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fundamentalprinciplesofmicrobiology-210520075846.pptx
- 1. Lecture No. 01 M FUNDA ENTAL PRINCIPLES OF MICROBIOLOGY FUNDAMENTAL PRINCIPLES OF MICROBIOLOGY
- 2. 1 DEFINITION OF MICROIOLOGY 2 3 4 DEFINITION OF MICROORGANISM CLASSIFICATION OF MICROORGANISM STRUCTURE OF BACTERIA & VIRUS 5 6 7 ISOLATION OF PURE CULTURE STAINING OF BACTERIA TYPES OF STAINING
- 3. DEFINITION OF MICROBIOLOGY The word Microbiology is derived from- Micros Small Bios Life Logos To study or science Microbiology is the branch of science deals with the study of living micro-organisms. Eg., Bacterial, Virus, Fungi etc. The study includes structure, function, reproduction and multiplication of micro-organisms.
- 4. DEFINITION OF MICRO-ORGANISMS These are the small groups of living organisms which can not be seen by naked eyes and studied under microscope. Eg., Bacteria like streptococcal, pneumococcal, salmonella typhi. Virus like DNA or RNA virus, HIV.
- 6. BACTERIA These are the member of a large group of unicellular (Prokaryotic) microorganisms which have cell wall but lack of cell organelle like Golgi apparatus, Mitochondria etc. Size: - 1 5 micron. Shape: - Cocci, Spherical, Rod-shaped, Spiral, Thread shaped..
- 7. VIRUS These are non cellular, ultramicroscopic highly infectious agent and posses only one type of nucleic acid either DNA or RNA surrounded by protein (protective) coat called, Capsid. Size- 0.02 to 0.2 micron. Shape As in image
- 8. Difference between Bacteria & Virus
- 9. Isolation of Pure Culture Growth of microbes on laboratory medium is known as Culture. A culture which may contains only one species of microbe is called a pure culture and one which consist of several species is called mixed culture. It is very difficult to obtain pure culture of bacterias in nature because they exist as mixed culture. To obtain organisms in pure culture various techniques are used- 1. Streak plate method 2. Pour plate method 3. Spread plate method 4. Micromanipulator 5. Roll tube method
- 10. Staining Methods Stains are the organic dyes used for staining the micro-organisms. For ex, Crystal violet, methylene blue, safranin etc. Purpose of Staining: - 1. For greater visualization of cells. 2. For study of their structures. 3. To differentiate the cells. 4. To inhibit the growth of some organism so the others can be visualized.
- 11. Types of Staining Simple Staining Differential Staining Grams Staining Acid Fast Staining
- 12. Simple Staining It is also called as Monochrome technique. In this method only one stain is used. It used to study morphology i.e. size, shape and arrangement of microbes. Prepare a smear and fixed on slide Add stain for 30 sec to 3 min using methylene blue Wash with cool water Air dry and examine under oil immersion lens
- 13. Differential Staining Grams Staining: - A differential staining technique used to classify bacteria i.e. gram positive or gram negative and their specific structure. Gram staining was discovered by a Danish Physician Hans Christian Gram while working in Berlin in 1883 and later procedure published in 1884. Hence, it is called Grams staining. Requirements: - Staining reagents like 1. Crystal violet- Primary Stain 2. Grams Iodine- Mordant - fixative agent 3. Acetone 95% or Alcohol- Decolorizer 4. Saffranine / dilute carbol fuchsin counter stain
- 14. Grams Staining Crystal Violet: - All bacteria takes crystal violet so all are appears violet colour. Iodine: - Crystal violet-iodine (CV-I) complex is formed. Acetone: - Bacteria with high lipid content loose CV-I complex and appears colourless but bacteria with less lipid content retains CV-I complex and appears violet. Saffranine: - Only colourless bacteria takes saffranine and appears pink
- 15. Procedure
- 16. Observation If the bacteria shows violet or Gram purple then indicates Positive. Eg., E. Coli, Pneumococci If the bacteria shows pink or red then indicates Gram Negative. Eg., S. typhi, H. Influenzae
- 17. Acid fast staining technique This technique was discovered by the scientist Zeihl & Neelson, This technique is used to identify all the separation of Mycobacterium Group members from the others. It means it is used to identify the acid-fast micro-organism like Mycobacterium tuberculosis, Mycobacterium Leprae etc. Acid fast microorganism are characterized by wax like nearly impermeable cell walls means they contain mycolic acid and large amount of fatty acids, waxes and complex lipids. Acid-fast organisms are highly resistant to disinfectants because of the cell wall is so resistant to most compounds. Acid-fast microorganism required a special staining technique i.e. called Acid-fast staining method.
- 18. Acid fast staining technique For 10 Sec For 30 Sec Or Malachite green 20% Sulphuric Acid for 1 min.
- 19. Observation Those bacterias appears pinkish red are Acid-fast bacteria Those bacterias appears blue or green are Non-Acid fast bacteria
- 21. Virus Structure 1. Enveloped Icosahedral 2. Enveloped pliable helix