Introduction to Microbes PDF - The University of Sydney

Introduction to microbes Presented by Prof Vitali Sintchenko Faculty of Medicine and Health Originally developed by Dr Christina Adler Faculty of Medicine and Health The University of Sydney Page 1  Learning Objectives Define what are micro-organisms...

Introduction to microbes Presented by Prof Vitali Sintchenko Faculty of Medicine and Health Originally developed by Dr Christina Adler Faculty of Medicine and Health The University of Sydney Page 1  Learning Objectives Define what are micro-organisms Detail the different classes of micro-organisms and give examples of the classes Describe what is different between the classes Understand microbes are involved in human disease Detail how we know micro-organisms are involved in disease The University of Sydney Page 2  Learning material Lectures Textbooks 1. Introduction to microbes Prescott's Microbiology 2. Bacterial morphology and Eds: Joanne Willey, Linda nomenclature Sherwood, Chris Woolverton. 3. Bacterial metabolism Oral Microbiology 4. Host microbe interaction Eds: Philip D. Marsh, Michael V. 5. Pathogens Martin. 6. Acquisition of oral flora Oral Microbiology and Blood born viruses Immunology Fungi Eds: Richard J. Lamont, Donald Leblanc, Marilyn Lantz, Robert Caries Burne Periodontal disease The University of Sydney Page 3  What are micro-organisms? Micro-organisms are defined as those organisms too small to be seen by the unaided eye. Less than 1mm in diameter The University of Sydney Page 4  Why are they important? They make life possible Produce foods Cause disease The University of Sydney Page 5 The University of Sydney Page 6  Classes of microbes Microbes Cellular Acellular Viroids/ Bacteria Archea Fungi Protists Viruses Prions Virusoids Algae HIV, Herpes, Mad Cow Escherichia coli Methanogens Yeasts COVID Hepatitis D Disease Slime moulds The University of Sydney Page 7  Questions 1. Which of the following is not a cell? A.Bacteria B.Fungi C.Virus D.Archea 2. Which of the following is a prokaryote? A.Bacteria B.Fungi C.Animal D.Virus The University of Sydney Page 8 Cellular The University of Sydney Page 9  Bacteria – Prokaryote – Single celled – Cell walls contain peptidoglycan Porphymonas gingivalis – Ubiquitous in environment: soil, water, air – Ubiquitous on humans: human microbiome – Diseases: caries, periodontal disease, skin infections, food poising The University of Sydney Page 10  Prokaryote - Bacteria and Archea Gram-stain of coliforms Straight, short, evenly stained bacilli with parallel sides and rounded ends The University of Sydney Page 11  Fungi – Eurarkyotes – Diverse group – 90,000 identified, may be 1.5 million exist – Unicellular e.g. yeasts – Multicellular e.g. molds and mushrooms – Role in oral thrush e.g. Candida albicans The University of Sydney Page 12  Protists – Algae, together with cyanobacteria produce 50% of worlds 02 – Protozoa, motile, hunter- gatherer’s of the world – Slime molds – Water molds – Molds can look like fungi at different stages of life cycle – Human disease e.g. malaria The University of Sydney Page 13  Questions 1. Which of the following is not likely to be found in the mouth? A.Bacteria B. Fungi C.Algae D.Archea 2. Which of the following is eukaryote? A.Bacteria B. Fungi C.Archae D.Virus The University of Sydney Page 14 Acellular The University of Sydney Page 15  Viruses, Viroids and Virusoids – Not living entities – Must invade host cell to multiply – Virons simplest form = protein + nucleic acid – Human diseases e.g. HIV, flu, common cold – Viroids = RNA, plant diseases – Virusoids = nucleic acids, animal diseases The University of Sydney Page 16 Prions Proteins Infectious agents e.g. scrapie and mad cow disease The University of Sydney Page 17 Relative sizes Why do we need to know about different micro-organisms? The University of Sydney Page 18  Koch’s postulates Micro-organisms must be 1. present in every disease and Robert Koch absent in every health case (1843-1910) The suspected micro-organism 2. must be isolated and grown in pure culture The same micro-organism must 3. be reisolated from the diseased host Do Koch’s postulates apply to every human disease involving microbes? The University of Sydney Page 19  Reservoirs of microbes Mechanisms of transmission Humans Syphilis, Hepatitis B Animals (sources of zoonoses) Rabies, Ebola Soil Anthrax, tetanus Water Legionellosis, cholera The University of Sydney Page 20  Summary – Microbes are diverse – Divided between cellular and acellular – Cellular includes: Bacteria, archea, fungi and protists – Acellular includes: Viruses, viroids, virusoids and prions – Microbes involved in many human diseases, particularly oral infections The University of Sydney Page 21  COMMONWEALTH OF AUSTRALIA Copyright Regulation WARNING This material has been reproduced and communicated to you by or on behalf of the University of Sydney pursuant to Part VB of the Copyright Act 1968 (the Act). The material in this communication may be subject to copyright under the Act. Any further reproduction or communication of this material by you may be the subject of copyright protection under the Act. The University of Sydney Page 22