Transcript Introductory Microbiology - Biologi 2010 Universitas Airlangga

Introductory Microbiology
Dr. Heather Townsend
Summer 2009
Microbiology
•
•
The study of of organisms
(microorganisms or microbes) too
small to be seen without magnification
This includes:
1.
2.
3.
4.
5.
6.
Bacteria
Viruses
Fungi
Protozoa
Helminths (worms)
Algae
The Microbes
• 1. Bacteria
– Single-celled
organisms
– Various shapes
• Spherical
• Rod
• Spiral shapes
– Cellular
– Lack membraneenclosed cellular
structures
– Widely distributed in
nature
Klebsiella pneumoniae,
bacteria that causes
pneumonia in humans
The Microbes
• 2. Viruses
– Acellular
– Composed of nucleic
acid and a few
proteins
– Replicate
themselves to
display other
properties of living
organisms when they
invade living cells
Bacteriophages observed at 35,500X
• 3. Fungi
– Yeasts and molds
The Microbes
• Single-celled,
microscopic
– Mushrooms
• Multicellular,
macroscopic
– Cell nucleus and
other cellular
structures
– Absorb nutrients
from their
environment
– Widely distributed in
water and soil
– Act as decomposers
of dead organisms
Philobolus crystallinus, fruiting bodies
of this fungus
• 4. Protozoa
– Single-celled,
microscopic
organisms
– Have at least one
nucleus and many
cellular structures
– Obtain food by
engulfing or
ingesting smaller
organisms
– Most can move
– Found in many
different
environments
The Microbes
Amoeba
The Microbes
• 5. Misc.
– Large, multicellular
– Worms
• Helminths
– Arthropods
• Insects
Tapeworm Head
• 6. Algae
– Single-celled
microscopic
organisms
– Have a nucleus and
many membraneenclosed cellular
structures
– Photosynthesize
their own food
– Widely distributed in
fresh and salt water
– Important source of
food for other
organisms
The Microbes
Micrasterias, a green algae living in
fresh water.
Branches of Study Within
Microbiology
• Immunology:
– studies immune chemicals and cells that are produced in response
to infection
• Public health microbiology & epidemiology:
– aim to monitor and control the spread of diseases (CDC)
• Food, dairy and aquatic microbiology:
– examine the ecological and practical roles of microbes in food and
water
• Biotechnology:
– ranges from bread making to gene therapy
• Genetic engineering & recombinant DNA technology:
– altering the genetic makeup of organisms
Microbes Are Involved In:
• nutrient production & energy flow
– i.e., photosynthesis
•
•
•
•
decomposition and nutrient recycling
production of foods, drugs & vaccines
bioremediation
causing disease
Impact of Pathogens
• Pathogens
– Diseases-causing agents
• Nearly 2,000 different microbes cause
diseases in the human body
• 10 B infections/year worldwide
• 13 M deaths from infections/year
worldwide killing about 1/3 of the U.S.
population each year
Impact of Pathogens
• Emerging diseases
– Becoming more prominent over the years
– Zoonosis
• SARS
• Reemerging
– Older diseases increasing in occurrence
• TB
• Malaria
• Hepatitis
• Noninfectious diseases
Characteristics of Microbes
• Prokaryotic cells
– Smaller
– Lack special structures such as a nucleus and organelles
– All prokaryotic cells are microorganisms
• Only some microorganisms are eukaryotic
Lifestyles of Microorganisms
• Free existence
• Close associations
– Parasites
– hosts
Antonie van Leeuwenhoek
• First to observe living
microbes
• His single-lens
magnified up to 300X
(1632-1723)
Early Medical Microbiology
• Louis Pasteur:
– Worked in the wine industry
• Had knowledge about yeast
producing alcohol
– Swan-neck flasks
– Tipping the flask would allow
the microbes to enter the
infusion
• Cause them to become cloudy
• Main experiment that helped
disprove spontaneous generation
Early Medical Microbiology
•Pasteur discovered that some yeasts made good
tasting wine
•Mixtures of microbes competed with yeast
and made wine taste oily or sour
•Developed Pasteurization to deal with this
problem
–Heated the wine to 56°C without oxygen present for
30 minutes
•Developed a rabies vaccine
Early Medical Microbiology
• Robert Koch (~120 years
ago, German)
– Linked a microscopic organism
with a specific disease
(anthrax)
– Developed method to grow
bacteria in pure cultures
(cultures containing only one
kind of organism)
• Used solidified gelatin from
potato slices mixed with
agar
• Creates a firm surface that
microbes could grow on
Koch’s Postulates
1. The specific causative agent must be
found in every case of the disease
2. The disease organism must be
isolated in pure culture
3. Inoculation of a sample of the culture
into a healthy, susceptible animal must
produce the same disease
4. The disease must be covered from the
inoculated animal
Early Medical Microbiology
• Oliver Wendell (American
physician)
– observed mothers who gave birth
at home experienced fewer
infections than those that gave
birth in a hospital
• Ignaz Semmelweis (Hungarian
doctor)
– showed that women became
infected with puerperal fever
during delivery by doctors coming
directly from the autopsy room
Early Medical Microbiology
• Joseph Lister (English surgeon)
– Introduced aseptic techniques
• Aimed at reducing microbes in a medial setting
and preventing wound infections
– Improved sanitation
• Promotes use of carbolic acid on bandages and
medical instruments
Spontaneous Generation Theory
• Germ theory of disease:
– “Microorganisms can invade other organisms and
cause disease”
– Many diseases are caused by the growth of microbes
in the body and not by sins, bad character, or poverty,
etc.
• Spontaneous generation
– “Living things arise from nonliving things”
– Belief that some forms of life could arise from vital
forces present in nonliving or decomposing matter
• Maggots found in rotting meat arose from a nonliving factor
• Microorganisms found in broth that made it cloudy appeared
from a nonliving factor
What to expect……..
• Different microorganisms
• How to detect microorganisms
• Common disease caused by
microorganisms
• How to control the spread of
microorganisms
• Immune system