Corynebacterium Diphtheria. The Answered . The Pdf

¶ … Corynebacterium diphtheria. The answered . The pdf file attached referenced. The paper written format a scientific paper a microbiology . These textbooks great sources reference: Willey, J.

Corynebacterium diphtheriae is a bacterium that is pathogenic and is the leading cause of diphtheria. Due to the resemblance in their shape and sizes, bacteria and archaea were earlier classified as one but on discovery of their metabolic and biochemical differences, it was determined that they had different evolution histories. The bacillus falls under the nonlipophilic fermentative bacteria in classification. Structurally, it possesses cell membranes formed from a combination of the hydroxyl group and fatty acids. Unlike the bacteria, the archaea has linkages that contain ether bonds (Willey, 2003). The cell wall of C.diphtheriae is made up of peptidoglycan bonds which is a great variance from that of the archaea which contains no such bonds. Another major cutting edge factor that classifies C.diphtheriae as bacteria is the RNA analysis whereby, the bacterium possesses a single RNA polymerase while the archaean possess three RNA polymerases. This difference also clearly rules out the fact and believed history that the archaea and bacteria had a similar evolution origin (Lammert, 2007).

The bacterium is best described in shape as a being rod- shaped bacteria and that it's non-motile and pleomorphic. Its size varies between 2-6 micrometers in length and its 0.5 micrometers in diameter. Though the bacillus has swollen terminus, it is non-spore forming. When stained, they are seen to form irregular shaped arrangements that are either in a club shape or differ in that they are V- shaped and it gives an impression of Chinese letters. This is due to the type of division they undergo usually snapping like. Deeper into its structure, it contains the pili which are appendages that are found on its outer surface and they are hair like in appearance and its made up of proteins that arranged in a helical form. The function of the pili is of conjugative purposes, the pili usually allow for the transfer of the genes between the pairs that are mating through the formation of a bridge between the bacteria (Kayser, 2005).

There are three types of pili, conjugative pili, the type IV pili and the fimbriae. The fimbria is also protein formed in nature with a helical arrangement. Fimbriae are exceptionally useful for attachment purposes where they are used to attach the microorganism to the host and the colonization of the organism will solely and successfully depend on the possession of the fimbriae. It contain a flagellum which is a projection from the body that is tail like and is a hollow tube of size twenty nanometers. Its main function is propulsion and by rotation from the motor through the hook, helical screw is able to propel the bacterium far from a repellent or towards an attractive body (Holmes, 2000). The bacillus is encapsulated. The organism is divided into three sections if view with close scrutiny, these are the three cultural types, mitis, intermedius, and gravis. In these divisions the areas containing tellurium or selenite colors the organism red or black, there are granules containing selenium and tellurium.

The cell wall composition of the bacterium is gram positive. When stained, the bacillus takes up the colour of the crystal violet and maintains the dark blue colour due to the high amount of peptidoglycan that maintains the stain. This is a layer of that is made up of sugar and amino acid that forms outside the plasma membrane. Unlike the Gram- positive bacteria, the gram negative bacteria upon staining cannot maintain the crystal violet stain and instead it retains the counterstain leading to a red or pink appearance. Another structural difference between the Gram positive and negative bacteria is that, there is a covalent bond between the peptidoglycan molecules in Gram negative and they have no intervening bridge while in Gram positive the individual peptidoglycan molecules with catalysis from DD-transpeptidase enzyme, are cross-linked by pentaglycine chains (Lammert, 2007).

The bacilli in study are aerobic. Through aerobic respiration, the C.diphtheriae can be able to survive in an oxygenated surrounding. During this process, oxygen is used up in the respiration and glucose which is the energy needed organism for general metabolic functions is produced. Corynebacterium diphtheriae bacteria by being a facultative anaerobe means that they in absence a section of the bacilli ferment and some use anaerobic process. Other Corynebacterium bacteria are Chemoorganotrophs meaning that they usually oxidize the chemical bonds in organic compounds from energy and attain cellular function from the carbon molecules from the organic compounds (Holmes, 2000).

Being a facultative anaerobe, the gram positive bacteria manufactures glucose in the form of ATP, through aerobic process in the presence of oxygen but in the case where there lacks oxygen, the organism they exhibits a translation that leads to its fermentative metabolism. In fermentation form of metabolism, the ATP is produced partial oxidation of the organic compound with its intermediates as acceptors and donors electrons (Willey, 2003). The ATP in question is produced by substrate level phosphorylation. The end products of the metabolism is usually lactic acid

The genome of C.diphtheriae has a single circular chromosome of 2 488-635 bp, without plasmids. This is in contrast to Corynebacterium's, Mycobacterium tuberculosis, where there is little evidence of recent horizontal DNA acquisition. Biasness is witnessed in the genome and it's much more in G+C close to the terminus origin (Kayser, 2005).

Horizontal gene transfer is a feature that is mostly demonstrated in the C.diphtheriae. It is about the transfer of viral gene into C.diphtheriae which leads to virulent strains from a non-virulent strain. This usually results in patients infected with the pathogen not exhibiting the related symptoms, but convert to a different state later (McClane, 1999). The process of genetic exchange is divided into three, which includes transformation, transduction and conjugation. In C.diphtheriae the process witnessed is Transduction. This process involves genetic exchange and is used by C.diphtheriae to disseminate diphtheria toxin gene to those C.diphtheriae that possess the gene, it's here that the organism is infected with a bacteriophage that works by integrating the toxin-encoding genetic components into the C.diphtheriae bacteria (Holmes, 2000).