Microbiology-Chapter 1 Humans and the Microbial World

What kind of impact have influenza and the Black Death had throughout history?

- In 1918-1919 influenza killed more Americans than died in WWI, WWII, Korean, Vietnam, and Iraq wars combined - Black Death killed over 6 million people

how are most microorganisms transmitted?

- by sharing a glass/drink - biological vector such as tick or flea or mosquito (west nile mode of transmission)

list some examples of commercially valuable products produced by bacteria.

- cellulose (stereo headsets) - ethanol (biofuel) - hydrogen gas (possible biofuel) - insect toxins (insecticides) - antibiotics (treatment of disease) - amino acids (dietary supplements)

what virus causes canker-sores?

- herpes simplex I

What is the structure of Eukarya?

- membrane bound nucleus and other organelles - more complex than prokaryotes

What has been used in attempt toe due incidences of the worst diseases?

- modern sanitation vaccination and effective antimicrobial treatments

What is the structure of bacteria?

- no other membrane bound organelles - no membrane-bound nucleus - DNA in nucleoid - Specific shapes include rod, spherical, spiral - rigid cell wall containing peptidoglycan (unique bacteria)

What are some examples of multicellular animal parasites?

- Eukaryotes - multicellular animals - parasitic flatworms and roundworms called helminths (heartworm is an example)

What is the structure and function of protozoa?

- single-celled - complex, larger than prokaryotes - no rigid cell wall - most motile - most ingest organic compounds

what is the structure and function of fungi?

- single-celled (e.g., yeasts) or multicellular (e.g., molds, mushrooms) - energy from degradation of organic materials

what is the structure and function of algae?

- single-celled or multicellular - photosynthetic (contains chloroplasts with chlorophyll or other pigments) - have rigid cell walls - have flagella (cell walls and flagella are distinct from those of prokaryotes)

what are some examples of the most newly recognized, emerging diseases that pose as future challenges?

- swine flu - severe acute respiratory syndrome (SARS) - Multidrug-resistant tuberculosis - lyme disease - hepatitis C - acquired immunodeficiency syndrome - mad cow disease - west nile encephalitis

what are some examples of non-living members of the microbial world?

- viruses, viroid, prions - acellular infectious agents (classified as not alive) not true life forms, disease agents (thus, not microorganisms)

How many steps does it take to make chocolate?

14 microbial steps

How many microbiota do we have and where do they reside?

500 and live in the small intestine

what produces de-bleaching of material?

A mushroom peroxidase

How are algae and protozoa termed?

A protists (some multicellular parasites including helminths (roundworms and tapeworms) are considered as well

What are some examples of microbes?

Algae, bacteria, molder fungi, parasite, mushrooms, viruses

which surfaces of the human body are populated by microorganisms?

All surfaces

What causes the Black Death?

Bacteria carried in fleas in rats called Yesinia pestis (has killed over 6 mil. proper in Europe in the 16th century)

How is microbiology involved in food production?

Baking bread uses yeast (Egyptian bakers as early as 2100 B.C.) Fermentation of grains to produce beer (Egyptian tombs revealed as early as 1500 B.C.) fermentation of milk (yogurt, cheese, buttermilk etc.)

What foods are microbes involved in?

Bread, cheese, yogurt, beer, wine, and even root beer

how is microbiology involved in biodegradation?

Degrades PCBs, DDT, tricholoethylene, and other pollutants - they help clean up oil spills - involved in bioremediation

What do you think of when you hear microbiology?

Disease, death, germs, and bacteria

What produces indigo blue color?

E. coli

What is another example of emerging diseases that are still present?

Evolution of infectious agents previously unable to infect humans (e.g., HIV/AIDS, SARS)

How many people die from the plague worldwide today?

Fewer than 100 people

what are the microbial members within the Eukarya domain?

Fungi, algae, protozoa

What is another name for the nitrogen cycle?

Geo-nutrient cycling

what bacteria produces cotton fiber?

Gluconacetobacter

what is one example of a harmful pathogen?

Influenza

why are we still seeing emerging diseases?

a lot of it has to do with timing - for example, hantavirus (carried in mice and transmitted to humans via dried urine), thus individuals in closer contact with these animals are at greater risk

What is peptidoglycan?

a network of sugar polymers cross-linked by polypeptides

how many people died from the plague in 1346-1350?

about 1/3 of population in Europe (or about 25 million individuals) died

How are protozoa classified?

by how they move (diverse Eukarya)

what assists emerging diseases such as hantavirus?

changing lifestyles (such as more people moving into rural areas that collide with mice populations) increase opportunities to spread said diseases

What other Developments have occurred in response to the plague?

control of rodent population harboring bacterium, and antibiotics are available.

Where can nitrogen-fixing bacteria be found?

free-living in soil or water, or they may form symbiotic relationships with their roots

Why was the smallpox vaccine resurrected after 9/11?

in concern of bio-weaponry, thus military individuals were vaccinated in vase that this virus was used as a weapon.

where are algae usually found?

in the water

what are prions?

infectious proteins in which misfolded versions of normal cellular proteins are found in the brain - misfolded proteins force normal proteins to misfold as well - abnormal proteins bind to form fibrils - cells are thus unable to function

what is the most common prion currently?

mad cow disease

What are some benefits of microorganisms?

nitrogen fixation, oxygen production, degradation of materials (e.g., cellulose, sewage and wastewater)

What are harmful microorganisms called?

pathogens

where are fungi found?

primarily on land living on decaying material

which algae are harmful?

red tide algae which produce some of the most harmful toxins known to mankind, some green algae species can also produce dangerous toxins (diverse group)

what do prions cause?

several neurodegenerative diseases in humans and animals

what viral disease was once a leading killer?

smallpox

define biotechnology

the use of microbes to produce foods and chemicals (insulin production, vaccine production, antibiotics etc.): this technique is centuries old

what does the microbe bacillus thrum function to do?

these microbes are pathogenic to aphids and are used as alternatives to chemical pesticides in preventing insect damage to agricultural crops, roses, and disease transmission

what are some disadvantages of microorganisms?

they have killed more people than have ever been killed in war (they have been used as weapons, and recently in bioterrorism attacks)

what could not exist without microbes?

us and the world

What is bioremediation?

use of living microorganisms to hasten decay of pollutants

how do bacteria move?

using flagella

how do bacteria multiply?

via binary fission

What do microbiota produce?

vitamin K and biotin

When are microbes not at their best function on the surfaces of our bodies?

when they change, and this is when we run into issues such as MRSA

What is the result within the host from pathogens?

Damage to body tissues --> disease symptoms (Herpes, HIC, smallpox, chicken pox etc.)

What does prokaryote stand for?

"prenucleus"

what does eukaryotes mean?

"true nucleus"

How many people died from smallpox?

Around 10 million deaths over 4,000 years (this was devastating to unexposed populations ex: Aztecs in New World)

Give an example of a product that can be produced by microbes.

Jeans that we wear

how has vaccination become a victim of its own success among emerging diseases?

Lack of firsthand knowledge of dangers of diseases can lead people to fear vaccines more than the diseases. - Ex: diseases such as measles, mumps, and whopping cough were nearly eradicated from U.S., but could re-emerge with declining vaccination rates

What are the benefits of microbes?

Less build-up of carcasses, plant material, and trash

What percent of bacteria cause diseases?

Less than 1%

what are considered beneficial microbes?

Normal microbiota aka normal flora

What is another major leading killer in history?

Plague

examples of plants in which plant-microorganisms symbiotic relationships are formed?

Rhizobium and legumes

what are prions resistant to?

Sterilization procedures

how are fungi classified?

Structure and method of reproduction (diverse eukaryote)

What are examples of a microbe that causes diseases?

The Black Death, and HIV which causes AIDA

What are bacteria?

They are single-celled prokaryotes

what do pathogens do?

They cause disease

what are normal flora/microbiotia?

They prevent diseases by competing with pathogens, they aid in digestion and they help develop immune system responses

what would plants not be able to do without microorganisms morning symbiotic relationships with their roots?

They would not be able to undergo nitrogen fixations

What parasite causes stone-washing looks?

Trichoderma

What do we do for microbiota?

We provide them a home

Advertisements tell you that bacteria and viruses are all over your home and that you need to buy antibacterial cleaning products. Should you?

While it may seem like a good idea to kill off bacteria and viruses that are not visible to the naked eye, our bodies also may be equipped to fight off these pathogens without the use of antibacterial cleaning products. There is a chance that over use of these cleaning products will allow the bacteria and viruses to evolve into more harmful/resistant forms that will no longer be killed off by the cleaning products, and consequently may even be able to evade our natural immune responses.

what was used in attempt to eliminate the smallpox disease?

Worldwide eradication (no reported cases since 1977)