Introduction to Microbiology - Lecture Notes | BIOL 2230, Study notes of Microbiology

Download Introduction to Microbiology - Lecture Notes | BIOL 2230 and more Study notes Microbiology in PDF only on Docsity! BIOL 2230 REEDER INTRODUCTION TO MICROBIOLOGY I. MICROBIOLOGY A. Defined & Described l. Study of living organisms that are individually too small to be seen with the naked eye (microorganisms, germs) 2. Agents of human Infectious diseases fall into the following branches: bacteriology (study of bacteria), virology (study of viruses), mycology (yeasts and molds), and parasitology (protozoans and helminth worms) 3. Studied organisms include viruses, bacteria (including the rickettsias and chlamydias), fungi, protozoans, and the parasitic helminth worms; nonpathogens included are the cyanobacteria and algal protistans (phycology) 4. Microscopic and submicroscopic forms a. smallest organism that can be seen with the naked eye is approximately 0.lmm; smallest organism that can be seen with the compound light microscope is approximately 0.2um (l um = 10-6m). l) The micrometer (symbol: um) is the basic measuring unit for most microorganisms (l um = 0.00l mm): cells of bacteria, fungi, algae, & protozoa a) A nanometer (nm) is 10-9 meter or 0.001 um b) An angstrom (A), is 10-10 meter 2) Viruses & subcellular structures (ribosomes, membranes) are measured in nm: requires electron microscopy 3) Atoms & molecules are measured in A units (0.1nm) 4) Bacteria normally range in size from about 0.2 to 5um a) The smallest bacteria (Mycoplasma) are about the same size as the largest viruses (poxviruses): 1 um to 100nm b) The longest bacteria rods approach the size of some yeasts and human red blood cells (7um) b. Viruses are the smallest, followed by bacteria, protozoans, fungi, algae, and the helminths 1) viruses: 100nm to 10 nm 2) amoeba: 100um 3) insect vectors (lice), fungal spore structures and helminths: 1mm and larger. c. Bacterial microorganisms can be "fixed" on slides and stained with various dyes to reveal various structures and distinguishing properties for study. B. Contributions from the Microbiology field l. Advances in the ability to control many infectious diseases: a. typhoid fever and cholera through proper sewage disposal and water sanitation b. small pox elimination (1979) and curtailment of paralytic polio c. the production and use of antibiotics in battling bacterial infections d. unfortunately, the World Health Organization (WHO) estimates more than 17 million people still dying yearly from preventable infectious diseases: 26%, pneumonia and respiratory; 18% each AIDS & diarrheal; 11% TB. 2. Knowledge gained of the many normal biochemical processes occurring in microorganisms that also parallel those in higher life forms as well a. Mechanisms of human metabolism, such as cell respiration (glycolysis, Kreb's cycle, electron transport and phosphorylation) b. Molecular genetics (recombinant DNA techniques that have resulted in the synthesis of specific substances such as human insulin and human growth factor; knowledge gained of the process of protein synthesis in living organisms). C. Practical Applications of Microbiology l. Knowledge is particularly important in medicine and allied health fields a. Protecting the patient from the hospital-acquired infections (nosocomial) b. "Knowledge of the enemy": ubiquity of microorganisms, their anatomy and physiology, techniques used to take samples, culturing, identifying and measures used to control: c. may result in the ability to take advantage of a microorganism's specific vulnerability 2. Not all organisms are pathogenic, as the majority are generally beneficial in some way to organisms and the environment; approximately 2,000 different microbes in human disease a. Decomposition of organics to inorganics making nutrients available to the ecosystem and enabling nutrients to be cycled: saprobes (bacteria) and saprophytes (fungi) b. water and sewage treatment via bacterial decomposition c. alleviate pollution, including toxic materials, via bioremediation 1) oil spills: technologists use nitrogen, phosphorus, and other mineral nutrients with water to encourage microbial growth and petroleum breakdown bio2230_intro_to_micro.doc Page 1 of 4 1/11/08 2) remove explosives, cleaning agents, and radioactive cpds d. normal flora on and in the body: nutritive and protective 1) may be source of infection; nosocomial route may aid e. food and beverage production: pickles, cheese, sauerkraut, sour cream, beer, wine, alcohol, tangy flavor of sausage, soy sauce, citric acid for soft drinks, silage, flavor and aroma of coffee, buttermilk, butter, yogurt, vinegar f. clues to evolution by studying microbial DNA g. looking for evidence of life on Mars and moons of Jupiter and Saturn h. manufacturing new drugs, enzymes, amino acids, antibiotics, food additives and flavors (lactic acid and peach and coconut flavoring agents called lactones) 1) biotechnology: transfer DNA among different species to transfer desirable qualities or induce production capabilities 2) Bt corn, cotton, and soybean with pest resistance as well as pesticide resistance 3) transfer herpes virus genes into soybean to make antibodies: “plantibodies”; fight genital herpes by eating a soybean product 4) use species of bacteria and yeast to produce insulin for diabetes, blood clotting Factor VIII for hemophiliacs, and human growth hormone for undersized individuals 5) mix bacteria with sand, calcium chloride and urea to form calcium carbonate (limestone) to fill cracks in concrete i. rDNA technology: gene probes (small fragments of DNA) used as diagnostic tests for identification of disease- causing organism or find the DNA fingerprint of microbial contaminant in an environmental sample D. The Scope of Microbiology 1. Practical Uses in industry and medicine a. Immunology 1) Serology: looks for the products of immune reactions in blood and tissues and aids in diagnosis of infectious diseases by that means. 2) Allergy: study of hypersensitive responses to ordinary, harmless materials 3) Vaccination b. Public health microbiology and epidemiology 1) monitor and control the spread of diseases in communities a) United States Public Health Service (USPHS) b) Centers for Disease Control and Prevention (CDC) c) World Health Organization (WHO) c. Food microbiology, dairy microbiology, and aquatic microbiology 1) ecological and practical roles of microbes in food & water: food spoilage, food-borne diseases, production, water purity and treatment 2) Probiotics: bacteria added to some fermented milk products are being touted by nutritionists as protecting against intestinal infections and bowel cancer or aid digestion d. Agricultural microbiology 1) emphasis on improving crop yields (soil fertility and nutritional interactions) and combating plant diseases 2) combating animal diseases e. Biotechnology 1) using the metabolism of living things to produce a desired product: from bread making to gene therapy 2) Industrial microbiology a) to produce or harvest large quantities of substances such as beer, vitamins, drugs, enzymes, etc. 3) Genetic engineering and recombinant DNA technology a) techniques that deliberately alter the genetic makeup of organisms (transgenic) to mass produce human hormones and other drugs, create novel substances, and develop organisms with unique methods of synthesis and adaptation. b) gene therapy: using viruses to deliver genes into humans to correct conditions such as cystic fibrosis, heart disease, and cancer. c) Genomics: science of sequencing an organism’s DNA to reveal potential, significant information and applications; 200 different bacteria have been sequenced. d) Proteomics: coded proteins from the genome and their function E. Historical Perspective on the Field of Microbiology (covers the last 300 years) l. Observation of microscopic life a. Robert Hooke's observation of cork (1665) with the compound microscope (300-500x) coining the term "cell" from cork and microscopic details of thread-like fungi. bio2230_intro_to_micro.doc Page 2 of 4 1/11/08