Title DIFFERENT METHODS OF CLASSIFICATION OF MICROBES AND STUDY OF BACTERIA, FUNGI, VIRUS, RICKETTSIAE, SPIROCHETES. (1).pdf ✅

PHARMD GURU Page 1 DIFFERENT METHODS OF CLASSIFICATION OF MICROBES:  Universally, all the organisms are classified into various groups based on the taxonomical hierarchy.  According to this all the organisms are divided in the following schematic way:  Nomenclature is the naming system in which a particular name is given to each organism that is universally accepted.  The commonly used nomenclature in the classification is a binomial nomenclature i.e. two words are used, in which the first word indicates the Genus of the organism and the second word indicates the Species of the organism.  The name should be written in Italics.  The generic name should start with capital letter and the species name should start with small letter, For example: Escherichia coil is a bacteria in which 'Escherichia' is the generic name and 'coil' is the species name. SPECIES GENUS FAMILY ORDER CLASS PHYLUM KINGDOM DOMAIN DIFFERENT METHODS OF CLASSIFICATION OF MICROBES AND STUDY OF BACTERIA, FUNGI, VIRUS, RICKETTSIAE, SPIROCHETES.
PHARMD GURU Page 2 STUDY OF BACTERIA: Bacteria are microscopic prokaryotic unicellular organisms. The size of bacteria is about 1.0 - 3.0 μm in length and 0.5 - 1.5 μm in diameter. CLASSIFICATION OF BACTERIA: ACCORDING TO SHAPES OF BACTERIA OR MORPHOLOGY:  The bacteria exist in a wide diversity of shape and sizes.  Bacterial species are either spherical shaped bacteria are called cocci (Greek: grain, seed) or rod shaped called bacilli ( Latin: Stick).  There are other shaped bacteria which are helically curved called spirilla and spirochetes, pleomorphic shaped (bacteria changes its shape according to the environment) and other shapes like pear shape, lobe, coma shape and disc shape etc., ACCORDING TO SPHERICAL SHAPE (COCCI) IS AS FOLLOWS:  Monococci (single cocci): They are also called micrococcus and represented by single, discrete round cell.  Diplacocci (two cocci): The cells remain attached to each other.  Streptococci (more than two cocci): The cells are arranged in the form of chain.
PHARMD GURU Page 3  Tetracocci: Four cocci forms are arranged in square like manner.  Staphylococci: Bunch of cocci forms are attached to one another.  Tetrad shaped: Cocci arranged in squares of 4.  Sarcina shaped: Cocci arranged in cubes of 8. CLASSIFICATION OF BACTERIA ACCORDING TO ROD SHAPE (BACILLI) IS AS FOLLOWS:  Monobacilli: Bacilli appear as single rods.  Diplobacilli: Diplobacilli appear in pairs after division.  Streptobacilli: The bacilli are arranged in chains, as the cells divide in one plane.  Coccibacilli: The bacilli shaped like coccus are short in nature.  Palisade Bacilli: The bacilli are attached at different angle and have angular patterns resulting due to bacilli bend at the points of attachment.  Mycelial or filamentous bacilli (actinomycetes): The filaments are branched, aseptate and thin. The external structure of bacteria consists of flagella, pill or fimbriae, and capsule. The flagellum is a long helical hair like structure which helps in the movement of bacteria. The flagellum is very thin with a diameter of 0.01 - 0.02μ. The arrangements of the flagella may be polar or lateral. BASED ON THE FLAGELLAR ARRANGEMENT, THE BACTERIA ARE CLASSIFIED AS:  Monotrichous bacteria: Flagella are present at one pole of the bacteria.  Lophotrichous bacteria: A cluster of flagella are present at one pole.  Amphitrichous bacteria: A cluster of flagella are present at both the poles.  Peritrichous bacteria: The flagella are present throughout the surface.  The flagellum contains three parts which are basal, hook, and filament.  The basal part is present within the cell wall which contains L-ring (made of lipo- poly-saccharide), P ring (made of peptidoglycan), S-ring (made of periplasmic space) and M-ring (made of cytoplasmic membrane).  The enzymes present in the cytoplasmic membrane provide energy to the flagella for locomotion.  The filament is made up of a protein called flagellin.