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Medical Microbiology Hyaluronic Acid

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Medical Microbiology Hyaluronic Acid Powered By Docstoc
					                      Medical Microbiology
                            Chapter 1                  Introduction
[Requirement]
Master the definition of microorganism
Master the classification of microorganism
[Class hour: 1 hours ]
[Outline]
I.       Microbes
     1. Definition (microorganism)
     2. Classification
     3. categories according to                structure
          1) Non—cellular type
              Virus: no cellular          structure
              Parasite in living       cell
              Only contain one kind of nucleic acid                 molecule , DNA/RNA
            2)Prokaryotic       type
              No nuclear membrane or mitotic apparatus                  nuclear region   can be
seen ,
             composed of DNA.
              No separate internal membrane bound organelles .


              Bacterium                               Mycoplusma
              Chlamydia                               Riclcettsia
              Spirochetes                             Actinomycetes
            3) Eulcaryotic type
               intracellular       membrane —enclosed organelles
                Fungi       :         hyphae
                                       yeast
               nucleus :        two    membrane layers
                 Endoplasmic            Reticulum (ER)        rough     ER
                                                              Smooth      ER
                  Mitochondria
      4.Distribution     of Microorganisms:              1)      In environments.
                                                         2)     In human organisms
II       Microbiology
      1 .research      objective : Pathogenic          Microbes
       1)biological     properties
       2)pathogenesis         and immune response
       3) Diagnosis and           protection
     2. History
        Leeuwenhock : invent                 Microscope in 1674 .
        Pasteur               : pasteurization , Vaccine
        Koch                  :    solid medium               purify    bacteria
                                     Pathogenic microbe criterion
        Lister            :       disinfection       aseptic technique
        Iwanovsky                 virus.
     3. Modern M
         1) Most       bacteria were controled           by     antibiotics.   Drug-resistant strains—>
            resistence plasmid.
            Normal flora—opportunistic              pathogens
                               (flora      disequilibrium super-infection )
            Hospital acquired infections.
            New       bacteria : Helicobacter pylori—chronic gastritis.
         2) Viral research made progress.
            AIDS
         3) New diagnostic techniques .
            ELISA
            PCR         :polymerase chain reaction.
         4) New type vaccine .
         5) Microbial genomic program,            MGP .




Chapter 2 Bacterial shape                         and structure
[Requirement]
Master the structure of bacteria and their functions
Master the following       concepts :
1.plasmid 2. flagellum 3. pillus 4. capsule
5.L-form bacterium 6. mesosome 7. lipopolysaccharide(LPS)
Understand the size and shape of bacteria.
[Class hour: 3 hours ]
[Outline]

Section I .             Bacterial Morphology
      Single cellular prokaryotic       microbe


I.      Size of bacteria
      Measure unit um(micrometer)
     Coccus 1 um bacillus 2—3um
II     Shape of bacteria
     1. coccus (cocci)
         1) diplococcus : in pairs
         2) streptococcus: long     chain
         3) staphylococcus: irregular cluster
     2. bacillus (bacilli): rod
     3. Spirilla bacterium
        1)vihrio    v. cholera
          2)Spirillum
     4. Campylobacter
             C. jejuni
             Helicobacter                                  H. pylori
                          Section II Bacterial                                 structure
Superficial       layer     cell     wall
(cell envelope)              cell membrane
                                 mesosome
       inner             -nucletid
                         plasmid
specific      structure      -external 1          flagellum 2         pillus
                                 supper-facial :capsule
                            inner:     endodpor .
I Basic       stucture
(I)cell          wall
1. function :1)protection 2) keep the                constant        shape . 3)antigenicity .4) exchange
   material
2. structure and           chemical composition peptidoglycan(mucopeptide)
   1)polysaccharide           backbone .                  N-acetyl          glucosamine    link   N-acetyl
   muramic
   acid with 1.4 –glucosidic              bond
   2)tetrapeptide         side            chain    link     muramic         acid .   ala   glu    lys   ala
   3)pentaptide         bridge         G+ 【L—glycine】


                                          -
                                      G       diaminopimelic acid
3. Special components of Gram-positive cell                          wall
           1. teichoic acids           wall teichoic acid
                                        membrane teichoic acid


     function :
      1) bind Mg2+(magnesium)                       upply       of this ion to the cell
       2) provide the cell with its                 consistency
       3) adhesion ------pathogenicity
       4) antigenicity
             2. polysaccharides
               may contain a variety of sugars.
4. Special components of Gram-Negative cell                            wall .
       1) lipopolysaccharide, LPS
        a complex           and    unique      glycolipid     consisting          of      there distinct       but
       covalently linked regions:
       ( 1 ) lipid            A      glucosamine          disaccharide            units      connected          by
       pyrophosphate bridge .             endotoxin , non-genus          specific
       (2)core polysaccharide
       (3)specific polysaccharide                 ―o‖Ag
       2) Outer membrane : exchange .receptor(sex pili phaqe)
       3) Lipoprotein
             Are firmly      but    non      covalently     attached       to     the      peptido-glycan and
             out membrane
       4) periplasmic space .
             between out membrane and inner                    membrane binding protein
                                                                           hydrolytic enzymes


                 function (1)transport .nonspecific diffusion
                              (2)barrier: resist-many antibiotic
                                                                   -
                comparision        of cell     wall G +        G
(II)Cell membrane
     mesosome :         invagination         vesicular    membrane              increase     membrane          area
like chondriosome
     septal mesosome : cell division
(III)Cytoplasm
        plasmid
        extra-chromosomal           genetic     material      circle ,          double       streands      DNA,
replicated     independently       , carry    genetic     information,          control     a wide      rang     of
function to     bacteria.
(Fertility)factor F ---------control                 sex pili
                 factor R----------control drug resistance
                 col     faction ------control E col: to              produce bacteriocin.
II.      Special        structure         of bacteria
          (I)capsule
              secret           a     slime layer    outside the        cell     wall
            composed of polysacchride or polypeptid
                                    pneumococcus          anthracis
>0.2um           capsule
<0.2um microcapsule
slime layer             Washed           off


                       does not appear to be associated                   with the cell.
      Function     condition , enviroment host            body
Function
1. anti—phagocytosis                     surface     phagocytosis             .opsonic    phagocytosis
2. rnti-dry
3. antigenicity
4. typing
(II)flagella
long      filamentous appendage.
Originate in the                   protoplasmic    membrance
Function :1. motility 2. antigenicity ―H‖Ag                       3. pathogenicity          somebacterin
(III)pili (pilus)
       filamentous             appendage             on         the             surface      of      bacteria,
shorter .straighter ,finer than flagella.
1. common              pili        100—200/cell
       adherente organ of bacteria, adhere to suface of mucosal membrance ,
associated       with         pathogenicity.
2.      sex pili 1—4/cell
male bacteria          with sex pili
transfer of genetic material(DNA)during                          bacteria   conjugation
               -
F+--------F
Section 3. Special living              form of          bacteria.
1. spore
    round       or       elliptic     minute         body       formed      inside   the   bacteria
    —endospore
      dormant          form (resting         forms )
          vegetative     form
1) forming: inadequate nutrition
2) structure (1)core DNA(chromosome)synthesis of proteins. Energy
                   (2)inner membrane
                       (3) cortex       (4)coat              (5)exosporium
3) germination
 spore                 vegetative     form
 activation             initiation                  outgrowth
4) function of spore
   highly resistant to              heat . chemical .dry.
reason:(1)many layers .thick                  coat
           (2)little water. 40% free water
                                      80% -----------
           (3)large amount of calcium dipicolinate
          (4)heat —stable enzyme (DPA,吡啶二羧酸钙)
destroy     spore: autoclave.121°C                  15—30′
(II)Bacteria L—Forms                         cell     wall      deficient form
   1) Morphology:           friend egg        —spherical body.
          Colonies                              large            body
          Filamentous colony —filamentous                    forms.
   2) Media . high osmotic .reversion
   3) Pathogenicity
         Similar to       the   infection   of virus    or     mycoplasma (organisms         without
         wall)
         Infiltration of mononuclear cells and lymphocytes and different from that
         of the bacterial infections , with mainly infiltration of neutrophils.

      Chapter3. Bacterial                multiplication           and     metabolism
[Requirement]
Master the mode and          spead of B. reproduction.
Master the reason that obligate anaerobes can’t grow in free oxygen condition.
Master the metabolic products of bacteria.
Master the following concepts:
1.pyrogen 2. antibiotics 3. bacteriocin
Understand bacterial nutrition.
Understand the growth and reproduction of bacteria
[Class hour: 2 hours ]
[Outline]
I .Bacterial nutrition
1. nutrient material
      (1) water    (2)carbon           source   : energy(3)Nitrogen       source          constituent
         protein(4)inorganic ions (5)growth
2. nutrient type 1)autotrophy 2)heterotroph               saprophyte


                                                             parasite
II.      Bacterial growth and reproduction
      1. growth          condition     (1)enough     nutrients (2) Suitable      PH (3) suitable
         temperature (4)suitable air
               obligate aerobe
               obligate anaerobe
               facultative anaerobe
               microaerophilic bacterium
      Reason      that      obligate     anaerobes     con’t       grow     in     free      uxygen
condition:(1) Lack of cytochrome and                   cytochromase----Eh           300mv/120mv
                                                                                                         -
       (2)     lack of      superoxide        dismutase (SOD)         catalase       , peroxidase.[O 2       ]
H2O.
III.         mode and       spead of B. reproduction
   1)Mode.          binary      flssion       .     chromosome     replication       . synthesize     cell
                                                                                 -
membrane and wall            G+B      chromosome          bind mesosome        G B. chromosome bind
membrane.
 2)speed generation time             20----30min        E. coli 10h    10T 2     1.5-----20HR       Myco.
Tuberculosis
(1) lag phase adapeatation
(2) logarithmic phase most rapid reproduction
(3) stationary phase .rate of reproduction                                       rate of deed
(4) decline       phase rate of dead > rate of reproduction.
IV.          Bacterial Metabolism
       1. Bacterial enzyme
       Exoenzyme         hydrolase
                      Some pathogenicity —coagulase
       Endoenzyme           metabolic enzyme
                            Respiratory    enzyme
       Metabolic products
       1. Catabolic products and biochemical reaction
       2. Anabolic products and clinical significance
              1) pyrogen
                                          -
                 polysaccharide of G              cell wall(LPS) anti-high temperature 121°C, 30’.
                 Fluid infusion reaction
              2) toxin and invasive enzymes
                 exotoxin
                 endotoxin
                 enzyme
              3) pigment
               water—soluble        P. aerogenosa ---green
               fat ---soluble       S. aureus —golden
          4) antibiotics
               Killing     or     inhibiting   substances    produced   by   some   kinds of
               microorganisms
               Actinomycete
          5) bacteriocin
               protein by certain bacteria , which can kill or inhibit the growth of related
               strains.


Chapter 4. Bacteriophage
[Requirement]
Master the interrelation between phage and bacteria
Master the following concepts :

1. lysogenic      state 2. lysogenic phage (temperate phage)
3.lysogenec      bacteria 4.prophage
Understand the.size, shape and structure of phage.
[Class hour: 1 hours ]
[Outline]
Infecting bacterial virus .
(1) viral common properties
     smallest
     simple structure           DNA/RNA
     parasite in living cell
(2) widespread       existence
(3) high host –specific parasitism
     I.        Biological properties
          1. Shape and structure
               Seen by EM
                 Tadpol microsphere slim rod                                 collar
                 head       core       DNA/RNA                      tail      pipe-like
                        capsid protein coat                                  base plate
           2. antigenicity                                                     tail fib
           3. resistive
                 >Bacteria           75°C            30′
                 sensitive to rays
     II.         Interrelation     between          phage and bacteria
           1. ph.           Reproduction            and     lyzing         B. virulent         ph       . which can
                 replicated in cell and released in lysis of B .
            replicatic cycle.
            1)       absorption and          tail     pins and      fibers absorb          teichoic         receptor     of
B,
                   call wall         G+
                                       -
                                   G
                                   Pr. LPS
                  Surface        structure .         sex pili
           2)         penetration          : lysosome            —like         substance            lyse,         Sheath
                    constract—injects DNA into                  bacteria.
           3)      Biosynthesis                                                                     structure
           Phage        DNA                transcribe mRNA                                protein
                                                                                          enzyme


           phage      DNA                     replication
           4) lysis
                encode lysosome                     lysis B.                release
     2.     lysogenic        state
            infected      bacterial        phage      doesn’t     replicate      it’s     gene      ,integrated        with
bacterial DNA, its replication is associated                           with      bacterial DNA
           lysogenic     phage (temperate phage)
          lysogenec bacteria
          prophage : The       DNA of       temperate       phage     integrated     into   bacterial
DNA.


     Chapter 5 . Bacterial inheritance                                and variation.
[Requirement]
Master the characteisticrs of plasmid.
Master the mechanism of mutation and gene transfer of bacteria.
Master the following concepts :
1. heredity(inberitance) 2. variation 3. Plasmid
4. Mutation 5. genetic transfer 6. Reassortment 7. Prion

[Class hour: 2 hours ]
[Outline]
Concept:
(1) heredity(inberitance)      general    stability    on      ―likeness‖ in   the    characteristics
     of progeny and parent.
(2) variation . the difference between                progeny and parent Heritable variation
genetic    substance     changes .nonberitable     variation         enviroment changes
    I.       Genetic substance
          1. chromosome
              consists    of   a   circular      double     strand    DNA      molecular,    control
              bacterial life without introne.
          2. Plasmid
              Extrochromosomal genetic substance.
              Circle double strand DNA
              (1) autonomous replication
                       binding to chromosome —episome
               (2)         tranfer from a          bacteria to another
     conjugative plasmid : F+            serpili
         nonconjugative          plasmid: phage
   (3)contral most               of auxiliary functions of bacterial cell
                    eg.   Antibiotic resistance —R plasmid .
                          the production of fimbriae—F
                          bacteriocin          —E. coli con.
   (4)bacterium can carry one or                           several plasmid
   (5)dispensable, it can be lost .
   (6)different size : small—a                  few genes .large—hundreds of genes.
       3. phage.
       III.        variation examples.
              1. shape and structure variation .
               eg . L form
                     Y . pestic 3—6%. Nacl                       pleomorphism
                     Protenus          media—H          colony


                                  Media(1%carbolic acid)                  O colony(no flagella)
              2. colony variation
                   smooth colony                rough      colony
              3. virulence variation                       vaccine
                    BCG : Bacilla of calmetter-Gueria                  230 passages, 13     years.
              4.      Resistance variation
III.          Mechanism           of        bacterial      variation     mutation.    Transfer       and
combination .
       1.Mutation
          (1) concept: a stable                heritable    change of bacterial gene ,


                            -          -9
          spontaneous 10 6~10


          inducing              inutagen
          (2) type         of mutation
               molecular foundation of mutation .
               Bacterial nucleotide sequence change
                       i.         base replacements
                                  transation (转换) A—G, C—T
                                  transversion(转换)A—T C—G
                       ii.        base deletion . one base or     fragment lost
                       iii.       base insertion .   one base or fragment
         type (according to code )
              missense        mutation: replacement in one code one amino acid
             changes


              nonsense        mutation: replacement in one code change into stop code


              frame    shift     mutation: deletion or insertion one base or fragment
       type (according to biological properties)
        resistant mutation
        nutrient deficient mutation
        iethal mutation
        conditional lethal mutation
2. mutation and       selection
fluctuation test
replica test(Ames test)
3.genetic transfer.
     Genetic substance of B.is tranfered to another bacteria.
          Donor bacteria : provide genetic substand


         Recipient bacteria : accept genetic substand
    1) transformation
        recipient B. takes up exogenous DNA of donor B.
        eg : Griffith’s experiment
           competence : bacterial state. In which bacteria can able to take up DNA from
           environment in logarithmic phase
   2) transduction .
           donor bacterial DNA is transfered         to recipient   bacterial by phage .
           (1) general transduction: any fragment of donor bacteria is transfered.
           (2) Specific transduction: the fragment near attachment is transfered.
           (3) Lysogenic conversion
                    Bacteria acquired       new properties    by phage lysogenization.
                    Eg C, diphtheria
3. conjuqation
    bacterial DNA is transferred from             donor bacteria to recipient bacteria by F
    pilus. Hfr(high        frequent recombinant bacterium )
   (1)F plasmid F’ plasmid intergrated into chromosome.
            F    plasmid     of   high   freguent     recombinant bacteria    separated    from
                  bacteria chromosome, carrying a       neighbour DNA.
                 Sexduction.
    (2)R plasmid
                conjugative R     plasmid     resistance transfer factor RTF
                                                resistance   factor (RF)
                 the   function of RTF is similar to F plasmid


                nonconjugative R plasmid.
     The result of gene tranfer
     i.      exogenous DNA          was degraded
     ii      exogenous DNA from             circular ds DNA
                 autonomous replication
                  abortive infection
    iii.         exogenous DNA recombine            with endogenous DNA
                 hemologeous recombination
                 site-spcific recombination
                      eg        phage
              transposable         elements         insertion    sequence
                                                     transposon


     IV.     Medical application
             1, Bacterial indentification
                     2. prevention treatment of diseases. Eg . vaccine
                     3. screening        potential carcinogen . Ames test
                     4. genetic        engineering
                     (1)prepare objective gene                   endonuclease            E COR I
                     (2)         objective gene recombines with vector
                                       vector: plasmid .phage .
                     (3)recombined DNA transfer to cell .eg . E. coli                                 (4)
                     Screen positive          cell.resistance—antibiotics.
                         (5) Amplify      objective gene and express.

Chapter              6       Disinfection                 and           sterilization
[Requirement]
Master the condition of physical methods of disinfection.
Master the mechanism of the antiseptic effect of chemical agents.
Master the following concepts :
1.disinfection 2. sterilization 3. asepsis 4.                      antisepsis
[Class hour: 1 hours ]
[Outline]:
Concept
1.    disinfection :            To pathogenic             microorganisms (vegetative       form)
2.   sterilization       :    To       kill   all   microorganisms . pathogenic /non-pathogenic ,
                                 vegetative /spore.
3.     asepsis        :            a     state       of     sterility    (no    living    bacteria) asepeic
technique
4.    antisepsis::           To inhibit          growth and reproduction of bacteria.
I.   Physical      methods
       1. heat lethal
          make         bacterial       protein   denature   .     bacterial   DNA degrade, injury
          cell membrane .
          dry heat: vegatatine 80---100°C 1hr
                               spore         160°C              2hrs
                               flame
                               hot air oven 160°C 2―3hrs
          moist heat
          advantages           over dry heat
          (1) Bacteria absorb H2O , proteinis easy to solidify and denature .
          (2) Strong           penetration
                 Eg. 100 th layer: dry heat 130-140°C 4hrs。72.5°C/100 th
                 Moist     heat 105°C            3hrs. 101°C/100 th
           (3) lalent heat             gas –liquid .
                 pasteurization 62°C 30′ 72°C , 30″
                 Boiling       100°C          5′
                 Steaming and intermittent sterilization                 Arnold 3times.
                 Autoclaving : 1.05 kg/ cm2, 121.3°C 15-30′-spore
       2. radiation
           1) ultraviolet light 200---300nm
                  interfere DNA replication                       dimmer of Thymine .
                  strongest      spectrum 260nm                  DNA absort      specfurm
                  weak penetration : definite time and intensity
                  stimulate skin, eyes,.
                  Application : air . operation room
           2) iDnizing radiation : eg ,x-ray . r-ray.
       3. filtration
         fiter           heat-labile       solution
                         eg.    Serum . toxin .antibiotics. etc.
                         seitz    filter: K>EK>EK-S
                         glassical filter: G1     G2     G3……6
                          thin membrane         filter
         4. other: low temperature( preserve bacteria)
   II.    Chemical disinfection
          Disinfectant
          Antiseptic
          1. chemical agents and mechanism
             1) heavy –metal salts
                 (1) bind to –SH and            destroy it, inhibit activity     of enzymes.
                 (2) Protein       denature. Merbromin .thimerosal 0.1%disinfectant
                                                                   0.01%antiseptic
             2) Oxidizer
                 H2 O 2 KMnO 4 CHCOOH(过氧乙酸)
                 Halogen(iodine ,chlorinated lime)
                 (1)SH                S—S—           enzyme
                   (2)       destroy amino          group, indol group.
                  (3)            denature protein
             3) surfactant
                 combine         with phospholipid
                 increast membrane permeability
                 bromogeramine(新洁尔灭)
                 domiphen(杜灭芬)
             4) aldehyde(醛类)
                 farmaldehyde、
                 enzyme deactivity
             5) alcohol           70% alcohal protein denature。
             6)phenol (酚类)protein denature , destroy                      cell   membrane。
2. Application
   skin: 2.5%碘酒 70%酒精
    mucosa 2% 红汞                  0.1%新洁尔灭
    drinking water 漂白粉
    patients excreta       5% phenol 2%lyson
    air: formalin spray
    3 . Affecting         factors ( 1 ) concentration        and     time     (2) properties   and
quantity
(3)emperature       and     PH       (4) antagonist:    organs     protein     , excreta

Chapter 7.                Normal flora
[Requirement]
Master the initiate infection of opportunistic         pathogenic B.
Master the functions of normal flora
Master the following concepts :
1. normal flora      2. opportunistic pathogenic B
[Class hour: 1 hours ]
[Outline]
Concept
1. normal flora: The             microorgomison that parasitize on the body surface or
   tracts connecting      with     external, don’t harm the host in ordinary condition.
2. opportunistic     pathogenic B
   some     bacteria      are    unable   to   cause    in   ordinary    condition , they initiate
   infection.
   If(1) they leave their ordinary habitant and         gain access to       other part.
(2) host immunity reduce.
(3) Owing to the wide use of antibiotic, hormone and anti-concer                    druges.
    I.      Distribution of normal flora
            Skin
                Mouth carity anaerobes
                Intestinal tract: anaerobes: aerobes =1000:1
                Vagina: Lactobacillus.
    II.     Role of normal flora.
              1. Biological barrier: antagonism
              2. nutrient synthesize : aa. VB.          K.   enhance absorb.
              3. immue:   enhance and develop and                maturation of immue     system
       III.     Flore disequilibrium (dysbacteriosis)
                Balance    of     normal       flora     was broken. Flora inbalance     symptom
                (superinfection) widely use antibiotics, sensitive bacteria          were killed ,
                the resistant bacteria reproduce rapidly.

Chapter 8. Bacterial pathogencity
[Requirement]
Master the mechanism of bacterial virulence
[Class hour: 3 hours ]
[Outline]

                                Section 1. Introduction
I.                pathogenicity
1.                Definition
Denotes the ability of B. to cause disease.
S. typhi             typhoid
M. tuberculosis                 tuberculosis
N . gonococcus                 gonorrhea
staphylococci                                   straom
 compare: S. aureus, S, epider, S, Saprophy
 Major properties of three           species of staphylococci
2.                Virulence
It refers to extent of pathogencity
Medium lethal dose, LD50
Medium infective          dose , ID50
II.               Pathogenic B, and non-pathogenic B.
III.              Infection and disease
1.                Immunity: The      host      can     protect   itself from and combat infections
disease.
2.              Bacteria: (1)Virulence invasiveness B . component
                                                       B. enzymes
                                     Toxins endotoxin
                                               exotoxin
                                         (2) the amount of invading bacteria
                                           (3) the portal of entry
All    people    are ―infected‖         from   birth    until     death,   why?Our     normal flora is
actually        an        infections.    Normal         flora                        pathogenic      B.
Translocation .Dysbacteriosis
IV.                        Mode of modern infection
Pathogenic B.                   healthy host


                          Non-pathogenic B                compromised
                              Normal flora                      host
                     (conditional pathogen)
Reason: (1) broad          spectrum antibiotic
           (2) method of modern .treatment and diagnosis.

Section 2. Bacterial virulence
I . Invasiveness
      The ability of B . to resist host         defence, colonize, multiply and            spread.
      1. Surface structure
           1).adhesive factor —adhesin
                (1)pili
                 V.        cholera
                     S. desentery                 specific      epithelial cells
                 N. gonococci
                 Small intestine                  rice –water stools
                 Segmented intestine                     abdominal cramp (colon)
                 Urethra and vagina                      urethritis
                 Vaccine
    (2). lipoteichoic acid, LTA
       group A strept . LTA                             fibrillae adhere to
                                      M-protein                                       LTA
       receptors
3) antiphagocytic factors
        (1) capsule >0.2um
               surface   phagocytosis: H,C3b


                                         C3b Bb
        (2) micro-capsule<0.2um
               S.typhi        Vi-Ag
               E, coli      K –Ag
        (3) flagella: V . choleva
               H.    pylori
     2. Exoenzyme
                 (1) coagulase: S. aureus
                     fibrinogen             fibrin
                     surround bacteria
                 (2) hyaluronidase (spreading          factor)
                     hydrolyze        hyaluronic     acid          tissue     loose    B.
                     spreads
                 (3) streptokinase. SK. Lyse          fibrin
                 (4) streptodornase, SD, resolve DNA.
         II.        Toxin
                    1. Exotoxin
                 (1) excreted by living cells , mainly G+ B.
                 (2) Polypeptide
                 (3) Heat-unstable, 60°C, 1-2hr destroy
                 (4) Strong antigenicity,exotoxin                toxiod
                 (5) highly toxic
               (6) high selection      for tissues
               exotoxin       subunit A: toxicity
                              subunitB:     non-toxicity
                              bind receptor of sensitive
                              cell
               a. neurotoxin: tetanospasmin                  spinal cord
               b. cytotoxin : diphtherotoxin             inhibit: elongation factor 2
                                                                cell protein synthesis
                 c. enterotoxin
                      cholera toxin
       2.Endotoxin
                                               -
               (7) integral     part of    G       B. Cell    wall. .Liberated     upon    their
                     disintegration.
               (8) LPS, main toxic part: Lipid A
               (9) Heat-stable: 160°C 2-4hr
               (10)      Can’t converted into toxiod
               (11)      Weakly toxic
               (12)      Non-specific
               Function: a, fever
               endotoxin stimulate                   reticuloendothelial cell    release
                                                      endothelial cell
                endogenous       pyrogen(IL-1)                 thermo-regulatory    centers in
               the hypothalamus.
          Repeated injection of endotoxin gives less and less fever response.
          Reason: ―tolerance‖ reticuloendothelia        blockade
                              IgM antibody to LPS.
(2)     WBC reaction
LPS induce             neutrophi releasing factor                WBC except S. typhi
(3) infectious shoclc
 LPS         blood platelet ,WBC,complement, kinin.                Vasoactive ,substances,eg,
Serotonin, kallikrein. Kinins                micro- circulation   failure
(4) disseminated intravascular coagulation
   DIC
Section 3. Occurance and development of infection
             I.      Origin of infection
                    1. Exogenous infection
                    (1) patient
                    (2) carrier
                    2. Endogenous infection
                  II.The mode of infection
                         1. resp. tract
                         2. digestive tract
                         3. damaged skin or mucous membranes
                         4. arthropod vector
                         5. contact: sex contact
          III.      The type and          outcome of infection
                      1. inapparent infection
                      2. apparent infection
                          toxemia
                          bacteremia
                          septicemia
                          pyemia
                        3. Carrier state

				
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Description: Medical Microbiology Hyaluronic Acid