Microbial World: History of Microbes

Flashcards covering the history of microbiology, classifications of microorganisms, key historical experiments, and specific microbial diseases based on the lecture notes.

Microorganism (Microbe)

An organism which is microscopic and cannot be seen with the naked eye.

Bacteriology

The scientific study of bacteria.

Mycology

The scientific study of fungi.

Parasitology

The scientific study of parasites.

Immunology

The scientific study of the immune system.

Virology

The scientific study of viruses.

Bacteria

Prokaryotic cells with peptidoglycan cell walls that reproduce by binary fission and gain energy from organic chemicals, inorganic chemicals, or photosynthesis.

Archaea

Prokaryotic cells with cell walls composed of S-layers (lacking peptidoglycan, except Methanogen) that live in extreme environments and have a distinct $16s rRNA$ nucleotide sequence.

Fungi

Eukaryotic cells that can be multicellular or unicellular, with cell walls containing chitin, glucan, and mannan.

Protozoa

Eukaryotic cells that absorb or ingest organic chemicals and achieve motility via pseudopodia, cilia, or flagella.

Virus

Acellular entities containing a $DNA$ or $RNA$ core surrounded by a protein coat (and sometimes a lipid envelope) that only replicate within living host cells.

Multicellular animal parasite

Eukaryotic organisms, such as helminths (flatworms and round worms), that live on or in a host to obtain food.

Spontaneous Generation

The hypothesis that living organisms arise from nonliving matter through a "vital force."

Biogenesis

The hypothesis that living organisms arise from preexisting life.

Francesco Redi ($1668$)

Performed an experiment with decaying meat in jars to disprove spontaneous generation by showing maggots only appeared in open jars.

Antoni van Leeuwenhoek ($1673-1723$)

Described live microorganisms observed in teeth scrapings, rain water, and peppercorn infusions.

John Needham ($1745$)

Claimed spontaneous generation occurred after finding microbial growth in heated nutrient broth that was placed in sealed flasks.

Lazzaro Spallanzani ($1765$)

Boiled nutrient solutions in flasks and sealed them, resulting in no microbial growth, countering Needham's findings.

Louis Pasteur ($1861$)

Demonstrated that microorganisms are present in the air and disproved spontaneous generation; also developed pasteurization and wine fermentation.

Robert Koch

Proved the germ theory of disease through his work on anthrax and developed a set of procedures known as Koch's postulates.

Koch's Postulates

A four-step process used to identify the causative agent of a disease by isolating it from a diseased organism and growing it in pure culture.

Edward Jenner ($1796$)

Conducted the first smallpox vaccination, marking the birth of vaccination history.

Paul Ehrlich ($1910$)

Developed salvarsan, a synthetic arsenic drug used to treat syphilis.

Alexander Fleming ($1928$)

Discovered the first antibiotic, penicillin, by observing an area of inhibition around a Penicillium colony.

Recombinant DNA Technology

Genetic engineering resulting from microbial genetics and molecular biology, often using $E. coli$ as a prokaryotic model system.

Escherichia coli ($E. coli$) $O157: H7$

A specific strain of gut bacteria associated with disease.

Staphylococcus aureus

Gram-positive cocci and facultative aerobes named "aureus" (yellow-gold) that are common pathogens in bovine mastitis.

Bovine mastitis

Inflammation of the mammary gland in cattle mainly caused by bacteria that enter the udder through the teat canal.

Bacillus cereus

A bacterium linked to cooked vegetables, meat, and rice that causes gastroenteritis characterized by diarrhea or vomiting.

Candida albicans

An opportunistic yeast that causes candidiasis (thrush) when the host's immune system is weakened or normal microflora is disrupted.

Microsporum canis

A pathogenic fungus known as ringworm that infects the upper, dead layers of skin on cats, dogs, and humans.

Bovine herpesvirus 1 ($BoHV-1$)

A virus of the Herpesviridae family linked to respiratory and reproductive problems in cattle, including infectious bovine rhinotracheitis ($IBR$).

African swine fever virus ($ASFV$)

A highly contagious virus from the Asfarviridae family causing hemorrhagic disease in pigs with mortality rates up to $100\%$.