Welcome to Microbiology 1

Transcription

1 Microbiology

2 Welcome to Microbiology 1 For Today Introduction to the course Explore the history and foundation of microbiology Dimensional Analysis

3 Chapter 1 The Microbial World and You

4 What is Microbiology? Microbes, or microorganisms are minute living things that are usually unable to be viewed with the naked eye. What are some examples of microbes? Bacteria, fungi, protozoa, algae, viruses are examples! Some are pathogenic Germ refers to a rapidly growing cell.

5 What is Microbiology? Microbiology is the Science that studies Microorganisms. Microorganisms, roughly, are those living things that are too small to be seen with the naked eye. Microorganisms cannot be distinguished Phylogenetically from Macroorganisms For example, many fungi are microorganisms, as well as all bacteria, all viruses, and most protists. Microbiology is more a collection of techniques: Aseptic technique Pure culture technique Microscopic observation of whole organisms A microbiologist usually first isolates a specific microorganism from a population and then cultures it.

6 Scale of Microbes

7 Types of Microorganisms Bacteria Domain eubacteria ( true bacteria) Archaeabacteria Domain Archaea (extremophiles) Single-celled members of domain Eukarya. Protozoa Microscopic Algae Microscopic Fungi Some parasitic worms Viruses

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9 What is Microbiology? Knowledge of Microbes allows humans to: Prevent food spoilage Prevent disease occurrence Treat disease occurrence Prevent contamination in medicine and in microbiology laboratories (aseptic techniques) Perform genetic, cancer, regenerative medicine, agricultural, industrial research Bioremediation (fixing toxic spills) Make foods/beverages Produce medicines / chemotherapeutics

10 Some organisms studies by microbiologists CAN be visualized without the aid of amplification [bread molds (fungus) and filamentous algae] These organisms are included in the discipline of microbiology because of similarities in properties and techniques used to study them Techniques necessary to isolate and culture microorganisms Isolation Sterilization Culture in artificial media

11 Microbiologists may be interested in specific types of organisms: Virologists - viruses Bacteriologists - bacteria Phycologists or Algologists - algae Mycologists - fungi Protozoologists - protozoa

12 Microbiologists may be interested in various characteristics or activities of microorganisms: Microbial morphology Microbial cytology Microbial physiology Microbial ecology Microbial genetics and molecular biology Microbial taxonomy

13 Microbes & Ecology Microbes are producers they provide energy to ecosystems Microbes are fixers they make nutrients available from inorganic sources, e.g., nitrogen Microbes are decomposers they free up nutrients from no longer living sources Microbes form symbioses (such as mycorrhizal fungi associated with plant roots) Microbes serve as emdosymbionts (e.g., chloroplasts and mitochondria) Aliens of the Deep

14 Microbes & Industry Industry: Fermentation products (ethanol, acetone, etc.) Food: Wine, cheese, yogurt, bread, half-sour pickles, etc. Biotech: Recombinant products (e.g., human insulin, vaccines) Environment: Bioremediation Each carton of Bugs+Plus provides easy to follow step-by-step instructions, containers of specially-formulated wet and dry nutrients and a container of microbes cultured for their ability to digest oil and other petroleum derivatives.

15 Microbes & Disease Microbes both cause and prevent diseases ~Less than 1% actually cause human disease Microbes produce antibiotics used to treat diseases The single most important achievement of modern medicine is the ability to treat or prevent microbial disease Most of this course will consider the physiology of microbes and their role in disease The Germ Theory of Disease = Microbes cause disease! (yes, it wasn t so long ago that humans didn t know this)

16 President Garfield s Vertebrae On the morning of July 2, 1881, Charles Guiteau fired two shots at President James Garfield as he entered a Washington, DC train station. One shot grazed Garfield's hand. The second entered the President's spine near the right 11th rib but did not exit. The x-ray, which would easily have pinpointed the bullet's location, had not yet been discovered. So the President's physicians did what all competent physicians had routinely done in such cases. They probed the entry wound with special instruments designed for that purpose - but without success. The bullet remained lost inside the President. Medical historians believe Garfield could have survived his injury if the attending physicians had washed their hands and used sterile instruments. In 1881, though, such antisepsis techniques were still under debate within the American medical profession.

17 Normal Flora These are the ~harmless microorganisms found on your body. Every part of your body that normally comes in contact with outside world (deep lungs and stomach are exceptions)

18 History of Microbiology Ancestors of bacteria were the first life on Earth.

19 History of Microbiology The first microbes were observed in In 1665, Robert Hooke (Englishman) reported that living things were composed of little boxes or cells.

20 History of Microbiology , Antoni van Leeuwenhoek (Dutch) described live microorganisms that he observed in teeth scrapings, rain water, and peppercorn infusions.

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22 History of Microbiology Many believed spontaneous generation: life can arise from non-living matter In 1668, the Italian physician Francesco Redi performed an experiment to disprove spontaneous generation. Can you think of an experiment that could disprove spontaneous generation?

23 History of Microbiology Redi filled six jars with decaying meat. Conditions Results 3 jars covered with fine net No maggots 3 open jars Maggots appeared From where did the maggots come? What was the purpose of the sealed jars? Spontaneous generation or biogenesis?

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25 History of Microbiology Rudolf Virchow (German) presented biogenesis: living cells can arise only from preexisting cells.

26 History of Microbiology So now there are two hypotheses: The hypothesis that living organisms arise from nonliving matter is called spontaneous generation. According to spontaneous generation, a vital force Forms life. The Alternative hypothesis, that the living organisms arise from preexisting life, is called biogenesis.

27 History of Microbiology 1861: Louis Pasteur demonstrated that microorganisms are present in the air. Conditions Nutrient broth placed in flask, heated, not sealed Nutrient broth placed in flask, heated, then sealed Results Microbial growth No microbial growth Spontaneous generation or biogenesis?

28 History of Microbiology Next experiment, Pasteur s S-shaped flask kept microbes out but let air in. These experiments form the basis of aseptic technique

29 History of Microbiology The Golden Age of Microbiology Beginning with Pasteur s work, discoveries included the relationship between microbes and disease, immunity, and antimicrobial drugs

30 History of Microbiology Pasteur showed that microbes are responsible for fermentation. Fermentation is the conversation of sugar to alcohol to make beer and wine. Microbial growth is also responsible for spoilage of food. Bacteria that use alcohol and produce acetic acid spoil wine by turning it to vinegar (acetic acid).

31 History of Microbiology Pasteur demonstrated that these spoilage bacteria could be killed by heat that was not hot enough to evaporate the alcohol in wine. This application of a high heat for a short time is called pasteurization.

32 History of Microbiology The Germ Theory of Disease 1835: Agostino Bassi showed a silkworm disease was caused by a fungus. 1865: Pasteur believed that another silkworm disease was caused by a protozoan. 1840s: Ignaz Semmelwise advocated handwashing to prevent transmission of puerperal fever from one OB patient to another.

33 History of Microbiology The Germ Theory of Disease 1860s: Joseph Lister used a chemical disinfectant to prevent surgical wound infections after looking at Pasteur s work showing microbes are in the air, can spoil food, and cause animal diseases.

34 History of Microbiology The Germ Theory of Disease 1876: Robert Koch provided proof that a bacterium causes anthrax and provided the experimental steps, Koch s postulates, used to prove that a specific microbe causes a specific disease. Koch was a physician and Pasteur s young rival

35 History of Microbiology Koch's Postulates are used to prove the cause of an infectious disease.

36 History of Microbiology Koch's Postulates are a sequence of experimental steps to relate a specific microbe to a specific disease.

37 History of Microbiology Vaccinations produced from avirulent microbial strains produced from live viruses produced from viral particles

38 History of Microbiology A young milkmaid informed the physician Edward Jenner that she could not get smallpox because she had already been sick from cowpox. 1796: Edward Jenner inoculated a person with cowpox virus. The person was then protected from smallpox. Called vaccination from vacca for cow The protection is called immunity

39 Edward Jenner Smallpox Vaccine (1796)

40 History of Microbiology What can you say about the cowpox and smallpox viruses?

41 Pasteur s Contribution to Vaccines Worked with vaccines for Cholera Using Koch s postulates, Pasteur was working toward a cure for cholera by studying chickens. Inadvertently used old stock to inoculate. Then re-inoculated with fresh, but the chickens did not get cholera. Led to his production of Rabies vaccine

42 Metchnikoff Discovered phagocytes cells inside living organisms that attack and eat microbes. Developed some vaccines however, he caused accidental infections due to using the French method for obtaining pure cultures. Poor suckers got STI s from his vaccines.

43 History of Microbiology Chemotherapy treatment with chemicals Chemotherapeutic agents used to treat infectious disease can be synthetic drugs or antibiotics. Antibiotics are chemicals produced by bacteria and fungi that inhibit or kill other microbes. Quinine from tree bark was long used to treat malaria.

44 History of Microbiology Chemotherapy treatment with chemicals 1910: Paul Ehrlich developed a synthetic arsenic drug, salvarsan, to treat syphilis. 1930s: Sulfonamides were synthesized.

45 History of Microbiology 1928: Alexander Fleming discovered the first antibiotic. He observed that Penicillium fungus made an antibiotic, penicillin, that killed S. aureus. 1940s: Penicillin was tested clinically and mass produced.

46 Modern Developments Bacteriology is the study of bacteria. Mycology is the study of fungi. Parasitology is the study of protozoa and parasitic worms. Recent advances in genomics, the study of an organism s genes, have provided new tools for classifying microorganisms.

47 Classification of Microbes Taxonomy The science of classifying organisms Provides universal names for organisms Provides a reference for identifying organisms

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49 Classification of Microbes Taxonomy Systematics or phylogeny The study of the evolutionary history of organisms All Species Inventory ( ) To identify all species of life on Earth

50 Classification of Microbes Taxonomic Hierarchy Domain Kingdom Phylum Class Order Family Genus Species Dumb Kings Play Chess On Funny Green Squares

51 Classification of Microbes Taxonomic Hierarchy Domain Kingdom Phylum Class Order Family Genus Species Binomal Nomenclature uses the Genus and Species name to identify each creature.

52 Classification of Microbes Taxonomic Hierarchy Each name is Latinized There is a specific way to write each name. Homo sapiens The first word is capitalized Name is in italics Homo sapiens H. sapiens

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56 Bacteria (or Eubacteria) Most abundant on earth They are nitrogen fixers and recycle carbon No membrane bound organelles

57 Archaea Methanogens Halophiles Hyperthermophiles

58 Classification of Microbes

59 Classification of Microbes Eukaryotic species: A group of closely related organisms that breed among themselves Prokaryotic species: A population of cells with similar characteristics Clone: Population of cells derived from a single cell Strain: Genetically different cells within a clone Viral species: Population of viruses with similar characteristics that occupies a particular ecological niche

60 Classification of Microbes

61 Classification of Microbes Let s examine some microbes Paramecium caudatum Euglena acus Peridiniumis - a dinoflagellate

62 Microbes and Human Disease Bacteria were once classified as plants which gave rise to use of the term flora for microbes. This term has been replaced by microbiota. Microbes normally present in and on the human body are called normal microbiota.

63 Microbes and Human Disease Normal microbiota prevent growth of pathogens. Normal microbiota produce growth factors such as folic acid and vitamin K. Resistance is the ability of the body to ward off disease. Resistance factors include skin, stomach acid, and antimicrobial chemicals.

64 Microbes and Human Disease When a pathogen overcomes the host s resistance, disease results. Emerging Infectious Diseases (EID): New diseases and diseases increasing in incidence

65 Major Taxonomic Groups of Bacteria per Bergey s manual Gracilicutes gram-negative cell walls, thinskinned Firmicutes gram-positive cell walls, thick skinned Tenericutes lack a cell wall & are soft Mendosicutes archaea, primitive procaryotes with unusual cell walls & nutritional habits

66 species a collection of bacterial cells which share an overall similar pattern of traits in contrast to other bacteria whose pattern differs significantly strain or variety a culture derived from a single parent that differs in structure or metabolism from other cultures of that species (biovars, morphovars) type a subspecies that can show differences in antigenic makeup (serotype or serovar), susceptibility to bacterial viruses (phage type) and in pathogenicity (pathotype).

67 Bacillus Rod-Shaped Bacteria

68 Cocci Spherical Bacteria

69 Spirillum Spiral-Shaped Bacteria Spirochete: Borrelia burgdorferi

70 Types: Algae Description: photosynthetic aquatic eucaryotes, cell walls, both unicellular and multicellular types Types: brown, red, green, diatoms, dinoflagellates, euglenoids Nutrient Type: photoautotrophs Durable state:? Diseases: Some poisonings associated with unicellular types: Alexandrium causes Paralytic Shellfish Poisoning (PSP), Dinophysis causes Diarrhetic Shellfish Poisoning (DSP), Pseudo-nitzschia multiseries causes Amnesic Shellfish Poisoning (ASP) [some would describe some as protists]

71 Types: Fungi Description: yeasts (unicellular fungi), molds (filamentous fungi) Types: eucaryotes, absorbers, dry conditions, plant decomposers, cell walls, ~100 human pathogens Nutrient Type: chemoheterotrophs Durable state: spores Diseases: mycoses: candida, ringworm (pictured), athlete's foot, jock itch, etc.

72 Types: Protozoa (Protists) Description: Unicellular and slime molds, flagellates, ciliates Types: eucaryotes, parasites, engulfers and absorbers, wet conditions, no cell wall, ~30 human pathogens Nutrient Type: chemoheterotrophs (some classifications include some photoautotrophs as well) Durable state: cysts (some) Diseases: malaria, giardiasis, amoebic dysentery, etc. (shown are harmless--to us--protist components of pond water: Amoeba, Blepharisma, Paramecium, Peranema, & Stentor)

73 Types: Viruses Description: Not cells but enveloped or non-enveloped Types: acellular, obligate intracellular parasites Nutrient Type: not applicable Durable state: virion particles, some can encase in durable state of host Diseases: common cold, flu, HIV, herpes, chicken pox, etc.