General Concepts of Microbiology PDF

General Concepts of Microbiology CHAPTER 1: INTRODUCTION TO MICROBIOLOGY First Semester, SY 2024-2025 Prepared by: Ms. Samantha Quiambao A. Terminologies and their definition Microbiology...

General Concepts of Microbiology CHAPTER 1: INTRODUCTION TO MICROBIOLOGY First Semester, SY 2024-2025 Prepared by: Ms. Samantha Quiambao A. Terminologies and their definition Microbiology ⎯ Biology of microscopic organisms or ‘microbes’ (organisms or agents which cannot be seen by eye and must be examined by microscope) such as, viruses, bacteria, many algae and fungi, and protozoa Early Beginnings Anton van Leeuwenhoek was the first to describe bacteria with his own microscopes rain water, pond water and scrapings from his own teeth minute moving objects =“animalcules” (now referred to as protozoa, yeasts and bacteria) Early Beginnings Disapproving Spontaneous Generation: Spontaneous Generation/Aristotelian abiogenesis is the theory stating that life comes from non-living things EX: lice were "generated" from sweat Aristotle Early Beginnings Disapproving Spontaneous Generation: 1. Francisco Redi (Italian Physician) – disputed spontaneous generation and showed that maggots on decaying meat came from fly eggs. At the time, prevailing wisdom was that maggots formed naturally from rotting meat.  Early Beginnings Disapproving Spontaneous Generation: 2. Lazzaro Spallanzani - disproved spontaneous generation after he boiled beef broth for an hour, sealed the flasks and observed no appearance of microorganisms Early Beginnings Disapproving Spontaneous Generation: 3. Louis Pasteur boiled broth samples maintained inside goose-necked flasks open to the air microorganisms were present in air and developed a method for controlling them (pasteurization) postulated the germ theory of disease GERM THEORY The theory that certain diseases are caused by the invasion of the body by microorganisms, organisms too small to be seen except through a microscope Ex: Salmonella typhi spread by Typhoid Mary (Mary Mallon) GERM THEORY Robert Koch - awarded a Nobel Prize in 1905 for his isolation of the Mycobacterium tuberculosis Koch's postulates: i. The suspect causative agent must be found in every case of the disease. ii. The specific type of microbe must be isolated from the infected individual and grown in a culture containing no other forms (pure culture). iii. Upon inoculation into a normal, healthy, susceptible animal, a pure culture of the microbial agent must produce the disease. iv. The same type of microbe must be recovered again from the experimentally infected host. Golden Age of Microbiology a. Edward Jenner - noticed that dairymaids often contracted cowpox, but seemed resistant to smallpox. He used fluid from pustules formed on young women infected with cowpox to prevent small pox and called the procedure vaccination (vacca = cow). b. Louis Pasteur - discovered that attenuated (weakened) microbial cultures could be used to prevent disease while studying chicken cholera. Pasteur called his attenuated cultures vaccines in recognition of the work carried out by Edward Jenner SMALL POX c. Alexander Fleming – found that fungi in the genus Penicillium could kill Staphylococcus and discovered Penicillin, one of the first antibiotics. Currently many different types of bacteria and fungi are used to produce antibiotics. d. Walter Hesse (and wife Fannie) – introduced the use Agar as solid growth medium e. Hans Christian Gram – developed a differential staining method (Gram stain) which exploits the difference between two basic variations in cell wall structure and is still essential in the classification of bacteria f. Richard Petri – developed the Petri dish g. Elie Metchnikoff – discovered that white blood cells (leukocytes) engulf and digest microorganisms that invade the body = phagocytes one of the first scientists to study the new area of biology called immunology JOHN TYNDALL AND FERDINAND COHN most important discoveries in sterilization some microorganisms are resistant to certain sterilization techniques. Some thermophiles resisted heat and could survive a bath in boiling water No magic bullet that killed all harmful microorganisms JOSEPH LISTER developed one of the most notable antiseptic techniques Carbolic acid (phenol) was one of the first surgical antiseptics A. Terminologies and their definition 1. Aerobe ⎯ organisms that grow in the presence of atmospheric oxygen 2. Anaerobe ⎯ grows in absence of free oxygen 3. Aerotolerant anaerobes ⎯ microbes that grow equally well whether or not oxygen is present 4. Facultative anaerobes ⎯ microbes that don’t require oxygen for growth but do grow better in its presence 5. Monotrichous ⎯ having a single flagellum  A. Terminologies and their definition 6. Amphitrichous ⎯ having single flagellum at each end 7. Attenuation ⎯ reduced virulence but can provoke the immune system 8. Virulence ⎯ degree or intensity of pathogenicity of an organism 9. Sterilization ⎯ process by which all living cells, viable spores, viruses, and viroid are either destroyed or removed from an object or habitat 10. Sanitization ⎯ reduction of the microbial population on an inanimate object to levels judged safe by public health standards A. Terminologies and their definition 11. Bacteremia ⎯ presence of viable bacteria in the blood 12. Viremia ⎯ presence of the virus in the blood 13. Hemolysis ⎯ disruption of red blood cells and release of their hemoglobin 14. Antibody ⎯ also known as immunoglobin, a glycoprotein produced in response to the antigen 15. Antigen ⎯ substance, when introduced into the body, stimulates the production of antibodies Types of Microorganisms Pathogenic Microorganism ▪ a disease-causing microorganism causing an infection ▪ Ex: Mycobacterium tuberculosis is the bacterium that causes tuberculosis. Types of Microorganisms Non-Pathogenic Microorganism microorganisms that are useful such as maintaining homeostasis in our bodies Ex: normal microbial flora are microorganisms comprises mainly bacteria, but viruses, fungi and protozoa's are also present Major groups of microorganisms 1. Viruses 2. Bacteria 3. Fungi 4. Algae 5. Protozoa Major groups of microorganisms 1. Viruses ✓Are submicroscopic, parasitic, acellular (not made of cells, cannot make their own proteins and don’t grow) entities composed of a nucleic acid core surrounded by a protein coat. ✓Parasitic acellular → a virus receives food and shelter from another organism and is not divided into cells. ✓EX. varicella-zoster virus which causes chickenpox in humans and Bacteriophages are viruses that infect bacteria. Bacteriophage Major groups of microorganisms 2. Bacteria ✓are prokaryotic organisms (do not have a true nucleus) ✓Many bacteria absorb nutrients from their environment and some make their own nutrients by photosynthesis or other synthetic processes. ✓EX. Escherichia coli (E. coli) can cause diarrhea, while others cause urinary tract infections, respiratory illness and pneumonia Major groups of microorganisms 3. Fungi ✓exist as either single cells (yeasts) or as multicellular organisms formed of thin, branching tubular structures called hyphae ✓A fungus is a eukaryotic organism, often microscopic, that absorbs nutrients from its external environment. Fungi are not photosynthetic ✓EX. Tinea pedis causes athlete's foot include an itchy, scaly rash Major groups of microorganisms 4. Algae ✓are eukaryotic photosynthetic organisms that transform sunlight into nutrients using photosynthesis. ✓They normally occur in moist soil and aquatic environments. ✓EX: seaweeds Major groups of microorganisms 5. Protozoa ✓animal-like single-cell microorganisms that can be found in aquatic and terrestrial environments ✓Many obtain their food by engulfing or ingesting smaller; have pseudopod for locomotion ✓EX. Amoeba proteus Amoeba proteus ROLES OF MICROORGANISMS Microorganisms in Environment Microbes help to break down organic matter from plants, animals, and other microbes. (fungi and bacteria=decomposers) They are involved with the nitrogen and carbon cycles (N cycle (78% of air we breath) Nitrification in soils is carried out by bacteria or nitrifying bacteria They also help animals ingest food by being part of the gut microbiome. (rumen is a large compartment in stomach of cow, cattles where Methanobacterium is found In rumen, these bacteria help in the breakdown of cellulose (fiber like structures in plants) and play an important role in nutrition of cattle. ROLES OF MICROORGANISMS Microorganisms in Medicine Early advances in the field of medicine that utilized microbes include the discovery of penicillin and the development of antibiotics in the early part of the 20th century and the discovery of an effective vaccine against smallpox in the 19th century. Microbes are used in numerous drug discovery studies today. In 1991, half the pharmaceuticals on the market were either natural products or derivatives. In 1997, 42% of the top-selling pharmaceuticals were obtained from natural sources. Many of today's antibiotics (to fight bacterial infection) stem from natural compounds made by bacteria that live in soil. The bacteria produce them to defend against other microorganisms. Antifungal med, antibiotics, vaccines ROLES OF MICROORGANISMS Microbes in the Food Industry Yeast is used to leaven bread as well as in the fermentation of alcoholic beverages lactic acid bacteria, are used to produce yogurt, cheese, and pickles. Weissella species have been used in the production of a variety of fermented foods and beverages and also as probiotics References Baniya, S. (2022, February 28). Terminology used in Basic Microbiology. The Biology Notes. https://thebiologynotes.com/terminology-used-in-basic-microbiology/ Britannica. (2019). Microbiology - Types of microorganisms | Britannica. In Encyclopædia Britannica. https://www.britannica.com/science/microbiology/Types-of-microorganisms Davey, R. (2021, November 19). How Important are Microorganisms? News-Medical.net. https://www.news-medical.net/life-sciences/How-Important-are-Microorganisms.aspx Fields of Microbiology - Basic Microbiology. (2019, February 8). Microbe Notes. https://microbenotes.com/fields-of-microbiology/ The five major groups of microbes. (n.d.). FutureLearn. https://www.futurelearn.com/info/courses/introduction-to-microbiology/0/steps/51408 Images: https://sites.google.com/site/bio2070discoverysite/_/rsrc/1472783948095/home/chapter-1/kinds- of-microorganisms/01-01_microorganisms_1.jpg THANK YOU