Microbiota Research Paper

Decent Essays
Microbiota are microscopic organisms such as viruses, bacteria, archaea, and eukaryotes that influence human health through a commensal interaction. Location of microbiota can be internal or external such as the gut, mouth, placenta, skin, and vagina. These microbes are classified into four major phyla: Firmicutes, Bacteriodetes, Actinobacteria, and Proteobacteria. Microorganisms in the Firmicute phylum are typically Gram positive bacteria, either rod-shaped or spherical and function as obligate or facultative anaerobes. Firmicutes are predominately found in the vagina. Microorganisms under the phylum Bacteriodetes are typically Gram negative bacteria and are strictly anaerobes. These are mainly found in the gut microbiome including 100 trillion …show more content…
The goblet cells of the intestinal epithelium secrete layers of mucus that prevent microbiota from contacting the epithelium too closely. The outer layer of mucus houses a large concentration of microbes whereas the inner mucus layer cannot be penetrated. However, because of the huge diversity and quantity of gut microbiota there is moments when the inner mucous is breached. The bacteria that have migrated into the inner mucus layer is recognized by innate immune cells termed dendritic cells. Dendritic cells contain pattern recognition receptors (PRRs) such as Toll-like receptors (TLRs) that recognize microbial associated molecular patterns (MAMPs). Both pathogen and commensal microbiota contain MAMPs such as peptidoglycans, lipopolysaccharides and flagella. Activation of TLRs sets off a signalling cascade of nuclear factor-kappa B (NF-kB) to initiates the production of cytokines that results in an inflammatory response (20). Dendritic cell also sample bacterium and transfers it to the mesenteric lymph nodes through the lymphatics of the intestine. Once the activated dendritic cell reaches the Peyer’s patches they interact with B-cells to produce Immunoglobulin A (IgA). IgA producing B-cells are brought back to the lamina propria of the intestinal epithelial where they differentiate into IgA plasma cells. These plasma cells secrete dimerized IgA from the Lamina propria to the inner mucous layer where they interact with the antigens present on bacteria, neutralizing and preventing their invasion into the epithelium. Bacteria that have crossed the epithelial cells into the Lamina propria can also be phagocytosed by macrophages that contain PRRs. Finally, the immune system also responds by secreting antimicrobial α-defensin protein and the antimicrobial lectin RegIII훾. It has been noted that α-defensin can alter microbial composition whereas RegIII훾’s function is to monitor

Related Documents

  • Decent Essays

    Pathogenic Bacteria

    • 1075 Words
    • 4 Pages

    SIgA covers the mucus membrane, and it is part of the primary defenses. SIgA acts as an opsonizing factor that binds to any non-self-antigens like bacterial antigens to stimulate the immune system (Geme et al., 1994). Haemophilus influenzae type B is a good illustration of a unique subversion mechanism for sIgA. Haemophilus subverts these antibodies by releasing proteolytic degrading enzyme, which destroys sIgA (Geme et al., 1994). Thus, the former examples demonstrate some pathogens’ approach to circumvent the primary…

    • 1075 Words
    • 4 Pages
    Decent Essays
  • Decent Essays

    Bacterial Biofilms

    • 1030 Words
    • 4 Pages

    The bacteria secrete an extracellular slimy substance comprised of proteins, polysaccharides, and nucleic acids to build the protective matrix biofilm structure. The bacteria now communicate by means of quorum sensing and use inducers to regulate gene expression within the bacterium. Quorum sensing is a bacterial mechanism entailed by consistent production and secretion of signaling molecules called inducers that creates a constant stimuli and response system that promotes biofilm formation. The biofilm grows by means of cell division and recruitment. The development of this complex biofilm makes the community of bacteria resistant the host’s immune response and to antibiotic…

    • 1030 Words
    • 4 Pages
    Decent Essays
  • Decent Essays

    Another mechanism used by the microbe involves binding of immune regulators produced by the host through the production of surface-bound molecules [5, 6]. Host cells produce Antimicrobial Peptides (AMPs) that help in exert cytotoxic activity on microorganisms. The capacity of S. aureus to counteract the activity of the AMPs is another mechanism that enables it to evade the immune system. The microbe has the ability to inhibit the cytotoxic effect through the alteration of the AMP by production of staphylokinase [4]. Neutrophil-mediated processes and phagocytosis are crucial in the host innate immune system.…

    • 378 Words
    • 2 Pages
    Decent Essays
  • Decent Essays

    Mannitol Salt Agar

    • 1936 Words
    • 8 Pages

    As explained by our textbook, “the chemical composition of the cell wall helps to differentiate major types of bacteria” (Tortora, Funke, and Case 84). The two main types of bacteria are gram positive and gram negative. Their cell walls are composed of peptidoglycan. The peptidoglycan is a chain of repeating disaccharide held together by polypeptides. The disaccharide…

    • 1936 Words
    • 8 Pages
    Decent Essays
  • Decent Essays

    Rosacea Infection

    • 1220 Words
    • 5 Pages

    Sometimes, an infection can be diagnosed solely by the patient’s signs and symptoms. We can also use Gram stain reaction and acid-fast reaction. Electron microscopy can also be used to identify whether the pathogen contains cell wall, flagella, or fimbriae. Then, we will use biochemical tests to examine the pathogen’s peptide composition of the cell wall, makeup of the membrane and lipids. A dichotomous key can allow us to organize and trace a route to eliminating various characteristics that the microbe does or does not contain to identify the correct microorganism.…

    • 1220 Words
    • 5 Pages
    Decent Essays
  • Decent Essays

    Microbiome Research Paper

    • 1601 Words
    • 6 Pages

    Moreover, there is evidence indicating that the bacterial culture in the intestine may be affected by the host major histocompatibility complex genes (they are specific genes of cells which work to control the immune system of the body). Recent findings have recommended that the microbial products can lead to the generation of pro-inflammatory molecules which affect the…

    • 1601 Words
    • 6 Pages
    Decent Essays
  • Decent Essays

    Metal Resistance Essay

    • 1630 Words
    • 7 Pages

    In Gram negative bacteria cadmium is targeted on DsbA gene in the periplasm. DsbA gene is responsible for the formation of disulfide. Cadmium resistance in some gram-positive bacteria was also found to be mediated by CadA-like proteins (Liu et al., 1997). In S. cerevisiae, cadmium is bound by glutathione, and the resulting cadmium-bis-glutathione to complex is transported by an ABC transporter the YCF1p transporter, into the vacuole (Li et al., 1996; Li et al., 1997). This may be a general principle in all eukaryotes.…

    • 1630 Words
    • 7 Pages
    Decent Essays
  • Decent Essays

    Innate Immune System

    • 1627 Words
    • 7 Pages

    The first signal is implemented by microbial molecules and cytokines that that bind to TLR receptor and induces the up-regulation the transcription of nuclear factor κB, which will synthesis NLRP3, pro-IL-1β and pro-IL-18. Common priming signals for immune cells of the body and human RPE cells are LPS, tumor necrosis factor-α (TNF-α), nitric oxide, and IL-1α. Once the NLRP3 is activated, it recruits ASC and mediates the proximity-induced procaspase-1 autoactivation. The assembled NLRP3 inflammasome then turns itself into a cytokine processing platform by cleaving pro-IL-1β and pro-IL-18 into mature cytokines and releasing them into extracellular space for downstream…

    • 1627 Words
    • 7 Pages
    Decent Essays
  • Decent Essays

    The first is known as the humoral response where antibodies are responsible for the defeat of the pathogen. It begins when a macrophage engulfs a cell with an antigen on its surface. The macrophage then has MHC II on its surface which bind to an inactive helper T cell. The helper T cell can then recognize whether the engulfed cell is foreign or not. Once it realized there is a foreign body the T cell begins changing and begins creating more helper T cells.…

    • 1693 Words
    • 7 Pages
    Decent Essays
  • Decent Essays

    Francisella Tularensis

    • 1621 Words
    • 7 Pages

    Francisella tularensis is an important microbial agent which causes the severe infection of tularemia. The intracellular life cycle of this bacterium is supported by a vast range of protective guards such as enzymes. Although several enzymes are recognized in different subspecies of the bacterium, acid phosphatase and superoxide dismutase are seen in all bacterial subspecies. On the other hand, the most important enzymatic system relating to host cells is NADPH oxidase. For this reason, the clear aim of this mini-review is to discuss about the intracellular life cycle of Francisella tularensis and important enzymatic machineries in association to bacterium and its host cells.…

    • 1621 Words
    • 7 Pages
    Decent Essays