Introduction to Microbiology

• Microbiology is the study of living things too tiny to see without aid
• Microorganisms are small life forms not visible without aid

Groups of Microorganisms

• Bacteria
• Algae
• Fungi
• Protozoa
• Helminths
• Viruses (not cells)
• Prions (not organisms)

Microbes and Diseases

• Microbes and diseases spread through respiratory droplets, dust, water, food, injury, insect bites, animals, human contact, and inanimate objects
• Pathogens are microbes that cause disease

Pioneers of Microbiology

• 1665: Robert Hooke used the term "cells"
• 1674: Leeuwenhoek saw microorganisms for the first time
• 1796: Jenner developed a vaccine for smallpox through inoculation
• 1847: Semmelweis discovered the cause of childbed fever
• 1854: John Snow contributed to epidemiology
• 1895: Pasteur disproved spontaneous generation
• 1865: Lister introduced antiseptic techniques
• 1876: Koch developed pure culture on agar
• 1892: Iwanowski discovered viruses
• 1894: Ehrlich contributed to selective toxicity
• 1929: Flemming discovered penicillin
• 1977: Woese classified archaea

Robert Hooke

• Published Micrographia including drawings of cork cells
• Showed the importance of looking at small things through a microscope

Antoni Van Leeuwenhoek:

• Sent 300 letters to England's Royal Society of London
• Described hundreds of moving particles he called animalcules
• Gave the first description of bacteria

Spontaneous Generation:

• Life forms from inanimate objects
• Considered an old belief that living things could come from non-living things
• Example, maggots appearing in rotting meat or mice forming from dirty clothes and wheat

Louis Pasteur

• Demonstrated that animalcules (microbes) arise from other animalcules in the air
• Used the swan-neck flask to prove organisms did not spontaneously generate from nothing
• In experiments with boiled nutrient broths, flasks with intact necks remained sterile, while microbes grew in flasks with broken necks exposed to the air
• Studied yeasts in juice, beer, vinegar, and wine, observing that soured wine was full of bacteria that could be killed by heating
• Led to the creation of pasteurization, uses heat to kill harmful bacteria in food and drinks without ruining their taste
• Formulated the germ theory of disease, which includes Koch's Postulates

Koch's Postulates

• If an animal is sick, scientists can take a sample and find tiny microbes inside
• Grow the organism in pure culture to ensure it's the only microbe present
• Inject the cultured microbe into a healthy animal to see if it causes the same disease
• The animal develops the same disease

Gelatin and Agar

• Discovered pure cultures of bacteria grew best on a solid culture surface
• Used gelatin in dishes to isolate pure cultures
• In 1882, Fanny Hesse suggested replacing gelatin with agar
• Later in 1887, Julius Petri developed the culture plate (Petri dish)

Pasteur and Koch

• Two scientists contributing to the new field of bacteriology
• Koch focused on etiology, or disease causation
• Koch's lab identified the causative agents of tuberculosis (1882) and cholera (1883)
• Pasteur focused on preventing disease through vaccination
• Vaccine for rabies was cultivated (1885)

Edward Jenner and Immunity

• Realized that dairymaids with mild cowpox infections did not get smallpox like everyone else
• Wondered if cowpox made them immune to smallpox
• Inoculated a child never affected by smallpox with cowpox, which prevented the boy from getting smallpox

Female Contributions to Microbiology

• Dr. Ruth Ella Moore found treatment for TB
• Dr. Jane Hinton co-developed Mueller-Hinton Agar
• June Almeida first saw Coronavirus in electron microscope

Paul Ehrlich

• Selective toxicity means a medicine kills harmful microbes without hurting the person taking it
• Developed drug for syphilis, which was a synthetic drug
• Sulfa drugs are antibiotics
• Penicillin has immunology

Modern Bacteriology Terms and Definitions

• Bacteriology is the study of bacteria
• Virology is the study of viruses
• Mycology is the study of fungus
• Parasitology is the study of protozoa and helminths
• Immunology is the study of the immune response

Areas of Microbiology

• Medical Microbiology
• Environmental Microbiology
• Breaks down and eliminate toxic waste
• Industrial Microbiology makes bread, wine, vinegar, cheese, olives, and vitamins
• Agricultural Microbiology kills insects and makes fertile soil

Viruses and Bacteria on Earth

• Viruses are more abundant than bacteria

Microbes and the Human Body

• Some microbes are temporary (transient)
• GI tract Microbes help prevent infectious diseases, aid in food breakdown, provide essential nutrients and vitamins humans can't make, communicate with the brain and immune system, and may influence obesity, asthma, and allergies

Drug Resistant Pathogens

• Bacteria evolve through beneficial mutations
• Bacteria can acquire resistance genes from other bacteria
• Antibiotics are abused and misused by medical professionals and patients, leading to superbugs

Bioterrorism

• Intentional or threatened use of biological agents to cause fear or inflict death/disease

Top 4 Bioterrorism threats

• Smallpox (virus)
• Anthrax (bacteria)
• Plague (bacteria)
• Botulism (toxin produced by bacteria)

Water

• A universal solvent
• Cells are about 70% water by mass
• Numerous chemicals, like salts, dissolve in water
• Dissolved chemicals, called solutes, can then interact in chemical reactions
• Water can also be a reactant or product in chemical reactions
• Dehydration synthesis is when two molecules stick together to form a bigger molecule, and in the process, they lose a water molecule
• Hydrolosis is when a big molecule breaks into smaller pieces, and to do this, it uses a water molecule
• Cohesion is when water molecules stick together by forming large numbers of hydrogen bonds

Acids/Bases and pH

• Acids are chemicals that increase H+ ions when they dissolve in water
• Bases are chemicals that donate OH- ions that tie up H+ ions in solution by forming water molecules
• pH is a measurement of H+ ions in a solution
• Acidic is less than 7 (0-6)
• Neutral is 7
• Basic/Alkaline is more than 7 (8-14)
• Buffers are like tiny sponges that keep the pH of a solution steady, buffering to keep solutions from being too acidic or basic

Proteins and their makeup

• Proteins are made up of carbon, hydrogen, oxygen, nitrogen, and sulfur polymers, built from chains of amino acids
• Amino acids are building blocks of protein that determine their function and form bonds, consisting of carbon, hydrogen, oxygen, nitrogen, and sulfur polymers

Protein Shape and Function

• Primary structure is a polypeptide chain of amino acids
• Secondary structure includes pleated sheets, alpha helices, and coils
• Tertiary structure is bonding between R groups to create the final 3-D shape of a polypeptide
• Quaternary structure is two or more folded polypeptides bonded together
• Denaturation is when proteins with broken bonds unfold and begin to lose function, leading to cell death

Nucleic Acids

• Unbranched organic molecules of carbon, hydrogen, nitrogen, and phosphorous atoms
• Two forms are DNA and RNA
• Makeup: five-carbon sugar, phosphate group, and nucleobase (adenine, guanine, cytosine, thymine, uracil)
• Rungs are nitrogenous bases held together with hydrogen bonds

DNA

• Double Helix
• Carries units of information called genes arranged on chromosomes (circular or linear)
• A pairs with T (A>T)
• C pairs with G (C>G)

RNA

• Single Stranded
• Intermediaries in carrying message to construct cellular proteins (mRNA)
• Genetic information unit in some viruses
• Regulates gene activity and protein synthesis
• Makes a good antibiotic target
• U binds with T instead of A

Explore the study of microorganisms, including groups like bacteria, algae, and viruses. Learn about the pioneers of microbiology and their contributions to understanding microbes and disease. Discover how microbes and diseases spread through various means.