1. Identification of Bacteria
depend on: 1 – Microscopic appearance :-under the compound light microscope which include a . Reaction with gram stain . b .Morphology and arrangement . c . Capsulated or not . d . Motile or not . e . Spore forming or not . 2 – Macroscopic appearance :include a . Culture appearance . b . Biochemical tests . c . Gene tests .

2. Culture Media Uses of culture media: Types of media:
common ingredient of culture media : pepton , meat extract , NaCl , agar , water .
Uses of culture media:
1-To obtain pure culture.
2-Identification and recognition of bacteria .
3-Some media use to study the bacteria.(to do biochemical tests).
Types of media:
According to
A- physical status there is : ● liquid media.
● solid media.
● semisolid media.

3. B_ use of the media: 1 . simple (basal) media : It uses for cultivation of common m.o. but not for fastidious bacteria e.g nutrient broth, nutrient agar.

4. 2.Special purpose media
A/ enriched media : e.g (blood agar ,Chocolate agar). It is simple media enriched with one of the following substance (blood, serum, glucose,…) it used to cultivate fastidious m.o. e.g. Neisseria gonorrhoeae, Haemophilus lnfluenzae.

5. B/selective media favor the growth of certain bacteria and inhibit growth of other bacteria because it contain inhibitory substance e.g: Mannitol salt agar : contain high conc. of NaCl that most bacteria cannot grow in this conc. except Staphylococcus spp.

6.   MacConky᾽s agar: contains bile salt that inhibit all kinds of bacteria except enterobacteriacea. Salmonella shigella agar (SS) is selective for Salmonella and shigella  

7. Bismuth sulfate agar is selective for Salmonella spp.

8. C/differential media It is used to recognize certain spp
C/differential media It is used to recognize certain spp . of bacteria either by :
1 -certain characteristic colonies : such as fermentation or non fermentation of lactose on MacConkey᾽s agar (these media contain neutral red as indicator which change in color during fermentation , because the gas will be produced and decrease in the pH.
left: no lactose fermentation
right: lactose fermentation

9. 2-certain effect on the media e
2-certain effect on the media e.g hemolytic or non hemolytic on blood agar Beta hemolytic β (complete hemolysis ) e.g Streptococcus pyogenes Alpha hemolytic α (incomplete hemolysis or partial hemolysis) e.g Streptococcus viridans Gamma hemolytic ϒ ( no hemolysis ) e.g Enterococcus faecalis

11. Macroscopic characteristics of the microorganism in any culture
1-Size : very small (pinhead ≤ 1mm ) Medium size =1-2 mm Large size > 2 mm 2-Shape :circular ,irregular ,radiated ,rhizoid , filamentous . 3-Elevation : flat , raised ,low convex ,convex dam , papillate . 4-Surface structure : smooth , rough ,granular ,ringed papillate . 5-Edge :entire , lobate ,cranate ,dentate,curled ,filament . 6-Color and opacity : transparent,translucent,opaque,fluorescence,metallic sheen . 7-Consistency :butyrous ,viscid ,friable ,membranous . 8-Emulsifinibility :easy or difficult ,homogenous granules, membranous .

12. 9-phenomenon : swarming (Proteus ) Medusa head (Bacillus)
Swarming of Proteus mirabilis
Medusa head of bacillus anthracis

13. 10-pigment a. exopigment :this pigment produce outside bacterial cell (in the media) e.g Pseudomonas aeruginosa produce pyocyanine (green pigment) and Pseudomonas fluorescens produce flourscine (blue pigment) Pseudomonas fluorescens
Pseudomonas aeruginosa
Pseudomonas fluorescens

14. b. endopigment : this pigment produce inside bacterial cell e
b. endopigment : this pigment produce inside bacterial cell e.g Staphylococcus aureus (golden colonies ), Staphylococcus citrus (yellow colonies) , Staphylococcus albus (white colonies )  

15. 11-odor: sweet odor (apple) such as Pseudomonas
11-odor: sweet odor (apple) such as Pseudomonas bad odor (fish) such as Proteus growth in semisolid media Gelatin test 13-haemolysis in blood

16. Methods of inoculation and isolation of pure culture Mixed bacterial population; sputum, urine, pus, infected wound, abscess, …. ect Pure culture: a single kind of m.o. growing alone in a protected environment. Bacterial colony: a mass composed of identical bacterial cells. Methods : 1- the streak plate method (e.g. Quadrant steak) 2- the pour plate method 3- the serial dilution method 4- the micromanipulater technique

18. Quadrant Streak plate method

20. The End