Chapter 1 Lecture Outline-1 PDF

Chapter 1 The Microbial World And You 1 The Microbial World and You Microbe (microorganism) - organism that is too small to be seen with the unaided eye What are the 4 major “groups” of microbes? Bacteria Bacteria Viruses Fungi Parasites 2 3 Microbes Are Closely Associated with Our Lives Important R...

Chapter 1 The Microbial World And You 1 The Microbial World and You Microbe (microorganism) - organism that is too small to be seen with the unaided eye What are the 4 major “groups” of microbes? Bacteria Bacteria Viruses Fungi Parasites 2 3 Microbes Are Closely Associated with Our Lives Important Roles of Microbes:  Key Ecological Roles  Bioremediation  Commercial Uses  Applications in Medicine 4 Key Ecological Roles of Microbes Refers to the natural role of microbes in the environment Natural process Examples: 1. Decomposers of organic wastes - by bacteria and fungi  Benefit to humans: breakdown wastes and recycle elements back into nature 2. Photosynthesis - by bacteria (Cyanobacteria) and protozoa (Algae)  Benefit to humans: produce oxygen 3. Nitrogen Fixation - by bacteria that capture free atmospheric Nitrogen (N2)  Benefit to humans: produce nitrates which is used by plants for development 5 Nitrogen (N2) Fixation 6 Bioremediation and Use of Bacteria Refers to the non-natural role of microbes in the environment Artificial process developed by human needs Certain bacteria can use pollutants as an energy source or produce enzymes that breakdown toxic wastes Examples: 1. Oil spills - bacteria introduced into the ocean  Benefit to humans: remove toxic substances from ocean 2. Drain clogs - bacterial enzymes are found in drain cleaners  Benefit to humans: remove clogs without adding harmful chemicals to environment 7 8 Commercial Uses of Microbes Bacteria Dairy products (cheese, yogurt) Cosmetic procedures (Botox) Fungi (yeast) Alcoholic beverages (wine, beer) Breads 9 Applications in Medicine and Use of Microbes Some microbes produce substances that are used today as antibiotics which can kill harmful bacteria Examples: Penicillin & Neomycin 10 Pathogenic Microbes Are all microbes harmful? Microbes can be characterized as either harmless or harmful Less than 1 percent (< 1%) of bacteria are harmful (pathogenic) Harmful microbes Pathogens - live agents capable of causing disease (harm) in a host  Examples: o Neisseria gonorrhoeae  Gonorrhea o Tinea pedis  Athlete’s foot o SARS-CoV-2  Coronavirus Disease 2019 (COVID-19) 11 A Summary of Microbes 12 Normal Microbiota Play important roles in human health and disease prevention AKA “normal flora” Resident microbes found both inside and outside the human body and cause no harm to the human host May sometimes be beneficial to the human host  Produce useful substances that humans cannot make (Ex - vitamin K)  Prevent overgrowth of harmful microbes Examples:  Streptococci - found in the mouth  Staphylococci - found on the skin  E. coli - found in the colon 13 Milestones and Major Contributions to Microbiology Anton van Leeuwenhoek Edward Jenner Louis Pasteur Joseph Lister Robert Koch Paul Ehrlich Alexander Fleming Barry Marshall Figure 1.5 14 Milestones and Major Contributions to Microbiology van Leeuwenhoek First scientist to observe live microorganisms through magnifying lenses Made detailed drawing of these microorganisms Jenner Contribution to immunization and elimination of Smallpox Observed milkmaids infected with Cowpox Virus were protected from Smallpox Took material from cowpox pustule (lesion)  injected it into healthy human host  healthy human host never developed Smallpox!  Developed the first “vaccine” (vaccine against Smallpox) 15 Milestones and Major Contributions to Microbiology Pasteur Disproved “Spontaneous Generation” (some forms of life could arise spontaneously from nonliving matter) Established “Theory of Biogenesis” (living cells arise only from pre-existing living cells), which was later supported by Robert Koch’s “Germ Theory of Disease” (microorganisms cause disease) 16 Disproving Spontaneous Generation Figure 1.4 17 Milestones and Major Contributions to Microbiology Lister Began using chemical solutions (antiseptics) to treat surgical wounds and to kill microbes Applied “Germ Theory of Disease” to medical procedures Practice reduced the number of surgical infections and deaths Koch Established the “Germ Theory” - infectious diseases are caused by live pathogens (microbes) Discovered bacteria (Bacillus anthracis) in cattle & sheep as cause of Anthrax Established rules called “Koch’s Postulates”  Sequence of experimental steps relating a specific microbe to a specific disease (with specific symptoms) 18 Milestones and Major Contributions to Microbiology Ehrlich Developed the concept of chemotherapy by discovering the first chemical substance against Syphilis Coined the term “magic bullet” to describe a chemical substance that could be made to selectively target and destroy a pathogen without harming the infected host Fleming Discovered the first antibiotic called Penicillin Observed how contaminated culture plates with mold colonies inhibited the growth of surrounding bacteria 19 Milestones and Major Contributions to Microbiology Marshall Proved that most peptic ulcers were caused by bacterium Helicobacter pylori Studies lead to understanding the causative link between H. pylori and gastric (stomach) cancer 20 Emerging Infectious Diseases (EIDs) Diseases that are new or changing and are increasing or have potential to increase in frequency in near future What are some EIDs currently prevalent in human populations? SARS-CoV-2  COVID-19 Zika Virus  Zika Virus Disease West Nile Virus  West Nile Virus Encephalitis Influenza Virus  Influenza 21 Key Factors Contributing to The Emergence of EIDs Global travel Rapid urbanization Natural disasters Climate change Frequent gene mutations Developing drug resistance 22