MEDI1000 Study Guide - Final Guide: Genitourinary System, Mycology, Enterococcus
16 Jun 2018
School
Department
Course
Professor
Foundations of Biomedical Science
Introduction to Microbiology
Microbiology
Micro = small (anything viewed with a microscope) !
bio = living organisms !
ology = study of !
MICROBIOLOGY - the study of small living organisms
Nomenclature!
Nomenclature - labeling/naming of the groups and the members of organisms
-All of the biological sciences generally utilise a Binomial System (all organisms)
-Genus and species names should be universal around the globe
-Both components are either italicised OR underlined
-e.g. the bacteria Staphylococcus aureus or Staphylococcus aureus
-Names have a Latin or Greek derivation
-First letter of genus is always capitalised
-Species designation is always lowercase
-Genus maybe abbreviated to first letter after first full use in text
-eg. S.aureus
-Species name is never abbreviated
-Informal designations(plurals ending in “i” are not italicised or capitalised
-e.g. staphylococci, streptococci, enterococci (these are not genus names)
The Role of micro-organisms
-Most organisms are harmless (87%)
-Many organisms are helpful
-Have an important role in the food chain
-e.g. decomposition, nitrogen fixation
-10% of organisms are opportunistic
-Microbes that are usually harmless !
Become pathogenic when placed in different conditions
-e.g. bowel flora that find their way into the bladder
-Only 3% of organisms are overtly pathogenic
-They usually cause disease when they are present on or in the human body, including
upon initial contact with, an otherwise, healthy person
-e.g. syphilis, tapeworm, tuberculosis, anthrax
Normal Flora
-Normal flora are the microbes that naturally inhibit surfaces of the human body
-Total microbial load > 1013 microbial cells in the body vs. 1013 body cells
-These organisms occur at sites exposed to, or that communicate with the external
environment
-e.g. skin, nasal passages, mouth, throat, urogenital tract, intestinal tract
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-Blood, tissues, lower respiratory tract are regarded as sterile
-The majority of the normal flora are found in the large intestine
-Much of the faecal mass is bacteria and water
-Importance of toilet/hand washing
-Normal Flora play a beneficial role in maintaining health
Importance of Microbial Discoveries
-The study of infectious disease causing microbes has led to an understanding of
-Personal and community hygiene
-Increase in hand washing and waste treatment/sanitation causing a decrease in
disease
-Microbial virulence and disease severity
-Increase virulence of an organism causing an increase in severity
-Prevention and control measures of microbial disease transmission
-Antimicrobial therapy/treatment of infection
-Disinfection
-Sterlisation
-Food processing and canning techniques
-Hygiene
-cooking
-pasteurisation
-Industrial microbiology
-brewing
-baking
-chemicals such as acetone
-Environmental
-bleaching
Major contributors to Microbiology
-Robert Hooke (1685)
-Wrote first book detailing observations with a microscope
-First person to describe a cell
-Antoni Van Leeuwenhoek (1673)
-Further developed the microscope - microscope with moveable stage
-First to describe bacteria including their shapes
-Ignaz Semmelweis (1847)
-First to use hand washing in clinical practice
-When he introduced hand washing he reduced obstetrics mortality from 18% to <1%
-Joseph Lister (1870)
-Credited with developing antisepsis for surgery
-Experimented with dressings soaked in carbolic acid used as an antiseptic
-Louis Pasteur (1861)
-Germ theory of fermentation
-Disproved theory of spontaneous generation (Abiogenesis)
-Discovered pasteurisation - originally used to prevent wine from spoiling
-Aspetic techniques and sterilisation
-Developed culture methods
-Robert Koch (1883)
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-First to study Anthrax and Tuberculosis
-Discovered the causative organism of cholera
-Found that micro-organisms can invade other organisms and cause disease
-Koch’s postulates - germ theory of disease
-Contributed to developing staining methods for microbes
Koch’s Postulates (Germ Theory of Disease)
1. The specific causative agent must be found in every case of an infectious disease
2. The disease organism must be isolated in a pure culture
3. Inoculation of a sample of the culture into a healthy, susceptible animal must produce
the same disease
4. The disease organism must be recovered from the infected animal
-A specific infectious disease is caused by a specific microbe
-Works with many bacteria
-Doesn't work with viruses or intracellular bacteria as you can not isolate them in a pure
culture
-Doesn't work with human only pathogens as there is no animal mode of the disease
-e.g. HIV
-Doesn't not work for non-infectious disease
-e.g. diabetes
3 Domains of Classification of Life
1. Eubacteria
-Gram positive bacteria
-Gram negative bacteria
-Cyanobacteria - obtain energy via photosynthesis
2. Archaea (specialised single cell organism that resemble bacteria)
-Used to be called Archaebacteria
-Methanogens - grow in the absence of O2 and produce methane (CH4)
-Halophiles - grow in areas of high salt concentration (5-17%)
-Thermophiles - grow in areas of high temperatures (45° - 122℃)
3. Eucarya
-Protozoa
-Algae
-Fungi
Classification of Micro-organisms
-Prokaryotes
-Archaea
-Eubacteria
-Eukaryotes
-Fungi
-Protozoa
-Algae
-Viruses
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Document Summary
Micro = small (anything viewed with a microscope) bio = living organisms ology = study of. Microbiology - the study of small living organisms. Nomenclature - labeling/naming of the groups and the members of organisms. All of the biological sciences generally utilise a binomial system (all organisms) Genus and species names should be universal around the globe. Both components are either italicised or underlined. E. g. the bacteria staphylococcus aureus or staphylococcus aureus. Names have a latin or greek derivation. First letter of genus is always capitalised. Genus maybe abbreviated to rst letter after rst full use in text. Informal designations(plurals ending in i are not italicised or capitalised. E. g. staphylococci, streptococci, enterococci (these are not genus names) Have an important role in the food chain. E. g. bowel ora that nd their way into the bladder. Only 3% of organisms are overtly pathogenic.
