Microbiology Lecture Ch.1-5 PDF

Chapter 1 MICROBIOLOGY—THE SCIENCE AFTER STUDYING THIS CHAPTER, YOU SHOULD BE ABLE TO: Define microbiology, pathogen, nonpathogen, and opportunistic pathogen Differentiate between acellular microbes and microorganisms and list several examples of each List several reasons why microbes...

Chapter 1 MICROBIOLOGY—THE SCIENCE AFTER STUDYING THIS CHAPTER, YOU SHOULD BE ABLE TO: Define microbiology, pathogen, nonpathogen, and opportunistic pathogen Differentiate between acellular microbes and microorganisms and list several examples of each List several reasons why microbes are important (e.g., as a source of antibiotics) Explain the relationship between microbes and infectious diseases Differentiate between infectious diseases and microbial intoxications Outline some of the contributions of Leeuwenhoek, Pasteur, and Koch to microbiology Differentiate between biogenesis and abiogenesis Explain the germ theory of disease Outline Koch’s Postulates and cite some circumstances in which they may not apply Discuss two medically related fields of microbiology Welcome to the fascinating world of microbiology: Learn about microscopic organisms that cannot be seen with the naked eye. Understand their impact on our daily lives and the environment. Discover their importance to healthcare professionals. Microbes can be both beneficial and harmful. Prepare for an exciting journey into the unseen world! key concepts other term; "akas" Examples What is Microbiology? Microbiology is an advanced biology course. It involves the study of living and nonliving organisms, known as microbes. S Microbes are too small to be seen without a microscope. Microbes are ubiquitous, meaning they are found everywhere. Photo credit: https://www.imperial.ac.uk/study/courses/undergraduate/microbiology/ Chapter 1 MICROBIOLOGY—THE SCIENCE Types of Microbes Acellular microbes: Viruses, prions. Cellular microbes: Bacteria, archaea, protozoa, some algae, fungi. Pathogens: Disease-causing microbes. Non-pathogens: Beneficial or neutral microbes.  Chapter 1 MICROBIOLOGY—THE SCIENCE Importance of Microbiology Microbes in Our Bodies 10 times more microbes on/in the body than human cells. Indigenous microflora—beneficial microbes that inhibit pathogens. Opportunistic Pathogens Normally harmless but can cause infections in certain conditions. Bioremediation Use of microbes to clean up industrial waste (e.g., oil spills). Elemental Cycles Microbes play key roles in the carbon, nitrogen, oxygen, sulfur, and phosphorus cycles. Microbes in Food Chains Algae and bacteria serve as food for tiny animals, forming the base of many ecosystems.  Chapter 1 MICROBIOLOGY—THE SCIENCE Microbes in Biotechnology & Health Digestive Aid E. coli in the human gut produces vitamins K and B1. Termites rely on protozoa to digest wood. Food, Beverage, and Biotechnology Microbes are used to produce enzymes, chemicals, and antibiotics. Genetic Engineering Microbes engineered to produce insulin, growth hormones, vaccines. Cell Models Microbes like E. coli help scientists understand cell functions. Chapter 1 MICROBIOLOGY—THE SCIENCE Microbes and Disease Types of Diseases Infectious diseases: Caused by pathogen colonization (e.g., bacteria, viruses). Microbial intoxications: Caused by ingestion of microbial toxins. Healthcare Implications Understanding pathogens is crucial for healthcare professionals to prevent disease transmission. Importance of sterile and aseptic techniques in medical settings. Bioterrorism Awareness of biological warfare agents and how to protect against them.  Chapter 1 MICROBIOLOGY—THE SCIENCE First Microorganisms on Earth Earth formed around 4.5 billion years ago. No life existed for the first 800 million to 1 billion years. Fossils of primitive microbes discovered in Stromatolites in Hamelin Pool, Shark Bay, Western rocks dating back 3.5 billion years in Australia Image adapted from: Paul Morris; CC BY SA 2.0 Northwestern Australia. Archaea and cyanobacteria considered candidates for the first microbes on Earth.  Chapter 1 MICROBIOLOGY—THE SCIENCE Earliest Known Infectious Diseases Infectious diseases likely existed as long as humans and animals. Mummies and early fossils show signs of diseases such as tuberculosis, syphilis, and parasitic worm infections. Tuberculosis patient Syphilis First recorded epidemic in Egypt 17th-century around 3180 BC. Depiction of Plague Doctor Early mentions of diseases like smallpox, plague, rabies, and typhoid fever. Syphilis was first recorded in Europe in 1493, with multiple names across countries. smallpox patient  Chapter 1 MICROBIOLOGY—THE SCIENCE Pioneers in the Science of Microbiology Anton van Leeuwenhoek (1632–1723)- First person to observe live bacteria and protozoa. Known as the "Father of Microbiology," "Bacteriology," and "Protozoology." Not a trained scientist, but a skilled lens maker who created single-lens microscopes. Observed "animalcules" in various samples like teeth scrapings, water, and stools. Contributed to the realization of the existence of microorganisms, but did not associate them with diseases. Chapter 1 MICROBIOLOGY—THE SCIENCE Pioneers in the Science of Microbiology Paul de Kruif’s “Microbe Hunters” (1926) Highlighted Leeuwenhoek’s discovery of the microscopic world, unseen by humans before. Described microbes as powerful and sometimes deadly, though also sometimes friendly.  Chapter 1 MICROBIOLOGY—THE SCIENCE Spontaneous Generation vs. Biogenesis Spontaneous Generation (Abiogenesis) ↳ The belief that life could arise spontaneously from nonliving material. Popular belief from 1650 to 1850. Biogenesis Proven by Louis Pasteur and John Tyndall: life arises from preexisting life. First proposed by Rudolf Virchow in 1858.  Chapter 1 MICROBIOLOGY—THE SCIENCE Louis Pasteur (1822–1895) French chemist and key figure in microbiology, often considered foundational to modern medicine. Major Contributions: Alcoholic Fermentation: Discovered that different microbes produce different fermentation products. Example: Yeasts convert glucose to ethanol, while Acetobacter converts it to acetic acid (vinegar). Spontaneous Generation: Conducted experiments that disproved the theory of spontaneous generation. Aerobes and Anaerobes: Discovered life forms that could exist without oxygen and coined the terms "aerobes" and "anaerobes." Pasteurization: Developed the process of pasteurization to prevent spoilage of liquids like wine by killing pathogens. Modern pasteurization heats liquids to 63°C for 30 minutes or 73°C for 15 seconds. Chapter 1 MICROBIOLOGY—THE SCIENCE Louis Pasteur (1822–1895) Silkworm Disease: Identified infectious agents responsible for silkworm diseases and methods to prevent them, saving France's silk industry. Germ Theory of Disease: Contributed to the theory that specific microbes cause specific infectious diseases, such as anthrax (Bacillus anthracis) and tuberculosis (Mycobacterium tuberculosis). Hospital Practices: Advocated for improved hospital practices to minimize disease transmission. Vaccines: Developed vaccines for chicken cholera, anthrax, swine erysipelas, and rabies. His rabies vaccine was used successfully on a human for the first time in 1885, saving a boy bitten by a rabid dog. Pasteur Institute: Founded in 1888 in Paris, the institute became a hub for rabies treatment, infectious disease research, and scientific education. Ethical Dilemma: " In 1885, Pasteur faced an ethical challenge when he administered his experimental rabies vaccine to a 9-year-old boy, Joseph Meister, who had been bitten by a rabid dog. Although not a physician, Pasteur's decision saved the boy's life, marking a turning point in rabies treatment.  Chapter 1 MICROBIOLOGY—THE SCIENCE Robert Koch (1843–1910) a German physician, made groundbreaking contributions to microbiology, especially in establishing the germ theory of disease. Major Contributions: Germ Theory and Anthrax: Proved that the anthrax bacterium (Bacillus anthracis) was the cause of anthrax by using a systematic procedure that later became known as Koch’s Postulates. Spore Formation: Discovered that B. anthracis produced resistant spores, which allowed the bacterium to survive under harsh conditions. - Bacterial Cultivation: Developed innovative methods to culture bacteria on solid media, which revolutionized microbiology research. Petri Dish: His colleague, R.J. Petri, invented the Petri dish to facilitate bacterial growth. Agar as Solidifying Agent: Frau Hesse, the wife of one of Koch’s colleagues, suggested using agar (derived from seaweed) to solidify culture media.  Chapter 1 MICROBIOLOGY—THE SCIENCE Robert Koch (1843–1910) Bacterial Identification: Discovered the bacterium responsible for tuberculosis (Mycobacterium tuberculosis). Identified cholera bacteria (Vibrio cholerae). Tuberculin: His work with a protein derived from M. tuberculosis eventually led to the tuberculin skin test, an important diagnostic tool for tuberculosis. Koch's Postulates: Koch established four key steps, known as Koch’s Postulates, to demonstrate that a specific microbe causes a specific disease: 1. The microbe must be found in all organisms suffering from the disease, but not in healthy ones. 2. The microbe must be isolated and grown in pure culture. 3. The same disease must develop when microbes from the pure culture are introduced to a healthy organism. 4. The microbe must be re-isolated from the newly infected organism and be identical to the original microbe.  Chapter 1 MICROBIOLOGY—THE SCIENCE Robert Koch (1843–1910) Exceptions to Koch's Postulates: Obligate intracellular pathogens: Some pathogens, like viruses and certain bacteria (rickettsias, chlamydias), cannot be grown on artificial media as they require living host cells to survive. Species specificity: Some pathogens only infect humans, making it challenging to test on animal models. Synergistic infections: Some diseases result from the combined action of multiple microbes, which complicates fulfilling the postulates. These exceptions highlighted the complexity of microbial diseases beyond what Koch’s Postulates could address. Chapter 1 MICROBIOLOGY—THE SCIENCE Careers in Microbiology A microbiologist is a scientist who studies microorganisms (microbes), and they can have various educational backgrounds, such as a bachelor’s, master’s, or doctoral degree in microbiology. There are numerous career paths within the field of microbiology, depending on the type of microbes studied or the application of microbial knowledge.  Chapter 1 MICROBIOLOGY—THE SCIENCE Careers in Microbiology Specializations in Microbiology: 1.Bacteriology: Focuses on bacteria, their structure, function, and activities. A scientist in this field is called a bacteriologist. 2.Phycology (Algology): The study of algae, with scientists known as phycologists or algologists. 3.Protozoology: This branch deals with protozoa, the study of their biology and activity. Specialists are referred to as protozoologists. 4.Mycology: The study of fungi, with experts in the field called mycologists. 5.Virology: Focuses on viruses and their interactions with living cells. Virologists may also study prions and viroids, which are infectious agents even smaller than viruses. 6.Genetic Engineering: Virologists and cell biologists can engage in genetic engineering, where they transfer DNA between cells, exploring the genetic aspects of microorganisms.  Chapter 1 MICROBIOLOGY—THE SCIENCE Careers in Microbiology Applied Microbiology: Applied microbiology involves using knowledge of microbes in practical ways to benefit society, including medicine and industry. Medically Related Fields in Microbiology: 1.Medical Microbiology: A crucial field for those interested in medicine and microbiology, focusing on: 1. Pathogens and the diseases they cause. 2. The body’s immune response and defense mechanisms. 3. Epidemiology (study of disease patterns) and pathogen transmission. 4. Disease prevention methods and the development of vaccines. 2.Advances in medical microbiology have contributed to the eradication of diseases like smallpox and polio, and have made modern surgery safer. 3.Clinical (Diagnostic) Microbiology: A branch of medical microbiology, it deals with the laboratory diagnosis of infectious diseases. This is an ideal career for individuals interested in working in laboratories, diagnosing diseases, and contributing to public health. Both medical and clinical microbiology are critical for developing better healthcare solutions and safeguarding public health through research, diagnostics, and disease prevention. Exercises 1. Which of the following individuals is considered to be the “Father of Microbiology?” a. Anton von Leeuwenhoek b. Louis Pasteur c. Robert Koch d. Rudolf Virchow Exercises 2. The microbes that usually live on or in a person are collectively referred to as: a. germs. b. indigenous microflora. c. nonpathogens. d. opportunistic pathogens. Exercises 3. Microbes that live on dead and decaying organic material are known as: a. indigenous microflora. b. parasites. c. pathogens. d. saprophytes. Exercises 4. The study of algae is called: a. algaeology. b. botany. c. mycology. d. phycology. Exercises 5. The field of parasitology involves the study of which of the following types of organisms? a. arthropods, bacteria, fungi, protozoa, and viruses b. arthropods, helminths, and certain protozoa c. bacteria, fungi, and protozoa d. bacteria, fungi, and viruses Exercises 6. Rudolf Virchow is given credit for proposing which of the following theories? a. abiogenesis b. biogenesis c. germ theory of disease d. spontaneous generation Exercises Rey need grow to inside cell the 7. Which of the following microbes are considered obligate intracellular pathogens? a. chlamydias, rickettsias, M. leprae, and T. pallidum b. M. leprae and T. pallidum c. M. tuberculosis and viruses d. rickettsias, chlamydias, and viruses Exercises 8. Which of the following statements is true? Pasteur's discoveries a. Koch developed a rabies vaccine. - b. Microbes are ubiquitous. c. Most microbes are harmful to humans. -not all microbes d. Pasteur conducted experiments that proved the theory of abiogenesis. - Biogenisis sa kamyor  Exercises 9. Which of the following are even smaller than viruses? a. chlamydias b. prions and viroids c. rickettsias d. cyanobacteria  Exercises 10. Which of the following individuals introduced the terms “aerobes” and “anaerobes”? a. Anton von Leeuwenhoek b. Louis Pasteur c. Robert Koch d. Rudolf Virchow  Chapter 2- VIEWING THE MICROBIAL WORLD Chapter 2- VIEWING THE MICROBIAL WORLD Explain the interrelationships among the following metric system units of length: centimeters, millimeters, micrometers, and nanometers State the metric units used to express the sizes of bacteria, protozoa, and viruses Compare and contrast the various types of microscopes, to include simple microscopes, compound light microscopes, electron microscopes, and atomic force microscopes  Chapter 2- VIEWING THE MICROBIAL WORLD In microbiology, metric units (primarily micrometers and nanometers) are used to express the sizes of microbes. It should be noted that the old terms micron ( )a and millimicron ( ) have been replaced by the terms micrometer ( ) and nanometer (nm), respectively. An angstrom (Å) is 0.1 nanometer (0.1 nm). Using this scale, human red blood cells are about  Chapter 2- VIEWING THE MICROBIAL WORLD The size of the bacteria are expressed in micrometer ( ), whereas the sizes of viruses are expressed in nanometers (nm). Chapter 2- VIEWING THE MICROBIAL WORLD The sizes of cellular microbes are measured using an ocular micrometer. The ocular micrometer is used to measure the dimensions of objectives being viewed with a compound microscope. Need for Calibration Before using the ocular micrometer, it must be calibrated. Calibration Tool: Stage Micrometer A stage micrometer is a slide with a known scale. Objective Lenses Calibration Calibration is required for each objective lens to determine the exact distance between marks on the ocular micrometer. Measurement of Objects Once calibrated, the ocular micrometer can measure the lengths and widths of microbes and other objects on specimen slides.  Chapter 2- VIEWING THE MICROBIAL WORLD Optical Instruments & Microscopy Optical Instruments Overview Includes: Human eye, telescope, binoculars, magnifying glass, and microscope. Each has a limit of resolution, called resolving power. Microscope An optical instrument used to observe tiny objects. Necessary for viewing objects not visible to the naked eye. Resolving Power (Resolution) Ability of an optical instrument to distinguish between two adjacent objects. Limits what can be seen using a particular instrument.  Chapter 2- VIEWING THE MICROBIAL WORLD Simple Microscopes Defined as microscopes with only one magnifying lens. Example: Magnifying glass with 3x to 20x magnification. Anton van Leeuwenhoek used simple microscopes with up to 300x magnification. Compound Microscopes Contains more than one magnifying lens. First constructed by Hans and Zacharias Jansen. Typically magnifies objects up to 1,000 times. Photomicrographs are photos taken through compound microscopes. Compound Light Microscope Uses visible light for illumination. Limited by the wavelength of light (~0.45µm). Cannot see objects smaller than half the light wavelength.  Chapter 2- VIEWING THE MICROBIAL WORLD Magnification Process Ocular Lens (Eyepiece): Magnification power of 10x. Objective Lenses: Positioned above the object with powers of 4x, 10x, 40x, and 100x. Oil-immersion lens (100x) is required to study bacteria. Oil-Immersion Objective Immersion oil is required to prevent light scattering and ensure light enters the lens. Necessary for observing tiny organisms like bacteria. Light Adjustment Proper light adjustment is critical for clear observation. Light adjustments made via condenser, iris diaphragm, and rheostat. Higher magnification requires more light. Resolving Power: Approximately 1,000 times better than the unaided human eye. Can observe objects up to 1,000 times smaller than visible with the naked eye. Can view objects as small as 0.2 µm in diameter. Limitations: Adding more lenses does not increase resolving power. Visible light limits resolving power; objects smaller than half the light wavelength are not visible. Increasing magnification without improving resolution is called empty magnification.  Chapter 2- VIEWING THE MICROBIAL WORLD Brightfield and Darkfield Microscopy Brightfield Microscope: Observes objects against a bright background. Also called a brightfield microscope. Darkfield Microscope: Uses a darkfield condenser to view objects against a dark background. Converts brightfield microscope to darkfield. Used to diagnose primary syphilis (Treponema pallidum). Other Types of Compound Microscopes Phase-Contrast Microscope: Fluorescence image Observes unstained living microorganisms. Increases contrast between cells and surrounding medium. Fluorescence Microscope: Uses UV light to cause fluorescent substances to glow against a dark background. Common in immunology for detecting antibody-antigen reactions.  Chapter 2- VIEWING THE MICROBIAL WORLD Electron Microscopes Observation of Small Infectious Agents: Developed to observe viruses like rabies and smallpox. Could not be seen with traditional microscopes. Limitations: Cannot observe living organisms. Organisms are killed during specimen processing. Organisms cannot survive in the vacuum inside the electron microscope. Electron Microscope Components Illumination: Uses an electron beam instead of light. Magnets are used to focus the beam. Electrons in a vacuum have a much shorter wavelength than visible light (~100,000 times shorter). Resolving Power: Much greater than compound light microscopes. Achieves magnifications up to 1 million times.  Chapter 2- VIEWING THE MICROBIAL WORLD Types of Electron Microscopes Transmission Electron Microscope (TEM): Electron gun fires a beam of electrons. Thin specimens (