Chapter 1 - Microbiology and Parasitology

Microbiology

is the study of microbes

Acellular Microbes (Infectious Particles)

include prions and viruses

Cellular Microbes

include the less complex prokaryotes and the more complex eukaryotes

Prokaryotes

organisms composed of cells that lack a true nucleus, such as archaea and bacteria

Eukaryotes

organisms composed of cells that contain a true nucleus, such as algae, protozoa and fungi

Algae

a very rare cause of infections, but they can cause intoxications (which result from ingestion of toxins)

Bacteria

Anthrax, botulism, cholera, diarrhea, diphtheria, ear and eye infections, food poisoning, gas gangrene, gonorrhea, hemolytic uremic syndrome, intoxications, legionnaires disease, leprosy, Lyme disease, meningitis, plague, pneumonia, spotted fever, scarlet fever rickettsiosis, staph infections, strep throat, syphilis, tetanus, tuberculosis, tularemia, typhoid fever, typhus, urethritis, urinary tract infections, whooping cough

Fungi

Allergies, cryptococcosis, histoplasmosis, intoxications, meningitis, pneumonia, thrush, tinea infections, yeast vaginitis

Protozoa

African sleeping sickness, amebic dysentery, babesiosis, chagas disease, cryptosporidiosis, diarrhea, giardiasis, malaria, meningoencephalitis, pneumonia, toxoplasmosis, trichomoniasis

Viruses

AIDS, bird flu, certain types of cancer, chickenpox, cold sores, common cold, dengue, diarrhea, encephalitis, genital herpes infections, german measles, hantavirus pulmonary syndrome, hemorrhagic fevers, hepatitis, infectious mononucleosis, influenza, measles, meningitis, monkeypox, mumps, pneumonia, polio, rabies, severe acute respiratory syndrome, shingles, smallpox, swine flu, warts, yellow fever

Indigenous Microbiota

microbes that live on and in the human body. Inhibit the growth of pathogens in areas of the body where they live by occupying space, depleting the food supply, and secreting materials.

Opportunistic Pathogens (opportunists)

the microbes do not cause us any problems but they have the potential to cause infections should there be any opportunity.

Decomposers / Saprophytes

Many microbes are involved in the decomposition of dead organisms and the waste products of living organisms

Decomposition

is the process by which substances are broken down into simpler forms of matter

Saprophyte

is an organism that lives on dead or decaying organic matter

Bioremediation

involves the use of genetically engineered microbes to clean up pollutants.

Microbial Ecology

The study of the relationships between microbes and the environment

Biotechnology

The use of living organisms or their derivatives to make or modify useful products or processes

Antibiotic

is a substance produced by a microbe that is effective in killing or inhibiting the growth of other microbes.

Genetic Engineering

a gene or genes from one organism is/are inserted into a bacterial or yeast cell.

Infectious Diseases and Microbial Intoxications

Pathogens cause two major types of diseases

Infectious Disease

results when a pathogen colonizes the body and subsequently causes disease.

Microbial Intoxication

results when a person ingests a toxin (poisonous substance) that has been produced by a microbe.

Archaea and Cyanobacteria.

Candidates for the first microbes on Earth

Pestilence

occurred in Egypt about 3180 BC.

Bubonic Plague

Around 1900 BC, near the end of the Trojan War, the Greek army was decimated by an epidemic

Smallpox

occurred in China around 1122 BC

Syphilis

It made its first appearance in Europe in 1493

Antoni van Leeuwenhoek

described live microorganisms that he observed in teeth scrapings, rain water, and peppercorn infusions.

Louis Pasteur

demonstrated that microorganisms are present in the air.

The Golden Age of Microbiology 1857-1914

Beginning with Pasteur’s work, discoveries included the relationship between microbes and disease, immunity, and antimicrobial drugs

Fermentation

is the conversation of sugar to alcohol to make beer and wine

Pasteurization

involved heating wine to 55°C and holding it at that temperature for several minutes

Robert Koch

provided proof that a bacterium causes anthrax and provided the experimental steps

Koch’s Postulates

used to prove that a specific microbe causes a specific disease. Are a sequence of experimental steps to relate a specific microbe to a specific disease.

Alexander Fleming

discovered the first antibiotic

Penicillium fungus

made an antibiotic, penicillin, that killed S. aureus

Bacteriology

is the study of bacteria

Mycology

is the study of fungi

Parasitology

is the study of protozoa and parasitic worms

Genomics

the study of an organism’s genes

Taxonomy

The science of classifying organisms. Provides universal names for organisms. Provides a reference for identifying organisms

Systematics or phylogeny

The study of the evolutionary history of organisms

Binomal Nomenclature

uses the Genus and Species name to identify each creature

Eukaryotic Species

A group of closely related organisms that breed among themselves

Prokaryotic Species

A population of cells with similar characteristics

Clone

Population of cells derived from a single cell

Strain

Genetically different cells within a clone

Viral species

Population of viruses with similar characteristics that occupies a particular ecological niche