Introduction to Medical Microbiology PDF

* College of Medicine Department of Microbiology Batch 10, semester 5 7/28/2006 Abdullah Mohammed Hussain 1  Introductory session to Medical Microbiology Abdullah Mohammed Hussain B.Sc, M.Sc Microbiology and Immun...

* College of Medicine Department of Microbiology Batch 10, semester 5 7/28/2006 Abdullah Mohammed Hussain 1  Introductory session to Medical Microbiology Abdullah Mohammed Hussain B.Sc, M.Sc Microbiology and Immunology [email protected] 2020 7/28/2006 Abdullah Mohammed Hussain 2 7/28/2006 Abdullah Mohammed Hussain 3  Recommended references: 7/28/2006 Abdullah Mohammed Hussain 4  Recommended references: 7/28/2006 Abdullah Mohammed Hussain 5  Recommended references: 7/28/2006 Abdullah Mohammed Hussain 6  Introduction ‘Microbiology’ should be an easy word to define: the science (logos) of small (micro) life (bio), or to put it another way, the study of living things so small that they cannot be seen with the naked eye. Microbiology is the sciences that deals with the study of micro-organisms, their activates and their influences on different aspects of life. 7/28/2006 Abdullah Mohammed Hussain 7  Introduction the following list of some of the general areas in which the expertise of a microbiologist might be used: 1-Medicine 2- Medical laboratory Sciences 3- Nursing 4- Environmental science 5- Pharmaceutical industry 7/28/2006 Abdullah Mohammed Hussain 8  Introduction Microbiology comprises many disciplines, that are categorized on either taxonomic or functional bases: (1) Taxonomic disciplines of microbiology are: Bacteriology (Study of bacteria). Mycology (Study of fungi). Virology (Study of viruses). Parasitology ( Study of parasite) (now it is an independent subject). 7/28/2006 Abdullah Mohammed Hussain 9  Introduction 2) Functional disciplines of microbiology are: Immunology (host reaction to micro- organisms) Medical Microbiology (role of organism in infectious disease) Genetic engineering 7/28/2006 Abdullah Mohammed Hussain 10  Historical background Microorganisms had been on the Earth for some 4000 million years, when Antoni van Leeuwenhoek started out on his pioneering microscope work in 1673. Leeuwenhoek was an amateur scientist who spent much of his spare time grinding glass lenses to produce simple microscopes. 7/28/2006 Abdullah Mohammed Hussain 11  Antoni van Leeuwenhoek Father of Microbiology 7/28/2006 Abdullah Mohammed Hussain 12  Historical background The first proof of the involvement of bacteria in disease and the definitive proof of the germ theory of disease came from the German Robert Koch. In 1876 Koch showed the relationship between the cattle disease anthrax and a bacillus which we now know as Bacillus anthracis. 7/28/2006 Abdullah Mohammed Hussain 13  Robert Koch Father of Medical Microbiology 7/28/2006 Abdullah Mohammed Hussain 14  Historical background These results led Koch to formalize the criteria necessary to prove a causal relationship between a specific disease condition and a particular microorganism. These criteria became known as Koch’s postulates and are still in use today. 7/28/2006 Abdullah Mohammed Hussain 15  Box (1) Koch’s postulates (1) The microorganism must be present in every instance of the disease and absent from healthy individuals. (2) The microorganism must be capable of being isolated and grown in pure culture. (3) When the microorganism is inoculated into a healthy host, the same disease condition must result. (4) The same microorganism must be re- isolated from the experimentally infected host. 7/28/2006 Abdullah Mohammed Hussain 16  Table (1) The discovery of some major human pathogens Year Disease Causative agent Discoverer 1876 Anthrax Bacillus anthracis Koch 1879 Gonorrhoea Neisseria gonorrhoeae Neisser 1880 Typhoid fever Salmonella typhi Gaffky 1880 Malaria Plasmodium sp Laveran 1882 Tuberculosis Mycobacterium tuberculosis Koch 1883 Cholera Vibrio cholerae Koch 1883/4 Diphtheria Corynebacterium diphtheriae Klebs & Loeffler 1885 Tetanus Clostridium tetani Nicoaier & Kitasato 7/28/2006 Abdullah Mohammed Hussain 17  Year Disease Causative agent Discoverer 1886 Pneumonia (bacterial) Streptococcus pneumoniae Fraenkel 1892 Gas gangrene Clostridium perfringens Welch & Nuttall 1894 Plague Yersinia pestis Kitasato & Yersin 1896 Botulism Clostridium botulinum Van Ermengem 1898 Dysentery Shigella dysenteriae ______ Shiga 1901 Yellow fever Flavivirus _______ Reed 1905 Syphilis Treponema pallidum Schaudinn & Hoffman 1906 Whooping cough Bordetella pertussis Bordet & Gengou 1909 Rocky Mountain spotted fever Rickettsia rickettsii Ricketts 7/28/2006 Abdullah Mohammed Hussain 18  Louis Pasteur 7/28/2006 Abdullah Mohammed Hussain 19  Leeuwenhoek’s Microscope The lens (a) was held between two brass plates and used to view the specimen, which was placed on the mounting pin (b). Focusing was achieved by means of7/28/2006 two screws (c) andAbdullah (d).Mohammed Hussain 20  Classification of Micro-organism The agents of human infectious belong to five major groups of micro-organisms bacteria, fungi, viruses protozoa and helminthes. Based upon cell characteristic, living organism are recognized as having Euocaryotic or procaryotic cell type. 7/28/2006 Abdullah Mohammed Hussain 21  Classification of Micro-organism Bacteria belong to the prokaryotic. fungi and protozoa are Eucaryotic cell type. Viruses are classified by some scientist as kingdom viruses they are acellular (non- cellular). 7/28/2006 Abdullah Mohammed Hussain 22  Differences between Eukaryotes and prokaryotes Eukaryotes prokaryotes Size Larger Relatively small Structure of cell Complex Primitive DNA content Nucleus Nucleoid Nuclear content Present Absent Mitochondria Present Absent Multiplication Mitotic Binary fission Enzyme system Complex Simple Golgi bodies Present Absent Respiration Via Mitochondria Cytoplasmic membrane 7/28/2006 Abdullah Mohammed Hussain 23  Prokaryotic cell 7/28/2006 Abdullah Mohammed Hussain 24  Eukaryotic cell 7/28/2006 Abdullah Mohammed Hussain 25  Classification of Micro-organism The kingdom procaryote is further divided into division classes orders families genus species strain (subspecies) Practically, only the name of genus and species are used the generic (genus) name is always given a capital letter the specific (species) name is given a small letter the generic and specific name are italicised, or, if this isn’t possible, underlined. 7/28/2006 Abdullah Mohammed Hussain 26 7/28/2006 Abdullah Mohammed Hussain 27 ANY QUESTION? 28 Abdullah M.Bakheit