Introduction to Microbiology Lecture Flashcards

Flashcards covering the history of microbiology, cell theory, spontaneous generation debates, pH scales in the human body, and various emerging diseases.

Cell Theory

The scientific theory stating that all living things are comprised of cells and that cells come from preexisting cells.

Van Leeuwenhoek

The scientist who first used a simple microscope (magnifying glass) to see smaller microbes.

Spontaneous Generation

The belief that life comes from nonliving matter, a concept often tied to historical religious beliefs.

Biogenesis

The theory that everything living must come from preexisting life.

Francesco Redi (1668)

Conducted an experiment with open and covered jars of meat to show that maggots come from flies, supporting biogenesis.

John Needham

Heated nutrient broth and placed it in a sealed flask but saw growth, which he used to support spontaneous generation (though the contamination likely came from the container).

Louis Pasteur (1861)

Conclusively disproved spontaneous generation using S-shaped flasks that allowed air in but kept microbes out.

Fermentation

The process by which microbes take a sugar or carbohydrate and produce acid, gas, and sometimes alcohol.

pH Scale

A measure of acidity or alkalinity where each number shift (e.g., from 7 to 6) represents a tenfold ($10\times$) difference.

Blood pH

Typically maintained at a range of approximately $7.35$ to $45$.

Urine pH

Approximately $6.0$, which can be up to a thousand times ($1,000\times$) more acidic than blood.

Stomach pH

Maintained at a level of approximately $4$ to break down proteins and kill most bacteria.

Pasteurization

A process using high temperature for a short time to kill microbes in liquids like milk or juice.

Thermoduric Organisms

Microbes that can withstand the high heat of pasteurization and eventually spoil products like milk.

Semmelweiss

A figure in the 1840s who advocated for handwashing to reduce the spread of infections.

Lister

The first to use chemicals like hydrogen peroxide or phenol-based substances to clean surgical wounds.

Koch’s Postulates

A set of steps used to isolate an organism from a diseased animal to prove it causes a specific disease.

Edward Jenner

Developed the first vaccination by using cowpox lesions to protect against smallpox.

Smallpox

The only disease in history that has been officially eradicated from the human population.

Antibiotics

Chemicals produced naturally by bacteria and fungi that inhibit or kill other microbes.

Alexander Fleming

Discovered the first antibiotic, penicillin, which is produced by a fungus.

Rebecca Lansfield

Developed serotyping in 1933 to classify Streptococcus into groups (such as Group A) based on unique antibodies.

E. coli O157:H7

A toxin-producing strain of bacteria where "O" stands for the cell wall polysaccharide and "H" stands for the flagella protein.

Ebola Virus

A hemorrhagic disease transmitted through saliva, blood, or bodily fluids, often with an extremely high death rate.

Cryptosporidiosis

A disease caused by a protozoan that produces cysts resistant to chlorination, responsible for about $30$% of all diarrhea.

Zika Virus

A mosquito-borne virus that can lead to microencephaly (small head size) and nervous system complications in fetuses.

Legionnaires' Disease

A pneumonia-like respiratory disease caused by Legionella bacteria, often transmitted through aerosolized mists and cooling vents.