miocrobiology 药学英语 大二下 有难度啊课件

1、Microbiology1.Introduction Microbiology is the study of microorganisms, which are unicellular or multicellular microscopic organisms. This includes eukaryotes such as fungi and algae(藻类) and prokaryotes such as bacteria. Viruses, though not strictly classed as living organisms, are also studied. Mic

2、robiology is a broad term which includes many branches like virology, mycology, parasitology and others. A person who specializes in the area of microbiology is a microbiologist. 2. Bacteria Most bacteria (singular: bacterium) are unicellular microorganisms. They grow in soil, acidic hot springs, ra

3、dioactive waste, seawater, and deep in the Earths crust. There are approximately ten times as many bacterial cells as human cells in the human body, with large numbers of bacteria on the skin and in the digestive tract. A few are beneficial, some are pathogenic bacteria and cause infectious diseases

4、.2.1 Morphology Bacteria display a wide diversity of shapes and sizes, called morphologies. Most bacterial species are either spherical, called cocci (sing. coccus) or rod-shaped, called bacilli (sing. bacillus). Some rod-shaped bacteria, called vibrio（弧菌）, are slightly curved or comma-shaped; other

5、s, can be spiral-shaped, called spirilla（螺菌）.Escherichia coli大肠埃希杆菌Bacillus bifidus 双歧杆菌Bacillus anthracis炭疽芽孢杆菌bacillus (bacilli)Vibrio cholerae霍乱弧菌Spirilla螺旋菌 capsule(荚膜):protection against phagocytosis and desiccation，help attachment of bacteria to other cells or surfaces，composed of polysacchari

6、des and sometimes protein cell wall: prevents osmotic lysis of cell protoplast（原生质体） and confers rigidity and shape on cells Gram-positive bacteria: peptidoglycan（肽聚糖） complexed with teichoic acids（磷壁酸） Gram-negative bacteria: peptidoglycan surrounded by phospholipid，lipoprotein and lipopolysacchari

7、de( LPS,脂多糖) Plasma membrane: permeability barrier; transport of solutes; energy generation; location of numerous enzyme systems; composed of phospholipid and protein Ribosome(核糖体): sites of translation (protein synthesis), composed of RNA and protein Plasmid(质粒): extrachromosomal genetic material,

8、composed of DNA Pili（菌毛） and Flagella（鞭毛） : Swimming movement, composed of protein nucleoid：an irregularly-shaped region within the cell of prokaryotes which has nuclear material without a nuclear membrane and where the genetic material is localized.3.2 Structure Each viral particle, or virion, cons

9、ists of genetic material, DNA or RNA, within a protective protein coat called a capsid.Hepatitis B virus乙型肝炎病毒Influenza virus流感病毒3.3 ReplicationAttachment（吸附） is a specific binding between viral capsid proteins and specific receptors on the host cellular surface. This specificity determines the host

10、 range of a virus. For example, the human immunodeficiency virus (HIV) infects only human T cells, because its surface protein, gp120, can interact with CD4 receptor on the T cells surface.Penetration（侵入）: following attachment, viruses enter the host cell through receptor mediated endocytosis or mem

11、brane fusionUncoating（脱壳）: a process in which the viral capsid is degraded by viral enzymes or host enzymes thus releasing the viral genomic nucleic acidBiosynthesis（生物合成）: synthesis of viral protein and replication of viral genome.Assembly（装配）: assembly of intact virus Release（释放）: Viruses are rele

12、ased from the host cell by lysis4.Importance of microorganisms to humankind 4.1 Microorganism and disease Pathogen: infectious agent, or more commonly germ, is a biological agent that causes disease to its host. Viral infection influenza（流感）, measle（麻疹）, chickenpox（水痘）, smallpox（天花），mumps（腮腺炎） Bacte

13、rial infection tuberculosis（肺结核），pneumonia（肺炎）， diphtheria（白喉） Parasitol infection malaria（疟疾）：caused by plasmodium(疟原虫) fungal infection: onychomycosis(甲癣) 4.2 Microorganism and medicine 4.2.1 Antibiotics the substance, such as penicillin or streptomycin（链霉素）, produced by or derived from certain mi

14、croorganisms such as actinomycetes(放线菌）, fungi and bacteria（细菌）, that can destroy or inhibit the growth of other microorganisms. In clinic, it is used to fight against infectious diseases. Metabolism of microorganisms Primary metabolites (初级代谢产物）: amino acids , nucleic acids, vitamins Secondary meta

15、bolites(次级代谢产物）: antibiotics, hormones, pigments Classification according to chemical structure-lactam（-内酰胺） antibiotics：penicillin derivatives，cephalosporins（头孢菌素类）Aminoglycoside（氨基糖苷） antibiotics ：streptomycin， kanamycintetracycline antibiotics: tetracycline, chlortetracycline（金霉素） Macrolide（大环内酯）

16、 antibiotics：erythromycinpolypeptide antibiotics：polymyxin（多粘菌素）， bacitracin（杆菌肽） 4.2.2 Vaccine is a biological preparation that establishes or improves immunity to a particular disease. Vaccines can be prophylactic or therapeutic . Vaccination（接种疫苗） is the administration of antigenic material (the

17、vaccine) to produce immunity to a disease .Vaccination is also called active immunization because the immune system is stimulated to develop its own immunity against the pathogen. Passive immunity, in contrast, results from the injection of antibodies formed by another animal (e.g., horse) which pro

18、vide immediate, but temporary, protection for the recipient. 3. Toxoids A toxoid is a bacterial toxin (usually an exotoxin) whose toxicity has been weakened or suppressed either by chemical (formalin) or heat treatment, while other properties, typically immunogenicity（免疫原性）, are maintained. Toxoids

19、are used in vaccines as they induce an immune response to the original toxin. Examples of toxoid-based vaccines include tetanus and diphtheria .4. Subunit vaccine Rather than introducing an inactivated or attenuated micro-organism to an immune system ,a fragment of it can create an immune response. A subunit vaccine is composed of a purified antigen molecules or antigenic determinant that is separated from the virulent organism. Important morphemes parasit-parasite ectoparasite, endoparasite, parasiticide bacteri-bacteria bactericide, bacterist