Microbiology and Disease Understanding Quiz

Microorganisms and Early Disease Understanding

• Microorganisms are organisms too small to be seen with the naked eye.
• Early civilizations recognized a link between sewage management and disease, illustrated by the construction of aqueducts for waste disposal.

Contributions to Medical Notions and Microscopy

• Hippocrates, known as the “Father of Western Medicine,” argued for natural causes of diseases over supernatural beliefs.
• Thucydides, referred to as the “Father of Scientific History,” promoted an evidence-based approach to understanding disease causation.
• Varro suggested invisible organisms could cause diseases, laying groundwork for microbiology.
• Janssen invented the first simple microscope; Hooke improved microscopy techniques, and van Leeuwenhoek, known as the “Father of Microbiology,” was the first to observe microbes.

Golden Age of Microbiology

• Louis Pasteur established germ theory, disproving spontaneous generation and developing rabies vaccines.
• Robert Koch identified specific pathogens responsible for cholera and anthrax, advancing disease understanding.
• The attenuation principle highlights methods to reduce pathogen dangers in vaccinations.

Taxonomy and Organism Classification

• Taxonomy is the classification of living organisms.
• Linnaeus introduced binomial nomenclature; Haekel added the protista and monera kingdoms; Whitaker proposed a five-kingdom system; Woese formulated the three domains: Bacteria, Archaea, Eukarya.
• A phylogenetic tree visually represents the relationships among various organisms.
• Current recognized kingdoms include Animalia, Plantae, Fungi, Protista, Archaea, and Bacteria.

Naming and Identifying Organisms

• Organism names in binomial nomenclature are italicized with only the genus capitalized.
• Bergey’s manual serves as a resource for classifying and identifying prokaryotes.

Sizes and Structure of Cells

• Limitations of the human eye restrict visibility to 1mm or 100 micrometers.
• Average sizes: Animal cells (10 micrometers), Bacterial cells (1 micrometer), and Viruses (0.1 micrometer).
• Bacterial cells consist of a cell wall, plasma membrane, cytoplasm, ribosomes, and DNA.
• Common bacterial shapes include bacilli (rod-shaped), cocci (spherical), and spirilla (spiral).

Unique Features and Applications

• Archaea can survive extreme environments.
• Algae are utilized in biofuels, food products, pharmaceuticals, and oxygen production.
• Protozoa classification is based on movement mechanisms such as cilia, flagella, and pseudopods.
• Fungi can be unicellular (yeasts) or multicellular (molds) and function as decomposers.

Helminths and Viruses

• Helminths are multicellular parasitic worms that can produce microscopic eggs.
• Viruses consist of DNA or RNA, are unable to reproduce independently, and do not carry out metabolic processes.

Subfields of Microbiology

• Bacteriology focuses on bacteria.
• Mycology studies fungi.
• Protozoology analyzes protozoa.
• Parasitology deals with helminths and other parasites.
• Virology examines viruses.
• Immunology investigates the immune system.

Abiogenesis Experiments

• Abiogenesis suggested life could arise from non-living matter.
• Francisco Redi disproved this by showing decaying meat was infested with fly eggs.
• Louis Pasteur demonstrated that microorganisms do not grow in sterile broth without exposure to air.

Cell Theory and Germ Theory

• Cell theory states that all cells arise from pre-existing cells.
• Robert Hooke discovered cork cells, coining the term “cells.”
• Germ theory asserts that diseases may arise from microbial infections.

Epidemiological Advances

• Ignaz Semmelweis found that handwashing with lime solutions lowered childbirth mortality.
• John Snow identified a cholera outbreak source via mapping contaminated water sources.
• Joseph Lister advocated for carbolic acid application to surgical wounds to prevent infections.
• Florence Nightingale emphasized the role of statistics in studying infections' preventable causes.

Koch’s Postulates

• Koch’s postulates include:
  • Microbe must be present in every disease case.
  • Microbe must be isolated and cultured outside the body.
  • Microbe should cause disease when introduced to a healthy organism.
  • Microbe must be re-isolated from the infected host.
• Exceptions to these postulates include pathogens not always being isolable and some causing multiple diseases.

Modern Germ Theory Focus

• Current focus includes studying antibody resistance, new diseases, and the mechanisms of microbial action.