Microbiology and parasitology

• Microbiology is the study of microorganisms, which are organisms invisible to the naked eye
• Parasitology is the study of parasites, their hosts, and the relationship between them
• Reasons to study microbiology:

  • Impact on Human Health
  • Balance of Nature: food source, decomposition, aiding in digestion for animals like cattle, sheep, and termites
  • Environmental benefits: providing safe drinking water, biodegradable product development, bioremediation for oil spills
  • Industrial applications: food production (beer, wine, cheese, bread), antibiotics, insulin, genetic engineering
  • Agricultural advancements: research leading to healthier livestock and disease-free crops
• Classification of microorganisms includes 5 major groups: Bacteria, Algae, Fungi, Protozoa, and Viruses
• Two types of cells:

  • Prokaryotic: no membrane-bound nucleus or organelles, includes only bacteria
  • Eukaryotic: have membrane-bound nucleus and organelles, includes protozoans, fungi, algae, animals, and plants
• Bacteria:

  • Prokaryotic, unicellular, much smaller than eukaryotic cells
  • Bacteriology is the study of bacteria
  • Two groups: Archaebacteria (ancient bacteria) and Eubacteria (true bacteria)
  • Shapes include bacillus (rod), coccus (spherical), spirillum (spiral), vibrio (curved rod)
  • Obtain energy through photosynthesis, chemosynthesis, or from outside organic sources
• Algae:

  • Eukaryotic, unicellular or multicellular, photosynthetic autotrophs
  • Not disease-causing
• Fungi:

  • Eukaryotic, unicellular or multicellular, nonmotile
  • Obtain energy as heterotrophs, important for decomposition
• Protozoa:

  • Eukaryotic, unicellular, motile or nonmotile, obtain energy as heterotrophs
  • Examples of disease-causing: malaria, giardiasis
• Viruses:

  • Acellular, obligate intracellular parasites
  • Basic structure: nucleic acid enclosed by a protein coat, much smaller than bacterial cells
  • Can be lytic (kill the host cell) or lysogenic (integrate into the host cell's genome)
• Helminthes:

  • Worms, some stages are microscopic in their life cycles
  • Examples include tapeworms, hookworms, pinworms, heartworms, and Chinese liver flukes
• Koch's experiments proved that particular microbes cause particular diseases
• Koch's 4 Postulates:

  1. The causative agent must be present in every individual with the disease.

  2. The causative agent must be isolated & grown in pure culture.

  3. The pure culture must cause the disease when inoculated into an experimental animal.

  4. The causative agent must be reisolated from the experimental animal & reidentified in pure culture
• Ways to control infectious diseases:

  1. Immunity:

  • Immunization: produce immunity by providing exposure to altered organisms that do not cause disease.

  2. Public Hygiene:

  • Improving sewage disposal
  • Assuring a clean public water supply
  • Food preservation & inspection
  • Improving personal hygiene

  3. Chemotherapy:

  • Paul Ehrlich discovered a drug treatment for syphilis
  • Alexander Fleming discovered the first antibiotic, penicillin
• • Sanitary Microbiology: includes processing and disposal of garbage and sewage wastes, and purification of water supplies.
  • Veterinary Microbiology: focuses on infectious diseases in animals, zoonoses, and transmission of diseases from animals to humans
• Careers in Microbiology:

  • Agricultural Microbiology: studies the beneficial and harmful roles of microbes in soil formation and fertility, and in the production of crops and foods.
  • Biotechnology (Industrial Microbiology): uses microorganisms in industry to produce various products.
  • Environmental Microbiology and Bioremediation: concerned with water and sewage treatment, and bioremediation to clean up landfills and industrial wastes.
  • Microbial Genetics and Genetic Engineering: study of microbial DNA, chromosomes, plasmids, and genes with applications in various fields.
  • Microbial Physiology: research contributes to understanding the structure and functions of microbial cells.
  • Paleomicrobiology: study of ancient microbes and molecular fossils.
  • Parasitology: studies parasites and their life cycles to control and treat diseases they cause.