Microbiology Notes PDF

First stage Lab. 1 Microbiology st-grade Anesthesia Technology Medical Technical College Al Farahidi University Biology: The study of living organisms. Micro: Very small (Need a microscope to be seen). Microbiolo...

First stage Lab. 1 Microbiology st-grade Anesthesia Technology Medical Technical College Al Farahidi University Biology: The study of living organisms. Micro: Very small (Need a microscope to be seen). Microbiology: Is the study of very small living organisms, these organisms include Viruses, Bacteria, Algae, Fungi, and Protozoa. BRANCHES OF MICROBIOLOGY 1. Bacteriology: Study of the bacteria. 2. Mycology: Study of the fungi. 3. Virology: Study of the viruses. 4. Parasitology: Study of protozoa and parasitic worms. 5. Immunology: Study of the immunity. Classification Of Microorganism Archaea Cellular Prokaryotes Eukaryotes  ARCHAEA BACTERIA General characteristics of archaea: General characteristics of bacteria: 1. Prokaryotic. 2. Lack of peptidoglycan. 1. Unicellular organisms 2. Prokaryotic. 3. Peptidoglycan found in bacteria.  Structure of bacteria A bacterial cell includes: Capsule: A layer found in some bacteria on the outside of the cell wall. A. Protecting & Increase ability of bacteria to causes disease. Cell wall: A rigid external layer that surround the bacteria. A. Responsible for the shape of the cell & gives the bacteria protection. Plasma membrane: Found within the cell wall, This membrane is permeable, which means the substances can pass through the cell. Cytoplasm Nucleoid (Genetic region of bacteria) Ribosomes: proteins synthesis. Flagellum: It is used for movement. Pili: Structure of bacteria  Classification of Bacteria Shape Gram Stain Oxygen Demand Cocci Gram positive Aerobic Bacilli Gram negative Anaerobic Spiral Gram - (E. coli ) Gram + (S. aureus)  Gram Staining Instructions The basic principle of gram staining involves the ability of the bacterial cell wall to retain the crystal violet dye during solvent treatment. G+ve MO has higher peptidoglycan content, whereas G-ve has higher lipid content.  Culture Media Culture media: The food material or substance required for growing microorganisms in vitro (Outside the body). Composition of culture media: Water Amino acids. Glucose. Protein. Mineral salt (NaCL). Special growth factors (Vitamins, Hormone,….).  Culture Media Agar: Is a jelly-like substance consisting of polysaccharides obtained from algae. It melts at 100C and solidified at 45C.  Type of culture media Classification based on physical state (Solidity): A. Liquid media. Ex: Nutrient broth B. Semi solid media. Ex: Semisolid mannitol. Liquid media. C. Solid media. Ex: Blood agar, MacConkey Agar. Semi solid media Solid media.  Type of culture media Classification based on the Function: A. Simple media. B. Enriched media. C. Selective media. D. Differential media.  Antibiotic Antibiotics: A chemical substance produced by microorganisms or synthetically that inhibits the growth or kills other microorganisms at very low concentrations. Classification of antibiotics: Antibiotics are classified in several ways On the basis of the mechanism of action On the basis of the spectrum of activity On the basis of the mode of action  Antibiotic 1.Based on mechanism of action Inhibition of protein synthesis. Inhibition of cell wall synthesis. Inhibition of DNA & RNA synthesis. Inhibition of folic acid synthesis.  Antibiotic 2- Based on the spectrum of activity Broad-spectrum antibiotics: Are affect a wide range of bacteria. Ex: Tetracycline Narrow-spectrum antibiotics: Are active against a selected group of bacteria. Ex: Vancomycin 3-Based on the mode of action a. Bacteriostatic agent: Is a chemical agent that inhibition the growth of bacteria. Ex: Azithromycin b. Bactericidal: This is a chemical agent that kills the bacteria. Ex: gentamicin. Kirby-Bauer Test The results of this test provide an accurate the chose of which antibiotics are to be effective against the bacteria. The results are reported as S (sensitive), I (intermediate), and R (resistant) to antibiotics. A sensitive (S) result indicates the bacteria will die when it is exposed to the antibiotic. An intermediate (I) result indicates the antibiotic must be used in combination with another antibiotic to clear the infection. A resistant ( R ) result indicates the antibiotic does not kill the bacteria.  Immunity Immunity: Is the body's ability to protect against an infectious agent. Types Immune System 1- Innate 2- Adaptive (Nonspecific) (Specific) line of defense line of defense  Antigen and antibody Antigen: Is any substance that induce immune system to produce antibodies against it. Thank You