Microbiology Lecture Presentation PDF

PowerPoint® Lecture Presentations prepared by Bradley W. Christian, McLennan Community College CHAPTER 1 The Microbial World and You © 2016 Pearson Education, Ltd.  Microbes in Our Lives Microbiology : is the study of the biology of microscopic organisms....

PowerPoint® Lecture Presentations prepared by Bradley W. Christian, McLennan Community College CHAPTER 1 The Microbial World and You © 2016 Pearson Education, Ltd.  Microbes in Our Lives Microbiology : is the study of the biology of microscopic organisms. Microorganisms or microbes are organisms that are too small to be seen with the unaided eye without a microscope. Microbes include bacteria, fungi, protozoa, microscopic algae, and viruses © 2016 Pearson Education, Ltd.  Microbes in Our Lives A few are pathogenic (disease-producing) Decompose organic waste Generate oxygen by photosynthesis Produce chemical products such as ethanol, acetone, and vitamins Produce fermented foods such as vinegar, cheese, and bread Produce products used in manufacturing (e.g., cellulase) and disease treatment (e.g., insulin) © 2016 Pearson Education, Ltd.  Microbes in Our Lives Knowledge of microorganisms allows humans to Prevent food spoilage Prevent disease Understand causes and transmission of disease to prevent epidemics and pandemics © 2016 Pearson Education, Ltd.  The microbiome An adult human body is composed of roughly 30 trillion body cells. Harbors another 40 trillion bacterial cells The microbiome is a group of microbes that live stably on\in the human body. - help to maintain good health. - can prevent growth of pathogenic microbes. - May help the immune system to discriminate threats © 2016 Pearson Education, Ltd.  Naming and Classifying Microorganisms Carolus Linnaeus established the system of scientific nomenclature in 1735 Each organism has two names: the genus and the specific epithet ( species ) © 2016 Pearson Education, Ltd.  Nomenclature Scientific names Are italicized or underlined The genus is capitalized; the specific epithet is lowercase Are "Latinized" and used worldwide, Latina is the universal scientific language. May be descriptive or honor a scientist. © 2016 Pearson Education, Ltd.  Nomenclature Escherichia coli Honors the discoverer, Theodor Escherich Describes the bacterium's habitat—the large intestine, or colon © 2016 Pearson Education, Ltd.  Nomenclature Staphylococcus aureus Describes the clustered (staphylo-) spherical (coccus) cells Describes the gold-colored (aureus) colonies © 2016 Pearson Education, Ltd.  Nomenclature After the first use, scientific names may be abbreviated with the first letter of the genus and the specific epithet: Escherichia coli and Staphylococcus aureus are found in the human body E. coli is found in the large intestine, and S. aureus is on skin © 2016 Pearson Education, Ltd.  Types of Microorganisms Bacteria Archaea Fungi Protozoa Algae Viruses Multicellular Animal Parasites © 2016 Pearson Education, Ltd.  Figure 1.1 Types of microorganisms. Bacteria Sporangia Food particle Pseudopod CD4 + T cell HIVs © 2016 Pearson Education, Ltd.  Bacteria Classified as prokaryotes. Single celled Peptidoglycan cell wall Divide by binary fission Derive nutrition from organic or inorganic chemicals or photosynthesis. May ‘’ swim’’ by using appendages called flagella © 2016 Pearson Education, Ltd.  Archaea Are prokaryotes Lack the peptidoglycan cell walls - may lack cell wall entirely Often live in extreme environments include: - Methanogens -extreme halophiles (salty environments) - extreme thermophiles © 2016 Pearson Education, Ltd.  Fungi Eukaryotes - the have a distinct nucleus surrounding DNA Chitin cell walls Absorb organic chemicals for energy Yeasts are unicellular Molds and mushrooms are multicellular © 2016 Pearson Education, Ltd.  protozoa Eukaryotes Absorb or ingest organic chemicals May be motile via pseudopods, cilia or flagella Free-living or parasitic ( derive nutrients from a living host), some of the protozoa are photosynthetic Reproduce sexually or asexually. © 2016 Pearson Education, Ltd.  Viruses Acellular Consist of DNA or RNA core, that surrounded by a protein coat The protein coat maybe enclosed by a lipid envelope. They are replicated only when they are in a living host cell © 2016 Pearson Education, Ltd.  The First Observations in Microbiology The first microbes were observed from 1623–1673 by Anton van Leeuwenhoek "Animalcules" viewed through magnifying lenses. The discovery of the cell By Robert Hooke in 1665, he reported that living things are composed of little boxes or cells. Also, he marked the beginning of cell theory: that all living things are composed of cells. © 2016 Pearson Education, Ltd.  Figure 1.2b Anton van Leeuwenhoek's microscopic observations. Lens Location of specimen on pin Specimen- positioning screw Focusing control Stage- positioning screw Microscope replica © 2016 Pearson Education, Ltd.  The debate over spontaneous Generation Spontaneous generation: the hypothesis that life arises from nonliving matter, a vital force is necessary for life. This theory led to development of scientific method. Biogenesis: the hypothesis that living cells arises only from preexisting living cells. Louis Pasteur demonstrated that microorganisms are presented in the air © 2016 Pearson Education, Ltd.  Louis Pasteur 1822–1895 Pasteur showed that microbes are responsible for fermentation Fermentation is the microbial conversion of sugar to alcohol in the absence of air Microbial growth is also responsible for spoilage of food and beverages Bacteria that use air spoil wine by turning it to vinegar (acetic acid) © 2016 Pearson Education, Ltd.  Louis Pasteur Pasteur demonstrated that these spoilage bacteria could be killed by heat that was not hot enough to evaporate the alcohol in wine Pasteurization is the application of a high heat for a short time to kill harmful bacteria in beverages © 2016 Pearson Education, Ltd.  The Germ Theory of Disease 1876: Robert Koch discovered that a bacterium causes anthrax and provided the experimental steps, Koch's postulates, to demonstrate that a specific microbe causes a specific disease (Germ theory of disease) © 2016 Pearson Education, Ltd.  Vaccination 1796: Edward Jenner inoculated a person with cowpox virus, who was then immune from smallpox Vaccination is derived from the Latin word vacca, meaning cow The protection called immunity © 2016 Pearson Education, Ltd.  The Birth of Modern Chemotherapy Treatment of disease with chemicals is called chemotherapy Chemotherapeutic agents used to treat infectious disease can be synthetic drugs or antibiotics Antibiotics are chemicals produced by bacteria and fungi that inhibit or kill other microbes © 2016 Pearson Education, Ltd.  Brief history of antimicrobial Paul Ehrlich speculated about a "magic bullet" that could destroy a pathogen without harming the host 1910: Ehrlich developed a synthetic arsenic drug, Salvarsan, to treat syphilis (STI), sexually transmitted infection, that caused by a bacterial called Treponema pallidum. Quinine became widely used as an antimalarial after it was isolated from the cinchona tree. Sulfonamides : they are synthetic antimicrobial that block folic acid production in the bacteria. © 2016 Pearson Education, Ltd.  A Fortunate Accident—Antibiotics 1928: Alexander Fleming discovered the first antibiotic (by accident) Fleming observed that Penicillium fungus made an antibiotic, penicillin, that killed S. aureus 1940s: Penicillin was tested clinically and mass- produced © 2016 Pearson Education, Ltd.  Figure 1.5 The discovery of penicillin. Staphylococcus Penicillium Zone of inhibited growth Growth inhibition of Staphylococcus by Penicillium © 2016 Pearson Education, Ltd.