1. History and Intro to pathogenesis

Earliest form of vaccination

Variolation

Variolation

an early method of inoculating individuals with smallpox material to induce immunity.

Variolation risk

1-2% death rate

Robert Hooke

Developed the first microscope

Who coined the term cell

Robert hook when observing plant cells

Micrographia

Published work by Robert Hooke describing his observations through the microscope, including the structure of cork and plant cells.

Edward Jenner

Credited with doscovering vaccination using cowpox to prevent small pox

John Snow

Founder of epidemiology as he discovered a well was causing cholera outbreak in London by mapping cases and identifying contaminated water.

Antonie van Leeuwenhoek

First to visualize bacteria, but hindered the field because he would not shared his microscope designs and techniques

Gregor Mendel

Father of modern genetics using pea plants to study inheritance patterns and establish the laws of inheritance.

Medelian genetics

Identified 2 alleles for each trait
Dominant/Recessive
Only 1 allele from mom and 1 from dad

Joseph Lister

Pioneer of aseptic surgery bc he developed the ideas and procedures for cleaning wounds to prevent infection

Listeria bacterium was named after

Joseph Lister due to his contributions to sanitation and infection prevention in surgery.

Louis Pasteur

Known as father of microbiology and made significant contributions to germ theory, including the development of pasteurization to kill harmful microorganisms.

Who discovered that attenuated bacteria can be used to vaccinate with lower risk

Louis Pasteur, who demonstrated that weakened forms of bacteria could protect against disease with anthrax and rabies

Who discovered anthrax and TB bacterium

Robert Koch, who identified the bacteria responsible for anthrax and tuberculosis, establishing a foundation for microbial pathogenesis.

Koch’s postulate

A set of criteria developed by Robert Koch to establish a causative relationship between a microbe and a disease.

Koch’s postulate 1

The microorganism must be found in abundance in all organisms suffering from the disease, but should not be found in healthy organisms.

Koch’s postulate 2

The microorganism must be isolated from a diseased organism and grown in pure culture.

Kochs postulate 3

The cultured microorganism should cause the disease when introduced into a healthy organism.

Kochs postulate 4

The microorganism must be re-isolated from the inoculated, diseased experimental host and identified as being identical to the original specific pathogen.

Stanley Falkow

used a molecular version of Koch’s postulates to prove that specific genes can
be responsible for a pathogen’s ability to cause disease

Paul Ehrlich

First to stain bacteria and developed treatment for syphylis

Emil von Behring

A pioneering immunologist who discovered diphtheria antitoxin

Friedrich Loeffler

Discovered the organisms that cause diphtheria and foot-and-
mouth disease

Watson, Crick, and Franklin

were key figures in the discovery of the double helix structure of DNA, which laid the foundation for modern genetics.

Frederick Sanger

Developed technique to sequence DNA called Sanger sequencing

Kary Mullis

Developed PCR

Craig Venter

Completed the first human genome sequence

Who to focus on for test

Van lee
Pasteur
Koch
Falkow
Watson
Sanger
MUllis
Venter

Bacterial pathogenesis

ability of bacteria to cause disease

What differentiates between commensal and pathogenic bacteria

Virulence factors

How would a commensal bacteria evolve into pathogenic bacteria

Gene acquisition via HGT to produce toxins and adhesins

Corynebacterium diphtheriae

Causative agent of diptheria, which is mostly due to the diptheria toxin produced

How did Corynebacterium diphtheriae acquire this toxin

HGT via a phage

Transformation

uptake of DNA from the environment (used frequently in lab setting to induce plasmid uptake

Transduction

when DNA is moved between bacteria via a phage

Conjugation

when DNA is transferred between bacteria during cell-to-cell contact (usually via a pilus)

Outer membrane vesicale HGT

bacteria release small membrane-bound vesicles that can transfer DNA (virulence factors) and other molecules to neighboring cells

2 main cells types

Prok
Euk

3 domains of life

Bacteria
Archaea
Eukarya

Shared characteristics of prok/euk

Chromosomes
Ribosomes
Plasma membrane

LPS

Virulence factor of gram negative bacteria that can trigger strong immune responses.