1. introduction to microbiology

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Page 1: 1. introduction to microbiology
Page 2: 1. introduction to microbiology

Scope of MicrobiologyScope of MicrobiologyScope of MicrobiologyScope of Microbiology

MicrobiologyMicrobiology

Micro: Small, Bio: Live, Logy: ScienceMicro: Small, Bio: Live, Logy: Science Study of organisms too small to be seen by Study of organisms too small to be seen by

the naked eye.the naked eye.

MicroorganismsMicroorganisms

Bacteria, viruses, fungi, algae, protozoa and Bacteria, viruses, fungi, algae, protozoa and helminthes. helminthes.

Page 3: 1. introduction to microbiology

Branches of StudyBranches of StudyBranches of StudyBranches of Study

BacteriologyBacteriology Study of bacteriaStudy of bacteria

Mycology Mycology Study of fungi and yeastStudy of fungi and yeast

Virology Virology Study of virusesStudy of viruses

Parasitological Parasitological Study of parasitic protozoan and Study of parasitic protozoan and helmintheshelminthes

Immunology Immunology Study of the humoral and cellular Study of the humoral and cellular immune response to immune response to

disease disease agents and agents and allergensallergens

Page 4: 1. introduction to microbiology

Importance of MicrobiologyImportance of MicrobiologyImportance of MicrobiologyImportance of Microbiology

First bacteriaFirst bacteria

Photosynthesis and decompositionPhotosynthesis and decomposition

Human use of microorganismsHuman use of microorganisms

Infectious diseasesInfectious diseases

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Modern Uses of MicrobesModern Uses of MicrobesModern Uses of MicrobesModern Uses of Microbes

Biotechnology:Biotechnology: Production of food and chemicalsProduction of food and chemicals

Genetic engineering:Genetic engineering: Molecular biology and Molecular biology and recombinant DNA techniquesrecombinant DNA techniques

Gene therapy: Gene therapy: Replaces missing or defective Replaces missing or defective genes in human cells through genetic engineering.genes in human cells through genetic engineering.

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Infectious DiseasesInfectious DiseasesInfectious DiseasesInfectious Diseases

Worldwide infectious disease statistics

United States Public Health Service (USPHS) - agency where notifiable diseases are reported

Centers for Disease Control (CDC)-collects disease data around the U.S. and publishes the MMWR (Morbidity and Mortality Weekly Report)

World Health Organization (WHO)-medical arm of the U.N., monitors diseases worldwide.

Page 7: 1. introduction to microbiology

Microbial TaxonomyMicrobial TaxonomyMicrobial TaxonomyMicrobial Taxonomy

Traditional Whittaker 5 Kingdom System

Page 8: 1. introduction to microbiology

Microbial TaxonomyMicrobial TaxonomyMicrobial TaxonomyMicrobial Taxonomy

Woese-Fox 3 Domain System

Page 9: 1. introduction to microbiology

NomenclatureNomenclatureNomenclatureNomenclature

Each organism has two names: the genus and Each organism has two names: the genus and

speciesspecies

Italicized or underlineItalicized or underline

Genus name is capitalized and species in lower Genus name is capitalized and species in lower case.case.

Page 10: 1. introduction to microbiology

Scientific NamesScientific NamesScientific NamesScientific Names

Staphylococcus aureusStaphylococcus aureusDescribes clustered arrangement of cells and Describes clustered arrangement of cells and golden yellow color of coloniesgolden yellow color of colonies

Escherichia coliEscherichia coliHonors the discoverer, Theodor Escherichia Honors the discoverer, Theodor Escherichia and describes its habitat, the colon.and describes its habitat, the colon.

After the first use, scientific names may be After the first use, scientific names may be abbreviated with the first letter of the genus abbreviated with the first letter of the genus and full letters of the species (Ex: and full letters of the species (Ex: E. coliE. coli))

Page 11: 1. introduction to microbiology

General CharacteristicsGeneral CharacteristicsGeneral CharacteristicsGeneral Characteristics

Prokaryotes Prokaryotes

EukaryotesEukaryotes

A cellular agentsA cellular agents Genomes contain either Genomes contain either DNA or RNA; e.g. Virus, DNA or RNA; e.g. Virus,

newer agent is proteinaceousnewer agent is proteinaceous

Page 12: 1. introduction to microbiology

Differences between prokaryotes and eukaryotesDifferences between prokaryotes and eukaryotes

ProkaryotesEukaryotes

Cell size0.2-2 micrometerIn diameter

10-100 micrometerIn diameter

NucleusNo nuclear membrane or nucleoli (nucleoid)

True nucleus, consisting of nuclear membrane &

nucleoli

Cell DivisionBinary FissionMitosis

Cell wallUsually present; chemically complex

(typical bacterial cell wall includes peptidoglycan)

When present, chemically simple

Page 13: 1. introduction to microbiology

Cell TypesCell TypesCell TypesCell Types

Comparative Cellular Structures of Microbes

Page 14: 1. introduction to microbiology

The MicrobesThe MicrobesThe MicrobesThe Microbes

Viruses Protozoa

Bacteria

Bacteriophage

Algae

SpirochaetesCyanobacteria

Fungi

Page 15: 1. introduction to microbiology

Size of MicrobesSize of MicrobesSize of MicrobesSize of Microbes

Microbes vary in size ranging from 10 nm (nanometers) to 100 mu (micrometers) to the macroscopic.

Viruses in nm = 10-9 m (meter)

Bacteria in um = 10-6 m

Helminths in mm = 10-3 m

Page 16: 1. introduction to microbiology

BacteriaBacteria

Prokaryotes

Peptidoglycan cell walls

Binary fission

Eg., Escherichia coli

Page 17: 1. introduction to microbiology

FungiFungiFungiFungi

Eukaryotes

Chitin cell walls

Molds and mushrooms

are multicellular

Yeasts are unicellular

Page 18: 1. introduction to microbiology

ProtozoaProtozoaProtozoaProtozoa

Eukaryotes Mostly saprobes and

commensals May be motile by means of

pseudopod, cilia or flagella

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HelminthesHelminthesHelminthesHelminthes

Eukaryotes Multicellular animals Parasitic flatworms and roundworms

called helminthes Microscopic stages in life cycles

Page 20: 1. introduction to microbiology

AlgaeAlgaeAlgaeAlgae

Eukaryotes

Cellulose cell walls

Photosynthetic Produce molecular oxygen and

organic compounds

Part of food chain

Page 21: 1. introduction to microbiology

VirusesVirusesVirusesViruses

A cellular

Obligate intracellular parasites

Genome consist of DNA or RNA

Surrounded by protein coat

May be enclosed in lipid envelope

Page 22: 1. introduction to microbiology

The First MicroscopeThe First MicroscopeThe First MicroscopeThe First Microscope

Microbes were first observed by Antonie van Leeuwenhoek using a simple microscope (ca. 1673)

Reported his “animalcules” to the Royal Society of London

Page 23: 1. introduction to microbiology

Spores and SterilizationSpores and SterilizationSpores and SterilizationSpores and Sterilization

John Tyndall: John Tyndall: Some microbes in dust and Some microbes in dust and

air were resistant to heat air were resistant to heat

Ferdinand Cohn:Ferdinand Cohn: Discovered and described Discovered and described endospores endospores

Sterile:Sterile: Complete removal of all life forms Complete removal of all life forms including endospores including endospores

Page 24: 1. introduction to microbiology

Louis PasteurLouis PasteurLouis PasteurLouis Pasteur

Microbes caused Microbes caused

fermentationfermentation

Pasteurization:Pasteurization: Prevent Prevent

spoilagespoilage

Page 25: 1. introduction to microbiology

Antiseptics and Hand WashingAntiseptics and Hand WashingAntiseptics and Hand WashingAntiseptics and Hand Washing

1860s:1860s: Joseph Lister:Joseph Lister: Used, carbolic Used, carbolic

acid, a chemical antiseptic to prevent acid, a chemical antiseptic to prevent

surgical wound infectionssurgical wound infections

Ignaz Semmelweis: Ignaz Semmelweis: Introduced hand Introduced hand washing as a means of preventing transfer washing as a means of preventing transfer of puerpueral sepsis in obstetrical patientsof puerpueral sepsis in obstetrical patients

Page 26: 1. introduction to microbiology

Infection and DiseaseInfection and DiseaseInfection and DiseaseInfection and Disease

Infection:Infection: Entry of a microbe into the hostEntry of a microbe into the host

Disease:Disease: Appearance of signs and Appearance of signs and symptomssymptoms

Pathogen:Pathogen: An infectious agentAn infectious agent

Opportunistic pathogen:Opportunistic pathogen: A microbe that cause A microbe that cause disease in immuno compromised hosts or when the disease in immuno compromised hosts or when the normal microbiota is alterednormal microbiota is altered

Page 27: 1. introduction to microbiology