Microbiology Chapter 1

Microbiology The study of organisms too small to be seen without magnification The study of organisms too small to be seen without magnification bacteria bacteria viruses viruses fungi fungi protozoa protozoa helminths (worms) helminths (worms) algae algae

The six main types of microorganisms The six main types of microorganisms 3

Microbial Dimensions 4

5 Characteristics of Microbes Two cell lines Two cell lines Prokaryote – microscopic, unicellular organisms, lack nuclei and membrane-bound organelles Prokaryote – microscopic, unicellular organisms, lack nuclei and membrane-bound organelles Eukaryote – unicellular (microscopic) and multicellular, nucleus and membrane-bound organelles Eukaryote – unicellular (microscopic) and multicellular, nucleus and membrane-bound organelles Viruses Viruses Acellular, parasitic particles composed of a nucleic acid and protein Acellular, parasitic particles composed of a nucleic acid and protein

Branches of study within microbiology Immunology Immunology Public health microbiology & epidemiology Public health microbiology & epidemiology Food, dairy and aquatic microbiology Food, dairy and aquatic microbiology Biotechnology Biotechnology Genetic engineering & recombinant DNA technology Genetic engineering & recombinant DNA technology

7 Origins of Microorganisms Bacteria-like organisms have existed on earth for about 3.5 billion years (give or take a few million) Bacteria-like organisms have existed on earth for about 3.5 billion years (give or take a few million) Prokaryotes (pre-nucleus): Simple cells Prokaryotes (pre-nucleus): Simple cells Eukaryotes (true nucleus): Complex cells Eukaryotes (true nucleus): Complex cells

Microbes are involved in nutrient production & energy flow nutrient production & energy flow decomposition decomposition production of foods, drugs & vaccines production of foods, drugs & vaccines Bioremediation Bioremediation biotechnology biotechnology causing disease causing disease

Lifestyles of Microorganisms Majority live a free existence, are relatively harmless and often beneficial Majority live a free existence, are relatively harmless and often beneficial Many microorganisms have close associations with other organisms Many microorganisms have close associations with other organisms Parasites Parasites Hosts Hosts 9

10 Infectious Diseases Pathogens: Microorganisms that do harm Pathogens: Microorganisms that do harm Nearly 2,000 different microbes cause diseases Nearly 2,000 different microbes cause diseases 10 B new infections/year worldwide 10 B new infections/year worldwide 12 M deaths from infections/year worldwide 12 M deaths from infections/year worldwide

Worldwide infectious disease statistics

12 Historical Foundations of Microbiology Last 300 years Last 300 years Prominent discoveries include: Prominent discoveries include: Microscopy Microscopy Scientific method Scientific method Development of medical microbiology Development of medical microbiology Vaccines Vaccines Medicine Medicine Cause of disease Cause of disease Microbiology techniques Microbiology techniques

Antoni van Leeuwenhoek Dutch Draper Dutch Draper First to observe living microbes First to observe living microbes his single-lens magnified up to 300X his single-lens magnified up to 300X ( )

14 Insert figure 1.9 (a) microscope

Leeuwenhoek’s Drawings

Robert Hooke ( )

Hooke’s microscope

Hooke’s Micrographia

Hooke’s cork drawings

Hooke’s flea drawing

Edward Jenner ( )

Cowpox pustules

“First” vaccination

24 Development of Aseptic Techniques Hypothesis: The human body is a source of infection Hypothesis: The human body is a source of infection Dr. Oliver Wendell Holmes – observed that mothers of home births had fewer infections than those who gave birth in hospitals Dr. Oliver Wendell Holmes – observed that mothers of home births had fewer infections than those who gave birth in hospitals Dr. Ignaz Semmelweis – correlated infections with physicians coming directly from autopsy room to maternity ward Dr. Ignaz Semmelweis – correlated infections with physicians coming directly from autopsy room to maternity ward

Oliver Wendell Holmes (1809 – 1894)

Ignaz Semmelweiss ( )

Semmelweiss (handwashing)

28 Pathogens and Germ Theory of Disease Most diseases are caused by the growth of microbes in the body and not by sins, bad character, or poverty, etc. Most diseases are caused by the growth of microbes in the body and not by sins, bad character, or poverty, etc. Two major contributors: Two major contributors: Robert Koch Robert Koch Louis Pasteur

Robert Koch Established a sequence of experimental steps, Koch’s Postulates, to show that a specific m.o. causes a particular disease Established a sequence of experimental steps, Koch’s Postulates, to show that a specific m.o. causes a particular disease Developed pure culture methods Developed pure culture methods Identified cause of anthrax, TB, & cholera Identified cause of anthrax, TB, & cholera ( )

Robert Koch in his laboratory

Louis Pasteur Showed microbes caused fermentation & spoilage Showed microbes caused fermentation & spoilage Disproved spontaneous generation Disproved spontaneous generation Developed aseptic techniques Developed aseptic techniques Developed the rabies vaccine Developed the rabies vaccine ( )

Spontaneous generation Early belief that some forms of life could arise from vital forces present in nonliving or decomposing matter. (flies from manure, etc)

Pasteur’s Swan Neck Flask Experiment

Swan Neck Flask

Joseph Lister Joseph Lister – introduced aseptic techniques reducing microbes in medical settings and preventing wound infections Joseph Lister – introduced aseptic techniques reducing microbes in medical settings and preventing wound infections Involved disinfection of hands and room using chemicals (carbolic acid) prior to surgery Use of heat for sterilization of instruments ( )

Lister

37 Discovery of Spores and Sterilization John Tyndall and Ferdinand Cohn each demonstrated the presence of heat resistant forms of some microbes. John Tyndall and Ferdinand Cohn each demonstrated the presence of heat resistant forms of some microbes. Cohn determined these forms to be heat- resistant bacterial endospores. Cohn determined these forms to be heat- resistant bacterial endospores. Sterility requires the elimination of all life forms including endospores and viruses. Sterility requires the elimination of all life forms including endospores and viruses.

Alexander Fleming ( )

Penicillin growing on Petri dish

Electron Microscope

Cocci shaped bacteria

Streptococci

Staphylococcus

Rod shaped bacillus

Rod Shaped

Spirillum shaped bacteria

Gram Stain

Pour Plates

Petri dish growth

Antibiotic Sensitivity Tests

DNA Plasmid

Sex Pilus

Bacteria conjugation

Bacteria - binary fission

Bacteria undergoing binary fission

Bacteriophage

Bacteriophage on bacteria

Herpes virus

Herpes Simplex II

Influenza virus

Avian Influenza Virus

Human Immunodeficiency Virus

Kaposi Sarcoma

Archaea Bacteria Extremophiles Extremophiles Love salt Love salt Low pH Low pH High pressure High pressure High temperatures High temperatures

Yellowstone

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