Development of microscopy:• Aristotle (384-322) and others believed that living organisms could develop from non- living materials.• 1590: Hans and Zacharias Janssen (Dutch lens grinders) mounted two lenses in a tube to produce the first compound microscope.• 1660: Robert Hooke (1635-1703) published "Micrographia", containing drawings and detailed observations of biological materials made with the best compound microscope and illumination system of the time.
• 1676: Anton van Leeuwenhoek (1632- 1723) was the first person to observe microorganisms.• 1883: Carl Zeiss and Ernst Abbe pioneered developments in microscopy (such as immersion lenses and apochromatic lenses which reduce chromatic aberration) which perist until the present day.• 1931: Ernst Ruska constructed the first electron microscope
Spontaneous generation controversy• John Needham – English scientist who theorized that life comes from non life demonstrated by maggots developing on a piece of rotting meat• 1688: Francesco Redi (1626-1678) was an Italian physician who refuted the idea of spontaneous generation by showing that rotting meat carefully kept from flies will not spontaneously produce maggots.
• 1836: Theodor Schwann (1810-1882) helped develop the cell theory of living organisms, namely that that all living organisms are composed of one or more cells and that the cell is the basic functional unit of living organisms.• 1861: Louis Pasteurs (1822-1895) famous experiments with swan- necked flasks finally proved that microorganisms do not arise by spontaneous generation.
• This eventually led to: Development of sterilization Development of aseptic technique
Proof that microbes cause disease• 1546: Hieronymus Fracastorius (Girolamo Fracastoro) wrote "On Contagion" ("De contagione et contagiosis morbis et curatione"), the the first known discussion of the phenomenon of contagious infection.• 1835 Agostino Bassi de Lodi showed that a disease affecting silkworms was caused by a fungus - the first microorganism to be recognized as a contagious agent of animal disease
• 1847: Ignaz Semmelweiss (1818-1865), a Hungarian physician who decided that doctors in Vienna hospitals were spreading childbed fever while delivering babies. He started forcing doctors under his supervision to wash their hands before touching patients.• 1857: Louis Pasteur proposed the "germ theory" of disease.
• 1867: Joseph Lister (1827-1912) introduced antiseptics in surgery. By spraying carbolic acid on surgical instruments, wounds and dressings, he reduced surgical mortality due to bacterial infection considerably• 1876: Robert Koch (1843-1910). German bacteriologist was the first to cultivate anthrax bacteria outside the body using blood serum at body temperature. Building on pasteurs "germ theory", he subsequently published "Kochs postulates" (1884), the critical test for the involvement of a microorganism in a disease:
– The agent must be present in every case of the disease. – The agent must be isolated and cultured in vitro. – The disease must be reproduced when a pure culture of the agent is inoculated into a susceptible host. – The agent must be recoverable from the experimentally-infected host• This eventually led to: – Development of pure culture techniques – Stains – Agar & culture media – petri dishes
• 1890 – Von Berring – Diphtheria antitoxin• 1890 - Ehrlich – Theory of Immunity• 1892 – Winogradsky – sulfur Cycle• 1898 – Shiga – Shigella dysenteriae• 1910 – Chaga – Trypanosoma cruzi• 1910 – Ehrlich – SyphilisGolden age of Microbiology is so named because numerous discoveries during this period led to the establishment of microbiology as a science.
Career opportunities• Research • Supervisor/lab associate manager• Food , industrial & • Instructor/ environmental Professor tech. • Scientist• Clinical & medical • Research Director• Medical • Consultant technologist • Infectious disease• Veterinary specialist microbiologist
Trivia: What is the origin of the caduceus???? ??? ?? ??? Ano daw?!?
The caduceus, symbol of the medicalprofession, was designed from the procedurefor removing parasitic guinea worm(Dracunculus medinensis)
What’s new?• WNE – West Nile Encephalitis – 1999 – 3559 cases in 35 states of USA• BSE – Bovine spongiform encephalopathy – Mad cow disease – 1996• CJD – Creutzfeldt Jakob Disease - 2002 – Caused by prion in bovine– UK 138 cases human• E. coli O157:H7 – 1996 – 2000 cases Japan
• IGAS – Invasive Group A streptococcus – 1995 – flesh eating bacteria• EHF – Ebola hemorrhagic Fever – 1995 – 315 cases – 75% mortality – 1996 – monkeys from RP to USA (+)• HPS– Hantavirus Pulmonary syndrome – 1993• SARS – ( I think you have heard?)• H1N1, H5N1 – New Bird Flu strains
And the latest . . . .• Influenza AH1N1• 4 viral strands : 2 bovine, 1 avian, 1 human• Variant strain of the old influenza virus that killed 25 million in Europe• Originated from Mexico• Mortality rate is high if untreated• There is a cure and highly treatable
What’s the latest?• DIC – Differential Interference Contrast – Uses differences in refractive indexes to produce image – Uses 2 beams of light separated by prisms, the specimen appears colored as a result of the prism effect. No staining required.• Confocal – uses LASER light to illuminate 1 plane of the specimen at a time
Scanned probe• Scanning tunneling – Uses a thin metal probe to scan a specimen and produce an image revealing the bumps and depressions of the atoms on the surface of the specimen. Resolution is greater than the EM and no special preparation required.• Atomic force – Uses metal & diamond probe gently force down the surface of the specimen to produce a 3D image without any special preparation.