Title: Sterilization by Saturated Steam
Introduction: The sterilization process is done to completely eliminate all microorganisms that could potentially be a contaminant and lead to occurrences of hazards (Chi, 1993). Sterilization is a process defined by killing all living microorganisms, including bacteria and spores. This process can be done chemically, physically, and by means of physiochemical methods (Soper & Davies, 1990). Chemicals used in these processes to ensure all microorganisms no longer exist are known as sterilizing agents and are called chemisterilants. The result of sterilization often depends on the type of substance being sterilized and the conditions made to suitably sterilize it (Soper & Davies, 1990). The types of sterilization methods differ from the usage of saturated steam under pressure or by using heat, which can be categorized into moist and dry heat. Usage of heat is considered to be the oldest and most reliable method of sterilization. A few other ways of sterilization include ionizing radiation, filtration, and the input of gas.
Moist heat sterilization can be carried out by exposing microorganisms to saturated steam under pressure in an operating machine called the autoclave. Once the microorganisms are sealed in the autoclave, their enzymes and structural components of proteins will start changing, and the changes formed are not reversible (Yesair, 1946). As the temperature in the autoclave increases, the amount of water in the autoclave will decrease. This method of sterilization requires accurate time, temperature, and pressure measurement. Cleanliness and removal of any debris found in the autoclave machine should be removed. When initiating this method, air should be removed from the autoclave to prevent any air pockets from forming. Flash sterilization is a questionable practice that requires proper usage (Gardner, 2002). Step-by-step flash sterilization is a method that can be used to sterilize items that cannot withstand the standard autoclave process (Chobin, 2007). Physical methods of sterilization of microorganisms have been studied, and it has been found that moist heat is the most effective method (Rahn, 1945).
In conclusion, sterilization is a crucial process that ensures the complete elimination of all microorganisms that could potentially be a contaminant and lead to occurrences of hazards. The usage of saturated steam under pressure or by using heat is considered to be the oldest and most reliable method of sterilization. The autoclave is an operating machine that can be used to carry out moist heat sterilization. Accurate time, temperature, and pressure measurement are required for this method to be effective. Flash sterilization is a questionable practice that requires proper usage. Physical methods of sterilization of microorganisms have been studied, and it has been found that moist heat is the most effective method.
Comment on class result with respect to differences in filter types, differences in filter assemblies, and overall on the confidence you would have in using this type of sterilisation process in preparation of pharmaceutical products. List the factors that may cause contamination during filtration. (20 marks)
The most interesting science concept we learned was that boiling one of our methods was proven the worst for us, but is the best way out of the three for purified water. This is scientifically proven because when in process of boiling the liquid changes state of matter, leaving behind the bacteria and the water evaporating leaving all unnecessary weight needed, also because most heat kills the bacteria. Ultra violet light on the other hand only kills the microbes, nothing else. The ultra violet light is not very effective because it leaves the remains of the bacteria in the water.
Coli. Each culture was grown in an M9 medium. One culture utilized glucose as a carbon source, while the other utilized succinate as a carbon source. Two other treatments of E. Coli were also tested, one without succinate and one without glucose. These two treatments were added as a baseline to compare how much succinate and how much glucose actually helped the E. coli grow. The two treatments were covered with parafilm and for the purposes of this experiment, will be called blanks. These cultures remained within their assigned group all day to measure the growth of E. Coli. The following process was repeated by all groups throughout the day. A cuvette was labeled with the sample that was being tested. The writing was at the top of the cuvette to prevent light from being disturbed and affecting results. 3 mL of the tested sample were placed in a flask using a sterilized 1 mL pipet. The spectrophotometer was then rezeroed with the corresponding blank inside. This was so that only growth would be measured. After recording measurements the flasks were returned to the incubator and the pipets were disposed of in a red biohazard bag. The contents of the cuvette were poured into 50% bleach to kill any E. coli. The cuvette was rinsed with distilled water. This process was repeated every 30 minutes over the course of eight and a half hours. Measurements at 12:00, 12:30, and 15:30 were missed due
Kapper, J.B. Nataro, J.P. & Mobley, H.L.T. 2004, "PATHOGENIC ESCHERICHIA COLI", Nature Reviews, vol. 2, pp. 123-140.
Newsom, S.W.B, “Pioneers in infection control-Joseph Lister.” Journal of Hospital Infection 55, (2003): 246-253, accessed March 7, 2014, http://www.sciencedirect.com.ezproxy.gsu.edu/science/article/pii/S0195670103003049?
Germany and the Nazi doctors were not the first country to sterilize. “It led to the sterilization of more than 200,000 Germans” (Gotz). In another article it says, “Between 1907 and 1939, more than 30,000 people in twenty-nine states were sterilized, many of them unknowingly or against their will, while they were incarcerated in prisons or institutions for the mentally ill” (“Nazi Medical Experiment.”). Sterilization was a normal occurrence in the early 1900s. The sterilization process performed by the doctors was also thought as Charles Darwin’s theory of natural selection brought to life. There were two common methods of sterilization, X-rays and injections. The X-ray method was frequently linked to Dr. Horst Schumann from the Auschwitz concentration camp. In this process the ovaries and testicles were exposed to radiation two to three times a week. This procedure caused serious burning and swelling. This approach did not work as well as castration. (Gotz). Although it was not very effective, the practice was still continued. (Gotz). The injection sterilizations consisted of a phenol injection, which usually killed the subject. After the patient died the bodies were autopsied. If the patient refused the injection they were placed in a gas chamber to await their death. (Gotz). Men were also guinea pigs in the methods of sterilization. Their private parts would be exposed to x-rays and then their parts would be removed two weeks later. The men also did not have to give any consent to have the procedure performed (Korda 34). The practice of sterilization was inhumane and
Molinari, J., & Hart, J. (2010). How to Choose and Use Environmental Surface Disinfectants. Cottone's Practical Infection Control in Dentistry (Third Edition ed., pp. 185- 193). Philadelphia: Wolters Kumar Lippincott Williams & Wilkins.
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The main goal of sterilization was to discover a rapid, inexpensive, and unobtrusive method to wipe out Russians, Poles, Jews, and other races (Berenbaum, 347). Nazis hoped to sterilize millions with minimum time and effort (Pbs.org, 5). Even though a method already existed, surgical sterilization, doctors thought it was too slow and expensive. These experiments occurred in camps such as Auschwitz and Ravensbruck (Berenbaum, 247). There were mainly two doctors known for sterilization, Gebhardt and Clauberg. Gebhardt worked at Ravensbruck by the surgical method. The method Clauberg used was by an injection. Dr. Karl Clauberg conducted it on a large scale (Berenbaum, 348). He was the main man for sterilization (Lifton, 271). Although the doctors knew how they wanted to sterilize, a formula had to be developed. Since Dr. Clauberg was the head of these experiments, he developed his own formula, but he was very secretive about the substances he used. Researchers today assume he used formalin and novocain (Lifton, 271-272). Formalin is a clear watery solution of methanol used as a preservative. Novocain, also known as procaine, is a local anesthetic drug used as a sodium channel blocker. This impairs the conduction of sodium ions. This injection was done in three stages over a few months. Unfortunately, Clauberg used over 300 women over the course of his work (Lifton, 272). Not just women had to face the horrors
Leboffe, M. J., & Pierce, B. E. (2010). Microbiology: Laboratory Theory and Application, Third Edition 3rd Edition (3rd Ed.). Morton Publishing
Biological monitoring is basically evaluating a sterilization process by rendering highly resistant bacterial spores biologically inert. The highly resistant bacterial spores used varies depending on what kind of sterilizer was used. For example Bacillus stearothermophilus spores for steam and chemical vapor sterilizers, Bacillus subtilis spores for dry heat and ethylene oxide sterilizers. These specific Bacillus spores are used because they are more resistant, and present in greater numbers than are the common microbial contaminants found on patient care equipment. If it is proven that these spores have been killed, it is strongly implied that other potential pathogens in the load have also been killed.
The duration of the experiment should be increased as the thermal death times of B. subtilis at 60, 70 and 80°C were unable to be determined within 110 minutes. The duration can be increased to 180 minutes so as to better investigate its thermal death times. If the presence of bacterial growth was still observed after 180 minutes of exposure, it can be assumed that B. subtilis is able to survive well in that temperature. An exposure time of one day can be carried out to confirm this assumption.
Where used cleaning cloths, pot scrubs etc. shall be cleaned and sanitised or they shall be disposed of after use in order to ensure that they are not a source of contamination. (Unsure)
Water plays such an important role in our daily lives. 70% of our body is composed of water. 70% of the earth surface is also made up of water, but out of the 70%, only 1/3 of water is consumable. In fact, this amount has been continuously to decrease as more and more industries began to pollute and damage the water. For example, many toxic chemicals may be released into the water thus making the water impure. Such pollutions and damages lead the water to be contaminated and inconsumable as it may cause severe diseases. Water purification can remove all the unnecessary bacteria and viruses from the water that is hazardous for our health. Water purification may also improve the flavor and appearance of water. It removes the unpleasant odor. Therefore, water purification became one of the most useful and popular process used by people all over the world today. It is by far the most recommended and safest water treatment that is commonly used to purify damaged water into consumable water. Water purification provides us with safe, pure and clean water to consume and use.