Introduction to Microbiology PDF

Introduction to Microbiology Pharmaceutical Microbiology and Parasitology (PHMP 211) Our Lady of Fatima University College of Pharmacy Objectives: 1. Define microbiology 2. Outline some contributions of Hooke, Leeuwen...

Introduction to Microbiology Pharmaceutical Microbiology and Parasitology (PHMP 211) Our Lady of Fatima University College of Pharmacy Objectives: 1. Define microbiology 2. Outline some contributions of Hooke, Leeuwenhoek, Pasteur and Koch to microbiology 3. List some areas of microbiological study 4. List some important functions of microorganisms in the environment 5. Differentiate each type of microscope Microbiology: Micro means very small, bio means living organisms, logy means the study of. Therefore microbiology is the study of very small living organisms (microorganisms). History of Microbiology Week 1: Introduction to Microbiology History - The First Observations Robert Hooke observed that plant material was composed of cells (1665). In 1663 and 1664, Hooke made his microscopic, and some astronomic, observations, which he collated in Micrographia in 1665. History - The First Observations Anton van Leeuwenhoek was the first to observe microorganisms (1673). ”Among these there were, besides, very many little animalcules, some were round, while others a bit bigger consisted of an oval.” History - The First Observations Zacharias Janssen Credited for the invention of Microscope. History - The Debate Over Spontaneous Generation Francesco Redi demonstrated that maggots appear on decaying meat only when flies can lay eggs on the meat (1668). History - The Debate Over Spontaneous Generation John Needham claimed that microorganisms could rise spontaneously from heated nutrient broth (1745). History - The Debate Over Spontaneous Generation Lazzaro Spallanzani repeated Needham’s experiments and suggested that results were due to microorganism in the air entering his broth (1765). History - The Debate Over Spontaneous Generation Rudolf Virchow introduced the concept of biogenesis (1858). “ Father of modern Pathology” omnis cellula e cellula, which translates to each cell comes from another cell Coined the word “leukemia” History - The Debate Over Spontaneous Generation Louis Pasteur demonstrated that microorganisms are in the air everywhere (1861). (but biogenesis is attributed to Pasteur) History - The Golden Age of Microbiology a. Fermentation and Pasteurization Pasteur found that yeast ferments sugar to alcohol and that bacteria can oxidize alcohol to acetic acid (1858). Pasteurization was used to kill milk and alcoholic beverage pathogens (1866). Fermentation: ☐Use of Yeast: ☐Saccharomyces cerevisiae ☐Conversion of sugar to alcohol Pasteurization: ☐High Temperature Short time (HTST) ☐71 degrees Celsius for 15 seconds ☐Ultra High Temperature (UHT) ☐138- 150 degrees Celsius for 2 seconds ☐Commercial pasteurization of beverages and liquid products ☐VAT pasteurization ☐63 degrees Celsius for 30 mins History - The Golden Age of Microbiology b. The Germ Theory of Disease Joseph Lister introduced aseptic technique (1860). “ Father of Antiseptic Surgery” Carbolic acid/ phenol: Creosote History - The Golden Age of Microbiology b. The Germ Theory of Disease Robert Koch proved that microorganism cause disease (1876). “Koch Postulate” Discovered TB bacilli History - The Golden Age of Microbiology c. Vaccination Edward Jenner used cowpox material as vaccine for smallpox (1768). “ Father of Immunology” History - The Golden Age of Microbiology c. Vaccination Pasteur discovered 3 vaccines; for fowl cholera (1881), anthrax (1881) and rabies (1885). ☐Pasteurella multocida: Fowl cholera ☐Bacillus antrhacis: anthrax ☐Lyssavirus: Rabies virus History - The Birth of Modern Chemotherapy Paul Ehrlich introduced the arsenic- containing compound called Salvarsan or Arsphenamine (compound 606) to treat syphilis (1910). Treponema pallidum: causative agent of syphilis History - The Birth of Modern Chemotherapy Alexander Fleming discovered penicillin (1928). Penicillium notatum Ignaz Semmelweis Washing hands with chlorine solution for gynecological examination and prevented Puerperal fever in mothers giving birth Other Notable Scientists of the “Golden Age of Microbiology” and the Agents of Disease They Discovered History - Modern Developments in Microbiology The Study of AIDS, analysis of interferon action, and the development of new vaccines are among the current researches in immunology. Summary History - Modern Developments in Microbiology New techniques in molecular biology and electron microscopy have provided tools for the advancement of our knowledge in virology. The development in recombinant DNA technology has helped scientists advance in all areas of microbiology. Scope of Microbiology Week 1: Introduction to Microbiology General field Bacteriology – study of bacteria Phycology – study of various types of algae Virology – study of viruses Mycology – study of fungi Protozoology – study of protozoans Specialized field a. General Microbiology – the study of the classification on microorganisms and how they function. b. Medical Microbiology – the study of pathogens, the diseases caused by them, and the body’s defense against them. c. Veterinary Microbiology – study of the spread and control of diseases among animals. Specialized field d. Agricultural Microbiology – study of the beneficial and harmful roles of microbes in soil formation and fertility. e. Sanitary Microbiology – includes the processing and disposal of garbage and sewage wastes as well as the purification of water supplies. f. Industrial Microbiology – includes the proper way to grow and maintain certain microbes in industries. Specialized field g. Microbial Physiology and Genetics – study of the function of microorganisms, the structure of DNA and the science of genetics in general. h. Environmental Microbiology / Microbial Ecology – includes soil, air, water, sewage, food and dairy microbiology. Microbes and Human Welfare Microorganisms degrade dead plants and animals and recycle chemical elements to be used by living plants and animals. ☐Saprotrops- known as decomposers Bacteria are used to decompose organic matter in sewage. ☐Tetrasphaera, Trichococcus, Candidatus Bioremediation processes use bacteria to clean toxic wastes. ☐Pseudomonas aeruginosa: oil spills Microbes and Human Welfare Bacteria are used as insecticides and pesticides. ☐Bacillus thuringiensis: Insecticide for caterpillar Microbes are used to make food and chemicals ☐Acetobacter cerevisiae: beer fermentation Using recombinant DNA technology, bacteria are used to produce insulin, growth hormones, and vaccines. ☐Escherichia coli: Insulin In gene therapy viruses are used to carry replacements for defective or missing cells into human genes. Microscope Week 1: Introduction to Microbiology Microscopy: the instruments 1. Compound Light Microscope – the most common microscope used in microbiology, it uses two sets of lenses; ocular and objective. 2. Darkfield Microscope – shows a light silhouette of an organism against a dark background 3. Phase-contrast Microscope – uses a specialized condenser to enhance differences in the refractive indices of the cell’s parts and surroundings. Microscopy: the instruments 4. Differential Interference Microscope – provide a colored, 3-dimensional image of the object being observed. 5. Fluorescence Microscope – uses fluorochromes and ultraviolet light. 6. Electron Microscope – uses a beam of electrons instead of light. Manipulation of the Compound Microscope Calculate the total magnification of an object by multiplying the magnification of the objective lens by the magnification of the ocular lens. The compound microscope uses visible light. Specimens are stained to increase the difference between the refractive indexes of the specimen and the medium. Immersion oil is used with the oil immersion lens to reduce light loss between the slide and the lens. Bacterial Stains A. Simple stains – the use of one dye to stain the organism. B. Differential stains – the use of 2 or more dyes to stain the organism. e.g. Gram staining Acid fast staining Simple stain Differential stain Cell Walls Composed of a macromolecular network called peptidoglycan (also referred to as murein; murus means wall) ☐Peptidoglycan consists of repeating disaccharides attached by polypeptides. ☐N-acetylglucosamine (NAG) ☐N-acetylmuramic acid (NAM) Peptidoglycan Component Peptidoglycan Component Cell Walls Gram-positive ☐Thick peptidoglycan layer ☐With teichoic acid (lipoteichoic/wall teichoic acid) Cell Walls Gram-negative ☐Thin peptidoglycan layer ☐With lipopolysaccharide (LPS) Damage to Cell Walls The beta-lactam ring of the Penicillins can inhibit the synthesis of new cell walls and thus kill bacteria through osmotic pressure. ☐Lysozyme – a constituent of tears, mucus, saliva, etc. that digest the cell walls of bacteria ☐Particularly active on Gram-positive ☐If G(+), w/o cell wall = Protoplast ☐If G(–), w/o cell wall = Spheroplast Cells without cell wall can still metabolize but will burst when subjected to pure water or high salt concentration. Gram Stain Developed in 1884 by Hans Christian Gram One of the oldest and most useful methods of staining bacteria Uses four reagents—crystal violet, Gram’s iodine, alcohol, and safranin ☐G(+) if they retained the 1st stain after treatment with the mordant and decolorizer ☐G(–) if they retain the 2nd stain General Rule on Gram Stain 1. All cocci are gram(+), except Neisseria, Veinella, Moraxella 2. All bacilli are gram(–) except Clostridia, Bacillus, Corynebacteria, Lactobacillus, Listeria monocytogenes, Erysipelothrix rhusiopathiae 3. All spiral organism are reported as gram(–) 4. Yeasts are gram(+) Acid Fast Stain Used to stain Mycobacterium and Nocardia These acid-fast organisms resist decolorization with acid alcohol due to its high mycolic acid (a waxy material) content in the cell wall thus retaining the primary stain, carbol fuschin. Non-acid fast organisms are easily decolorized thereby taking up the color of the counter stain. Acid Fast Stain Heat and/or solvents are needed to drive the stain into the cell wall of the Mycobacteria. But once stained, they are difficult to decolorize. Malachite green or methylene blue are then used as counterstains. Acid Fast Stain Purpose Ziehl-Neelsen Kinyoun Primary stain Carbol Fuschin Carbol Fuschin Mordant Heat Phenol 3% acid-alcohol 3% acid-alcohol Decolorizer (Nocardia- 1% H2SO4) Counter stain Methylene blue Malachite green Result: Acid fast Red Red Non-acid fast Blue Green Acid Fast Stain Bacterial Stains C. Special Stains – used to stain special structures of bacteria. ☐Negative Staining for Capsules – negatively charged dyes like India ink or Nigrosin stain ☐Endospore – Schaeffer-Fulton stain (malachite green is used), Wirtz and Conklin stain Special Stain Bacterial Stains Flagella stain – Leifson Metachromatic Granule Stain – Loeffler’s Alkaline Methylene Blue (L.A.M.B.) Bacterial Stains D. Indirect Stain – also known as relief or negative stain. The background is stained instead of the organism. ☐Negative Staining for Capsules – negatively charged dyes like India ink or Nigrosin stain End of Discussion.