Microbiology and Parasitology Lecture MSN-EAC 2024 PDF

MICROBIOLOGY AND PARASITOLOGY lECTURE MSN-EAC 2024 | MIDTERM MICROBIOLOGY AND PARASITOLOGY LECTURE | MIDTERM MICROBIOLOGY ❖ MICROBIAL INTOXICATION...

MICROBIOLOGY AND PARASITOLOGY lECTURE MSN-EAC 2024 | MIDTERM MICROBIOLOGY AND PARASITOLOGY LECTURE | MIDTERM MICROBIOLOGY ❖ MICROBIAL INTOXICATION Clostridium Tetani- bacteria cause “tetanus”, toxin; hindi - Biology is the study of living organisms. ang bacteria ang harmful, it is the toxin - Microbiology is an advanced biology course dealing with the study of microbes, which are extremely small (microscopic) living organisms and certain Microbes play significant roles in our lives; they are essential for life on this non living entities. planet. - Living microbes are known as cellular microbes or microorganisms; examples include bacteria, archaea, some algae, protozoa, and some Examples: fungi. Photosynthetic algae and bacteria (such as cyanobacteria) produce much of the - Non Living microbes are known as acellular microbes or infectious oxygen in our atmosphere. particles; examples include viroids, prions, and viruses. Microorganisms are involved in the decomposition of dead organisms and - Microbes are ubiquitous (i.e., they are found virtually everywhere). waste products. Saprophytes (eg., fungi) are organisms that live on dead and/or decaying ACELLULAR AND CELLULAR MICROBES organic matter. The use of microbes to clean up toxic wastes and other industrial waste products is known as bioremediation. ❖ Sa Acellular Infectious Agents, walang viroids since nakukuha sya sa plants. ❖ Prokaryotes - pro “before”, Karyo “nucleus”; primitive nucleus, no nuclear membrane; called “nucleoid” ❖ Eukaryotes- Eu “true”; with nucleus membrane Fungi- dandruff (cutaneous mycosis), mushroom Protozoa- amoeba IMPORTANCE OF MICROBIOLOGY - The microbes that cause disease are sometimes referred to as "germs." - Many microbes play essential roles in various elemental cycles, such as the - The scientific term for disease-causing microbes is pathogens. carbon, nitrogen, oxygen, sulfur, and phosphorus cycles. Microbes that do not cause disease are called nonpathogens; - Algae and bacteria serve as food for tiny animals; they are important links in majority of microbes are non-pathogens (eg., yeast “saccharomyres cerevisiae”) food chains. - Microbes that live in the intestinal tracts of animals aid in the digestion of food - Microbes that live on and in our bodies are referred to as our indigenous and produce beneficial substances. microbiota - For many years, microorganisms have been used as "cell models"; the more ❖ Lactobacillus acidophilos- “doder lain’s Bacillus”, found in the scientists learned about microbial cells, the more they learned about cells in vagina, a bacteria that maintains the acidity of pH, general prevents microorganisms from developing in urinary tract; prevents UTI - Some members of our indigenous microbiota are opportunistic pathogens - Opportunistic pathogens are microbes that can cause disease, but usually do not; they can be thought of as microbes that are awaiting the opportunity to cause disease ❖ E.g, HIV, AIDS, bagong panganak Pathogens cause two categories of diseases: 1. Infectious diseases 2. Microbial intoxications CATEGORIES OF DISEASES CAUSED BY PATHOGENS - Microbes are used in many industries, such as food, beverage, chemical, and antibiotic industries and in genetic engineering. - In genetic engineering, a gene(s) from one organism is inserted into a bacterial or yeast cell; the cell that receives the new gene(s) is then capable of producing the gene product(s) coded for by the new gene(s). - The use of living organisms or their derivatives to make or modify useful products or processes is called biotechnology. ARCHAEA- No cell wall; live in extreme environments 1. Methanogens- methane gas 2. Extremely Halophilic- Salt loving 3. Extremely Thermophilic- heat loving MICROBIOLOGY AND PARASITOLOGY | 1  PRODUCTS REQUIRING MICROBIAL PARTICIPATION IN THE MANUFACTURING PROCESS CATEGORY EXAMPLES Louis Pasteur Swan Neck Experiment FOODS Acidophilus milk, bread, butter, buttermilk, chocolate, coffee, cottage Pasteur filled a flask with medium, heated it to kill all life, and then drew out cheese, cream cheese, fish sauces, the neck of the flask into a long S. green olives, kimchi (from cabbage), This prevented microorganisms in the air from entering the flask yet allowed meat products (e.g., country-cured air to flow freely. hams, sausage, salami), pickles, poi If the swan neck was broken, microbes could enter the flask and grow (fermented taro root), sauerkraut, sour cream, sourdough bread, soy sauce, various cheeses (e.g., cheddar, Swiss, Limburger, Camembert, Roquefort and other blue cheeses), vinegar, yogurt ALCOHOLIC BEVERAGES Ale, beer, brandy, sake (rice wine), rum, sherry, vodka, whiskey, wine CHEMICALS Acetic acid, acetone, butanol, citric acid, ethanol, formic acid, glycerol, isopropanol, lactic acid ANTIBIOTICS Amphotericin B, bacitracin, cephalosporins, chloramphenicol, cy- cloheximide, cycloserine, erythromycin, griseofulvin, kanamycin, lincomycin, neomycin, novobiocin, nystatin, penicillin, polymyxin B, streptomycin, Louis Pasteur (1822-1895) tetracycline French chemist who made numerous contributions to microbiology Investigated different fermentation products Developed the pasteurization process FIRST MICROORGANISMS ON EARTH Discovered life forms that could exist without oxygen (anaerobes) Developed several vaccines, including rabies and anthrax vaccines - Fossils of primitive microorganisms date back about 3.5 billion years. - Candidates for the first microorganisms on Earth are archaea and FERMENTATION- Anaerobic breakdown of carbohydrates; no oxygen cyanobacteria. Yeast ferment = alcohol - Infectious diseases of humans and animals have existed for as long as humans Bacteria ferment = acid (vinegar) and animals have inhabited the planet. - Earliest known account of pestilence occurred in Egypt in about 3180 BC Robert Koch (1843-1910) German physician who made numerous contributions to microbiology PIONEERS IN THE SCIENCE OF MICROBIOLOGY Made significant contributions to the germ theory of disease Discovered that Bacillus anthracis produced spores Anton van Leeuwenhoek (1632-1723) Developed methods of fixing and staining bacteria The first person to see live bacteria and protozoa. Developed methods to cultivate bacteria The Father of Microbiology. The Father of Bacteriology. Koch's Postulates The Father of Protozoology. During the mid- to late-1800s, Robert Koch and his colleagues established an He was a fabric merchant, a surveyor, a wine assayer, and a minor city official in experimental procedure to prove that a specific microbe is the cause of a specific Delft, Holland. infectious disease. This scientific procedure, published in 1884, became known As a hobby, he ground tiny glass lenses, which he mounted in small metal as Koch's Postulates. frames, thus creating what today are known as single-lens microscopes or simple microscopes SPONTANEOUS GENERATION THEORY John Needham By 1745 an English scientist used microscopic observations to support the theory of abiogenesis. (absence of life) To test this, he boiled meat broth for several minutes in a loosely sealed flask. (allow to cool down the flask) Immediately after boiling he saw under the microscope that the broth had no living things. After a few days he examined the flask and found microorganism. CAREERS IN MICROBIOLOGY A microbiologist is a scientist who studies microbes. There are many career fields within the science of microbiology: Bacteriology Phycology Protozoology DISPROVING SPONTANEOUS GENERATION Mycology Francesco Redi Parasitology Proved that maggots did not come from a piece of meat Virology. Medical microbiology Lazaro Spallanzani Involves the study of pathogens, the disease they cause, and the Heated the soup before culturing. body's defenses against disease MICROBIOLOGY AND PARASITOLOGY | 2  Concerned with epidemiology, transmission of pathogens, Leeuwenhoek's simple microscopes had a maximum magnifying power of disease-prevention measures, aseptic techniques, treatment of about x300 (about 300 times). infectious diseases, immunology, and production of vaccines NOTE: RESOLUTION : resolving power; ability to identify parts of the image you VIEWING THE MICROBIAL WORLD magnifying MAGNIFICATION : the ability of microscope to enlarge the object in number of USING THE METRIC SYSTEM TO EXPRESS THE SIZES OF MICROBES times Metric units are used to express the sizes of microbes. Compound Microscopes The basic unit of length in the metric system is the meter (m); it is equivalent to 39.4 inches. A compound microscope contains more than one magnifying lens. The sizes of bacteria and protozoa are usually Because visible light is the source of illumination, a compound microscope is expressed in terms of micrometers (μm). Α micrometer is one millionth of a also referred to as a compound light microscope. (light : natural and artificial; meter. bec. Of illumination/ a light source) A typical spherical bacterium (coccus) is approximately 1 µm in diameter. Compound light microscopes usually magnify objects about 1,000 times. A typical rod-shaped bacterium (bacillus) is approximately 1 µm wide x 3 µm The resolving power of a compound light microscope is approximately 0.2 µm long (about 1,000 times better than the resolving power of the unaided human eye). Total magnification is calculated by multiplying the magnifying power of the ocular lens by the magnifying power of the objective lens being used. x10 ocular x x4 objective = x40 total magnification - SCANNER (RED) x10 ocular x x10 objective = x100 total magnification - LPO (YELLOW) x10 ocular x x40 objective = x400 total magnification - HPO (BLUE) x10 ocular x x100 objective = x1,000 total magnification - OIO (WHITE) Photographs taken through the lens system of the compound light microscope are called photomicrographs. Because objects are observed against a bright background or "bright field," the compound light microscope is sometimes referred to as a brightfield microscope.(Most common type of microscope) If the condenser is replaced with what is known as a darkfield condenser, illuminated objects are seen against a dark background or "dark field"; the microscope is then called a darkfield microscope. Other types of compound microscopes include - Phase-contrast microscopes - Fluorescence microscopes RELATIVE SIZES OF STAPHYLOCOCCUS AND CHLAMYDIA BACTERIA AND SEVERAL VIRUSES The sizes of viruses are expressed in terms of nanometers (nm). A nanometer It is the wavelength of visible light (~0.45 µm) that limits the size of objects that is equal to one billionth of a meter. can be seen. Most of the viruses that cause human diseases range in size from 10 to 300 Objects cannot be seen if they are smaller than half of the wavelength of visible nm. light. One exception is Ebola virus, a cause of viral hemorrhagic fever. Ebola viruses Today's laboratory microscope contains two magnifying lens systems: can be as long as 1,000 nm (1 µm). The eyepiece or ocular lens (usually x10) When using a microscope, the sizes of microorganisms are measured using an The objective lens (x4, x10, x40, and x100 are the four most ocular micrometer. commonly used objective lenses) MICROSCOPES The human eye, a telescope, a pair of binoculars, a magnifying glass, and a microscope are various types of optical instruments. Darkfield and Fluorescence Micrographs of Treponema A microscope is an optical instrument that is used to observe tiny objects, pallidum (the Bacterium That Causes Syphilis) objects so small that they cannot be seen with the unaided human eye. Each optical instrument has a limit as to what can be seen using that instrument; this limit is referred to as the resolving power or resolution of the instrument. The resolving power of the unaided human eye is approximately 0.2 mm. Simple Microscopes Phase-Contrast and Fluorescence Microscopes A simple microscope is one that contains only one magnifying lens. Phase-contrast microscopes are used to observe unstained living microorganisms. A magnifying glass could be considered a simple microscope; when using a Organisms are more easily seen because the light refracted by living cells is magnifying glass, images appear 3 to 20 times larger than the object's actual different from the light refracted by the surrounding medium. size. MICROBIOLOGY AND PARASITOLOGY | 3  Fluorescence microscopes contain a built-in ultraviolet (UV) light source. When the UV light strikes certain dyes and pigments, these substances emit a longer-wavelength light, causing them to glow against a dark background Electron Microscopes Electron microscopes enable us to see extremely small microbes such as rabies and smallpox viruses. Living organisms cannot be observed using an electron microscope--the processing procedures kill the organisms. An electron beam is used as the source of illumination, and magnets are used to focus the beam. Electron microscopes have a much higher resolving power than compound light Microscopes. There are two types of electron microscopes transmission and scanning Transmission Electron Microscope Ultra structure of the cell Eukaryotic cells contain a “true” nucleus, whereas prokaryotic cells do not. A This microscope uses an electron gun to fire a beam of electrons through an true nucleus consists of nucleoplasm, chromosomes, and a nuclear membrane. extremely thin specimen (