Biology 318 Introduction to Microbiology

Transcription

1 Biology 318 Introduction to Microbiology Microbiology The study of small living things Cells - Bacteria, Algae, Protozoa, Fungi Not Cells - Viruses and Prions All are UBIQUITOUS

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3 Prokaryotic Cells Simpler, smaller, and the most primitive Include Eubacteria - 3% disease, a.k.a. Bacteria Include Archaea - extreme habitats, no disease

4 Eukaryotic Cells More complex, larger, and modern Include Algae, Protozoa, Fungi, Animals, Plants Penicillium

5 Viruses and Prions All are infectious pathogens Not made of cells

6 Microbiology Is Far-Reaching and Beneficial Sub-Disciplines of Microbiology Medical and Veterinary Agriculture Waste Management Industrial Biotechnology Basic Research and Genetics Environmental

7 Waste Management Soil bacteria and fungi - decomposers Many perform bioremediation - consume toxins Water treatment, composting, landfills (produce methane)

8 Industrial and Biotechnology Products Vitamins and essential amino acids in the gut Soured foods and alcohol - food preservation Medical tools - antibiotics and vaccines Genetic engineering - cloning tools

9 Nitrogen Fixation Only some bacteria capture nitrogen from air Convert it to parts of proteins and DNA Basis for crop rotation, biological fertilizers

10 Indigenous Microflora or Normal Flora Natural inhabitants of or on the body (10 11 ) 10 TIMES more of them than your own cells Either beneficial OR have no effect

11 Microbes and Medicine Pathogen Microbes that cause disease Only 3% of known microbes are pathogens

12 Infectious Diseases 50,000 people per day die from these 24 million people per year die from these 40% third world deaths 4% first world deaths

13 Opportunistic Pathogen Cause disease given the opportunity wrong place or wrong time Some normal flora can become opportunists

14 Infectious Diseases

15 B.C. Microbiology Egypt, Greece, China Hygiene standards Understood transmission Primitive vaccines Practiced biowarfare

16 Biblical Laws and Public Health Leviticus refers to personal hygiene practices Defines public waste management Prohibits eating animals that died naturally

17 Middle Ages Cultural stagnation and crowding - epidemics Smallpox, syphilis, plague, rabies People believed diseases were acts of God Bizarre and illogical treatments

18 Spontaneous Generation False idea spawned in Middle Ages Said that life could arise from non-living things Maggots from meat, spoilage for no reason

19 Anton van Leewenhoek (1600s) Built microscopes (300X) - saw first microbes Pepper water, tooth plaque, gutter water, feces Also saw cells in semen, urine, and blood

20 Redi s Experiments

21 Louis Pasteur (1800s) Alcohol fermentation and anaerobic metabolism Disproved Spontaneous Generation Decontamination standards - Pasteurization Improved hospital practices to reduce disease Developed many early vaccines

22 Downfall of Spontaneous Generation Milk, broth, beer/wine did not spoil If heated to C for 15 minutes Pasteurization - decontamination

23 Robert Koch (1800s) Germ Theory of Disease and Koch s Postulates Isolated anthrax, TB, and cholera bacteria Developed fixing and staining methods With colleagues, developed media and tools Developed skin test for TB - immunology

24 Germ Theory of Disease Diseases do not come from nothing Specific diseases are caused by specific agents First link - Bacillus anthracis and anthrax

25 Koch s Postulates Agent detected ONLY in diseased individuals Isolated in pure culture outside host Pure isolates cause disease in test animals Same agent re-cultured from test animals

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27 Modern Exceptions to Koch s Postulates Many agents do not grow outside living cells Not all agents cause disease in animal hosts Many diseases are asymptomatic Some diseases involve more than one agent Some diseases not caused by microorganisms Some diseases involve more than one agent Detection now includes antibodies and DNA HIV/AIDS REQUIRES that we use and accept many of these modern exceptions.

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