MicrobiologyMicrobiologyAn introduction to microbiology designed for allied health majors

By BugLady

How to Ace this ClassHow to Ace this Class

Book and slides are no substitute for active engagement

Participate: post questions and ask for helpDon’t wait to ask Take notes aka active learning

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Writing EssaysWriting EssaysTake brief notes as you go

Record all references

Create an outline

Rewrite information in your own words Use peer-review or credible sources

PMC: full length, peer-reviewed articles HON: Health on the Net; look for badge on the website

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Introduction to MicrobiologyIntroduction to Microbiology

Overview of course

What is microbiology?

History of microbiology

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Course OverviewCourse Overview

Biochemistry and MicroscopyBiology of microorganismsMetabolismGrowth and EcologyContainment of MicroorganismsGenetics and BioengineeringMutations and Bacterial RecombinationViruses

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CourseCourse Overview OverviewAntibioticsInnate Immune SystemAdaptive Immune SystemHost Microbe InteractionsDisorders of the Immune SystemEpidemiologyClassification

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MicrobiologyMicrobiology

Microbiology is the study of all the organisms that are too small to be seen with the naked eye (<0.1mm)

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Size of Particles and Size of Particles and MicroorganismsMicroorganisms

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Limit of light microscope

Why Study Microbiology?Why Study Microbiology?

Impact on human life

Decomposers

Microbes are ubiquitous: soil, water, ice cap, hot vents, body

Extremely adaptable

Simple models to study biological processes

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Positive Impact on Human LifePositive Impact on Human Life

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Negative Impact on Human LifeNegative Impact on Human Life

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Scientific NamesScientific NamesEscherichia coli

o Honors the discoverer, Theodor Escherich, and describes the bacterium’s habitat, the large intestine or colon.

Staphylococcus aureuso Describes the clustered arrangement of the cells

(staphylo-) and the golden color of the colonies.

After the first use, scientific names may be abbreviated with the first letter of the genus and the species:

• Staphylococcus aureus and Escherichia coli are found in the human body: S aureus on skin and E coli in the large intestine.

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Use of LatinUse of Latin

One bacterium – many bacteriaOne medium – several mediaOne bacillus – many bacilliOne staphylococcus – many

staphylococci

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Two Empires and Three DomainsTwo Empires and Three Domains

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Pathogens are disease causing agents or organisms

PrionsPrions

Prions Proteinaceous infectious particles

Diseases linked to the presence of prions are transmissible spongiform encephalopathies (e.g. mad cow disease).

Misfolded proteins

Slow infection (20-30 years)

No cure

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VirusesVirusesNot cellsWill not propagate on their ownNo metabolismContain genetic/protein materialPhages, tobacco mosaic virus,

HIV, causative agents of common cold, flu, polio, chicken pox

Viruses infect organisms from the 3 domains of life

04/15/23 16National Institute of General Medical Sciences

Three DomainsThree Domains

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http://www.ucmp.berkeley.edu/exhibits/historyoflife.php

Prokaryotes and EukaryotesProkaryotes and Eukaryotes

Prokaryote = no nucleus

Archaea and Bacteria are prokaryotes

Eukaryote = true nucleus

Protists, plants, fungi, and animals are eukaryotes

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Archaea Archaea are Prokaryotesare ProkaryotesNo true nucleus, no organelles, 1-5µ length

Classified as Bacteria until 1979

Molecular structures closer to Eukaryotes

Eukaryotes and Bacteria diverged from Archaea

Oldest known organisms on Earth. o Fossil records show over 3.6 BILLION years ago

No known pathogens

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ExtremophilesExtremophiles

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Hydrothermal vent Courtesy: NASADead Sea Courtesy: EXACT-ME

Geyser Courtesy: Volcano Hazards Team/USGS

Polar ice Courtesy: NOAA

BacteriaBacteriaBacteria are unicellular microscopic organisms that lack a true nucleus.

Less than 10% of bacteria cause diseases

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Staphylococcus epidermidis Neisseria sicca

Bacteria or EubacteriaBacteria or Eubacteria

Bacteria grow in a wide variety of habitats and conditions.

Bacteria have a wide range of environmental and nutritive requirements.

Bacteria play important roles in the global ecosystem.

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BacteriaBacteria

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Bacilli

Escherichia coli

Courtesy: Public Health LibraryCourtesy: Environmental Protection Agency

EukaryaEukarya

The word 'eukaryote' means 'true nucleus’

Eukaryotes contain a true nucleus and membrane-bound organelles

Nucleus: genetic material

Organelles:o specific function

o subcellular structures bound by membranes

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ProtistsProtistsUnicellular or poorly differentiated organisms

Plankton, flagellates, protozoa, algae…are all protists.

Important infectious diseases are caused by parasitic protists: malaria, sleeping sickness, dysentery

Red tide causes poisoning

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Trypanosoma brucei gambiense Courtesy of CDC

Cyclospora cayetanensisCourtesy of CDC

FungiFungiUse organic materials for energy

Both multicellular (molds and mushrooms) and unicellular - single cell- (yeasts) organisms

Source of antibiotics, food, bread and alcohol

Mycosis are fungal infectionso Pneumocystis (pneumonia in HIV patients), tinea

(athlete’s foot), thrush

04/15/23 26Courtesy: CDC

Helminthes Helminthes

Helminthes are parasitic wormso Tape worms, flukes, pinworms

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Courtesy of the Public Health Library

ReviewReview

http://www.quia.com/rr/240939.html

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History of MicrobiologyHistory of Microbiology

The Golden Ages1850s: Gram, Pasteur, Koch…1940-1950s: antibioticsNow: Microbiome, metagenomics,

probiotics, asthma, MS, RA

History of Microbiology IHistory of Microbiology IThe Golden Age (mid-19The Golden Age (mid-19thth century) century)

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Scientific Discovery Technical Progress

Cell theory – Schwann, Virchow 1858

Growth media – Koch’s Lab 1880s

Disproving spontaneous generation – Pasteur 1865

Staining protocols – Gram 1884

Postulate rules – Koch 1890 Disinfection - Semmelweis 1847 Lister 1867

Development of vaccines- Jenner 1796

Sterilization procedures – 1879Tyndall, Pasteur’s Lab

The First ObservationsThe First Observations

Antoni van Leeuwenhoek (1673-1723)

Described live microorganisms in teeth scrapings, rain water, and peppercorn infusions.

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VaccinationVaccination

1796: Edward Jenner and cowpox

Called vaccination from vacca for cow

The protection is called acquired immunity

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The Debate Over Spontaneous The Debate Over Spontaneous GenerationGeneration

Spontaneous Generation:oLiving organisms arise

from nonliving matter.

BiogenesisoLiving organisms arise

from preexisting life.

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Louis Pasteur

Louis PasteurLouis PasteurPasteur developed swan necked flask to show

that air is filled with microbes

Was able to demonstrate infusions remained sterile even if flask was left open

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Original sketches of Pasteur (1861)

The Germ Theory of DiseaseThe Germ Theory of DiseasePasteur’s work showed microbes are in the air, can

spoil food, and cause animal diseases

Joseph Lister (1860s) o used a chemical disinfectant to prevent

surgical wound infections.

Robert Koch (1876)o provided proof that a bacterium causes

anthrax

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Koch’s PostulatesKoch’s Postulates

The agent must be present in every case of infection and absent from healthy individuals

The agent can be isolated from infected organism and grown in a pure culture

The disease can be reproduced by inoculating a healthy organism with a pure culture

The agent can be isolated from the newly infected organism

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Courtesy: CDC Adapted from: Hosp Epidemiol Infect Control, 2nd Edition, 1999

History of Microbiology IIHistory of Microbiology II

Antibiotics 1940-current

Biotechnology 1978-current

Genetics 1920-current

Human Microbiome Project

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Gentlemen, microbes will have the last Gentlemen, microbes will have the last word!word!

“…It is time to close the book on infectious diseases…”

William Stewart, US Surgeon General in a message to Congress 1969

Antibiotics resistance

The big 3: TB, HIV, malaria

Microbiome, obesity, allergies

New threats: Health Acquired Infection (HAI), MERS, H7N9, Ebola virus

Ecological balance

Bioremediation

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