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Identification of bacteria in microbiology
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Recommended: Identification of bacteria in microbiology
INTRODUCTION
The purpose of this investigation was to identify an unknown bacterium. “At any time there are millions of bacteria living around, on, or inside us” (The Plague). Bacterium can’t be identified by merely looking at it. Many bacteria have the similar appearances in growth. “In most cases, detection is based on the reaction of an enzyme with a certain substrate” (Sigma-Aldrich). Identification is usually based on the results of the bacterium’s cells metabolic capacities.
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.
During the investigation, seven test were used to determine the unknown bacterium as Salmonella typhimurium. “Salmonella typhimurium is a genus of gram-negative, non-lactose fermenting, medium-sized, rod-shaped, bacteria, members of the family Enterobacteriaceae, most species having flagella and pili” (medical-dictionary). This bacterium is known for causing food poisoning. This illnesses usually last 4-7 days. Treatments for the illnesses caused by this bacterium are dependent upon the severity of the symptoms, the age of the patient, and the comorbidities.
MATERIALS AND METHODS
During this investigation to identify the unknown bacterium, seven different biochemical tests were performed. All biochemical tests were performed according to the Eastfield Microbiology Lab Manual. As with...
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...alth issues, the symptoms may be more severe.
REFERENCES
Eastfield College Microbiology Lab. (2013). [Comparison Chart of Biochemical Test Results]. Unpublished raw data.
Eastfield College Microbiology Laboratory Manual, 1st edition, Oliver, T. D. (Book Must Be Purchased New from Eastfield Bookstore and Cannot Be Sold Back to Bookstore at the End of the Semester), Kendall Hunt Publishing, 2013, Dubuque, IA. ISBN 9781465223784.
Microbiology with Diseases by Body System (Hardcover) & MasteringMicrobiology, 3rd edition, Bauman, R. W., Benjamin- Cummings Publishing Company, 2012, San Francisco, CA. ISBN 9780321716378. OR
Cefrey, Holly. The Plague. New York: Rosen, 2001. Print. http://www.sigmaaldrich.com/analytical-chromatography/microbiology/identification-tests/reagents.html 2013
“Welcome to Microbugz.” Welcome to Microbugz. Linda Beaver and Mary Rutter, web. 2000
The isolate possesses some enzymes required for hydrolytic reactions. Hydrolytic enzymes found to be secreted from the bacterium, are -amylase, casein, and PYRase. In the starch hydrolysis and casein tests, there was a zone of clearing around the bacterium, which was indicative of the secreted enzymes necessary to break down starch and casein. In the PYR test, the presence of PYRase was detected by a color change to red on the PYR disc after the addition of the PYR reagent (p-dimethylaminocinnamaldehyde). Hydrolytic enzymes for which the EI tested negative were urease, gelatinase, and DNAse. In the Urea Hydrolysis test, it was observed that the urea broth did not have a color change, indicating that there was no urease secreted to break down urea in the broth. Similarly, there was no gelatinase present to break down gelatin in the Gelatin Hydrolysis test, so the nutrient gelatin remained solid. It was concluded that the EI does not possess DNase because there was no clearing zone around the bacteria, indicating that DNA had not been
After 5 days of growth each slant was tested using the gram staining technique to confirm the complete isolation of the bacteria. Both isolations were completely successful. Then each sample of bacteria was subjected to a series of tests for identification.
Streak plate technique was used to isolate pure culture for each bacteria (2). The Gram stain was used to determine Gram reaction and morphology of each bacteria (2) Selective and differential media such as, salt agar, MacConkey agar and blood agar were used for bacterial identification (2). Gelatin deeps were inoculated to detect production of gelatinase (2). Starch Agar plate were inoculated to detect amylase (2). Ocular reticle used to determine bacteria size (2). Motility deeps were inoculated to detect motility on bacteria (2). Thioglycollate broth used to determine oxygen requirements (2). Carbohydrate fermentation
The purpose of this study is to identify an unknown bacterium from a mixed culture, by conducting different biochemical tests. Bacteria are an integral part of our ecosystem. They can be found anywhere and identifying them becomes crucial to understanding their characteristics and their effects on other living things, especially humans. Biochemical testing helps us identify the microorganism present with great accuracy. The tests used in this experiment are rudimentary but are fundamental starting points for tests used in medical labs and helps students attain a better understanding of how tests are conducted in a real lab setting. The first step in this process is to use gram-staining technique to narrow down the unknown bacteria into one of the two big domains; gram-negative and gram-positive. Once the gram type is identified, biochemical tests are conducted to narrow down the specific bacterial species. These biochemical tests are process of elimination that relies on the bacteria’s ability to breakdown certain kinds of food sources, their respiratory abilities and other biochemical conditions found in nature.
Diagnosis of salmonellosis involves testing a sample of stool, as well as isolation from samples of tissue, blood, or urine. Since it is commonly mistaken for the flu and involves similar symptoms to other illnesses, the method of diagnosis for salmonellosis is pretty hard to come by. Most people with salmonellosis don’t seek treatment, so they’re never aware that they even had it. Since it is a foodborne pathogen, has a common route of infection via oral ingestion, and is found in food products that we consume on a daily
The purpose of this laboratory is to learn about cultural, morphological, and biochemical characteristics that are used in identifying bacterial isolates. Besides identifying the unknown culture, students also gain an understanding of the process of identification and the techniques and theory behind the process. Experiments such as gram stain, negative stain, endospore and other important tests in identifying unknown bacteria are performed. Various chemical tests were done and the results were carefully determined to identify the unknown bacteria. First session of lab started of by the selection of an unknown bacterium then inoculations of 2 tryptic soy gar (TSA) slants, 1 nutrient broth (TSB), 1 nutrient gelatin deep, 1 motility
If the oxidase test was to be negative then the bacteria would have to be S. flexnery. S. flexneri is a bacterium that causes diarrheal disease, and it’s a “facultative anaerobe belonging to the family Enterobacteriaceae” (“Shigella flexneri”, n.d). However, if the oxidase test came as positive then the bacteria would have to either P. aeruginosa or A. faecalis (“Microbiology 20 Biochemical Unknown, 2009). Then an indole test will have to be done. An indole test is to identify if the bacteria could produce the enzyme tryptophase (SIM Medium”, n.d). If the test came as positive then unknown bacteria 2 would be P. aeruginosa (“Microbiology 20 Biochemical Unknown, 2009). P. aeruginosa is a bacterium that is the number one leading infections in humans. The bacterium is Gram negative that can lead to “endocarditis, meningitis, etc. (Friedrich.M, Dec 5, 2016). In the other hand if the bacteria came as indole negative then bacteria 2 would be A faecalis. A faecalis is a Gram-negative, rod-shape bacterium with flagella, and that belongs to the family Alcaligenaceas”, and it’s an opportunistic pathogen that induces infection (“Alcaligenes faecalis”, n.d). All in all, skills were practices to determine two unknown
The purpose of this project was to identify unknown bacteria species from a mixed culture. The two unknown species were initially plated onto Tryptic Soy Agar (TSA), Eosin Methylene Blue (EMB), Mannitol Salt Agar (MSA), and blood agar plates to distinguish between the two different bacteria using colony size, color, shape, and growth characteristics. By identifying and inoculating the differing types of colonies, the two unknown bacteria were purified and able to be tested
Abstract: Salmonella is a bacterium that causes one of the most common intestinal infections in the United States - Salmonellosis. The chance of contracting this disease is significantly high, and more and more people are suffering from the symptoms and complications of Salmonella. This paper will discuss about the disease itself, the current outbreaks that are related to this disease, preventions and the treatments.
Salmonella is one of the most common causes of food poisoning. It is a gram-negative, aerobic (oxygen requiring), rod-shaped bacterium that can infect humans, birds, reptiles, and other animals. It results in the swelling of the lining of the stomach and intestines. Salmonella food poisoning occurs worldwide, however it is most frequently reported in North America and Europe. In the United States, Salmonella is responsible for about 15% of all cases of food poisoning (Salmonella food poisoning).
So as you can see Salmonella typhimurium is a serious microorganism that can create a lot of havoc if it gets inside of a person’s system and although there are many ways to diagnosis it, it must be diagnosed quickly or a person could end up in the hospital.
Murray, Patrick R., Ken S. Rosenthal and Michael A. Pfaller. Medical Microbiology, 6th Edition. Philadelphia: Mosby Elsevier, 2009.
This may sound like the beginning of a horror movie, but it isn’t. It is actually a very basic description of a very broad subject: microbiology.
The term “microbiology” refers to the branch of study that deals with microorganisms. Microbiology is extremely important in today’s time for the crucial information that the study provides. Human’s have had a long and cruel history of disease and sickness, for example the bubonic plague, but microbiology gives scientists the ability to observe, study, and prevent sickness like the bubonic plague to ever happen again. At the center of microbiology lies the bacterial cell, one that differs from those of a plant or animal because it lacks a nucleus and membrane-bound organelles which, in turn are traded for pili, flagella, and in some cases a cell capsule. Bacteria that are capable of causing illness or disease are called pathogens, pathogens work by releasing toxins in the body or directly damaging the host’s cells. An article by Lise Wilkinson explains that the earliest categorizations of bacterial cells first occurred in the late eighteen-hundreds to the early nineteen-hundreds by scientists (at the time) O. Muller and C. Ehrenburg (Wilkinson, 2004). The observation and identification of unknown bacteria that emerge is crucial because these new bacteria might be pathogenic and cause illness so it is very important that the bacteria is identified as soon as possible in order to either prevent the upcoming illness or treat it. While the common person is unable to identify if they are carrying bacteria (which is very likely), specialized tests that are ran in a lab can identify different types of bacteria and can even help
Salmonella is also a bacterium that is widespread in the intestines of birds, reptiles, and mammals. It can spread to the human species a variety of different ways; through foods or animal origins. Some examples of food involved in outbreaks are eggs, poultry and other meats, raw milk and chocolate. The illnesses it causes are typically fever, diarrhea, and abdominal cramps. In people with poor underlying health or weakened immune...