacteria
Cocci
Micrococcus
Staphylococci
Irregular clusters of cocci
Diplococci
Pairs of cocci
Streptococci
Chains of cocci

34. Classification of bacteria
Bacilli
Rod like
Diplobacilli
Pairs of bacilli
Streptobacilli
Chains of bacilli
Spirochetes
Spiral

36. Size of bacteria Unit of microbial measurement
 micrometers (um)
1 um being 10-6  m   or m(1/25,000 inch)
nanometers 
1 nm being 10-9 or m.
Pathogenic bacterial species vary from approximately 0.4 to 2 um in size

38. Taxonomy
Taxonomy is the classification of organisms. The most common system in use today is the Five Kingdoms:
Monera (Prokaryota),
Protista,
Fungi,
Plantae, and
Animalia.
Organisms in each kingdom are divided into phyla.
In each phylum, organisms are separated into classes.
In each class, organisms are segregated into orders.
In each order, organisms are divided into families.
In each family, organisms are separated by genus.
And finally, in each genus organisms are divided into species.
Just remember that King Philip Can Order For Genial Students.

39. Naming micoorganisms Binomial (scientific) nomenclature
Gives each microbe 2 names
Genus - noun, always capitalized and may be abbreviated
species - adjective, lowercase, never abbreviated
A genus name may be used alone to indicate a genus group; a species name is never used alone
eg: Bacillus subtilis       B. subtilis
Both italicized or underlined
Staphylococcus aureus (S. aureus)
Bacillus subtilis (B. subtilis)
Escherichia coli (E. coli)

40. Nomenclature Common or descriptive names (trivial names)
Names for organisms that may be in common usage, but are not taxonomic names
eg: tubercle bacillus         (Mycobacterium tuberculosis)
meningococcus (Neiserria meningitidis)
Group A streptococcus (Streptococcus pyogenes)

41. Eukaryotes

42. Prokaryotes Kingdom - Monera Domain - Bacteria Phylum – Proteobacteria
Class – Gammaproteoba
Order – Enterobacteriale
Family – Enterobacteriace
Genus – Escherichia
Species – Escherichia coli

43. "The role of the infinitely small in nature is infinitely large"
Louis Pasteur

44. Historical Perspectives

45. Historical YEAR NAME ACHIEVEMENT 1st century BC Varo
Concept of “Animalia minuta”
1546
Fracostorius
Contagion- Cause of syphilis
1590
Jensen
Hand lens
1683
Antony van Leeuwenhoek
First Microscope
“Animalcules”
1678
Robert Hook
Compound microscope
1745
Needham (Priest)
Abiogenesis
1836
Schulze & Schwan
Air contains microbes
1840
Oliver Homes, Poet physician
Contageousness & Puerperal fever
1846
Ignaz Semmelweis
Cause, concept & prophylaxis of child-bed fever
1853
Augustino Bassi
Silk worm disease due to a fungus

46. Pioneers of Microbiology
Robert Hooke, UK (1665)
Proposed the Cell Theory
Observed cork with crude microscope
All living things are composed of cells
Spontaneous generation
Some forms of life could arise spontaneously from non-living matter
Francesco Redi, IT (1668)
Redi’s experiments first to dispprove S.G.

47. Antonie van Leeuwenhoek
First to observe living microbes
his single-lens magnified up to 300X
( )

48. Louis Pasteur (1822-1895) French chemist
Father/Founder of Modern Microbiology
Fermentation – a microbiological process
Beer/Wine not produced without microbes
Showed microbes caused fermentation & spoilage
Disproved spontaneous generation of m.o.
Developed aseptic techniques.
Developed a rabies vaccine.
( )

49. Louis Pasteur 1822-95 Methods & Techniques of cultivation
Introduced sterilization
Tyndalization (Tyndal-1877)
Studied Silkworm disease, anthrax, chicken cholera, hydrophobia.
Introduced live vaccines – Jenner (Cow-pox vaccine)
Antirabic vaccine
Pasteur Institutes

50. Joseph Lister 1867 Prof of Surgery, Glasgow Royal Infirmatory
Introduced Antiseptic Surgery
Called Father of Antiseptic Surgery

51. Robert Koch (1843-1910) German general practitioner
Perfected bacteriological techniques
Isolated pure cultures of bacteria for the first time
Discovered Anthrax bacilli, Cholera vibrio, M. tuberculosis
Father of Medical Microbiology
Hypersensitivity
Established a sequence of experimental steps to show that a specific m.o. causes a particular disease.
( )

53. Highlights in the History of Microbiology
1900
Proved mosquitoes carried the yellow fever agent (Walter Reed)
1910
Discovered cure for syphilis (Paul Ehrlich)
1928
Discovered Penicillin (Alexander Fleming)
1887
Invented Petri Dish
(R.J. Petri)
1892
Discovered viruses (Dmitri Iosifovich Ivanovski)
1899
Recognized viral dependence on cells for reproduction (Martinus Beijerinck)

54. Highlights in the History of Microbiology
1977
Developed a method to sequence DNA (W. Gilbert & F. Sanger)
1983
Polymerase Chain Reaction invented (Kary Mullis)
1995
First microbial genomic sequence published (H. influenzae) (TIGR)