Introduction to Microbiology and Parasitology Louie Oalin Domingo, MD Professor I
Oct 28, 2014
Introduction to Microbiology and Parasitology
Louie Oalin Domingo, MDProfessor I
Brief History of Microbiology
Robert Hooke (1665)
- described a thin slice of cork called “little boxes” or “cells”
- started the Cell Theory ( all living things are composed of cells)
Brief History
Anton van Leeuwoenhoek (1632-1723)
- Father of Microbiology/
Bacteriology/ Protozoology
- saw through his
single-lens microscope
“animalcules” (little animals)
- examined scrapings from his teeth, water from ditches and ponds, stools, water soaked in blood, sperm, peppercorn
Brief History
Spontaneous Generation Theory (Abiogenesis) (1650- 1850)
- a theory proposed by some scientists that living things came from non-living things
Brief History
Francisco Redi (1668)- strong opponent of spontaneous
generation theory- theorized that maggots did not arise from
decaying meat- set-up six jars with decaying meat: three
jars sealed; three jars unsealed- not all scientists convinced; they argued
that air is needed for life to thrive- set up three jars with decaying meat
covered by fine nets
Brief History
John Needham (1745)
- favored spontaneous
generation theory
- found that even he
heated broth, before putting
it in a flask, cooled solutions were teaming with organisms
- claimed that organism developed spontaneously from fluids
Brief History
Lazaro Spallanzani (1755)
- opposed John
Needham’s theory
- he said that
microorganism from air
might have entered the flasks after they were boiled
Brief History
Theory of BIOGENESIS (1858)
- states that all living things arise from pre-existing living things
- proposed by Rudolph Virchow
Brief History
Louis Pasteur (1822-1895)
- strongly supported biogenesis theory
- said that microorganism are present in air and can contaminate sterile solution
- placed a broth in the flask, boiled it and bent the tube into S-shape
- put a fatal blow in theory of spontaneous generation
Brief History
Golden Age of Microbiology (1857-1914)
- many microbiologic advances were made
- spearheaded by Koch’s and Pasteur
Golden Age of MicrobiologyYear Scientist Discoveries
1857-1864 Louis Pasteur Fermentation, Pasteurization and disproved spontaneous generation theory
1867 Joseph Lister Aseptic Surgery
1876 Robert Koch Germ theory of disease
1879 Neisser Neisseria gonorrhoeae
1881- 1883 Robert Koch Pure cultures/ Mycobacterium tuberculosis and Vibrio Cholera
1884 Metchnikoff
Gram
Escherich
Phagocytosis
Gram staining
Escherichia coli
Golden Age of Microbiology
Year Scientists Discoveries
1887 Petri Petri Dish
1889 Kitasato Clostridium tetani
1890 Von Bering Diphtheria antitoxin
Ehrlich Theory of Immunity
1898 Shiga Shigella dysenteriae
1910 Chagas Trypanosoma cruzi
Ehrlich Treponema pallidum
Brief History
Louis Pasteur (1857)- Fermentation was
discovered
- He was asked by
a group of merchant why
beer and wine soured (spoilage)
- He found out that yeasts convert sugar to alcohol that makes it sour
- He boiled (55 C) the wine and beer enough to kill bacteria (PASTEURIZATION)
Brief History
Louis Pasteur
- discovered that some microorganism require oxygen to live (aerobes) while others do not (anaerobes)
- discovered the infectious agent that cause silkworm disease and how to prevent it
- developed vaccines to fight cholera, anthrax and swine erysipelas (skin disease)
Brief History
GERM THEORY OF DISEASE
- theory that microorganism have similar relationship with plants and animals
- microorganism can cause disease
- strongly proved by Robert Koch
Brief History
Robert Koch (1843 – 1910)
- discovered Bacillus
anthracis, a bacteria that
causes anthrax (his basis
for Koch’s postulate)
-discovered Mycobacterium tuberculosis (Pulmonary Tuberculosis) and Vibrio cholera (cholera)
Brief History
Koch’s Postulate (1884)- strengthened Germ theory of disease- Isolated Bacillus antrhacis from dead
cattle then cultured (cultivate/grow) it- the cultured organism was injected to
healthy animal- the healthy animal which becomes sick,
took sample of their blood and isolated the organism
- he found out that the cultured organism was same as the isolated organism
Brief History
KOCH’S POSTULATE principles:1. A particular microorganism must be found in all
cases of the disease and must not be present in healthy animals or humans
2. The microorganism must be isolated from the disease animal or human and grown in pure culture in laboratory
3. The same disease must be produced when microorganisms from pure culture are inoculated into healthy susceptible laboratory animals
4. The same microorganism must be recovered from the experimentally infected animals and grown again in pure culture
What is Microbiology?
Study of very small living organisms (microorganism) or microbes (Burton’s)
“micro” =small; “bio”= life; “logos”=study
Why Study Microbiology?
Indigenous Micro flora/ Normal Flora/ Mircrobiota
Some organism causes diseases (Opportunistic pathogen)
Contribute to balance Eco-system (ecology)Important in various industries (food and
beverage)AntibioticGenetic Engineering
Types of Microorganisms
Bacteria (sing. bacterium)- simple, unicellular organisms- prokaryotic - not enclosed in a nuclear
membrane- have several shapes (rod, bacilli,
cocci, spiral)- produced by binary fission- e.g. Staphylococcus, Streptococcus
Types of Microorganism
Archaea
- prokaryotic
- not known to cause disease in humans
- divided into three groups: a. Methanogens: produced methane as by
product
b. Halophiles: lived in extremely salty environment
c. Thermopiles: lived in hot sulfurous environment
Type of Microorganism
Fungi (sing. Fungus)
- eukaryotic
- unicellular or multicellular
- have special cell walls called chitin
- most typical fungi are Molds
- e.g. Pityriasis versicolor (“an-an”)
Tinea pedis (athlete’s foot)
Type of Microorganism
Protozoa (sing. Protozoan)
- unicellular, eukaryotic
- move by pseudopods, cilia, flagella- pleomorphic (assumes many sizes and shapes)
- free-living and/or parasitic
- e.g. Entamoeba histolytica- Amoeba
Types of Microorganism
Algae (sing. Alga)
- photosynthetic eukaryotes
- unicellular
- composed of cell wall called cellulose
- play a vital role in balance of nature
- produces oxygen and carbohydrates used by other animals
Types of Microorganism
Viruses- very small (cannot be seen by a
naked eye)- acellular (not cellular)- multiply once inside the host cell but
inactive when outside the host (INERT)- e.g. Measles virus, Influenza A
(H1N1), HIV, Rotavirus, Human Papilloma Virus
Types of MicroorganismParasites
- multicellular- strictly not microorganism but of
medical importance- the host is usually harmed (disease)- e.g. Ascaris lumbricoides (roundworm)
Enterobius vermicularis (pinworm or seatworm)
Sarcoptes scabies (scabies or “galis-aso”)
Naming and Classifying Organism
Established by Carolus Linnaeus in 1735Became the Linnaean System of
ClassificationScientific names were Latin because it is
traditionally used by scholarsAssigned organism with two names:
GENUS and SPECIES
Naming and Classifying Organism
GENUS- first letter is capitalized
• Species- all small letters
• Both Genus and Species are underlined OR italicized
Examples:Staphylococcus aureusAscaris lumbricoidesStreptococcus pyogenesHomo sapiens