Transcript TLCppt

TLC Event
Microbes Are Everywhere: Do They
All Want To Kill Me?
Part I: What is a microbe
Amy Czura
Part II: Micro lab: making slides
Amy Czura & Paul Anderson
Part III: Micro lab: observing your bacteria
Amy Czura & Paul Anderson
Microbes Are Everywhere: Do They All Want To Kill Me?
NO!
What are Microorganisms / Microbes:
-they are typically unicellular
-they are typically too small to see with the unaided eye
-they include:
bacteria & archaea
fungi
protozoa
algae
viruses
Microorganisms / Microbes Continued:
-they are located almost everywhere on the planet
-only a small % are pathogens
pathogen = organism that causes disease
-most are involved in environmental / ecosystem balance:
*breakdown waste
*fix nitrogen
*photosynthesis – carbon fixation
foundation of food chains
*digestion in animals
Bacteria
Coccus
Bacillus
Spiral
How big is a bacterium?
About one micrometer (µm): one one-thousandth of a
thousandth of a meter. Very, very small.
Average Human Cell = ~50µm
Bacteria
Average Bacterium = ~1-3µm
A dime ($0.10) = 18,000µm
It would take over 127 million
bacteria to cover one face of a
dime!
Human Cheek Cell
Archaea
Methanogens
Halophiles
Thermophiles
Fungi
Protozoa
Algae
Viruses
Virus: an obligate intracellular parasite
Integrating Viruses
Herpes
HIV
ChickenPox /Shingles
The next new flu
Influenza virus: constantly changing
Prions
“proteinaceous infectious particle”
PrPC protein in neurons, folded incorrectly
Prions
Disease: spongiform encephalopathy
Mad cow, Sheep scrapie, Kuru, Creutzfeldt-Jakob
BioQUEST
First bacteria appear in the fossil record 3.5 billion years ago,
first cellular life on earth, but
Microbes were not discovered until the 1670s:
Antoni van Leeuwenhoek (bacteria & protozoa)
Microbes not linked to disease until 1876:
Robert Koch (Bacillus anthracis causes Anthrax)
Koch’s Postulates
Viruses were discovered in the late 1890s as “filterable
infectious agents” but were not observed until the electron
microscope was developed in the 1930s
HEPA “high efficiency particulate air” filters trap things
0.2µm and larger:
typical bacterium is 1µm
typical virus is smaller than 0.1µm
First antibiotic was discovered in 1928: Fleming
(Penicillium mold contamination on Staphylococcus plates)
Production of penicillin for public use not until the 1940s
1950s through 1970s and beyond: New antibiotics discovered,
new chemotherapy agents designed in lab
Late 1960s – early 1970s public health officials declare
society is witnessing the end of infectious disease!
(Meanwhile Penicillin went into public use in 1943 and the
first Penicillin resistant strain of Staphylococcus was
discovered in 1947)
Widespread overuse and misuse of antibiotics &
antimicrobial drugs has resulted in the evolution of multidrug resistant bacteria strains
In the U.S. death rates from infectious disease increased 58%
between 1980 and 1992
In 2009 infectious disease was still the 4th leading cause of
death in the U.S. after heart disease, cancer, and stroke
Worldwide, in the 21st century, infectious disease still
accounts for 16-26% of all deaths annually
Total microbes on earth that are pathogens is less than 10%
Most microbes are beneficial!
Normal Microbiota
-colonize inside and outside surfaces:
skin: Staphylococcus species
mouth/nose: Staphylococcus and Streptococcus species
large intestine: Enterobacteriaceae family e.g. E. coli
vagina: Lactobacillus species
-often protective:
E. coli produce bacteriocins to kill Salmonella
Lactobacillus create acid pH to prevent yeast growth
All occupy space preventing pathogen colonization
-other beneficial activities:
vitamin production in gut
Vitamin K for clotting factor synthesis
Biotin for glucose metabolism
Vitamin B5 for neurotransmitter synthesis
Normal Microbiota
-can be opportunistic pathogens
Staphylococcus infections of wounds
UTIs from intestinal bacteria
-immunocompromised patients:
organ transplant recipients
cancer patients
HIV positive / AIDS
Microbes are good for the environment
Recycling nutrients back into the food chain:
Decomposition
QuickTime™ and a
YUV420 codec decompressor
are needed to see this picture.
Play Decomposers.mov
Photosynthesis: Cyanobacteria & Algae
Carbon fixation
Harvesting light energy to convert carbon dioxide and
water into glucose and oxygen
Nitrogen fixation & Nitrification
Microbes are very useful to humans
Wastewater (Sewage) treatment
www.wedotanks.com
Compost
Methane
Bioremediation
= using microbes to break down toxins
e.g. Pseudomonas has enzymes to digest crude oil as a
food source
Commercial applications:
Produce acetone, vinegar, methanol, ethanol...
Household enzyme based cleaners and detergents
Biodegradable plastic-like polymers
Your favorite blue jeans:
“Stone washed” denim: cellulase from fungus
Cotton and polyester: polymers made by bacteria
Peroxidase from mushrooms for bleaching
Indigo dye from indole made in bacteria
Agriculture: Insect Pest Control
Bacillus thuringiensis
Agriculture: Genetic Engineering of Plants
Agrobacterium tumefaciens
insert genes for:
-pest control
-nitrogen fixation
-drought tolerance
Therapeutics:
Antibiotics
Human gene products
-insulin
-growth hormone
Vaccines
Food