Microbiology An Introduction PDF

Vocabulary People Microbiology an Introduction Thirteenth Edition Microbes in Our Lives...

Vocabulary People Microbiology an Introduction Thirteenth Edition Microbes in Our Lives Microorganisms are organisms that are too small to be seen with the unaided eye Chapter 1 Microbes include bacteria, fungi, protozoa, The Microbial World and You microscopic algae, and viruses also worms Germ refers to a rapidly growing cell Copyright © 2019 Pearson Education, Inc. All Rights Reserved Copyright © 2019 Pearson Education, Inc. All Rights Reserved 1 2 Microbes in Our Lives Microbes in Our Lives A few are pathogenic (disease-producing) Knowledge of microorganisms allows humans to Decompose organic waste – Prevent food spoilage – Prevent disease Generate oxygen by photosynthesis – Understand causes and transmission of disease to Produce chemical products such as ethanol, acetone, prevent epidemics and vitamins Produce fermented foods such as vinegar, cheese, Led to aseptic techniques to prevent contamination in and bread medicine & in microbiology laboratories Produce products used in manufacturing (e.g., cellulose) and disease treatment (e.g., insulin) Copyright © 2019 Pearson Education, Inc. All Rights Reserved Copyright © 2019 Pearson Education, Inc. All Rights Reserved 3 1914 – Chaim Weizmann, a Russian-born chemist working 4 in England discovered the process of using microbes to produce acetone & butanol, which became important 1  The Microbiome The Microbiome An adult human is composed of 30 trillion body cells Normal microbiota is the collection of acquired – Harbors another 40 trillion bacterial cells microorganisms on or in a healthy human being – Begin to be acquired as newborns The microbiome is a group of microbes that live stably on/in the human body – May colonize the body indefinitely – Help to maintain good health – May colonize the body fleetingly (making them transient microbiota) present for short time wo causing – Can prevent growth of pathogenic microbes disease – May help train the immune system to discriminate Colonization can only occur at body sites that provide threats nutrients and the right environment for the microbes to flourish Copyright © 2019 Pearson Education, Inc. All Rights Reserved Copyright © 2019 Pearson Education, Inc. All Rights Reserved 5 Bacteria in the intestines aid digestion & synthesize some 6 Factors that influence what types of microbes can vitamins like vitamin B for metabolism & vitamin K for flourish: temp, Ph, & presence/absence of chemical blood clotting compounds Naming and Classifying Normal Microbiota Microorganisms Normal microbiota prevent growth of pathogens Carolus Linnaeus established the system of scientific nomenclature in 1735 Normal microbiota produce growth factors such as vitamins B and K Each organism has 2 names: the genus & the specific epithet Resistance is the ability of the body to ward off disease Resistance factors include skin, stomach acid, and antimicrobial chemicals Copyright © 2019 Pearson Education, Inc. All Rights Reserved Copyright © 2019 Pearson Education, Inc. All Rights Reserved 7 8 2  Nomenclature Nomenclature Scientific names Escherichia coli – Are italicized or underlined – Honors the discoverer, Theodor Escherich ▪ The genus is capitalized; the specific epithet is – Describes the bacterium's habitat—the large lowercase intestine, or colon – Are “Latinized” and used worldwide – May be descriptive or honor a scientist Copyright © 2019 Pearson Education, Inc. All Rights Reserved Copyright © 2019 Pearson Education, Inc. All Rights Reserved 9 10 Nomenclature Nomenclature Staphylococcus aureus After the first use, scientific names may be – Describes the clustered (staphylo-) spherical abbreviated with the first letter of the genus and the (coccus) cells specific epithet: – Describes the gold-colored (aureus) colonies – Escherichia coli and Staphylococcus aureus are found in the human body A bacterium commonly found on human skin – E. coli is found in the large intestine, and S. aureus is on skin Copyright © 2019 Pearson Education, Inc. All Rights Reserved Copyright © 2019 Pearson Education, Inc. All Rights Reserved 11 12 3  genetic material isn't enclosed in a special nuclear membrane Types of Microorganisms Bacteria Bacteria Prokaryotes (bacteria & archaea) – “Prenucleus” Archaea Single-celled (unicellular) Fungi Peptidoglycan cell walls Protozoa Divide via binary fission Algae Derive nutrition from organic chemicals (dead/living Viruses animals), photosynthesis, or from inorganic substances Multicellular Animal Parasites May “swim” by using moving appendages called flagella Copyright © 2019 Pearson Education, Inc. All Rights Reserved Copyright © 2019 Pearson Education, Inc. All Rights Reserved 13 14 Individual bacteria may form pairs, chains, clusters, or other groupings Are enclosed in cell walls that are largely composed of a carbohydrate & protein complex Several shapes: Bacillus, Coccus, & Spiral; Star-shaped or square Sporangia Archaea Fungi Are prokaryotes Eukaryotes Lack peptidoglycan cell walls – Distinct nucleus surrounding DNA – May lack cell wall entirely Chitin cell walls Often live in extreme environments Absorb organic chemicals for energy Include: produce methane as a waste product Yeasts are unicellular – Methanogens from respiration – Extreme halophiles live in extremely salty environments Molds and mushrooms are multicellular – Extreme thermophiles live in hot sulfurous water Consists of masses of mycelia, which are composed of filaments called hyphae Generally do not cause disease in humans Copyright © 2019 Pearson Education, Inc. All Rights Reserved Copyright © 2019 Pearson Education, Inc. All Rights Reserved 15 16 4  Protozoa Algae Eukaryotes Eukaryotes Absorb or ingest organic chemicals Cellulose cell walls May be motile via pseudopods, cilia, or flagella Found in freshwater, saltwater, and soil Free-living or parasitic (derive nutrients from a living Use photosynthesis for energy host) – Produces oxygen and carbohydrates – Some are photosynthetic Sexual and asexual reproduction possible Reproduce sexually or asexually Copyright © 2019 Pearson Education, Inc. All Rights Reserved Copyright © 2019 Pearson Education, Inc. All Rights Reserved 17 18 Viruses Multicellular Animal Parasites Acellular Eukaryotes Consist of DNA or RNA core Multicellular animals Core is surrounded by a protein coat Not strictly microorganisms – Coat may be enclosed in a lipid envelope Parasitic flatworms and roundworms are called Are replicated only when they are in a living host cell helminths - Inert outside living hosts Some microscopic stages in their life cycles - Obligate intracellular parasite Copyright © 2019 Pearson Education, Inc. All Rights Reserved Copyright © 2019 Pearson Education, Inc. All Rights Reserved 19 20 5  The Debate over Spontaneous The First Observations Generation 1665: Robert Hooke reported that living things are Spontaneous generation: the hypothesis that life composed of little boxes, or “cells” arises from nonliving matter; a “vital force” is Marked the beginning of cell theory: all living things necessary for life are composed of cells Biogenesis: the hypothesis that living cells arise only from preexisting living cells The first microbes were observed from 1623 to 1673 by Anton van Leeuwenhoek – “Animalcules” viewed through magnifying lenses Copyright © 2019 Pearson Education, Inc. All Rights Reserved Copyright © 2019 Pearson Education, Inc. All Rights Reserved 21 22 The Theory of Biogenesis The Theory of Biogenesis 1858: Rudolf Virchow said cells arise from preexisting 1861: Louis Pasteur demonstrated that cells microorganisms are present in the air Conditions Results Nutrient broth placed in Microbial growth flask, heated, NOT sealed Nutrient broth placed in No Microbial growth flask, heated, then immediately sealed Spontaneous generation or biogenesis? Copyright © 2019 Pearson Education, Inc. All Rights Reserved Copyright © 2019 Pearson Education, Inc. All Rights Reserved 23 24 6  The Golden Age of Microbiology The Theory of Biogenesis Pasteur also used S-shaped flasks 1857–1914 – Keep microbes out but let air in Beginning with Pasteur's work, discoveries included Broth in flasks showed no signs of life the relationship between microbes and disease, immunity, and antimicrobial drugs Neck of flask traps microbes Microorganisms originate in air or fluids, not mystical forces Copyright © 2019 Pearson Education, Inc. All Rights Reserved Copyright © 2019 Pearson Education, Inc. All Rights Reserved 25 26 The Golden Age of Microbiology The Golden Age of Microbiology Pasteur showed that microbes are responsible for Pasteur demonstrated that these spoilage bacteria fermentation could be killed by heat that was not hot enough to evaporate the alcohol in wine Fermentation is the microbial conversion of sugar to alcohol in the absence of air Pasteurization: the application of a high heat for a Microbial growth is also responsible for spoilage of short time to kill harmful bacteria in beverages food and beverages or the spoilage bacteria Bacteria that use air spoil wine by turning it to vinegar (acetic acid) Copyright © 2019 Pearson Education, Inc. All Rights Reserved Copyright © 2019 Pearson Education, Inc. All Rights Reserved 27 28 7  The Germ Theory of Disease The Germ Theory of Disease 1860s: Applying Pasteur's work showing that microbes 1876: Robert Koch discovered that a bacterium are in the air, can spoil food, and cause animal causes anthrax and provided the experimental steps, diseases, Koch's postulates, to demonstrate that a specific Joseph Lister used a chemical antiseptic microbe causes a specific disease (phenol) to prevent surgical wound infections Copyright © 2019 Pearson Education, Inc. All Rights Reserved Copyright © 2019 Pearson Education, Inc. All Rights Reserved 29 30 The Birth of Modern Chemotherapy: Vaccination Dreams of a “Magic Bullet” 1796: Edward Jenner inoculated a person with Treatment of disease with chemicals is called cowpox virus, who was then immune to smallpox chemotherapy Vaccination is derived from the Latin word vacca, Chemotherapeutic agents used to treat infectious meaning cow disease can be synthetic drugs or antibiotics The protection is called immunity Antibiotics: chemicals produced by bacteria & fungi that inhibit or kill other microbes Copyright © 2019 Pearson Education, Inc. All Rights Reserved Copyright © 2019 Pearson Education, Inc. All Rights Reserved 31 32 8  The First Synthetic Drugs A Fortunate Accident—Antibiotics Quinine from tree bark was long used to treat malaria 1928: Alexander Fleming discovered the first antibiotic Paul Ehrlich speculated about a “magic bullet” that (by accident) could destroy a pathogen without harming the host – 1910: Ehrlich developed a synthetic arsenic drug, Fleming observed that salvarsan, to treat syphilis Penicillium fungus made an antibiotic, penicillin, that 1930s: Sulfonamides were synthesized killed S. aureus 1940s: Penicillin was tested clinically and mass- produced Copyright © 2019 Pearson Education, Inc. All Rights Reserved Copyright © 2019 Pearson Education, Inc. All Rights Reserved 33 34 Problems with Antimicrobial Figure 1.9 Rebecca Lancefield (1895– Chemicals 1981) Overuse can lead to resistance Rebecca Lancefield (1895–1981), who discovered differences in the chemical composition of a Some drugs can be toxic to humans polysaccharide in the cell walls of many pathogenic – Especially antivirals streptococci. Research used to overcome these problems has ushered in a Third Golden Age of Microbiology from the late 1980s to the present Copyright © 2019 Pearson Education, Inc. All Rights Reserved Copyright © 2019 Pearson Education, Inc. All Rights Reserved 35 36 9  Virology Molecular Genetics Virology is the study of viruses Microbial genetics: the study of how microbes inherit traits Dmitri Iwanowski in 1892 and Wendell Stanley in 1935 discovered the cause of mosaic disease of tobacco to Molecular biology: the study of how DNA directs protein be a virus synthesis Genomics: the study of an organism's genes; has Electron microscopes have made it possible to provided new tools for classifying microorganisms study the structure of viruses in detail Recombinant DNA: DNA made from two different sources – In the 1960s, Paul Berg inserted animal DNA into bacterial DNA, and the bacteria produced an animal protein Copyright © 2019 Pearson Education, Inc. All Rights Reserved Copyright © 2019 Pearson Education, Inc. All Rights Reserved 37 38 Biotechnology and Recombinant Molecular Genetics DNA Technology 1941: George Beadle and Edward Tatum showed that Biotechnology is the use of microbes for practical genes encode a cell's enzymes applications, such as producing foods and chemicals 1944: Oswald Avery, Colin MacLeod, and Maclyn Recombinant DNA technology enables bacteria and McCarty showed that DNA is the hereditary material fungi to produce a variety of proteins, vaccines, and enzymes 1953: James Watson & Francis Crick proposed a – Missing or defective genes in human cells can be model of DNA structure replaced in gene therapy 1961: François Jacob and Jacques Monod discovered – Genetically modified bacteria are used to protect the role of mRNA in protein synthesis crops from insects and from freezing Copyright © 2019 Pearson Education, Inc. All Rights Reserved Copyright © 2019 Pearson Education, Inc. All Rights Reserved 39 40 10  Microbiology an Introduction Thirteenth Edition Biofilms Microbes attach to solid surfaces and grow into masses They will grow on rocks, pipes, teeth, and medical Chapter 10 implants Classification of Microorganisms Can cause infections & are often resistant to antibiotics Copyright © 2019 Pearson Education, Inc. All Rights Reserved Copyright © 2019 Pearson Education, Inc. All Rights Reserved 41 42 The Study of Phylogenetic Relationships Figure 10.1 Three-Domain System Taxonomy is the science of classifying organisms – Shows degree of similarity among organisms Systematics, or phylogeny, is the study of the evolutionary history of organisms Key Concepts All organisms evolved from cells that formed over 3 billion years ago. The DNA passed on from ancestors is described as conserved. The Domain Eukarya includes the kingdoms Fungi, Plantae, and Animalia, as well as protists. The Domains Bacteria and Archaea are prokaryotes. Copyright © 2019 Pearson Education, Inc. All Rights Reserved Copyright © 2019 Pearson Education, Inc. All Rights Reserved 43 44 11  Scientific Nomenclature Classification of Prokaryotes Common names vary with languages and geography Prokaryotic species: a population of cells with similar characteristics Binomial nomenclature is used worldwide to consistently and accurately name organisms – Culture: bacteria grown in laboratory media – Genus – Clone: population of cells derived from a single parent cell – Specific epithet (species) Strain: genetically different cells within a clone Copyright © 2019 Pearson Education, Inc. All Rights Reserved Copyright © 2019 Pearson Education, Inc. All Rights Reserved 45 46 Classification of Eukaryotes Classification of Viruses Protista: a catchall kingdom for a variety of organisms; Not a part of any domain; not composed of cells; autotrophic and heterotrophic require a host cell – Grouped into clades based on rRNA Viral species: population of viruses with similar Fungi: chemoheterotrophic; unicellular or multicellular; characteristics that occupies a particular ecological cell walls of chitin; develop from spores or hyphal niche fragments Plantae: multicellular; cellulose cell walls; undergo photosynthesis Animalia: multicellular; no cell walls; chemoheterotrophic Copyright © 2019 Pearson Education, Inc. All Rights Reserved Copyright © 2019 Pearson Education, Inc. All Rights Reserved 47 48 12  Methods of Classifying and Methods of Classifying and Identifying Microorganisms Identifying Microorganisms (6 of 6) Classification: placing organisms in groups of related Morphological characteristics: useful for identifying species eukaryotes; tell little about phylogenetic relationships – Lists of characteristics of known organisms Differential staining: Gram staining, acid-fast staining; Identification: matching characteristics of an not useful for bacteria without cell walls "unknown" organism to lists of known organisms Clinical lab identification Biochemical tests: determine presence of bacterial enzyme Copyright © 2019 Pearson Education, Inc. All Rights Reserved Copyright © 2019 Pearson Education, Inc. All Rights Reserved 49 50 Emerging Infectious Diseases When a pathogen invades a host and overcomes the host's resistance, disease results Emerging infectious diseases (EIDs): new diseases & diseases increasing in incidence Copyright © 2019 Pearson Education, Inc. All Rights Reserved 51 13