Microbiology Chapter 1.txt

Embraces a biologically diverse group of usually small life forms, encompassing primarily microorganisms.

• Bacteria
• Fungi
• Algae
• Protozoa
• Viruses
• Microbes for short

Disease causing agents

Curves outward

• A Dutch spectacle maker
• Discovered two convex lenses put together made small object appear larger

Italian Francesco Stelluti or Giovanni Faber in 1625

• Drew cork and called the structure "cells" like a prison. Said he saw a "great many little boxes"
• First person to draw a microorganism, a mold he found growing on a sheepskin cover of a book.

• A cloth merchant interesting in inspecting the quality of fiber
• Developed a single lens microscope capable of 200x magnification
• Called living things observed in a drop of water animalcules.
• Sent letters describing his discoveries to the Royal Society
• In 1683, his 39th letter described and illustrated bacterial cells taken from dental plaque for the first time.

• The idea that organisms could arise from non-living matter
• Developed by Aristotle by observing maggots appearing on rotting meat

• One of the first controlled experiments
• In 1668, he covered jars with paper or gauze preventing flies from landing on meat. This indeed caused no maggots to appear.
• It took 193 years to prove Redi was right

• British clergyman and naturalist
• In 1748 he suggested that animalcules resulted from a vital force that reorganized decaying matter from more complex organisms.
• Boiled tubes of mutton broth and sealed with cork. After several days, the "gravy swarm'd with life, with microscopical animals of most dimensions"
• Convinced that putrification could generate vital force needed for Spontaneous Generation

• Italian cleric
• Repeated Needham's experiments in 1765 boiling tubes for longer
• Left some tubes open to air and others loosely stoppered with corks
• After several days, the open tubes had lots of life and the cork tubes only had a little. Sealed tubes had none.
• Declared "The number of animalcula developed is proportional to the communication with the external air".

• In 1861, designed an experiment that proved Spontaneous Generation was false
• The tubes were open to the air, but the broth was block with a bent section of tube that contained water and trapped the entering microbes.
• Developed the Germ Theory of Disease
• Found that yeast fermented grape juice into wine.
• Observed that only sour wine had bacterial cells.
• Recommended heating wine to 55 deg C after fermentation to keep it from souring (pasteurization).
• Silkwork disease - identified the protozoa responsible and separated healthy silkworms from diseased and stopped the spread of the disease
• Used broth for growth medium which made it impossible to isolate a pure culture

In 1546 he suggested that disease transmission could occur by direct human contact, lifeless objects like clothing and eating utensils, and through the air

An ill-defined idea of the 1700s and 1800s that suggests diseases were caused by an altered chemical quality of the atmosphere

Mala aria - bad air

• The scientific study from which the source, cause and mode of transmission of disease can be identified.
• Ignaz Semmelweis and John Snow were instrumental in suggesting how diseases were transmitted and how simple measures could interrupt transmission.

• Obstetrician
• Noticed 29% of medical student's L&D patients died of child bed fever (puerperal fever) vs 3% of midwives
• Deduced infection came from the cadavers.
• Directed his staff to wash hands with chlorine water before entering the maternity ward and deaths droped.

In 1854 he plotted the location of Londoners sick with choler and tracked it to a public well. Removing the well hammer stopped the spread of the disease.

Blowing ground up small pox scab powder into the nose or inoculating under the skin to protect from the disease.

• An English country surgeon
• Learned that milk maids that got cow pox didn't get small pox.
• In 1796, he inoculated a boy named James Phipps with cow pox. James developed a fever and then recovered. Six weeks later, he inoculated James with small pox. James developed a reaction at the inoculation site but did not develop small pox.

• Vacca = cow
• Coined by Edward Jenner who noticed milk maid who got cow pox didn't get small pox.

• German biologist
• Suggested the rod-like looking organisms be called bacteria (backterion = "little rod")

• Swiss Physician
• Suggested living organisms could cause disease in 1840

Discovered the rod-shaped cholera bacteria in stool samples.

• Around 1854 to World War 1
• During these 60 years, many branches of microbiology were established and the foundations were laid for the modern biology

Some microorganisms are responsible for infectious disease.

A splitting of sugar molecules into simpler products including alcohol, acid, and gas (CO2)

• Professor of Surgery at Glasgow Royal Infirmary of Scotland
• After learning Pasteur's germ theory argued that surgical infects resulted from living organisms in the air.
• Used carbolic acid spray in surgery in 1865 with great success.

The use of chemical methods for disinfection of external living surfaces such as the skin

• German county doctor
• Formalized standards to identify germs with infectius diseases
• Studied anthrax in sheep
• Injected mice with anthrax, autopsied the mice, isolated bacteria from the corpse, grew them in an ox eye, watch until spores were produced and finally injected the spores into healthy mice. The healthy mice developed anthrax.
• Grew pure cultures on potatoes, gelatinized broth and agar broth
• Coined the term colony
• Cultured TB, cholera,

Small masses of bacterial cells

• 1. Same microorganism present in every case of disease
• 2. Microorganisms are isolated from dead animal and pure culture is prepared
• 3. Microorganisms from the pure culture are inoculated into a healthy animal
• 4. Identical microorganisms are isolated and recultivated from tissue of the experimental animal

rod shaped

To reduce or weaken

• First successful rabies vaccination
• Became Pasteur's lab assistant

Poison

• Discovered plague bacteria
• Anerobic bacteria
• Tetnus

Yellow Fever in Panama transmitted by mosquitos

• British
• Showed mosquitoes transferred malaria to birds

The study of algae

• 10 million species estimated
• Most are small singled-celled
• Many associate in a biofilm
• May be spherical, rod or spiral shaped
• Many are helpful decomposers & recyclers
• backterion = "little rod"

• Bacteria reassigned to a new group.
• Found in extreme environments, like very hot (Yellowstone hot springs), extremely salty (the Dead Sea), or acidic environments (acidic mine drainage).

Carry out photosynthesis

• Not cellular and cannot be grown in a pure culture
• Have a core of nucleic acid (DNA or RNA) surrounded by a protein coat
• Need the metabolic machinery of a cell to replicate
• Neither Prokaryote nor Eukaryote

• Include unicellular yeasts and multi-cellular mushrooms
• 100,000 species described
• Grow in warm moist places
• Secrete digestive enzymes that break down nutrients into smaller bits that can be absorbed easily.
• Live in their food supply

• Single celled protozoa and algae
• Locomotion achieved by flagella or cilia or crawling movement
• Malaria, sleeping sickness and several types of diarrhea are caused by protista

Permanent alterations in DNA base sequences

Deoxyribonucleic acid

Allowed scientists to true see the bacterial cells

• Eu = true; Karyon = nucleus
• Contain a cell nucleus that houses the chromosomes & is physically separated from the rest of the cell structures by a membrane
• Protista
• Fungi
• Plantae
• Anamilia

• Pro = before
• Bacteria and archaeal cells
• No cell nucleolus
• DNA chromosome not surrounded by membrane

Synthesized salvarsan, a "magic bullet" that could kill pathogens

• A compound that contained arsenic and cured syphilis
• Created by Paul Ehrlich

• Scottish
• Discovered Penicillium mold killed bacteria in 1929

• Discovered actinomycin & streptomycin
• Streptomycin - 1st effective antibiotic for tuberculosis

Anti-microbial substances naturally produced by mold and bacterial species that inhibit growth or kill other microorganisms

Better microscope design, Abbe condenser

• Great Britain
• Proved tsetse flies transmit sleeping sickness