Western Sydney University YR1 Lecture 1H - Introduction to Microbiology 2021 PDF

Introduction to Microbiology A/Prof Slade Jensen Microbiology and Infectious Diseases School of Medicine Western Sydney University Med Yr1-2 Micro/ID Lectures, online modules, clinical classrooms and PBLs Exam questions will be based on all of the above Concepts applicable to real patients in hospit...

Introduction to Microbiology A/Prof Slade Jensen Microbiology and Infectious Diseases School of Medicine Western Sydney University Med Yr1-2 Micro/ID Lectures, online modules, clinical classrooms and PBLs Exam questions will be based on all of the above Concepts applicable to real patients in hospitals and clinics Med Yr1-2 Micro/ID Year 1 – Lectures Introduction to microbiology (1st Sem) Host-pathogen interactions (1st Sem) Benefits and mischiefs of intestinal flora (Gastro, 2nd Sem) Strategies for respiratory infections (Resp, 2nd Sem) Year 2 – Lecture Bone and joint infections (Musculoskeletal, 1st Sem) – Lectures, online modules, clinical classrooms and PBLs Several as part of Micro-Immuno (2nd Sem) Med Yr1-2 Micro/ID Important characteristics of the common pathogenic organisms Host-pathogen interactions Common types of infections Importance of pathology laboratory Antimicrobials Infection control (everybody’s responsibility) Learning objectives Understand the importance and basic classification of microorganisms History of microbiology – key events/discoveries Types of microorganisms and how they differ – bacteria (grampositive vs. gram-negative), viruses, fungi, parasites and prions Difference between normal flora and pathogenic microorganisms Relationships between organisms – commensalism, mutualism, opportunism and parasitism 5 Overview The importance of microbes A brief history of microbiology Classification of microorganisms Host-pathogen interactions (intro) 6 The Importance of Microbes Why is Microbiology Important? Microbes affect – all life – physical and chemical makeup of the earth 5x1030 microbial cells exist on earth In/on our bodies – ratio bacterial:human cells = 1.3:1 – 30% of our DNA is of viral origin Microbes Earliest forms of life Cycle carbon, nitrogen, sulphur, hydrogen and oxygen Regulate and affect growth of plants and animals Constitute 90% of Earth’s biomass At the base of most food chains More Areas where Microbes are Important Food production – bread, cheese, wine, etc. Nutrient absorption – bowel flora breakdown some foods Commercial applications – food production – production of biopharmaceuticals The Dark Side Small notorious set of bacteria, fungi, parasites & viruses cause disease Historically one of the most important causes of death Multiple epidemics & pandemics 19th and 20th Centuries – engineering – immunisation – antibiotics reduced impact of infections Definitions Microorganism – small (invisible to the naked eye) life form bacterium, virus or fungus Microbiota – microorganisms of a particular place/niche or geological period Microbiology – the scientific study of microorganisms Microbiology Clinical Micro and ID Clinical Microbiology – application of the scientific study of microorganisms to the observation and treatment of patients Infectious Diseases – diseases caused by microorganisms Clinical Infectious Diseases – internal medicine subspecialty concerned with patients with infections A Brief History of Microbiology Prehistory-1850 (before microbial life was known) Prehistory – death in all phases of life common – low life expectancy – infections, trauma – epidemics 1546 - Fracastoro - invisible particles cause disease 1665 lib.uiowa.edu 1676 - Antony Van Leeuwenhoek First microscope 1676 www.vanleeuwenhoek.com 1796 – First vaccine (smallpox) Edward Jenner myartprints.co.uk; microbes.historique.net 1847 - Semmelweis puerperal fever is a contagious disease commons.wikimedia.org Semmelweis - 1847 Infection was related to STUDENTS Not effectively cleaning their hands between performing autopsies and examining women in labour Introduced antiseptic hand wash Using chlorinated lime, both infection and mortality rates fell Hand Hygiene Not a New Concept Maternal Mortality from Postpartum Infection, General Hospital Vienna 1841 - 1850 Hand washing intervention May 1847 15 10 Docters/Medical students Midwives 5 0 18 41 18 42 18 43 18 44 18 45 18 46 18 47 18 48 18 49 18 50 % Maternal Mortality 20 Year 1853 – John Snow Cholera from Broad Street pump The “Father of Epidemiology” – Traced source of a cholera outbreak in Soho, London sphtc.org Cholera Outbreak Sudden epidemic Immediate digestive problems: cramps, vomiting, diarrhoea Face, feet and hands shrivelled; died in less than a day Probably spread by vomiting and diarrhoea Dr John Snow found strong association with drinking water from the pump and cholera ph.ucla.edu Snow’s findings disputed – Found evidence that supported findings – Found the index case infant died from cholera nappies >> cesspit 1m from Broad St. pump cesspit leaking ph.ucla.edu The Great Experiment # Houses # Deaths Companies 1&2 40,046 1263 Water from Chi-square test (not available London P