Microbiology 6e

1
Chapter 10 Microbial Ecology
http//www.medicalecology.org/diseases/influenza/i
nfluenza.htm
2
Basic Concepts Ecology
The Study of Organisms and their
interrelationships with the world around them.

• Our wet moist openings and,
• our dark food filled places
• Ears and eyes
• Mouth and upper Respiratory tract
• Skin
• Gastrointestinal
• Genitourinary

3
30 or so common types of indigenous
Microflora Dependant on PH, temp, salinity, waste
products and other microbes
4
Symbiotic Relationships
Parasitism
Mutualistic
Commensalism
(Both organisms benefit)
(One organism benefits The other unaffected)
(One organism benefits The other one loses)
5
Synergistic Infections

• Two organisms working to cause one bad infection
• Gingivitis
• Bacterial vaginosis

6
Indigenous Microflora
Typically 10 trillion bacterium on and in your
body. Blood, lymph, spinal fluid, and most
internal tissues not invaded by
microorganisms. Indigenous Microflora, always on
or in the body. Temporary residents , transient
microflora.
7
Common culprits
Ears and eyes, bacterium causing middle ear
infections Respiratory tract, diptheria,
menengitis, pnuemonia, and whooping cough. Oral
cavity, gingivitis, periodontal disease,
cancer. Gastrointestinal tract, Helicobacter
pylori causes ulcers, E. coli common cause of
urinary infections. Genitourinary tract,
Chlamidia, tractomatis, Neisseria gonorrhoeae
and mycoplasmas, introduced by urethra problems
and sexual intercourse.
8
Beneficial and harmful roles
Normal flora benefits Prevent bad microbes from
becoming established by microbial
antagonism. Intestinal bacteria produce needed
substances we dont Synthesize ( vitamins K and
B12, pantothenic acid, pyridoxine and
biotin). Produce bacteriocins killing harmful
bacteria. The paradox many of the beneficial
bacterium found in the wrong places are
opportunists pathogens causing infection ( exp
E.coli, Staphylococcus aureus and Enterococcus
spp.)
9
Microbes play a big part in many elemental cycles
10
Soil Microbes that can cause infection Human
pathogens
Clostridium spp C. tetani, causative agent in
tetanus, C. botulinum, causative agent for
botulism and the C.spp,causative agent for gas
gangrene. Bacillus anthracis, causative agent
for anthrax. Various other fungi and yeast can
cause respiratory infections.
11
Diseases of farm animals
12
Diseases of plants
13
Biotechnology big business Jobs (Techs) and
Money (Start-ups)
The average annual wage of U.S. bioscience
workers was 65,775 in 2004, more than 26,000
greater than the average private sector annual
wage. Market capitalization, the total value of
publicly traded biotech companies (U.S.) at
market prices, was 410 billion as of Dec. 31,
2005. The biotechnology industry has mushroomed
since 1992, with U.S. health-care biotech
revenues increasing from 8 billion in 1992 to
50.7 billion in 2005. From the biotechnology
industry organization.
14
Bioremediation making microbes work for us.
Bioremediation uses living organisms to clean up
contaminated soil or water. Despite its broad
definition, bioremediation usually refers
specifically to the use of microorganisms.
Bioremediation is a combination of two words
bio, short for biological, and remediation,
which means to remedy.
15
Types of Bioremediation
Biostimulation -- Nutrients and oxygen - in a
liquid or gas form are added to contaminated
water or soil to encourage the growth and
activity of bacteria already existing in the soil
or water. The disappearance of contaminants is
monitored to ensure that remediation occurs.
16
Types of Bioremediation
Bioaugmentation -- Microorganisms that can clean
up a particular contaminant are added to the
contaminated soil or water. Bioaugmentation is
more commonly and successfully used on
contaminants removed from the original site, such
as in municipal wastewater treatment facilities.
To date, this method has not been very
successful when done at the site of the
contamination because it is difficult to control
site conditions for the optimal growth of the
microorganisms added. Scientists have yet to
completely understand all the mechanisms
involved in bioremediation, and organisms
introduced into a foreign environment may have a
hard time surviving.
17
Types of Bioremediation
Intrinsic Bioremediation -- Also known as natural
attenuation, this type of bioremediation occurs
naturally in contaminated soil or water. This
natural bioremediation is the work of
microorganisms and is seen in petroleum
contamination sites, such as old gas stations
with leaky underground oil tanks. Researchers are
studying whether intrinsic bioremediation
happens in areas with other types of chemical
contamination. Application of this technique
requires close monitoring of contaminant
degradation to ensure that environmental and
human health are protected.