MICROPARA

• Roman Philosopher Lucretius and Girolamo Fracastoro suggested that diseases were caused by invisible living creatures
• Francesco Stelluti made the earliest microscopic observations on bees and weevils using a microscope probably supplied by Galileo
• Anton Van Leeuwenhoek is considered the "First true microbiologist" and used his self-made lens microscope with 50-300x magnification to study protozoans and bacteria
• Aristotle mentioned Spontaneous Generation - life arose from non-living matter
• Francesco Redi demonstrated that maggots do not arise spontaneously from decaying meat
• John Needham observed microorganisms in boiled mutton broth, proposing that organic matter possessed a "vital force" that could give rise to life
• Lazzaro Spallanzani improved Needham's experiments by heating broth in sealed jars, concluding that air carried microorganisms to the culture medium
• Rudolf Virchow proposed Biogenesis - living cells can only arise from preexisting living cells
• Theodore Schwann observed no growth in a flask containing nutrient solution after allowing air to pass through a red-hot tube
• Louis Pasteur resolved the issue of spontaneous generation, showing that microorganisms can contaminate sterile solutions but do not originate from the air
• Ferdinand Cohn demonstrated the presence of heat-resistant bacterial spores in boiled flasks
• John Tyndall showed that dust carries germs that contaminate sterile broth, introducing "Tyndallization" as a sterilization method
• Theodore Schwann stated that yeast cells convert sugars to alcohol, while Pasteur described fermentation by yeast in the absence of air
• Pasteurization, heating beer and wine to kill bacteria, was proposed by Pasteur
• Charles Chamberland created a porcelain bacterial filter and developed anthrax vaccine with Pasteur
• Ignatz Semmelwels demonstrated that routine hand washing can prevent the spread of disease
• Joseph Lister developed the antiseptic system of surgery, introducing hand washing and phenol as an antimicrobial agent
• Robert Koch established the Germ Theory of Disease, proving that bacteria cause diseases and developing Koch's Postulates
• Collaborators of Koch, Fannle Hesse suggested the use of agar, and Julius Richard Petri developed the Petri dish
• Edward Jenner experimented with cowpox to protect against smallpox, while Louis Pasteur used the term "vaccine" for preventive inoculation
• Emil von Behring prepared antitoxins for diphtheria and tetanus
• Alexander Fleming accidentally discovered penicillin antibiotic and the enzyme lysozyme
• Howard Florey and Ernst Chain purified penicillin, and Edward Abraham proposed the correct biochemical structure of penicillin
• Paul Ehrlich discovered salvarsan for syphilis treatment
• Chemotherapy is the treatment of disease using chemical substances, including synthetic drugs and antibiotics
• Taxonomy is a formal system for organizing, classifying, and naming living things, based on genotype and phenotype similarities
• The classification system includes Domain, Kingdom, Division, Class, Order, Family, Genus, and Species
• Carl von Linne laid down the basic rules for taxonomic categories using the binomial system
• Bacterial morphology, structure, and classification involve organizing microorganisms with similar traits into specific groups based on morphologic, physiologic, and genetic similarities
• Martinus Beljerinck and Sergle Winogradsky developed the enrichment-culture technique and introduced the use of selective media
• Taxonomy hierarchy:

  • Kingdom
  • Phylum
  • Class
  • Order
  • Family
  • Genus
  • Species
  • Subspecies
• Nomenclature:

  • Naming microorganisms according to established rules and guidelines
  • Genus name capitalized, species epithet lowercase
  • Genus and species italicized in print, underlined in script
  • Group names not capitalized or underlined
• Identification:

  • Process of delineating key features of a microorganism
  • Discovering and recording traits for taxonomic placement
• Genotypic characteristics:

  • Relates to organism's genetic makeup
  • Detection of genes or RNA products
  • Confirmatory method for organism presence
• Phenotypic characteristics:

  • Based on features beyond genetic level
  • Includes observable characteristics and those requiring extensive analysis
• Major characteristics used in taxonomy:

  • Classical characteristics: morphology, physiology, ecology, genetic analysis
  • Molecular characteristics: study of nucleic acid composition and proteins
• Terminologies:

  • Strain: population of organisms differentiated within a taxonomic category
  • Biovars: variant prokaryotic strains with biochemical or physiological differences
  • Serovars: strains with distinctive antigenic properties
  • Morphovars: variant prokaryotic strains differing morphologically
• Prokaryotes:

  • Organisms without a true nucleus or organelles
  • Functions occur in the cytoplasm or cytoplasmic membrane
• Bacterial cell structure:

  • Cell envelope: outermost structure with outer membrane, cell wall, periplasm, and plasma membrane
  • Cell wall: peptidoglycan layer maintaining cell shape
  • Plasma membrane: phospholipid bilayer with embedded proteins
• Gram-positive cell wall:

  • Thick peptidoglycan layer with glycan chains
  • Antigenic polysaccharides on surface
  • Target of antimicrobial agents like penicillin