Effectiveness of antimicrobial disinfectants
Disinfectants are extensively utilized in several places including homes, schools, offices and hospitals to control infections by infectious microbes such as bacteria. For example, surface disinfectants are used daily to decontaminate various work areas, especially in hospitals to reduce the contamination of say media and samples in the laboratories. Hands, for instance, are a major cause of infection due to their nature of touching different contaminated surfaces during the day. A good disinfectant is the one that has an excellent disinfectant activity to guarantee the final result if controlling infection. Controlling microorganisms is the reduction in number or minimizing the total microbial activity load (Ziembinska, Duda, & Muc-Wierzgon, 2011).
Disinfectant concept involves approaches of microorganism control through the use of chemicals as well as their removal mechanically. The majority of bacteria die leaving a few during these activities. The vegetative forms of bacteria and other microbes are affected by chemical disinfectants even though some viruses and spores are mostly very resistant to them. Ideally, disinfection aims at interrupting the route of transmission of microbes between the source of infection and subjects that are healthy. In an integument injury situation, the most significant measure in preventing infections is to kill many microbes on the skin, wounds and other cavities in the body of a human. According to the information given by essay writing service, during the 19th century creation of many antimicrobial agents began due to steady knowledge development. It was when disinfectant agents were designed to remove microorganisms from the human body. Today, there is a wide range of antimicrobial disinfectants available in the markets and consumers need to understand their effectiveness when making their decisions to purchase them for efficiency. There are several qualities of a good disinfectant including its ability to provide an effective disinfection in a very short time, ability to affect majority of microorganism species. It should possess a broad spectrum action, have minimal harmful effects on the skin, the membranes, and wounds, not be toxic, and not have sensitization effects. There are both organic and inorganic antiseptics.
Relevance of Testable Question
The question that this experiment seeks to answer is “Which of iodized water, potassium permanganate, salicylic alcohol solution and iodine tincture chemical disinfectant preparation is the most effective?” The microorganisms’ resistance to chemical elements used in the preparations of disinfectants is increasing in a very fast rate, and it is critical to select an appropriate disinfectant that is capable of preventing bacterial infection promptly and efficiently. This experiment attempts to estimate the effectiveness of chemical disinfectant preparations namely iodized water, potassium permanganate, and salicylic alcohol solution and iodine tincture.
A1. Literature Review
Testing the efficacy of disinfectant is a component that is very important in infection control but it is largely overlooked in most cases. Since 1881, when disinfectant testing was started by Robert Koch, when he used silk threads put in liquid culture of bacteria called Bacillus anthracis, many conceptual milestones have been reached over the years and many approaches have been developed with an aim of standardizing testing conditions to get quantitative outcomes through reduction in the growth of microbes, which is the basis of the performance of a particularly tested disinfectant.
The structure of the disinfectants is the basis of their mechanisms of actions. There are those disinfectants that act by damaging the cytoplasmic membranes of microorganisms by causing changes in the lipid-protein structures, by a reduction in tension of surfaces or even through denaturation of proteins and inhibitions of secretion of enzymes because of their denaturations. Other disinfectants block an active medium such as thiol groups that react with the nucleic acids (Pendlington, Whittle, Robinson, & Howes, 2001).
Iodized water is usually 3% hydrogen peroxide, which is ordinarily used to disinfect wounds. Other than its antibacterial effect being very weak, the disinfectant is also bleaching and dehydrating. When its concentration is raised to say 30%, it irritates the tissue very strongly, and its only use is in dentistry for canal cleaning as well as hair bleaching in cosmetology. Moreover, it is non stable. On the other hand, salicylic alcohol solution is prepared by mixing salicylic acid with ethyl alcohol and water to make 2% solution. The activity against microbes such as bacteria is demonstrated by alcohols. However, the ethyl alcohol is weak antimicrobial agent even though when prepared in suitable concentrations it can be an effective bactericide against most common microbes. Ethyl alcohol denatures proteins. If a solution is made to contain 70% ethyl alcohol, it reduced the microorganisms on the skin by 90% immediately (Ziembinska & Szpindor, 2013; McDonnell, & Russell, 2015).
Iodine is known to be an essential disinfectant because it acts fat and effectively. It can kill protozoa and has germicidal, sporicidal, virucidal and fungicidal properties. Iodine does not affect the skin making it very comfortable to work with. Therefore, iodine tincture is used in disinfecting areas around the wound. Potassium permanganate easily dissolves in water to form a dark purple solution. It is known to have germicidal as well as fungicidal effects. However, high concentrations of say 0.02% irritates the tissues while low concentrations of say 0.01% are not irritating but have reduced effect and acts slowly. When using this disinfectant, many bacteria need a longer exposure time (Ziembinska & Szpindor, 2013).
A2. Experimental Design
A2a. Experimental Design Steps: Description of the Steps in the Experimental Procedure
The bacteriological material that was required for the analysis was taken from the epidermis surface of the palm. The inner part of the palm was wiped for one minute to isolate the bacteria using a sterile swab. A test tube was prepared with 9ml of sterile physiological saline where the swab was placed and the material shaken for 5minutes for the bacterial suspension to be obtained for use in the analysis. 1ml of the prepared bacterial suspension was mixed at a ratio of 1:1 (v/v) with disinfectant solutions that included 3% iodized water, 2%salicylic alcohol, 3%iodine tincture and 0.05% potassium permanganate. Each of the mixtures that resulted was inoculated on the surface of Petri dishes that had broth medium. Four repetitions were made. The bacterial suspension from the epidermis that was not mixed with any disinfectant served as the control sample for this analysis. The inoculated Petri dishes were incubated at 28.2 degrees Celsius, which is the temperature similar to that experienced by the epidermis surface of the palm for 24 hours. The numbers of bacteria colonies grown on the plates were counted after incubation in every dish.
A2b. Reasoning: Discussion of the Reasoning for Choosing this Particular Experimental Design Plan
The main reason of choosing this particular experimental design plan because it enabled the treatments (different disinfectants chosen for this study) to be imposed on the subject, which in this case was the bacterial suspension collected from the epidermal surface of the palm. The plan was also efficient in allowing the observation of the response after treatments. Through this experimental design plan, it was easy to obtain strong interpretation evidence. The independent variable for the experiment was controlled with an aim of removing any unwanted or extraneous variables. It means in this plan, the control over irrelevant variables is usually higher than in other methods r types of research. It is also easy to manipulate the independent variable to determine easily the relationship of cause and effect. Compared to other methods, this design is controlled under strict condition which yields better results. Additionally, it is possible to repeat the entire experiment to check the results gain. Since the level f control is very high, a variable is tested at a time making the results to be more relevant compared to other research forms. It is easy to see the success and failure of effects during the analysis of the collected data.
A2c. Sequence of Events: Explanation of the Sequence of Events Used to Collect Quantitative Data
In this experimental design, quantitative data collection was done through observation. The observation was structured to there was a defined purpose to the observation. First, the disinfectants were expected to act on the bacteria that were in suspensions where they were mixed differently through the reduction of their numbers. Using observational measurement required a careful definition of what was to be observed, which was the number of bacterial colonies in each of the Petri dishes with the expectation that where the disinfectant had acted, there would be a reduction in the number of colonies counted. After the decision was made to what was to be observed, a decision was next made concerning how the observations were to be made, recorded and coded. In this case, the Petri dished were removed from the incubator and each was checked by the human eye for the number of colonies on the surface. The numbers were counted manually and recorded on a table that had been prepared, which had rolls for the four repetitions that had been made for each treatment and the control.
A2d. Tools, Technologies & Measurement Units: Description of the Tools, Technologies, and Measurement Units that were Used to Collect Quantitative Data
Observation was the approach that was used to collect the quantitative data for this experiment. The data was recorded numerically as it was easy to calculate the number of bacterial colonies in each of the Petri dish after incubation.
A3. Variables: Explanation and Identification of the Dependent, Independent, and Controlled Variables for the Study
In experiments, there are factors that are likely to change, and are referred to variables. Typically, experiments have independent, dependent and controlled variables. The independent variable is the manipulated factor or element that the experimenter changes purposely during the investigation while the dependent variable is the responding element that changes in accordance with the independent variable. Moreover, the independent variable is the factor that the experimenter varies in the course of the experiment and thinks it will affect the dependent variable. In this experiment, the treatments, which are the disinfectants, are the independent variables while the numbers of colonies are the dependent variables as they depend on the type of treatment applied on a specific Petri dish. The controlled variable is the factor or element that the investigator holds constant. In this experiment, since the aim was to study the effect of each of the disinfectant, the independent variable, it was necessary to have a controlled variable that ensured that the possibility that other factors were to affect the outcome were eliminated. Therefore, this is why the experiment used the bacterial suspension that was not mixed with any of the disinfectants.
A4. Threat Reduction to Internal Validity: Explanation of What to Do to Reduce the Threats to Internal Validity
Validity is the degree with which right inferences can be made from the outcomes of research. Internal validity is the degree to which obtained results from a study are a function of the variables that were manipulated systematically, measured and observed in the experiment. Internal validity determines if there was any difference made by the independent variable. It tells whether a cause and effect relationship can be observed. In this case, the study was designed and conducted to ensure that only the independent variables determine the results. There was standardization of the conditions under which the experiment was carried out to minimize the threats of history and instrumentation to internal validity. The use of control selected similarly as the experimental sample and letting it experience the same concurrent treatment as the test sample was used to eliminate threats to internal validity (Ghosh, & Rao, 1996).
A5. Hypothesis: Coming up with the hypothesis
Experiments revolve around the hypothesis. Researchers need to make the right questions and then word their hypothesis statements correctly. First, this study started with a general hypothesis where a research problem was generated. When an individual is injured, pathogenic microorganisms can cause an infection if an appropriate disinfectant is not used. Every microorganism has a potential of causing an infection if they penetrate the wound. Therefore, it is important to disinfect the resultant injury adequately. There are many disinfectants used today, which require an investigation of their effectiveness regarding their antibacterial effect on bacterial isolates from the epidermis. The hypothesis is that different disinfectants have varying antibacterial effects. The null hypothesis for this experiment is that all disinfects acts the same, and none is more effective than the other.
Process of Data Collection: Explanation of the Process of Data Collection
The effectiveness of each of the used disinfectant in this analysis was characterized by the determination of a change in the number of bacteria that were samples before and after the application of disinfectants and then compared to the control sample where no disinfectant was applied. The plate method was used to conduct the analysis of the bacteria number.
The mixtures of the bacterial suspension and different disinfectants were incubated in Petri dishes and the colonies of bacteria per every dish were counted and recorded to allow comparison. The dishes were observed for the number of colonies in them after incubation.
Analysis was done on the effectiveness of antibacterial effect of the four chosen commonly used disinfectants, on bacterial isolates from the epidermis of the palm. The data was recorded in a table that showed the number of bacteria colonies from the palm epidermis in the sample used as control and after application of 3% oxidized water, 2% salicylic alcohol, 3% iodine tincture, and 0.05% potassium permanganate. After averages had been done of the four repetitions, a graph was made that presents average numbers of bacteria in the control sample and after application of the disinfectants.
The initial number of microorganisms in the sample studies was very high/ uncountable. When the studied disinfectants were applied, the number of the bacteria was reduced significantly in varying degrees depending on the type of the disinfectant. From the results, it is evident that iodine tincture solution is the most effective while potassium permangate is the least effective. It has the weakest germicidal effectiveness against the isolates of bacteria from the palm epidermis. The germicidal effect of iodine tincture in this experimented amunted to 100% as there was no any increase in the number of bacteria colonies demonstrated. It acts fast and used in disinfecting injuries as well as disinfecting the skin before an individual enters a sterile surgical room.
Conclusion derived from interpretation of the data
The experiment compared the germicidal effects of different disinfectants. The experiment results demonstrated that the strongest disinfected of the four that were used in this study was iodine tincture while potassium permanganate was shown to be the weakest of all. The weak germicidal effect of 2% salicylic alcohol was demonstrated and is attributed to the excessive dilution of the sample. On the other hand, the 3% solution of oxidized water was due to the fact that the experiment was conducted invitro and since catalase was lacking, the oxidized water was not decomposed quickly thereby enabling its effective action.
D1. Confirmation of Hypothesis
This study has refuted the null hypothesis and confirmed that indeed, the effectiveness f the selected disinfectant on their activity against bacteria varies significantly.
D2. Experimental Design as Key Factor in the success of the scientific inquiry
This experimental design was an essential factor in the success of the scientific inquiry as it allowed the determination of how the independent variables, the different disinfectants caused the changes in the number of bacterial colonies counted after their application. It was easy to control the threats to internal validity which made the experiment a success as it is easy to make inferences (Ghosh, & Rao, 1996).
This experiment can be replicated by another person by simply following the provided steps in the methodology and using the specified tools and methods. The replication is necessary when one needs to confirm the results.
D3a. Evaluation of Validity
In an experiment, replication is used an evaluation of validity. Result from a simple experiment cannot be accepted exclusive of questions. Replication improves the significance of an experiment. If indeed a treatment if effective, the final averaging effect of replication reflects the experimental worth. It is good to do replicates to reduce variability in the generated results by increasing their significance and confidence level, which is the bases upon which conclusions about factors of the experiments are made (Ghosh, & Rao, 1996).