A biological indicator is a device used to monitor the sterilization process for the standard population of bacterial spores. The biological indicators indicate that all the parameters necessary for sterilization were present. They are clear filter strips impregnated with bacterial spores and subjected to sterilization methods. They are tested for remaining presence of bacteria. The absence of bacteria in the final samples validates the method and determines sterilization accuracy levels. They are usually imbedded with bacteria that tend to be challenged by the sterilization process. In simpler terms, they are impregnated with bacteria spores that are difficult to kill. This indicates that all other bacteria present were also given the same treatment.
Great care is taken to minimize the chance of false positive readings which can cause expensive re-testing. Many government agencies from the FDA (Federal Drug Administration) to the Advancement of Medical Instrumentation (AMI) set standards for these biological indicators so that the medical profession can be sure their instruments are bacteria free and therefore safe to use. They ensure users of medical tools will not cause the death of patients while performing simple procedures.
The use of heat and fire dates all the way back to 1450 B.C. in the first pages of Leviticus, where god tells Moses to wash and burn the meat of animal sacrifices. It is said that ancient Greeks, would not wear wearing dirty clothes that touched open wounds because it could cause infection. They used fumes and burning chemicals for deodorizing and disinfecting purposes. In 460 A.D. to 377 B.C. Hippocrates of Con first separated philosophy and medicine, suggesting disease was not a punishment...
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References
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Infection Control Today (2004). Steam Sterilization cycle in healthcare facilities: What to Use and When to Use it. Retrived from http://www.infectioncontroltoday.com/articles/2004/12/steam-sterilication on March 27, 2010.
Statens Serum Institut (2012). Biological Indicators for Steam Sterilization. Retrieved from http://www.ssi.dk/English/SSI%20Diagnosica/Products%20SSI% on March 27, 2012.
I identified the genus and species of an unknown bacterial culture, #16, and I applied the following knowledge of morphologic, cultural and metabolic characteristics of the unknown microorganism according to the laboratory manual as well as my class notes and power point print outs. I was given an incubated agar slant labeled #16 and a rack of different tests to either examine or perform myself; the tests are as follows: Gram Stain; Nutrient Gelatin Test; Carbohydrate Fermentation; Dextrose, Lactose and Sucrose; IMVIC tests; Citrate, Indole, Mythel-Red and Vogues Proskauer test; as well as a Urease and TSI Test.
One bacterium was gram negative. It underwent four different tests. These tests were the EMB test (Eosin Mehylene Blue), the Sulfur Indole Motility (SIM) test, the Urease test, and the Simmon’s Citrate Utilization test. The EMB test checks for a bacteria’s ability to ferment lactose. This test is accomplished by placing the bacteria on Eosin Methylene Blue agar. The agar is selective for gram negative bacteria and those bacteria that can ferment lactose will have colored growth, usually a metallic green sheen.
After the end of the experiment the unknown 10 sample was Staphylococcus epidermidis. Came to this conclusion by first beginning with a Gram Stain test. By doing this test it would be easier to determine which route to take on the man made flow chart. Gram positive and gram negative bacteria have a set of different tests to help determine the unknown bacterium. Based on the different tests that were conducted in lab during the semester it was determined that the blood agar, MSA, and catalase test are used for gram positive bacteria while Macconkey, EMB, TSI, and citrate tests are used for gram negative bacteria. The results of the gram stain test were cocci and purple. This indicated that the unknown bacteria were gram positive. The gram stain test eliminated Escherichia coli, Klebsiella pneumonia, Salmonella enterica, and Yersinia enterocolitica as choices because these bacteria are gram negative. Next a Blood Agar plate was used because in order to do a MSA or a Catalase test there needs to be a colony of the bacteria. The result of the Blood Agar plate was nonhemolytic. This indicated that there was no lysis of red blood cells. By looking at the plate there was no change in the medium. Next an MSA test was done and the results showed that there was growth but no color change. This illustrates that the unkown bacteria could tolerate high salt concentration but not ferment mannitol. The MSA plate eliminated Streptococcus pneumonia and Streptococcus pyogenes as choices since the bacteria can’t grow in high salt concentration. Staphylococcus aureus could be eliminated because not only did the unknown bacteria grow but also it didn’t change color to yellow. Lastly a Catalase test was done by taking a colony from the Blood Agar plate...
The eighteenth exercise of the laboratory manual titled Unknown Identification and Bergey’s Manual is an experiment to identify an unknown bacterium. In this exercise, a student must randomly choose a numbered bacterium available to the class. The keys in Appendix H, located on the last pages of the book, are the major helpful tools in this exercise because it provides completed steps of tests that needs to be performed in order to distinguish certain bacteria. This means that in this exercise, various types of tests and techniques must be performed to identify the chosen unknown bacterium. The unknown bacterium that I selected was number thirty-nine in which I discovered as the Bacillus megaterium after conducting several tests.
Some bacteria are harmless and are part of our normal flora. While other bacteria are capable of causing diseases or death. In order to determine what type of bacteria is present, a set of biochemical test must be performed. With biochemical testing, the ability to identify the bacterium responsible for causing illnesses or diseases. Once this is determined, other tests can be performed to discover what treatments would work best in ridding the illness causing bacteria.
To identify an unknown microorganism by performing a series of biochemical tests on a pure bacterial culture.
We observed the agar plate for colonies that had a metallic look, because these were likely E.coli colonies. We then recorded what we saw. After selecting what we believed to be an E. coli coliform colony, we inoculated a TSA slant, in addition to another lactose broth, and incubated these for another 24 hours at 37°C.
The purpose of the study was to identify what are unknown bacteria by applying all the methods that we have learn in microbiology for the identification of are unknown. We apply the different test and be able to recognize the different characteristic of are unknown. Each test has its own purpose to help identify the bacteria by the reaction.
...nvironmental Microbiology. New York: A John Wiley & Sons, Inc; 1992. pp. 125?156. Accessed December 2, 2013.
To further determine the species of the unknown bacteria, an API 20E was used. API 20E system utilized a plastic strip with 20 separate compartments with each compartment consisting of cupule or a depression and a small tube containing a specific dehydrated medium (1). The ONPG tube consisted of an ingredient that functioned as an internal indicator. The ADH, LDC, ODC and URE tubes contain phenol red as the indicator. The CIT, GLU, MAN, INO, SOR, RHA, SAC, MEL, AMY and ARA tubes contain bromthymol blue as an indicator. The GEL tube contains charcoal and the H2S tube contains iron salts as indicators. The TDA, IND and VP tubes contain no indicator. All the tubes contain buffers and all the tubes with the exception of the CIT and URE contain
When people need surgery, they go to the hospital to get help. There, special tools are used to cut open the patient. When these tools are used they must be one hundred percent clean, of bacteria or any other foreign material. This will ensure the patient doesn’t contract any foreign materials in the body. To clean the tools, they are ran through an autoclave which sterilizes the equipment. The machines use steam, heat and pressure to kill any foreign material on the tools. I’m able to help out with this process by working on the units to make sure they work properly. I inspect these units in hospitals all over Arkansas. During my inspection I look over the unit, replace parts and, and perform test runs. Let me explain my step by step process I take when I examine these machines.
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 biosafety program ensures the competency of the laboratory staff in safely performing their job through training and documentation of technical expertise. The laboratory staff must manifest professional responsibility for management of research materials complying with appropriate materials management procedures. A hallmark of biosafety practices requires laboratory access to be limited to essential personnel only when work with biological agents is in progress. Biosecurity practices on the other hand ensure that access to the laboratory facility and biological materials are limited and controlled. An inventory system must also be in place so as to control and track biological stocks or other potentially hazardous biological agents in both biosafety and biosecurity programs. For biosafety, the transfer and shipping of infectious biological materials must comply with safe packaging, containment and appropriate transport procedures, while biosecurity ensures that transfers are controlled, tracked and documented relative to the potential risks of the materials being transferred. Both programs must involve the laboratory staff in the development of practices and procedures that fulfills the requirements of biosafety and biosecurity initiatives without hindering research or clinical/diagnostic activities. The success of both of these programs is anchored on a laboratory culture