Introduction deep into the body, causing deadly infections

Introduction to Pathogens Pathogens are microorganism like bacteria and viruses which causes infectious diseases in humans, animals or plants. Pathogens cause disease in two ways:Damaging cells: invading cells and organisms of the host and replicating on them. It is done by viruses.Producing toxins:  Living pathogen produced exotoxins, while damaged pathogens produce endotoxins. It is done by bacteria(Bbc.co.uk, 2018).Staphylococcus AureusS. aureus is a bacteria which causes infectious diseases, in order to initiate infection the pathogen must access to the host and get attached to it. It is resistant to many of the antibiotics used to treat normal Staphylococcal infections.Skin infections start as swollen, painful red bumps that may look like pimples or spider bites. The affected area could be:Warm to the touchFull of pusFeverSometimes the bacteria stays on the skin. But it can also go deep into the body, causing deadly infections in bones, surgical wounds, joints, the bloodstream, lungs and heart valves.The S. Aureus express a protein which will unite to the host. In addition, the strains present a Fibrinogen/fibrin protein which gets attach to the blood clots and traumatized tissues , this demonstrates that the Staphylococcus Aureus is a pathogen which damage the host creating and infection just like any other pathogen. Summary of virulence factors of Staphylococcus aureus.The evidence that these staphylococcal proteins are virulent bacteria (pathogen) is demonstrated in the study of defective mutants, in experimental infections and in in vitro adhesion assays. Defective mutants that bind to fibronectin and fibrinogen have reduced virulence in endocrine diseases, demonstrating that the binding of bacteria to sterile vegetations causes damage to the endothelial surface of the heart valve.Those responsible for the symptoms during S. aureus infection are caused by different types of toxins, those toxins damage the membrane.?-toxinThe ?-toxin is the most potent membrane that damages. It is expressed immediately when it binds to the membrane of susceptible cells. Those cells have specific receptors, which allows the low concentration of toxin to bind, causing small pores where ions can pass. When the concentration is higher, the toxin reacts non-specifically with the lipids of the membrane, this creates larger pores where small and divalent molecules can pass.In humans, monocytes and platelets are very sensitive to ? toxin as they have stronger intermolecular forces. Then there are series of secondary reactions that allow the release of eicosanoids and cytokines, this initiates the production of inflammatory mediators. causing the symptoms of septic shock.? toxinThe ?-toxin damage the membrane which produce sphingomyelinase lipid. Most of the human population does not express this toxin as a lysogenic bacteriophage needs to be inserted in the gene that encodes toxin.’Moreover, the majority of isolates from bovine mastitis express ?-toxin, meaning that the toxin is important in the pathogenesis of mastitis. This is supported by the fact that ?-toxin-deficient mutants have reduced virulence in a mouse model for mastitis.’?-toxin and leukocidinThe ?-toxin and the leukocidin are two components of the protein that damage the membranes. These proteins are expressed separately, but to damage the membrane they must act together. ?-toxin proteins express 3 proteins, components A and B are weak and hemolytic; on the other hand, components B and C of leukotoxin have little hemolytic activity.The Panton and Valentine (PV) leukocidin is different from the leukotoxin expressed by the ? toxin locus. This toxin has a high rate in necrotizing skin infections.(Foster, 2018)Influenza AInitially, the flu is caracterize for runny nose, sneezing and sore throat. Common signs and symptoms of the flu include:Fever over 100.4 F (38 C)Chills and sweatsHeadacheDry, persistent coughFatigue and weaknessNasal congestionSore throatThe flu is characterized by its RNA that needs to replicate in order to survive. This process is common in viruses, influenza viruses elude adaptive immune responses in many hosts, this is common in pathogens.Influenza viruses recognize N-acetylneuraminic acid (sialic acid) on the surface of the host cell. Sialic acids have nine carbons that are at the end of many glycoconjugates. After the union what is left over from the carbons of sialic acid binds to the peaks of HA on the surface of influenza viruses. Sialic acids with ?-2,3 terminal bonds are also present in the human respiratory epithelium; consequently, humans and other primates can become infected with the avian influenza virus.The result of this is firstly, the low pH causes the change to HA, the exposure to the peptide in the viral envelope against the endosomal membrane, and then the opening to which viral RNPs are released in the cytoplasm of the host cell. Second, the hydrogen ions in the endosome are pumped into the virus particle through the M2 ion channel. The M2 protein is found only in the influenza A virus. From the M2 channels, RNP are released from the viral matrix into the cell cytoplasm.Once RNPs are released, they are transported to the nucleus of the host cell by means of viral protein signals (NLS), which direct the cellular proteins to import the RNP. The nucleus is where the RNA synthesis of the influenza virus is located, both the messenger RNA (mRNA) that translates the viral proteins of the host cell and the vRNA segments that make up the genomes of the progeny virus.(Anon, 2018)The epidermis is the outermost layer of skin, which acts as a physical barrier between the body and infectious bacteria. Each cell in the epidermis is called keratinocyte. While the skin is healthy, bacteria and viruses cannot cross the barrier. But if the person has a skin wound bacteria and viruses can come in and create an infection.Defence Mechanism ExplanationSebumThe dermis is the inner layer of the skin, which contains different cells that protect it from disease. The sebaceous glands located in the dermis produce sebum, sebum is an oily substance that helps the skin retain moisture and prevent it from drying out. If the skin dries and breaks, this will allow infections to penetrate the skin.ImmunityThe skin also has Langerhans cells. These cells are very important since if an infectious bacteria invades the skin, these cells create a chemical substance that the white blood cells swell and release a chemical substance in the skin.Normal FloraMillions of healthy bacteria are called normal flora, these bacteria collapse out of the skin. They live on the outside of the skin and use dead cells and cells for their energy. These types of bacteria are not dangerous; they are considered healthy for the system