Effects of bottlebrush on quorum-sensing activities of Curvibacter - Introduction (Thesis Sample)

Effects of bottlebrush on quorum-sensing activities of Curvibacter 1.0. INTRODUCTION As the re-emergence of many new diseases comes to light in our generation, we can say that organisms that brought these diseases have learned to adapt to the various methods developed to keep them at bay. Antibiotics were hugely popular as a cure and prevention module around the 20th century, but by overuse and abuse, the bacteria these medications control learn to survive and continue reproduction even with the presence of antibiotics. This marks the possible emergence of a "post-antibiotic" era, where microorganisms are more resistant to antibiotics (Geddes, 2000). Microorganisms able to adapt to the environment will be the precursors to genetic modification. Adaptation to the environment is a possible reason for genetic modification. Since these modifications happen spontaneously when environmental conditions deviate from normal conditions, microorganisms tend to develop enhanced resistance as generations advance (Ramos et al., 1997). The genetic consequences of this phenomenon include mutagenesis, which may either be productive or destructive. Productive outcomes are the discoveries of novel drugs used to cure, prevent, or manage diseases while destructive outcomes might be in form of antibiotic drug resistance, increased pathogenicity, and further mutation of the already unfavorable genes into more undesirable ones. Quorum sensing is an organizational mechanism where microorganisms communicate with each other. It is started when chemical signals are emitted/produced/released when critical conditions arise (Miller and Bassler, 2001). Quorum sensing contributes significantly to bacterial cell-to-cell communication which allows them to form biofilms (McLean et al., 1997), exhibit bioluminescence (Nealson, 1977) and swarming (Eberl et al., 1996). Biofilm formation has proved to be a problematic event in the environment and the field of medicine. (Costerton, et al., 1995). In bacteria, signaling chemicals like an autoinducing peptide (AIP) in Gram-positive bacteria or an N-acyl-homoserine lactone (AHL) in Gram-negative bacteria (Fuqua et al., 2001) initiate quorum sensing (Asfahl and Schuster, 2017). The higher the population of the communicating bacteria, the stronger the concentration of the signaling chemicals (Biswas and Lokur, 2017). This contributes to the higher pathogenicity of the quorum and, thus the greater need for a stronger anti-quorum sensing effect (Al-Haidari, 2016). Previous studies using medicinal plants as substrates for quorum sensing inhibition proved that extracts used could indeed be used to disrupt cell-to-cell communication among bacteria. According to Lewis and Ausubel (2006), phytochemicals have been emerging as accessible and "healthier" alternatives to many types of medications. These are released by plants primarily as defense mechanisms against disease and predators (2006). Due to being highly linked to the terms "organic", "herbal", and "chemical-free", these phytochemicals have been associated with good human health and longevity. Public acceptance is a great way to open possibilities for substrates. By being considered "unprocessed" or "natural", people are more susceptible to influence for taking these kinds of medicinal plants; thus, the continued research for varying effects including antimicrobial effects. A study using vanilla bean extracts at 75% v/v and aqueous methanol inhibits quorum sensing activities of a Gram-negative rod-shaped bacterium that causes Urinary Tract Infections in humans. (Choo, et al., 2005). This shows that the anti-quorum sensing effect of plants also leads to antibacterial actions by the plant extracts. This suggests that taking the extract of a plant studied to have quorum sensing inhibitory effects on microorganisms can be a method of prevention of a disease caused by a specific organism (Bouyahya et al., 2017) thus; herbal supplements may be taken to prevent illnesses brought about by organized masses of bacteria.   1.1. STATEMENT OF THE PROBLEM            The quest for methods of preventing cell-to-cell communication and disrupting quorums of organized bacterial masses has been long, and many resources have been spent to deflate the rate of bacterial pathogenicity. Human diseases include bacterial activity-induced illnesses to genetic defects from the exposure to chemicals produced by bacterial invaders.         Our immune system, while efficient, cannot screen all possible threats to human health because sometimes, bacteria may not be harmful when present in small amounts. However, when critical conditions occur, these microorganisms communicate to form a bacterial mass, which then increases the concentrations of the chemical signals they release and use to communicate with each other. This, however, might cause problems for the host who does not fare well with the presence of these chemicals. When these events happen, antibiotics are prescribed and taken to kill all the microorganisms present in the human body. With the growing accessibility of antibiotic medications from a few years back, people have been self-medicating, thinking that antibiotics or cocktails of antibiotics can resolve various illnesses (Jain et al., 2011). However, this practice opened the gate to antibiotic abuse, which led to the mutation of microorganisms being controlled. These mutations led to the tolerance of many strains of bacteria to various antibiotics, cleaners, antibacterial solvents, and chemical agents used to control them. The bacterial predominance in the human microbiome is good since there are bacteria that benefit the human body like lactic acid bacteria or LABs which are found in the human gut and aid indigestion. The researcher aims to provide an answer to the following questions: 1.) How can the leaf extracts of Callistemon viminalis (bottlebrush) inhibit the quorum-sensing activity of Curvibacter species? 2.) Are there other ways to weaken the bacterial pathogenicity of Curvibacter spp. against its host? 3.) What other applications can Callistemon viminalis leaf extracts be used? 1.2. HYPOTHESIS  This study aims to prove the existence of the anti-quorum sensing effects of Callistemon viminalis (bottlebrush) leaf extract against Curvibcater species, a known bacterial invader of the metazoan Hydra spp. and is commonly found in places with stagnant water, for example, well water. The study will be conducted in vitro for the leaf extracts to be used cannot be easily found in nature because purification and extraction methods will have to be done to process the specimen leaves. It is assumed that this study will include only factors that can be controlled in the laboratory (e.g. temperature, humidity, nutrition level, concentration of extract, and other external and internal factors that may be considered).            This study will provide precursors for studying the possible genetic implications of an anti-quorum sensing substrate to various bacteria known to invade hosts and the data gathered might be used to determine which medicinal plants might be the best to use against strengthened bacterial pathogenicity brought about by stronger quorum sensing activities of microorganism concerned. The assumptions in this study are: 1.) Callistemon viminalis (bottle brush) leaf extracts will inhibit quorum sensing in Curvibacter species; 2.) After performing assays in vitro to support experimentation on the subjects, varying levels of treatment will provide differing results; 3.) Inhibition zones against species of Curvibacter will be present after using varying concentrations of bottlebrush leaf extract; 4.) Reported and analyzed data from experiments will provide an adequate conclusion; and 5.) Results will help reinforce current facts and provide timely updates to published studies. 1.3. SIGNIFICANCE OF THE STUDY            This study will benefit the academe through the provision of support to further pursuits for the betterment of life. It will become an addition to the tantamount knowledge we currently have and possible solutions to existing problems may be provided by the outcomes of this proposed study. The determination of the anti-quorum sensing effects of plants on bacteria will motivate many new scientific efforts to combat antibiotic resistance, which is a big problem nowadays. Hence, this study will also benefit the field of medicine and pharmaceuticals. Several studies present that medicinal plants contribute to some genetic changes in the bacteria themselves, proving that genetic mutation in these bacteria gives them advantages over our methods of eradicating them. Bacterial pathogenesis and its growing strength is a threat to human health and defining the limit of cell-to-cell communication of sickness-causing bacteria will give us a significant ...