Introduction_to_Medical_Microbiology.pdf

1 Introduction to Medical Microbiology  1. Giriş ve Tarihçe Dr. Özge YILMAZLI 2 Medical Microbiology  Microbes or microorganisms are minute things that are usually unable to be viewed with naked eye  Microbes appeared on this planet about 3.8 billion years 3 Medical Microbiology  Medic...

1 Introduction to Medical Microbiology  1. Giriş ve Tarihçe Dr. Özge YILMAZLI 2 Medical Microbiology  Microbes or microorganisms are minute things that are usually unable to be viewed with naked eye  Microbes appeared on this planet about 3.8 billion years 3 Medical Microbiology  Medical Microbiology; primarily deals with microorganisms which cause diseases in humans. The major working fields are;  the structures and growth properties of microorganisms,  pathogenic strategies they enhanced,  diagnostic approaches to infectious diseases,  efficiency of antimicrobial agents used for therapy 4 Medical Microbiology Medical Microbiology has a broad scientific fields which includes, 5 History  Hippocrates (460-370 BCE);  Hippocrates is considered the father of medicine, on which he wrote severeal books  He used the term “dangerous fumes” as a result of wrong diet, some indigestible residuals give out vapour and it cause illnesses 6 History  Anton van Leeuwenhoek;  Anton van Leeuwenhoek in 1676 as he observed a drop of water carefully by his microscobic lenses and discovered a world of millions of tiny “animalcules”  Commonly known as the father of microbiology and considered the first microbiologist  With his microscopes, Leeuwenhoek observed a variety of things like rain water, lake water and scrapings from his own teeth. He made accurate sketches and communicated with “Royal Society of London” with his findings 7 History ©Royal Society 8 History Louis Pasteur (1822-1895);  Pasteur developed vaccine against chicken cholera, anthrax and rabies  He showed the role of living microbes in the fermentation Robert Koch (1843-1910);  As the founder of modern bacteriology, he is known with his role in identifying the specific causative agents of tuberculosis and cholera,  Koch also laid down the conditions, known as Koch’s postulates 9 Koch’s postulates  The same microorganism must be present in every case of the disease  The microorganism must be isolated from the diseased organism and grown in pure culture  The microorganism from the pure culture must cause the disease when it is inoculated into a healthy organism  The microorganism must be reisolated from the inoculated, diseased host and must be shown to be the original microorganism 10 History Paul Ehrlich;  The era of chemotherapy began in 1910, when the German chemist Paul Ehrlich discovered the first antibacterial agent, a compound effective against the spirochete that causes. Alexander Fleming;  discovery of penicillin in 1928 11 History Gerhard Domagk;  discovery of sulfanilamide in 1935 Selman Waksman;  discovery of streptomycin in 1943 12 History Joshua Lederberg;  Conjugation was first discovered in 1946 by Joshua Lederberg Watson & Crick;  In 1956, Francis Crick and James Watson described the double helix structure of DNA  Thousands of scientists have followed these pioneers and each adding an observation that expanded our understanding of microbes and their role in disease 13 Nomenclature  In the binomial system of nomenclature, two names, the genus and species are used  Genus  1st , Capitalized  Species  2nd, Lower case  Both names are italicized ;  Escherichia coli (E. coli)  Salmonella typhi (S. typhi)  Clostridium difficile (C. difficile)  Entamoeba histolytica (E. histolytica)  Strongyloides stercoralis (S. stercoralis)  Giardia intestinalis (G. intestinalis)  Pneumocystis jirovecii (P. jirovecii) 14 Classification  Before the advent of the microscope, living organisms were conveniently divided into two kingdoms: plant and animal  In 1990, Woese and his colleagues proposed a new classification system containing 3 domains  In 1998, Cavalier-Smith presented another classification system containing 6 kingdoms 15 Classification 16 17 Classification 18 Medical Microbiology  All living organisms can be divided two groups depending on the fundamental structure of their cells:  Prokaryotes  Eukaryotes 19 Medical Microbiology  Prokaryotic cells do not have membrane-bound nucleus. Their DNA is not contained with in a separate inside the cell and they have no internal membrane-bound organelles within their cytoplasm  Eukaryotic cells have a true nucleus (meaning its DNA is surrounded by a membrane), and have other membranebound organelles 20 Medical Microbiology  Prokaryotes;  Archaebacteria  Bacteria  Eukaryotes;  Plants  Animalis  Fungi  Protists (Protozoa) 21 Medical Microbiology  Differences between Prokaryotic and Eukaryotic cells      Eukaryotes cells have membrane-bound nucleus whereas prokaryotic cells do not have membrane-bound nucleus, Eukaryotic cells have membrane-bound organelles such as mitochondria, ER and Golgi. Prokaryotic cells do not have membrane bound organelles Eukaryotic cells consist of multiple, linear DNA whereas prokaryotic cells consist of single, circular DNA Eukaryotic cell division occurs either through mitosis whereas prokaryotic cell division occurs through binary fission All prokaryotes have 70S ribosomes while eukaryotes contain larger 80S ribosomes in their cytosol 22