Lecture 1

• Prokaryotes


  Organisms without a true nucleus
• Eukaryotes


  Organisms with a true nucleus
• Bacterial shapes


  • Cocci
  • Bacilli
  • Spirochetes

  
• Gram positive


  Bacteria that retain the crystal violet dye in Gram staining
• Gram negative


  Bacteria that do not retain the crystal violet dye in Gram staining
• Strain


  A genetic variant or subtype of a microorganism
• Serovar


  A serological variant of a bacterial species
• Aerobic


  Requiring oxygen for growth
• Anaerobic


  Not requiring oxygen for growth
• Facultative aerobe


  Can grow with or without oxygen
• Obligate aerobe


  Can only grow in the presence of oxygen
• Facultative anaerobe


  Can grow with or without oxygen
• Obligate anaerobe


  Can only grow in the absence of oxygen
• Obligate pathogen


  A microorganism that can only survive and multiply in a host organism
• Obligate parasite


  A microorganism that can only survive and multiply within the living cells of another organism
• Blood agar


  A growth medium that contains red blood cells, used to detect hemolytic activity
• MacConkey agar


  A growth medium that selectively grows Gram-negative bacteria

  
• Sabouraud agar


  A growth medium that selectively grows fungi
• Growth conditions


  The environmental factors required for a microorganism to grow, such as temperature, pH, oxygen levels, etc.
• Important tests for bacterial identification include the oxidase test, catalase test, coagulase test, and CAMP test
• Establishment of infection


  1. Encounter

  2. Entry

  3. Multiplication and spread

  4. Damage

  5. Outcome
• Establishment of infections requires a breach in the host's defenses, and the way a bacterium combats the host's defenses determines the outcome of the infection
• This course will introduce students to important bacterial and fungal diseases of animals and help them develop a conceptual framework that can be adapted to incorporate novel approaches they will encounter during their veterinary careers
• Course objectives


  • Describe principles underlying bacterial and fungal infections in animals
  • Describe general characteristics of bacterial and fungal pathogens
  • Describe diagnosis, transmission, treatment and control of bacterial and fungal diseases
  • Describe pathogenesis of important bacterial and fungal agents
  • Describe different classes of antimicrobial agents and concepts in drug resistance
• Required and recommended texts

  • Veterinary Microbiology and Microbial Diseases by Quinn et al. 2nd ed.
  • Infectious Diseases of the Dog and Cat, Greene, 4th ed.
  • A textbook of the diseases of cattle, horses, sheep, pigs and goats, Constable et al., 11th ed.
• Lecture PowerPoints will be posted on Canvas at least 24 hours before class, and case reports will be available on Canvas
• Course grading


  • Quizzes: 20%
  • Non-cumulative exams: 70%
  • Final exam: 10%
• The approach to learning fundamentals of bacterial diseases will be systematic, studying prototypic pathogens for each body system
• The clinical case presented involves a 10-year-old Pekingese dog with a 6-day history of pyrexia, anorexia, depression, and multiple non-pruritic erythematous skin nodules
• The next steps are to create a problem list, determine the likely differentials (infectious vs. non-infectious), and develop a diagnostic plan to diagnose the condition and inform treatment and prevention