Microbiology: An Introduction - Tortura Ch. 1 2023

Microbes or Microorganisms

minute living things that individually are usually too small to be seen with the unaided eye. Ex. bacteria, fungi, protozoa and microscopic algae; also includes viruses.

Microbiome

organisms that live stably on a human, help to maintain good health, prevent pathogens

Pathogenic

disease-producing

Genus

the first name assigned to each organism and is always capitalized. The first name of the scientific name (binomial); the taxon between family and species.

Specific epithet

the second or species name in a scientific binomial, follows genus and is not capitalized

Bacteria/bacterium

relatively simple, single-celled organisms, found everywhere

Prokaryotes

includes both bacteria and archaea. From Greek words meaning prenucleus. Because their genetic material is not enclosed in a special nuclear membrane this is what bacterial cells are called.

Archaea

consist of prokaryotic cells but cell walls lack peptidoglycan. Found in extreme environments. Not known to cause disease in humans. Divided into 3 groups- methanogens (produce methane as a waste from respiration), extreme halophiles (live in extremely salty environments such as the Great Salt Lake and the Dead Sea) and extreme thermophiles (live in hot sulfurous water, such as hot springs at Yellowstone National Park)

Eukaryotes

organisms whose cells have a distinct nucleus containing the cell's DNA, surrounded by the nuclear membrane

Fungi/fungus

can reproduce asexually or sexually. Get nourishment from environment by absorbing solutions of organic material. Mushrooms (multicellular). Can't photosynthesize. Have cell walls made of chitin. Yeast (unicellular). Mold is most common.

Protozoa/protozoan

unicellular eukaryotic microbes. Move by s=pseudopods flagella, or cilia. Variety of shapes and live either as free entities or as parasites. Can reproduce sexually or asexually.

Algae/alga

photosynthetic eukaryotes with a wide variety of shapes and both sexual and asexual reproductive forms. Play important role in the balance of nature. Produce oxygen and carbohydrates that are utilized by other organisms.

Viruses

most can be seen only with an electron microscope. Acellular. Not considered to be living because they are inert outside living hosts. Can reproduce only by using the cellular machinery of other organisms. Only multiply within host cells they infect.

Helminths

2 major groups of parasitic worms are the flatworms and the roundworms. Microscopic suring some stages of their life cycle.

Spontaneous generation

until the 2nd half of the nineteenth century, many scientists and philosophers believed that some forms of life could arise spontaneously from nonliving matter

Biogenesis

the claim that living cells can arise only from preexisting living cells- German scientist Rudolf Virchow

Pasteurization

heat (beer and wine) just enough to kill most of the bacteria that cause spoilage. Commonly used to reduce spoilage and kill potentially harmful bacteria in milk.

Germ theory of disease

the principle that microorganisms cause disease

Koch's postulates

a sequence of experimental steps for directly relating a specific microbe to a specific disease

Immunity

protection from disease provided by vaccination or by recovery from the disease itself

Antibiotics

chemicals produced naturally by bacteria and fungi to act against other microorganisms

Biofilm

a complex aggregation of microbes. The slime on a rock in a lake. Film on your teeth. Can be beneficial. Protect mucous membranes from harmful microbes and in lakes are food for aquatic animals. Can be harmful by clogging water pipes, on medical implants can cause infections like endocarditis. Often resistant to antibiotics because of protective barrier of film.

Pasteur

disproved spontaneous generation using S shaped flasks

Hans Gram

Developed a staining method for identifying 2 major groups of bacterial species

Ignaz Semmelweis

Person who advocated hand-washing to prevention transmission from one patient to another

Rebecca Lancefield

Devised a classification system for the streptococci based on an immunological system of serotypes

Alexander Fleming (1928)

discovered the first antibiotic, penicillin

Edward Jenner

Developed a vaccine for smallpox in 1796

Carolus Linnaeus

Founder of taxonomy, the branch of biology concerned with naming and classifying organisms. Developed two part system of naming organisms.

Wendall Stanley

This person crystallized the filterable agent that was discovered could pass through ceramic filtration (viruses)

Joseph Lister

Began using disinfectants and antiseptics (phenols) during surgery to prevent infections

Paul Ehrlich

Discovered first cure for syphilis.

Sergei Winogradsky

soil microbiology

Winogradsky column w/ s soil and dirt

microcosm for study of microorganisms

Benefits of microorganisms

Environmental: nitrogen fixation, oxygen production, degradation of materials

Medical: production of antibiotics; production of things like insulin through recombitant DNA

Food production: fermentation (yeast; beer and other alcoholic beverages)

Inside us: healthy microflora prohibit colonisation by pathogens; help us to digest

base of food webs

Selman Waksman

studied soil and discovered streptomycin

normal microbiota

collection of acquired microorganisms on or in a healthy human being