Ch. 1 The Microbial World and You Flashcards
Global burden of infection Disease in common?
Extreme poverty and children get it worse
TB
1/3 of the world infected
Malaria
200 million
Influenza
4,000 deaths in US
40,000 globally
Hepatitis
Globally at least 50 million
AIDs
Cases in US 900,000 deaths
Globally 32 million (most in Africa)
Ascariasis
Round worm infection in lungs
Infected 1.5 billion
Types of Microorganisms:
- Bacteria & archae (living): archae doesn’t make us sick
- Fungi (yeast & molds) (living): Yeast is unicellular and mold multicellular
- Protozoam (living)
- Algae (living)
- Helminths (living): Animals (flukes & worms)
- Viruses (Not living)
- Prions (Not living): Modifies proteins
Cell
Smallest unit of life
Need at least 1 cell to be consider living.
Global burden
- 13 million deaths a year
- Ex: TB, AIDs, Influenza, Malaria, Influenza, Hepatitis, Cholera, Ascariasis, Staph, Diarrheal diseases (#2 killer of children)
Photosynthesis
A food and oxygen generating process that is critical to life on Earth.
Nomenclature
Naming system for microbes
- Genus + Species (Specific Epithet)
True or False
Most microbes are not pathogenic, few that can make us sick.
True
Aseptic Technique
Technique that prevents contamination by unwanted microorganisms.
Spontaneous generation
Ideal or proposal that you sent out to explore through experimentation
Biogenesis
The claim that living cells can arise only from pre-existing living cells.
Pioneer:
Robert Hooke
- Discovered and named cells –> cell theory (Ex: skin, leaves, tissues)
- Looked through homemade microscope
- Looked at a lot of sliced tissue
Pioneer:
Anton Von Leeuwenhoek
- Lens grinder
- 1st to observe microbes and some bacteria
- Made practical microscopes, 300x max
- 1st to observe amimacules, bc the chemist had molecules and they looked like animals, later called microbes (bacteria).
Pioneer:
Rudolph Virchow
Proposed Hypothesis called “biogenesis”
- Why smaller forms of life come about spontaneously when larger ones don’t (something contaminated with microbial growth)
Pioneer:
Louis Pasteur
- Master of Microbiology
- Yeast ferment sugars -> alcohol (grapes to wine)
- Acid producing bacteria -> acids by fermenting sugars (turns wine into vinegar)
- Pasteurization, to kill bacteria (aseptic technique)
- Demonstrated that microorganisms are in the air, everywhere and offered proof of biogenesis
- Discredited spontaneous generation theory
Pioneer:
Robert Koch
- Proved Anthrax is caused by Bacillus anthracis
* Koch’s postulates- steps to relate a microbe to an infectious disease
Pioneer:
Alexander Fleming
- Bacteriologist
- credited for discovering Penicillin
- Bacterial cidal- kill bacteria
- Penicillin- First successful antibiotic to be used to treat gram-positive infection.
Criteria for Koch’s postulates
1) Some pathogen must be present in the disease
2) Pathogen must be isolated from the disease
3) Pathogen from the pure culture
4) Pathogen must be isolated
What are the microbes that cause infectious disease?
- Bacteria
- Fungi
- Protozoans
- Algae
- Helminths
- Viruses and Prions (Considered non-living because their acellular)
Koch’s Postulates
- Pathogen present in every case of the disease
- Pathogen isolated from diseased host and grown in pure culture
- Pathogen from pure culture must cause disease when inoculated in healthy susceptible laboratory animal
- Pathogen must be isolated from inoculated animal and must be shown to be original organism
Pure Culture
Growing by itself without any contamination in the lab on a culture
How can microbes be used to benefit us? (6)
- Compost
- Vaccination
- Food and beverages (Fermentation)
- Pesticide via GM foods
- Sewage treatment (waste)
- Pharmaceuticals via GM yeast and bacteria
- Bioremediation
- Probiotics
Not so good side to microbes?
• Infectious diseases
• Food & water contamination
• New antibiotic resistant strain
• Crop destruction (mostly molds)
• Form biofilms
- Thick layer of microbes that line and stick to surfaces (Ex. catheters, central lines, ventilators)
- Approx. 70% or more of infections acquired in hospitals come from biofilms…they occur when correct aseptic techniques aren’t used
Germ theory of disease
- Microorganisms might cause disease
- First link was yeast play a role in fermentation…which showed the activity of microorganism and physical and chemical changes in organic materials
Roles in natural world
- Decompose organic and some inorganic compounds (matter)
- Recycle (O2 released via photosynthesis and Carbon via breakdown of organic compounds)
- Make O2 by photosynthesis (Ex. algae and cyanobacteria….microbes produces most O2)
- Fixation (Ex. N2 (2 nitrogens) fixation & C fixation)
- Normal microbiota
Amino acids
Contain Nitrogen
Make protein
Nucleotides
Contain Nitrogen
DNA and RNA, which are nucleic acids
Biofilms
A microbial community that usually forms as a slimy layer on a surface.
