2004 by Jones and Bartlett Publishers

You do not really understand something unless you can explain it to your grandmother.

--Albert Einstein

Chapter 1The Microbial World and YouList some ways in which microbes affect your liveUse scientific nomenclature : Genus and a specific epithet. List the three domains. Explain the importance of observations made by van Leeuwenhoek. Compare spontaneous generation and biogenesis. Describe experiments that helped to prove biogenesis.Highlight the major achievements of Pasteur and Koch. Identify the important work of Semmelweis and Lister. Identify the contributions to microbiology made by Jenner, Ehrlich and Fleming. Define bacteriology, mycology, parasitology, immunology, and virology. Explain the importance of recombinant DNA technology. List two examples of biotechnology that use recombinant DNA .Define normal microbiota and resistance. Define and describe several infectious diseases. Objectives

Microbes help us bydecomposing organic wasteperforming photosynthesisproducing ethanol, acetone, vinegar, cheese, bread, . . . producing insulin and many other drugs. . . Microbes harm us by

Naming and Classifying MicroorganismsCarolus Linnaeus established the system of scientific nomenclature in 1739.Each organism has two names Binomial nomenclature: Genus + specific epithet (species)Italicized (or underlined), genus capitalized, latinized, used worldwide.May be descriptive or honor a scientist.

ExamplesStaphylococcus aureus (S. aureus)Escherichia coli (E. coli)Streptococcus pneumoniae (S. pneumoniae)

1857 1911

Types of MicroorganismsBacteriaArchaeaFungiProtozoaAlgaeVirusesMulticellular animal parasitesPrions

Bacterium / BacteriaProkaryoticPeptidoglycan cell wallReproduction by binary fission

Gain energy from use of organic chemicals inorganic chemicals or photosynthesis

Figure 4.5bArchaeaProkaryoticNo peptidoglycanLive in extreme environmentsIncludeMethanogensExtreme halophilesExtreme thermophiles

Fungus/FungiEukaryoticChitin cell wallsUse organic chemicals for energy.Molds and mushrooms are multicellular consisting of masses of mycelia, which are composed of filaments called hyphae.Yeasts are unicellular.

Protozoan/ ProtozoaEukaryotesAbsorb or ingest organic chemicalsMay be motile via pseudopods, cilia, or flagella

VirusesAre acellularHave either DNA or RNA in coreCore is surrounded by a protein coat.Coat may be enclosed in a lipid envelope.Viruses only replicate within a living host cell.

Multicellular Animal ParasitesEukaryotesMulticellular animalsHelminths are parasitic flatworms and round wormsMicroscopic stages in life cycles

Three Domain Classification BacteriaArchaeaEukaryaProtistaFungiPlantsAnimals

Microbiology HistoryAncestors of bacteria were the first life on Earth1665: Cell theory Robert Hooke

The Beginnings 1673: First microbes observed Anton van LeeuwenhoekCompare to Fig 1.2

The Transition Period: Debate over Spontaneous GenerationAristotless doctrine of spontaneous generation. Hypothesis that living organisms arise from nonliving matter; a vital force forms life Biogenesis: Hypothesis that the living organisms arise from preexisting life

1668:Francesco Redithe beginnings of experimental sciencefilled 6 jars with decaying meat

ConditionsResultsThree jars covered with fine netNo maggotsThree open jarsMaggots appearedFrom where did the maggots come?What was the purpose of the sealed jars?Spontaneous generation or biogenesis?

1745: John NeedhamObjectionsPut boiled nutrient broth into covered flasks

ConditionsResultsNutrient broth heated, then placed in sealed flaskMicrobial growthFrom where did the microbes come?Spontaneous generation or biogenesis?

1765: Lazzaro Spallanzaniboiled nutrient solutions in flasks

ConditionsResultsNutrient broth placed in flask, heated, then sealedNo microbial growthSpontaneous generation or biogenesis?

1861: Louis Pasteurdemonstrated that microorganisms are present in the air

ConditionsResultsNutrient broth placed in flask, heated, not sealedMicrobial growthNutrient broth placed in flask, heated, then sealedNo microbial growthSpontaneous generation or biogenesis?

Figure 1.3Confirmation of BiogenesisPasteurs S-shaped (swan-neck ) flask kept microbes out but let air in

The Golden Age of Microbiology(1857-1914)Microbiology established as a scienceLouis Pasteur Spontaneous generation disproved Wine fermentation (yeasts and bacteria)Pasteurization

Ignaz Semmelweis (1840s) hand disinfection and puerperal feverBased on Pateurs and Semmelweis findings: Joseph Lister (1860s) antiseptic surgery (phenol)Pre-Pasteur:

Robert KochWork on anthrax proves the germ theory of diseaseProcedures become Koch's postulates (see Ch 14) Development of pure culture technique Nobel Prize in 1905

Nobelprize.org

Before the Golden Age Period: The Birth of VaccinationJenner and smallpox vaccination (1796)~ 100 years later: Pasteur shows how vaccinations work. (Creation of avirulent strains of bacteria during extended laboratory cultivation)

The Birth of Modern Chemotherapy1910: Paul Ehrlich developed a synthetic arsenic drug, salvarsan, to treat syphilis1930s: Synthesis of sulfonamides 1928: Alexander Fleming and the discovery of the first antibiotic

Fig 1.5

enicillin purification and clinical trials not until 1940sFig 1.5

Modern Developments in MicrobiologyBacteriology Mycology Parasitology Virology ImmunologyMicrobial genetics and molecular biology lead to Recombinant DNA Technology (genetic engineering). Prokaryotic model system: E. coli

Selected Nobel Prizes for Microbiology Research1901 von Behring Diphtheria antitoxin1902 Ross Malaria transmission1905 Koch TB bacterium1908 Metchnikoff Phagocytes1945 Fleming, Chain, Florey Penicillin1952 Waksman Streptomycin1969 Delbrck, Hershey, LuriaViral replication1987 Tonegawa Antibody genetics1997 Prusiner Prions2005 Marshall & Warren H. pylori & ulcers

Microbes and Human Disease Again many Challenges Normal microbiota (flora) in and on the human body Pathogens overcome the hosts resistance infectious disease Antimicrobial resistanceBioterrorism(Re-)emerging infectious diseases (EID): WNE, avian influenza, SARS, BSE, HIV/AIDS . . .

Avian influenza AInfluenza A virus (H5N1)Primarily in waterfowl and poultrySustained human-to-human transmission has not occurred yetWest Nile EncephalitisCaused by West Nile virusFirst diagnosed in the West Nile region of Uganda in 1937Appeared in New York City in 1999

MRSAMethicillin-resistant Staphylococcus aureus1950s: Penicillin resistance developed1980s: Methicillin resistance1990s: MRSA resistance to vancomycin reportedVISA: Vancomycin-intermediate-resistant S. aureus VRSA: Vancomycin-resistant S. aureus Bovine Spongiform EncephalopathyCaused by a prionAlso causes Creutzfeldt-Jakob disease (CJD). New variant CJD in humans is related to beef consumption

Figure 25.12Escherichia coli O157:H7Toxin-producing strain of E. coliFirst seen in 1982Leading cause of diarrhea worldwide

Acquired immunodeficiency syndrome (AIDS)Caused by human immunodeficiency virus (HIV)First identified in 1981Worldwide epidemic infecting 30 million people; 14,000 new infections every daySexually transmitted infection affecting males and femalesHIV/AIDS in the U.S.: 30% are female, and 75% are African American

**Microbes harm us by causing disease and causing food spoilage

**Portrait of Carl Linnaeus at 32 by J. H. Scheffel. Oil Painting, 1739. Reproduction courtesy Uppsala University Art Collections Scientists around the world are celebrating the 300th anniversary of the birth of Swedish botanist Carl Linnaeus. He is best known for instituting a two-name method for identifying plants and animals, called binomial nomenclature. Considered the father of modern taxonomy, Linnaeus named approximately 4,400 species of animals and 7,700 species of plants.

*Staphylococcus aureus: Describes the clustered arrangement of the cells (staphylo-) and the golden color of the colonies (aur-).E. coli: Honors the discoverer, Theodor Escherich, and describes the bacteriums habitatthe large intestine or colon.

************Ignaz Philipp Semmelweis (1818-65), a Hungarian obstetrician educated at the universities of Pest and Vienna, introduced antiseptic prophylaxis into medicine. In the 1840s, puerperal or childbirth fever, a bacterial infection of the female genital tract after childbirth, was taking the lives of up to 30% of women who gave birth in hospitals. Women who gave birth at home remained relatively unaffected. As assistant professor on the maternity ward of the Vienna General Hospital, Semmelweis observed that women examined by student doctors who had not washed their hands after leaving the autopsy room had very high death rates. When a colleague who had received a scalpel cut died of infection, Semmelweis concluded that puerperal fever was septic and contagious. He ordered students to wash their hands with chlorinated lime before examining patients; as a result, the maternal death rate was reduced from 12% to 1% in 2 years. Nevertheless, Semmelweis encountered strong opposition from hospital officials and left Vienna in 1850 for the University of Pest. As a professor of obstetrics at the University of Pest Hospital, he enforced antiseptic practices and reduced the death rate from puerperal fever to 0.85%. However, Semmelweis findings and publications were resisted by hospital and medical authorities in Hungary and abroad. After a breakdown, he entered a mental hospital in Vienna, where he died of an infection contracted during an operation he had performed. Information and photo from: funkandwagnalls.com Copyright 1999, 2000.******Bacteria were once classified as plants giving rise to use of the term flora for microbes. This term has been replaced by microbiota.

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