微生物的分布.ppt

1、Medical Microbiology,Introdution,Introduction,Microorganisms(Microbes) Microbiology Medical Microbiology,Microorganisms(Microbes),What are microorganisms? Categories of microorganisms. Relationship between microorganism and Human beings.,Definition,Microorganisms or microbes are generally regarded a

2、s living forms that are microscopic or submicroscopic in size and relatively simple, usually unicellular in structure. They are too small to be seen with naked eyes. Viruses , bacteria, fungi, protozoa and some algae are all in this category,bacteria,fungi,viruses,protozoa,algae,influenza virus,SARS

3、 coronavirus,Bovine spongiform encephalopathy Creutzfeldt-jakob disease,Prion (proteinacious infectious particles),Microorganisms,Distribution of microorganisms,Air Soil Water Animals Human body,Distribution of microorganism,100m,300m,1400m,2100m,3150m,4050m,6000m,Bacteria and related organisms (ric

4、kettsiae, chlamydia mycoplasmas, spirochaetes),prokaryotic,Fungi,eukaryotic,Viruses,no cell structure,Categories of Microorganisms,Characteristics of prokaryotes,No nuclear membrane, nucleolus Ribosome as unique organelles Both DNA and RNA bacteria. mycoplasmas, chlamydiae , rickettsiae , spirochaet

5、es and actinomycetes,anthrax bacillus,diphtheria bacillus,Bacteria,Rickettsiae (Rocky Mountain spotted fever),tick,Treponema - syphilis,Trachoma Chronic infection or repeated infection inflammation and follicle formation involving the entire conjunctiva,mycoplasma pneumoniae,primary atypical pneumon

6、ia,Characteristics of eukaryotic microbes,Have nuclear membrane, nucleolus Organelles are consummate,Characteristics of virus,Smallest microbe No typical cellular and enzymatic systems of respiration and photosynthesis Living in alive cells One kind of nucleic acid,Fig. EM of Poxvirus Scale bar =100

7、nm,Characteristics of three categories of microbes,Relationship between Microorganism and Human Beings,Microorganisms and Human Beings,Beneficial activities: Most microbes are of benefit to human beings, some are necessary( nitrogen, carbon cycles, etc) Harmful activities: A portion of microbes caus

8、e diseases and are poisonous to human, and these are really that concern us in the study of medical microbiology, etc,The Importance of Microorganisms,Environment Medicine Food Industry Agriculture Research Physiological functions of normal flora,Microbial Ecology Bacteria recycle carbon, nutrients,

9、 sulfur, and phosphorus that can be used by plants and animals. Bacteria degrade organic matter in sewage and detoxify pollutants such as oil and mercury,Few microorganisms cause diseases in the animals, plants and human beings. They are called pathogenic microorganisms. Some microorganisms are gene

10、rally harmless, but occasionally pathogenic under some certain circumstances, which are called opportunist pathogens.,Normal flora,The various bacteria and fungi that are permanent residents of certain body sites, especially the skin, oral cavity, colon and vagina, usually do not cause any problems

11、for the host body.,The distribution of normal flora,Normal flora,Skin Staphylococcus epidermis Diphtheroids Streptococci Peptococcus,Normal flora,The respiratory tract The digestive tract The genitourinary tract,Physiological functions of normal flora,Biotic antagonism action Trophic action Immunifa

12、ction Anti-aging action Anti-tumor action,few,many,most,Microbiology,Bioscience for the study evolution, classification , morphology of microbes, the law of their life activities, and their interaction with human being, animals or plants as well as natural environment.,The history of Microbiology,Ex

13、perience phase Experimental phase Modern phase,Experience phase,11th century, tuberculosis was caused by worm 14th century, smallpox innoculation 16th century, infection biology was developed,Experimental phase,Leeuwenhoek Pasteur Koch Lister,Antony Van Leeuwenhoek(1632 1723),Major contribution The

14、invention of the microscopes that magnified over 200 times In 1675 first saw microorganisms,Louis Pasteur( 1822-1895),Major contribution Proved the absence of spontaneous generation Research on Fermentation Technique of Pasteurization,Pasteur showed that microbes are responsible for fermentation Mic

15、robial growth is also responsible for spoilage of food Spoilage bacteria could be killed by heat that was not hot enough to evaporate the alcohol in wine. This application of a high heat for a short time is called pasteurization,Fermentation and Pasteurization,Joseph Lister (1827-1912) invented the

16、disinfection aseptic technique ( Asepsis),Robert Koch(1843-1910),Method for isolating pure culture of bacteria New methods of staining bacteria Kochs postulates,Kochs postulates,The microbe should be found in the body in all cases of the disease. The microbe should be isolated from a case and grown

17、in a series of pure cultures in vitro. The microbe should reproduce the disease on the inoculation of a late pure culture into a susceptible animal.,To prove that a particular microorganism was the cause of a particular disease,Edward Jenner (1749-1823) From the milk women, he discovered safe immuni

18、zation against smallpox (vaccination),Immunity and immunization,1910: Paul Ehrlich articulated the principles of chemotherapy. Treatment with chemicals is called chemotherapy.,The Birth of Modern Chemotherapy,Paul Enrlich,Chemotherapeutic agents used to treat infectious disease can be synthetic drug

19、s or antibiotics. Antibiotics are produced by bacteria and fungi that inhibit or kill other microbes. 1930s: Sulfonamides were synthesized.,Alexander Fleming discovered penicillin,He observed that Penicillium fungus made an antibiotic, penicillin, that killed S. aureus. 1940s: Penicillin was tested

20、clinically and mass produced. Be awarded the Nobel Prize with Florey in physiology or medicine in 1945.,Modern Microbiology,In 1979, eradication of smallpox worldwide Progresses in diagnosis, prevention and cure of some infectious diseases Recent advances in genomics, the study of an organisms genes

21、, have provided new tools for classifying microorganisms.,Modern Microbiology,(1)Discover new microbes (2) Mechanisms of diseases (3)New diagnostic techniques (4)Prevention,Emerging and Reemerging Infectious Disease,AIDS Tuberculosis Hepatitis Gastric ulcer SARS(severe acute respiratory syndrome) Bi

22、rd influenza Swine influenza(A/H1N1 influenza),A/H1N1 influenza virus,Swine flu,The World Health Organization declared the first influenza pandemic in more than 40 years,due to the spread of the H1N1 swine flu. The Geneva-based U.N. agency raised the pandemic flu alert to six, the highest level, whi

23、ch indicates that the disease is spreading world-wide.,SARS outbreak of February July 2003 , a total of 8,437 people worldwide became sick with SARS; of these, 813 died.,Bird influenza,“superbugs”,大约10 years ago，一种被称为“超级病菌”的耐甲氧西林金黄色葡萄球菌（MRSA）methicillin resistant staphylococcus aureus在世界迅速蔓延，让世界震惊。“

24、新德里金属蛋白酶-1”（简称NDM-1）的出现让人惊呼“超级细菌”时代来临。 NewDelhimetallo-lactamase1,New Delhi Metallo-beta-lactamase (NDM-1)is an enzyme that makes bacteria resistant to a broad range of beta-lactam antibiotics. Bacteria are often referred to in the news media as superbugs because infections caused by them are diffic

25、ult to treat. Indeed, the United Kingdoms Health Protection Agency has reported that most isolates with NDM-1 enzyme are resistant to all standard intravenous antibiotics for treatment of severe infections,The most common bacteria that make this enzyme are Gram negative such as Escherichia coli and Klebsiella pneumoniae, but the gene for NDM-1 can spread from one strain of bacteria to