PHARMACEUTICAL MICROBIOLOGY INTRODUCTION AND HISTORY

Introduction and history of microbiology

1. MICROBIOLOGY MICROBIOLOGY

2. INTRODUCTION Microbiology is the branch of science that studies microorganisms, including bacteria, viruses, fungi, protozoa, and algae. These microrganisms are found everywhere - air, water, soil, and even inside human body . Microbiology helps us understand how microorganisms function, how they interact with their surroudings, and how they can be beneficial or harmful.

3. HISTORY EARLY ERA (Before the 17th century): Miasma Theory - It was believed that diseases were caused by “bad air” or toxic vapours. Spontaneous generation - Many scientists believed that life could arise spontaneously from non-living matter. # Francesco Redi(1668) showed that maggots only appeared on meat if flies could lay eggs on it, disproving spontaneous generation for larger microorganisms. # Louis Pasteur conclusively disproved the spontaneous generation theory.

4. DISCOVERY ERA (17th-18th century): Robert Hooke (1665) - He made one of the first microscopes and was the oneto introduce the word ‘cell’ when he was looking at a cork underneath his microscope. Francesco Redi (1668) - An Italian scientist who experimented on meat to see how rotting/maggots were produced. He did this to disprove the spontaneous generation theory. He discovered this was wrong as there was no growth of microorganisms on the meat.

5. Antonie van Leeuwenhoek - Developed powerful single lens microscope with up to 300x magnification. He was the first to see a living organism through the eyes of a microscope, this happened when he was studying pond water. He named the moving organisms ‘animalcules’ because they looked like animals.

6. GOLDEN ERA (1857-1914): Louis Pasteur: Swan-Neck Flask Experiment (1861) - Pasteur filled a swan neck flask with a nutrient rich broth. - He boiled the broth to kill any existing microbes. - He let the broth settle. - He observed that the broth remained clear, indicating that no microbes had contaminated it. - He tilted the flask to allow the trapped microbes to mix into the broth. He observed that the broth became cloudy and microorganisms began to grow, indicating that microbes had been into the broth. - Disproved spontaneous generation theory.

7. 2) Fermentation Studies (1857) - Showed that microbes cause fermentation in wine and beer. - Identified that different microbes produce different fermentation products e.g. yeast produces alcohol. 3) Pasteurization (1864) - It is a process that involves heating food at a low temperature to kill harmful bacteria and extend its shelf life. - Types of pasteurization: a. Batch Pasteurization - A slow process that involves heating milk to 63 degrees celcius for 30 minutes. It’s mainly used for smaller volumes of milk and dairy products. b. Flash Pasteurization - A high-temperature short-time process that involves heating milk to 71.7 degrees celcius for 15 seconds. It’s used for pourable products like juices. c. Ultra-High Temperature Pasteurization - A process that involves heating milk to 135-140 degrees celcius for 2-4 seconds. It’s similar to sterilization and can extend the shelf life of milk up to 9 months.

8. 4) Germ Theory Of Disease (1865) - Proposed that microorganisms cause diseases in living organisms. 5) Vaccine Development - Developed vaccines for rabies and anthrax. Robert Koch: 1) Koch’s postulates a. Association - The microorganism must be found in abundance in all organisms suffering from the disease, but should not be found in healthy organisms. b. Isolation - The microorganism must be isolated from a diseased organism and grown in pure culture. c. Inoculation - The cultured microorganism should cause disease when introduced into a healthy organism. d. Re-isolation - The microorganism must be reisolated from the inoculated, diseased experimental host and identified as being identical to the original specific causative agent.

9. MODERN ERA (1940s - Present): Discovery of antibiotics - Alexander Fleming discovered penicillin, the first natural antibiotic. Howard Florey and Ernst Chain later developed it into a usable drug during World War-2. Molecular Biology and Genetics Revolution - Discovery of DNA structure (1953) - Recombinant DNA technolgy (1970s) - Polymerase Chain Reaction (1983)