Microbiology 101

• Microbiology - scientific study of microorganisms and their effects on other living organisms

  • Micro - small

  • Bio - life

  • ology - the study of

• Divisions of Microbiology

  • Bacteriology - study of bacteria

  • Rickettsiology - the study of rickettsia

  • Virology - study of viral diseases

  • Protozoology - science and study of protozoa

  • Mycology - the study of fungi

• History

  • 1400s-1500s: Girolamo Fracastoro disproved miasma theory

  • 1600s: Antoni van Leeuwenhoek began working on the microscope to view his “animalcules”

    • Francesco Redi proves that fly eggs on rotting meat came from flies and not spontaneous generation

  • 1800s: Louis Pasteur developed biogenesis theory stating that life only comes from other life

  • 1860s: Joseph Lister proved that microorganisms are the cause of infection and heating instruments and using phenol during surgery would prevent this

  • 1870s: Robert Koch demonstrated a relationship between Bacillus anthracis and anthrax in cattle and developed Koch’s postulates

  • 1900s: Paul Ehrlich began working on drug remedies for bacterial disorders

Classifying Organisms

• Prokaryotes

  • Small and simple organisms

  • No nucleus

  • No membrane-bound organelles

  • unicellular or multicellular

  • genetic information contained in a nucleoid

• Eukaryotes

  • More complex and organized organisms or cells

  • Unicellular or multicellular

  • Genetic information contained in a nucleus

  • Membrane-bound organelles

  • Genetic information exists in chromosomes and DNA is complex

• Nomenclature

  • Binomial Nomenclature - used in science to assign a genus and species to each organism using taxonomy

  • Taxonomy - groups organisms into cohorts based on similarities

• Taxa

  • Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

• When referring to Organims

  • All organisms have a first and last name

  • First name is the genus

  • Last name is the species'

  • Genus is capitalized and italicized

  • Species is just italicized

  • with bacteria, the names often give us much more information

• Domains of Life

  • Archaea

    • Prokaryontes

    • Single celled

    • No peptidoglycan in cell wall

    • Most are anaerobic

    • Inhabit extreme environments

    • Do not usually cause human disease

  • Bactieria

    • Prokaryotes

    • Peptidoglycan in the cell wall

    • Single-celled

    • can exist on their own or as parasites

    • Present everywhere

    • often cause disease

  • Eukaryotes

    • Animals, plants, protists

    • Complex and organized cells within a nucleus or nuclei

    • Complex structure

• Broad Classification

  • Bacteria - Prokaryotes found everywhere; they reproduce via Asexual reproduction

  • Viruses - tiny simple parasitic structures that are not cellular and not technically living; they require a host cell to replicate

  • Protazoa - unicellular eukaryotes that look like tiny animals; reproduction method varies

  • Fungi - a group of eukaryotes that are unable to photosynthesize, reproduce via spores