Microbiology and Epidemiology Quiz

Louis Pasteur's Contributions to Microbiology

• Discovered fermentation: Demonstrated fermentation (alcoholic) is caused by living yeast, producing lactic acid. This made wine sour. He showed microorganisms cause specific types of fermentation
• Developed pasteurization: Heating wine to 55°C killed bacteria, delaying spoilage. This process now used in preserving beer, milk, and other produce.
• Germ theory of disease: Pasteur's work with microorganisms in fermentation and pasteurization led to better understanding of germs causing disease. This led to improvements in medical settings through sterilizing and cleaning techniques, and antiseptic procedures in surgery.

John Snow's Contribution to Epidemiology

• Father of Epidemiology (1913-1858): Investigated cholera outbreaks 1854, London; Developed the concept of disease in populations.
• Skeptical of Miasma theory: Believed cholera was transmitted through contaminated water from the source.
• Used mapping to show cholera cases' association with a specific water source (Broad Street Pump)
• Removed pump handle, controlling epidemic.
• Set standards for public hygiene.
• Successfully controlled the cholera outbreak, even without knowing the pathogen.
• His work disproved the prevailing miasma theory and established the importance of public health.

Joseph Lister's Contribution to Modern Antisepsis

• Father of Modern Antisepsis (1867): Pioneered strict antiseptic surgical techniques and procedures.
• Recognized airborne germs causing surgical wound infections.
• Used carbolic acid (phenol) sprays and for instruments, wounds, and surgical incisions. Focused on hand-washing.
• His methods reduced gangrene incidence.
• Increased wound healing and surgical success rates.
• Implemented a better understanding of how to avoid infection leading to a new era of advancements.

John Tyndall's Contribution to the Germ Theory of Disease

• Discovered endospores: Some bacteria exist in two forms – heat-stable endospores and heat-sensitive vegetative cells.
• Endospores require prolonged, intermittent heating (Tyndallisation) to be killed.
• Sterilized liquids via continuous boiling and successive, periodic heating to kill bacteria containing endospores.

Robert Koch's Contributions to the Germ Theory of Disease

• Provided experimental support for the Germ Theory.
• Developed laboratory media for growing bacteria.
• Identified cause-and-effect relationship between bacteria and anthrax.
• Micro-microscopy: spore-forming bacterium (Bacillus anthracis) consistently present in diseased animals and used to infect healthy animals.
• Demonstrated that the bacteria could be cultivated within a pure culture and that the bacteria caused the same disease symptoms in the healthy animal.
• Establishing the link between microorganisms and infectious diseases (Anthrax, cholera, Tuberculosis)

Koch's Postulates

• Microorganism must be consistently found in diseased organisms, absent in healthy ones (with exceptions like asymptomatic carriers).
• Microorganism must be successfully cultivated in pure form.
• Introducing a pure culture of the microorganism should produce the disease in a susceptible organism.
• The same microorganism must be recovered from the experimentally infected organism and cultured.

Limitations of Koch's Postulates

• Some pathogens don't cause disease in all infected individuals.
• Viruses do not always replicate in cell cultures.
• Pathogenic organisms in some cases may be present in healthy individuals as well (asymptomatic carriers).
• Koch's postulates, despite limitations, set a strong foundation for microbial etiology.

Discovery of Antibiotics

• Alexander Fleming discovered penicillin (1929): Penicillin was produced by the fungus and bacteria seemed to dissolve when cultures were contaminated.
• Not produced in significant quantities until later, marking the "Antibiotic Era".
• Awarded the Nobel Prize in Medicine (1945).

Explore the significant contributions of Louis Pasteur and John Snow to microbiology and epidemiology. This quiz covers pivotal discoveries such as fermentation, pasteurization, and the foundations of disease transmission. Test your knowledge on these influential figures and their impact on science.