Normal Flora

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Normal Flora
By
Dr. Humodi A. Saeed Associate Prof. of Medical
Microbiology College of Medical Laboratory
Science Sudan University of Science and
Technology E mail address Biotechsust_at_hotmail.com
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Normal Flora
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Normal Flora

• Definition
• Normal flora is the mixture of microorganisms
  (bacteria and fungi) that are regularly found at
  any anatomical site of human body like

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Normal Flora

• Skin
• Eyes (i.e.Cunjunctiva)
• Nose (i.e. Respiratory tract)
• Mouth (i.e Human Oral Cavity)
• Ears
• Urogenetal tract
• Elementry tract

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Normal Flora

• Resident flora
• Acquired rapidly during after birth

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Normal Flora

• Resident flora
• Reflects age of person

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Normal Flora

Resident flora Changes continuously through out
life
.
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Normal Flora

• Resident flora
• Reflects nutrition of person

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Normal Flora

• Resident flora
• Reflects genetics of person

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Normal Flora

• Resident flora
• 90 is S. epidermidis S. aureus, may be in moist
  areas

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Normal Flora

• Resident flora
• Reflects environment of person

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Normal Flora

• Resident flora
• Reflects sex of person

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Normal Flora

• Sterile tissues
• In a healthy human, the internal tissues such as
• blood
• brain
• muscle
• cerbrospinal fluid (csf.)
• are normally free of microorganisms.

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Importance of The Normal Flora (Advantages)

• 1. They constitute a protective host defense
  mechanism
• by occupying ecological niches.

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Importance of The Normal Flora (Advantages)

• 2. They produce vitamin B and vitamin K in
  intestine.

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Importance of The Normal Flora (Advantages)

• 3. The oral flora contribute to immunity by
  inducing low levels of circulating and secretory
  antibodies that may cross react with pathogens.

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Importance of The Normal Flora (Advantages)

• 4. The oral bacteria flora exert microbial
  antagonism against nonindigenous species by
  production of inhibitory fatty acids, peroxides,
  bacteriocins, etc.

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Importance of The Normal Flora (Advantages)

• 5. The normal flora may antagonize other bacteria
  through the production of substances which
  inhibit or kill nonindigenous species.

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Importance of The Normal Flora (Disadvantages)

• 1. They can cause disease in the following
• a) When individuals become immunocompromised or
  debilitated.
• b) When they change their usual anatomic
  location.

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Importance of The Normal Flora

• 2. The oral flora of humans may harm their host
  since some of these bacteria are pathogens or
  opportunistic pathogens

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Estimation of the Normal flora

• It has been calculated that the normal flora
  human body about 1012 bacteria on the skin, 1010
  in the mouth, and 1014 in the gastrointestinal
  tract.

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Normal Flora of the Skin

• The most important sites are
• 1. Axilla
• 2. Groin
• 3. Areas between the toes

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Normal Flora of the Skin

• The majority of skin microorganisms are found in
  the most superficial layers of the epidermis and
  the upper parts of the hair follicles.

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Normal Flora of the Skin

• Important bacteria
• 1. Staphylococcus epidermidis
• 2. Micrococcus sp.
• 3. Corynebacteria sp.
• 4. Mycobacterium smegmatis

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Normal Flora of the Cunjunctiva

• 1. Staphylococcus epidermidis
• 2. Corynebacterium sp.
• 3. Propoinibacteriumacnes)
• 4. Staphylococcus aureus
• 5. Viridans streptococci
• 6. Neisseria sp.
• 7. Haemophilus influenzae

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Pathogens which do infect the conjunctiva

• Neisseria onorrhoeae
• Chlamydia trachomatis

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Normal Flora of the Respiratory Tract

• A) The nares (nostrils)
• 1. Staphylococcus epidermidis
• 2. Corynebacteria
• Staphylococcus aureus
• 4. Neisseria sp.
• 5. Haemophilus sp
• 6. Streptococcus pneumoniae

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Normal Flora of the Respiratory Tract

• B) The upper respiratory tract (nasopharynx).
• 1. Non-hemolytic streptococci
• 2. Alpha-hemolytic streptococci
• 3. Neisseria sp.
• 4. Streptococcus pneumoniae
• 5. Streptococcus pyogenes
• 6. Haemophilus influenzae
• 7. Neisseria meningitidis

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Normal Flora of the Respiratory Tract

• C) The lower respiratory tract (trachea, bronchi,
  and pulmonary tissues)
• Usually sterile.
• The individual may become susceptible to
  infection by pathogens descending from the
  nasopharynx e.g.
• H. influenzae
• S. pneumoniae).

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Normal Flora of the Human Oral Cavity

• Oral bacteria include
• 1. Viridans streptococci
• 2. Lactobacilli
• 3. Staphylococci (S. aureus and S. epidermidis)
• 4. Corynebacterium sp.
• 5. Bacteroides sp.
• 6. Streptococcus sanguis (dental plaque)
• 7. Streptococcus mutans (dental plaque)
• 8. Actinomyces sp.

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The Normal Flora of The Ears (i.e. external ear)

• The external ears contains avariety of
  microorganisms. These include
• 1. Staphylococcus epidermidis
• 2. Staphylococcus aureus
• 3. Corynebacterium sp

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Normal flora of the Urogenital Tract

• a) The anterior urethra
• 1. Staphylococcus epidermidis
• 2. Enterococcus faecalis
• 3. lpha-hemolytic streptococci.
• 4. Some enteric bacteria (e.g. E. coli, Proteus
  sp.)
• 5. Corynebacteria sp.
• 6. Acinetobacter sp.
• 7. Mycoplasma sp.
• 8. Candida sp.
• 9. Mycobacterium smegmatis

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Normal flora of the Urogenital Tract

• b) The vagina
• 1. Corynebacterium sp.
• 2. Staphylococci
• 3. Nonpyogenic streptococci
• 4. Escherichia coli
• Lactobacillus acidophilus
• Flavobacterium sp.
• 7. Clostridium sp.
• 8. Viridans streptococci
• 9. Other Enterobacteria

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Normal Flora of the Gastrointestinal Tract (GIT)

• In humans, the GIT flora are influenced by
• 1. Age
• 2. Diet
• 3. Cultural conditions
• 4. The use of antibiotics

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Normal Flora of the Gastrointestinal Tract (GIT)

• At birth
• The entire intestinal tract is sterile, but
  bacteria enter with the first feed. The initial
  colonizing bacteria vary with the food source of
  the infant.

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Normal Flora of the Gastrointestinal Tract (GIT)

• In breast-fed
• 1. Bifidobacteria account for more than 90 of
  the total intestinal bacteria.
• 2. Enterobacteriaceae
• 3. Enterococci
• 4. Bacteroides
• 5. Staphylococci
• 6. Lactobacilli
• 7. Clostridia

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Normal Flora of the Gastrointestinal Tract (GIT)

• In bottle-fed infants
• Bifidobacteria are not predominant. When
  breast-fed infants are switched to a diet of
  cow's milk or solid food, bifidobacteria are
  progressively joined by
• 1. Enterics
• 2. Bacteroides
• 3. Enterococci
• 4. Lactobacilli
• 5. Clostridia

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Normal Flora of the Gastrointestinal Tract (GIT)

• In the upper GIT of adult humans
• mainly acid-tolerant lactobacilli
• e.g. Helicobacter pylori

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Normal Flora of the Gastrointestinal Tract (GIT)

• The proximal small intestine
• 1. Lactobacilli
• 2. Enterococcus faecalis
• 3. Coliforms
• 4. Bacteroides

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The flora of the large intestine (colon)

• 1. Enterococci
• 2. Clostridia
• 3. lactobacilli
• 4. Bacteroides
• 5. Bifidobacterium (Bifidobacterium bifidum)
• 6. Escherichia coli
• 7. Methanogenic bacteria
• 8. Viridans streptococci
• 9. Staphylococcus sp.
• 10. Proteus sp.
• 11. Candida albicans (Yeast)
• 12. Mycoplama sp.

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THANK YOU
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43
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44
????? ??? ??????? ?????????? ??? ???????
??????? ???? ?????? ????? ??? ???????? ??? ?????

• 1. ??? ????????????? ??????? Food microbiology
• ???? ?????? ???????? ??????? ? ???????? ???????
  ? ????????? ???? ?????? ?? ???????.

45

• 2. ??? ????????????? ?????? Soil microbiology
• ???? ?????? ???????? ?????? ? ???????? ?????? ??
  ????? ????? ?????? ??????.

46

• 3. ??? ??????????????? ?????? Medical
  microbiology
• ???? ?????? ?????????? ??????? ??????? ?? ???
  ???????? ?? ???? ??????? ? ??????? ????? ???
  ??????.

47

• 4. ??? ????????????? ??????? Agricultural
  microbiology
• ???? ?????? ?????????? ???? ???? ??? ??????? ??
  ??????? ????????? ????????.

48

• 5. ??? ????????????? ??????? Industrial
  Microbiology
• ????? ?????? ?????????? ????????? ?? ???????
  ?????? ???????? ??????? ???????????? ??????????
  ????????? ??????.

49

• 6. ??? ????????????? ?????? ???????? Water and
  Sewage Microbiology
• ????? ?????? ???????? ?????? ???????? ?????????.
• ??? ??? ??? ????? ????? ?????? ??????? ???
  ?????

1. ??? ???? ??????? ??????? Microbial
ecology ???? ?????? ???? ??????? ???????.
2. ??? ????????? ??????? ??????? Microbial
Physiology ???? ?????? ????? ???????.
50
???? ??? ??????? ??????? Development of
Microbiology

• ???? ?????? ???????? ??????? ??? ????????
  ?????? ?????? ??? ?? ?????? ???????? ?????? ???
  ??????? Antony Van Leeuwenhock ??? ??????? ??
  ????? ??? ?????? ?? ??? ??? ??? ?????????

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????? ??????? ?????? Spontaneous Generation
Theory

• ???? ??? ?????? (1713-1781) ?????? ??? ????? ???
  ??? ??? ????? ?? ?????? ????? ?????? ????????
  ??????? ?? ????? ???? ?? ??? ?? ?????? ??? ? ????
  ???? ??? ?????? ?????? ??? ????????? ????? ????
  ?????? ?????? ?? ??? ???????? ???? ???? ?? ?????.
  

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??? ????? ??????? ?????? Disproof of Spontaneous
Generation

• 1. ????? ?????? ?????????? Lazaro Spallanzani
  Experiment

53

• 2. ????? ????????? ??????? ???? Franz Schulz
  Theodor Schwan

54

• 3. ????? ????
• ?? ??? ??? ?????? ???? ????? Schroeder ???? ???
  Von Dusch ?? ???? ????? ???? ??? ????? ????? ???
  ???? ???? ???? ????? ???? ??? ????? ?? ?????? ???
  ??? ?????????? ?????? ?????? ??????.

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• ???? ?????? Louis Pasteu
• ????? ?????? ??????? ???? ?????? (1822-1895 ?)
  ???? ????? ??? ??????? ???????? ???? ???????? ??
  ??? ??????

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• ?? ??? ??? ?????? ??????? Anthrax ?????? ????????
  ?????? ????? Bacillus anthracis ??? 1877.
• ?- ??? ??? 1880 ??? ???????? ?????? ???? ??????
  ??????.
• ?- ?????? ?? ?????? ?????? ?? ??? ???????? ????
  ????? ???? ?????????? ??? ????? ?????? ??? ?????
  ?????.
• ?- ????? ???????? ?????? ???? ?????Rabies .

• ?- ????? ????? ???? ?????? ??? ????? ?????
  ??????? yeast ???? ????? ????? ??? ????? ???.
• ?- ?????? ?? ???????? Bacilli ???? ???? ????????
  Lactic acid ?? ?????.
• ?- ????? ????? ??????? Pasteurization ?????????
  ??? ????? ?? ????? ???????.
• ?- ????? ????? ???? ???? ???? ???? ??? ?????
  ??????? ?? Pebrine ????? ???? ????? ?????? ??
  ?????.

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• ???? ????? ??? Robert Koch
• ???? ??? ??? ??????? ??????? ?? ?? ?????? ?????
  ??? 1843-1910 ??????? ????? ???? ?? ??? ????? ???
  ???? ????? ??? ????? ????

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• ?? ??? ???????? ?????? ???? ???? Mycobacterium
  tuberculosis ???? ?? ????? ????? Koch's bacilli.
• ?- ??? ??? 1883 ????? ???????? ?????? ????
  ???????? Vibrio cholerae.
• ?- ???? ?????? ???? ?????? ???? ????? ?? ??????
  ??? Koch's Postulates ???? ???????? ?????? ?????
  ??? ????? ???

• ?- ??? ?????? ?????? ??????? ?? ?? ????? ???? ??
  ???? ????Pure culture ?????? ??? ?? ???? ?????
  ??????? ??????.
• ?- ??? ??????? ???????? ??????? ????? ???? ????
  ??????? ?????? ?? ???? ??? ????? ?????.
• ?- ?????? ?? ???? ???????? ??? ???????????
  ?????????? ?????? ?????????? ??? ??????.
• ?- ?? ??? 1881 ?????? ???????? ?? ????? ?????
  ?????????? ??? ???? ??? ??? ?????????? ?????
  ???? ?????? ????? ??? ??? ?? ???? ????? ???????
  ?????? Pure culture.

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• ??????? ?????? ?? ??? ???????? ?????????? ????
  ?? ???? ??? ?????????? ???????? ?? ?????? ?? ???
  ???? ?? ???? ????? ?? ????????? ??? ???????
• Neisseria gonorrhoeae
• Mycobacterium leprae
• Chlamydia trachomatis
• Treponema pallidum

• 1. ?? ?? ??? ???? Infectious disease ???? ??
  ???? ????????.
• 2. ???? ??? ??? ???????? ?? ????? ???? Pure
  culture.
• 3. ??? ?? ?? ??????? ??????? ???? ???????? ????
  ??? ???????.
• 4. ???? ??????? ??? ???????? ?? ????? ???????
  ??? ????.

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??????? ??????????

• ???? ??? ??????? ?????? ?????? ???? ?????
  ??????? ?????? ???? ??? ?? ???????? ??????? ????
  ?? ???? ?????? ? ?? ???? ?? ???? ?? ????? ???? ??
  ????? ?????? ??? ??? ??????.

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??????? ??????? ?????? ?????????? Molecular
Structure of Bacterial Cell

• ????? ?????? ?????????? ?? ????? ????? ?????
  ???????
• ???? ?????? The cell membrane.
• ???? ?????? The cell wall.
• ??????????? The cytoplasm.

??? 1 ????? ?????? ??????????
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???? ?????? Cell membrane???? ???? ?????
??????? ? ???? ????? ????.

• ?????? ???????????? Cytoplasmic Membrane
• ?????? ?????? Celullar Membrane
• ?????? ????????????? Protoplasmic Membrane

????????? ????? ?? ?????? ?? ?????? ?????????
Phospholipids ?? ???? ??? ?????? ????? Polar
group ???? ??????? ? ?????? ????? ?? ??????
?????? Fatty acid-side chain ??? ????? ???? ???
??????. ????? ???? ????? ???? ?????? ??? ??????
?? ?????????? ????? ??????? ??? ????????.
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??? ??? ??????????

• 1. ??????????? ???? ?????
• DAN ?? ?? ???? ??????? ??????.
• Ribosomes ??????? ???????? ?? ????? ????????.
• ????? Water.
• ?????? ??? ????? Inorganic ions.
• ????? ?????? Amino acids.
• ?????? ?????????????? (Volutin) Metachromatic
  granule ??? ??? ?????? ????? ???????? phosphate
  ? ??????

• ?????????? ??????? Transport protein ???? ????
  ??? ?????? ? ?????? ??? ????????? ??????.
• ?????????? ????????? ?? ???? ????? Energy
  metabolism.
• ?????????? ????????? ?? ????? ???? ?????? The
  cell wall.
• ?? ??? ???? ??? ???? ?????? ???? ??

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• ?????? Glucose.
• ????? Sulpher.
• ???? Lipid.
• ???????? Glycogen.

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• 2. ??????????? Mesosomes
• ???? ???? ??? ?? ????? ????????. ??? ???? ?????
  ?? DNA ?????? ??????? ??????.

• ????? ???? ??????
• ????? ?? ???? ????? ?????? ??? ?????? ? ?????
  ???????? ???.
• ??? ?? ????????? ???? ?? ?????? ??????.
• ???? ???? ?????? Osmatic barrier ????? ??? ?????
  ??????? ???????.

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• ?? ??? ???? ????? ???? ??????
• ???? ???? Very delicate organelle.
• ????? ????? ???????? ???? Highly active
  metabolically.
• ????? ????????? ?????????? Selective permeability
  ?? ??? ?????? ??? ??????????? ??????? ???????
  ??????? .

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???? ?????? Cell wall???? ?????? ???? ??? ????
?????? ??? ?????? ?????? ???

• ??? ??? ?? ????? ?? ?????????? ????? ?????
  .Mycoplasma.
• ?? ????? ??????? ????? ??? ??????????? ???.
• ???? ?????? ?????????? ????? ???????? Rigidity
  ?????? ??????.
• ???? ????? ?????? ???????? ??????? Antibiotics
  ???? ???? " ?????? ?????????? " Selective
  toxicity ??? ?? ????? ??????? ?? ????? ???
  ??????.
• ???? ?????? ?? ???????? ????? ???? ?? ??? ?????
  ????????? Hypotonic ?? ??? ???? ???? ?? ??????
  ?????? ?? ???? ?????? ??? ??????? Abnormal
  expansion.
• ???? ??????????????? Peptidoglycan ?? ?? ????? ??
  ?????? ?????? Polysaccharides ????? ??????
  ?????? Peptide bonds.
• ??? ???????? ???? ????? ?? ??????N-acetyl
  glugsamine (NAG), Acetylmuramic acid (NAM).

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????? ??? ?????? ?????? ?????????? ??????? ?
??????? ????Differences between Gram ve and
Gram -ve bacterial cell wall

• ????? ??? ?????????? ???? ???? ???? ??????????
  ??????? ???? ?? ??? ??????? ???? ???? ??????? ??
  ???? (1).

???? 1 ?????????? ???????? ??? ?????????? ?????
???? ??????????? ????? ????
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??????? ??????? ?? ???? ?????? ??????

• ????? ?????? ?????? ?????????? ???? ??
  ???????? ??????? ?????? ???????? Penicillin ????
  ?? ???????? ?????????? ?????? Lyses enzymes
  ?????? ????????? Lysosyme ????? ????? ???? ??????
  ?????????? ?? ????? ????? ???????? ?? ?????????
  ???? ?????

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• ???????????? Protoplast
• ????? ?? ???????? ????? ???? Gram ve ????
  ?????? ?????? ???? ?? ????? ?????? ???????? ??
  ?????????.

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• 2. ????????????? Spheroplast
• ????? ?? ???????? ????? ???? Gram -ve ??? ??????
  ?????? ???? ?? ????? ?????? ???????? ??
  ?????????.

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• 3. ????? L. L-Forms
• ???? ????? ?? ????? ???????? ?????? ??????
  ??????? ????? ?? ???? ???? ????? ????? ??? ????
  ?????? ???????? ?????? ????? ????? ??????? ??
  ????????? ????????.

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• ????? ????? ?????? ?????????? ????? ???? ??
  ???? ????? ???? ??????? ?????????? ??? ????? ?
  ??? ???????? ??
• ?????? The capsule
• ???? ???? ??????? ??? ?????? ???????? Slime
  layer ??? ???? ??? ????? ????? ???? ?? ??????
  ?????? ?????? ??? ???? ???? ?? ?????? ????
  ??????? ?????????? ? ?? ???? ????? ???

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• ????? ?????? The Function of capsule
• ???? ?????? ???? ?????? ?? ????? ??????
  ?????????? ?? ???????? phogocytosis ??????
  ???????? phagocytes .

• ??????? ????????? ?????? The chemical nature of
  capsule

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• ???? ?????? ???? ?????? ?? ????? ??????
  ?????????? ?? ???????? phogocytosis ??????
  ???????? phagocytes .

2.???? ?????? ?????? ?????????? ?? ????????
?????? ?????? ?????????? Bacteriophages .
3. ???? ??????? ?????? ?????????? ?? ??????.