History of Disease Understanding

• Microbiology is the science of small living things
• The word "microbiology" comes from the Greek words "micros" (small), "bios" (life), and "logos" (science)
• Microorganisms are also known as microbes

Historical Figures and Concepts

• Hippocrates of Kos (BC 460) described malaria, spotted fever, smallpox, plague, and tuberculosis in his book
• Marcus Terentius Varro (BC 1st century) a Roman academician, suggested ranches shouldn't be built near swamps because of dangerous creatures that couldn't be seen but could cause serious illness
• Avicenna (Ibni Sina, 980-1037) proposed that contagious diseases were caused by little worms
• Avicenna also stated bodily fluids could be infected by organisms outside the body
• Avicenna believed diseases could be avoided by obeying rules to be clean and developed quarantine for tuberculosis and other diseases
• Akshamsaddin (1389-1459) stated that every disease has a seed and these seeds cause diseases by multiplying when they enter the body
• The 14th century plague spread from China to India, Iran, Turkey (Ottoman Empire), and Europe, resulting in 23 million deaths and socioeconomic, psychological, cultural, and religious effects

Key Discoveries and Theories

• Ibn Khatima died in 1369- He stated contagious diseases spread by little living things that enter our bodies
• Girolamo Fracastoro (1546-1553) proposed that epidemic/contagious diseases spread through direct, indirect, or long-distance contact with seed-like things
• Contagious diseases were once considered "diabolico", corresponding to the concept of abiogenesis theory
• Abiogenesis theory stated that life originates spontaneously from nonliving things, shown with the example of mice appearing after 21 days with old cloth and wheat

Development of Microscopy and Vaccination

• Robert Hooke (1665) was the first scientist to use a microscope and described plant cells in his book "Micrographia"
• Antonie van Leeuwenhoek (1674-5) was the first microbiologist, observing microorganisms (animaluca) with a microscope and noted they were live formats that couldn't be seen with eyes
• Children were vaccinated against smallpox using debris from infected patients in the Ottoman Empire
• Lady Montague, wife of the English Embassy in Istanbul, mentioned this practice in a letter to England in 1721
• It was realized that milkmaids in England did not get smallpox
• A similarity between the antigenic proteins of the viruses was found, cowpox providing cross immunization for human pox
• Edward Jenner (1749-1823) prepared a modern smallpox vaccine using the pustule of cows infected with cowpox
• Louis Pasteur (chemist, 1822-1895) stated making wine and bread involved mini living creators
• Pasteur found little spheres (yeast) in fermentation samples like unspoilwed beer and wine
• Pasteur saw long objects disturbing fermentation in spoiled ones and heated them in a process called Pasteurisation
• Pasteur showed Staphylococcus aureus and Streptococcus pneumoniae in pus
• Pasteur developed anthrax and rabies vaccines
• Pasteur developed protection against contagious diseases using vaccines, establishing the science of immunology

Koch's Postulates and Later Developments

• Robert Koch (1876) identified a lot of Bacillus anthracis in blood of cattle with anthrax
• Koch showed that a small amount of blood from an animal could cause anthrax disease when given to a healthy animal
• Koch proved that cultured bacteria could be introduced to an animal, causing the disease
• Koch's postulates say "one microbe and one disease"
• Ignaz Philipp Semmelweis (1818-1865) established sterilization and disinfection concepts
• Dr. Hüseyin Remzi (1839-1898) mandated smallpox vaccine under the Ottoman Empire
• Rabies vaccines were produced in 1886
• Vaccine and serums were produced locally during World War I

Conclusions from History

• Identification of microorganisms, lead to reduced fatality rates and increased mean life expectancy
• Some diseases have been eradicate from the world or countries (World small pox eradication -1979)
• The growth of microscope, optic, drug, diagnostic microbiology, protection from infectious diseases, vaccine and serum industries.
• The concepts of "Public Health" and "Human Health Rights" were emphasized
• Single-cell microorganisms occurred approximately 2.5 to 3 billion years ago and have a genetic variability and horizontal gene transfer
• High mutation rates have allowed adaptation to new environments and resistance to negative environmental pressures

Branches of Microbiology

• Medical microbiology is the study of human and animal health
• Health and hygiene microbiology studies food, environment, and space
• Industrial microbiology focuses on fermentation and antibiotics
• Agricultural microbiology studies plants, soil, and food

Classification of Microorganisms

• Procaryotes (bacteria)
• Eucaryotes (human, animal, plant, fungi, protozoa, helminths)
• Viruses
• Prions (proteins without nucleic acids or infectious proteins)

Eucaryotes

• Algae are eukaryotes
• Protozoa are eukaryotes
• Fungi (molds and yeasts) are eukaryotes
• Characterized by a real nucleatedcell and clearly defined nucleus

Procaryotes

• Procaryotes have a simpler structure than eucaryotes
• Procaryotes are bacteria
• There are 1,000,000,000,000 bacteria in 1 gram of feces
• Eucaryotes are greater than 2 micrometers
• Procaryotes are 0.2-2 micrometers
• Viruses are 25-300 nm (poliovirus - pox virus)

Fungi

• Yeasts cultured at 37°C
• Molds are cultured at 22-26°C
• Grow sexually and asexually, but medically important ones grow mostly asexually

Viruses

• Have no classical cell structures and no metabolic activity
• Need cells to grow inside

Prions

• Have no nucleic acids
• Are transmissible poteins
• Have proteinous structures (misfolded protein)

Explore the historical perspectives on disease, from Hippocrates to Fracastoro. Review key figures, theories, and societal impacts that shaped our understanding of disease transmission and prevention. Questions cover contributions of Varro, Avicenna, Akshamsaddin, and the impact of the 14th-century plague.