Microbiology Material for Exam 1

Personnel Notes from MicroBio Course

Lucretius

Disease caused by “invisible” living creatures; spontaneous generation (de novo - from scratch)

Antonie Van Leeuwenhoek

Father of MicorBio; drew and described bacteria and protozoa, wee animalcules (microorganisms)

Robert Hooke

first drawing of microorganisms, drew hairy mold, gave description on how to make microscopes

Microbiology development

slow, “not important”, arose in 19th century

Microbiology Applicable to two question

Spontaneous generation? Nature of contagious disease?

Spontaneous Generation

life from non-life (decaying matter) for COMPLEX organisms

Microorganisms

small living things - animal like

Disprooving spontaneous generation led to

germ theory, sterilization, understanding of infection, fermentation, microbial ecology

Van Leeuwenhoek scope

Redi’s experiment debunking spontaneous generation

Three flasks - one open with meat, one sealed with meat, one with fine gauze on top w/meat; maggots formed in the open flask and on top of the gauzed flask.

John Needham Hay Infusion experiment

Boiled hay infusions to kill all living things, and microbes still appeared (later found out his boiling was insufficient), believed in spontaneous generation

Protozoa

single celled eukaryotic (nucleaus) mircoorganisms, animal-like, make own food (heterotophic), after bacteria multiple, protozoa blooms and feed on them, symbionts - help host)

What does every experiment need?

trials, replication, technical vs. biological, and reproduce experiment at least three times

Louis Joblot

described protozoa

Lazzaro Spellazani

described bacterial binary fission

Binary Fission

replicates-singular circular chromosome, grows in size, divides into two genetically identical daughter cells (identical to parents cell, two new genetically identical cells)

Pasteur’s experiment debunking spontaneous generation Swa-neck flask

Broth sterilized with heat, broth allowed to cool; bactria and dust from air settle in bend, broth stays sterile indefinately (for years), flask tilted so that sterile broth comes in contact w/ bacteria + dust frtom air, hours/days later bacteria multiply in broth

results from Pasteur’s experiment

sterilization (killing all organisms), autoclave, high LVL disinfection kills almost everything, disinfection is chemicals on non-living objects

Robert Koch

found spore-like bodies in bacillus anthracis (causative agent of anthrax, a severe disease primarily affecting livestock and humans)

John Tyndall

heat resistant life forms present, dust does carry microbes

Ferdinand Cohn

named heat-resistant forms of bacteria “endospores”

Why do we need sterlization in microbiology?

Clear Culture

Microbes

Microorganisms

Bacteria that form Endospores

Bacillus, clostridia, sporrocina

Galen

theory: imbalance between 4 humours (blood, phlegm, yellow and black bile) called disease

Girolamo Fracastroro

Invisible organisms (germs) called diseases

Agostino Bassi de Lodi

Silkworm disease caused by fungus (Botrytis)

Jacob Henle and Robert Koch

Both studied anthrax

Jacob Henle

established criteria to relate anthrax to Bacillus anthracis (anthrax)

Robert Koch Anthrax

performed empirical studies, used postulates in etiology of tuberculosis

Koch’s Postulates 1

Microorganism present in every case of the disease

Koch Postulates 2

Microorganism must be grown in pure culture

Koch Postulate 3

Same disease when (healthy) second host inoculated with pure culture

Koch Postulate 4

Microorganism must be isolated from the infected host

Virus that doesn’t fit Koch’s postulates

HIV (Human immunodeficiency virus)

Molecular Postulated of Koch revised by Falkow 1

Virulence (level of severity of disease) trait seen with pathogenic strains, not nonpathogenic strains

Molecular Postulated of Koch revised by Falkow 2

Inactivation of gene(s) associated with virulence decreases pathogenicity (genes may be there, but knocked out [mutation/doesn’t work])

Molecular Postulated of Koch revised by Falkow 3

Replacement of the mutated (not working gene) with wild-type (original gene) gene restores pathogenicity

Molecular Postulated of Koch revised by Falkow 4

Gene should be expressed some time during infection and disease process

Molecular Postulated of Koch revised by Falkow 5

Antibodies (produced by B-cell = white blood cells) / immune system cells directed against gene products protect host (RBD)

RBD

Ribosome binding domain

Central Dogma

DNA replicates, transcribed to mRNA then translated to a Protein (chain of amino acids)

Papothogensity

Ability to cause disease

Varalence

level of severity of disease

Disinfect

used for inanimate objects

Antiseptic

safe for human/animal surfaces

Ignaz Semmelweis

hand washing prevents puerperal fever (fatal fever women had after childbirth)

Joseph Lister

Sterilization of instruments with heat (less likely to transfer), phenol as antiseptic

Jenner

first vaccination (smallpox) - subcutaneous (fatty tissue directly under the skin)

Pasteur

rabies vaccination

(current) Most transmissible virus

flu and measles

Can microbial diversity be detected?

only 0.4% of all bacteria in the natural world can be cultured

Great plate count

large discrepancy where the number of microorganisms observed microscopically greatly exceeds the number that can be cultured on plates

Agar

polysaccharide from seaweed; used to culture bacteria

Mother of Microbiology; used Agar

Fannie Eilshemius Hesse

Richard Petri

developed container to hold solidified media (petri dish)

Sergein Winogradsky

described lithotrophy (form of metabolism where an org. obtains energy by oxidizing inorganic compounds), used model ecosystem

Rita Colwell

Vibrios (single-celled and found in brackish and saltwater environments)

Lynn Marguelis

Endosymbiont hypothesis, gave rise to mitochondria nad chloroplasts

Thomas Brock

discovered archaeons (prokaryotic microorganisms)

Norm Pace

sequenced thermophiles (thrive in extreme heat 113 F - 176 F)

Carl Woese and George Fox

described archaeons, used 16S rRNA, developed “domains”

Ruth Patrick

freshwater ecologist and phycologist, biological diversity reflected environmental stress

Terry Hazen

Microbial ecologist, deep water horizon oil spill (lead to understanding of how marine ecosystems respond to and recover from massive hydrocarbon pollution)

Craig Venter

sequencing of bacterial genomes, first to sequence H.influenzae

Claire Fraser

(women) sequencing of bacterial genomes

Karen Nelson

(women) sequencing bacterial genome- thermotoga, showed lateral gene transfer from archaeon to bacteria

Hamilton Smith

Nobel Laureate discovered restriction enzymes, sequencing of bacterial genome with Venter-H.influenzae

Covid-19 Vaccine (Doctors)

Katalin Kariko, Drew Weissman, Kizzmekia Corbett Barney Graham

Neophile

young, inexperienced

Zacharias Janssen

credited with invention of first microscope in 1590

Christiaan Huygens

First to use two lens eyepiece in compound microscope

Four Ways light might interact with objects

absorption, reflection, refraction, scattering

Absorption

Energy gained from particle of light (photon)

Reflection

Wave of light bounces off surface at an angle of reflection theta

Refraction

light bends upon entering substance; key property allowing lens to magnify image

Scattering

wavefront pushed in all directions

refractive index

how much it can bend a light

Resolution

ability to clearly see image; only part of light wavefront enters, causing interference; there is a balance between magnification and resolution

Microscope

accurately enlarge or magnify an object

Contrast (difference between object and background)

Use of dyes for staining; staining process often kills cells

Types of Light Microscopy

Bright field, dark field, phase contrast, differential interference contrast

Types of Electron Microscopy

Scanning EM, Transmission EM

Scanning Probe

Scanning tunneling microscopy, atomic force microscopy

Bright Field Microscopy

typical lab microscope, used for stained and unstained specimens, magnifies image using two lens systems=compound microscope; objective lens is closer to the specimen; ocular lens or eyepiece does final magnification

Part of Light Microscope

ocular lens/eyepiece; objective lens (held by nosepiece); body of microscope (contains mirrors and prisms); stage; substage condenser lens, lens projecting above stage, controls numerical aperture (1.2-1.4); iris diaphragm (controls light entering condenser)

Objective lenses have specific properties

magnification, numerical aperture, focal length (distance required objective lens and top of object being viewed), wavelength of light also important

With increasing lens strength

theta widens and light is lost

0.2 micrometers

200nm

Meet the Microbes: Prokaryote

include domains Bacteria and Archaea; over 12,000+ bacteria as of 2018, new archaeons discovered continuously and bacteria

Meet the Microbes: Eukaryote

Includes fungi, algae, protozoa; reclassified in 2005; Fungi have 99,000+ species

Meet the Microbes: Viruses

acellular-no metabolism; DNA or RNA as genetic material (won’t have both at the same time, possible hybrids); obligate intracellular parasites; 11,273 ‘species’ in 2023; new oned discovered every month

Morphology

cell shape

major morphologies of prokaryotic cells

spherical of ovoid, cylindrical, curved or spiral; some stay grouped/clustered after cell division in characteristic arrangements

(prokaryotic cell) Streptococcus

grape-like clusters of Staphylococcus’, spirochetes (tightly coiled), appendaged bacteria, appendaged bacteria, and filamentous bacteria

Coccus

round

Bacillus

Rod

Coccobacillus

oval (between round and rod shaped)

Fusiform Bacillus

Spindle-like (needle shaped)

Vibrio

Curved