Tuesday, April 2, 2019

Analysis of Bacteria Strains: Phonotypical Tests

Analysis of Bacteria Strains Pho nonypical TestsKunthavai JeevananthanBacterial IdentificationAims To snap and identify 10 opposed strains of bacteria by conducting 19 get a lineable proves phonotypical scrutinys.Bacteria as well cognise as eubacteria argon microorganisms that argon invisible to the naked eye just now exist in ab bulge out all(prenominal) environments in the world. Bacteria atomic number 18 classified as voice of the Monera kingdom which implicates archaebacteria and cyanobacteria. Most bacteria argon morbific or disease ca exploitation however not all bacteria atomic number 18 harmful as there are a publication of bacteria that move be found in the human organic structure that have lordly benefit to their hosts such(prenominal) as help set up food, secrete hormones, chemicals and vitamins requi chromatic in cell metabolism and even debate off opposite harmful bacteria. Bacteria exist in versatile rod, spiral and spherical shapes and are mor e numerous than any other living organisms. It is important to be able to identify microorganisms in health check clinic in order to help selection of antibodies. Some pharmaceutical products are withal made using bacteria consequently many inexplicable and unidentified bacteria whitethorn be usanceful in the clinical industries. The taxonomy or a particular bacterial characteristic cigaret be used to identify similarities that show relationships with disease associate descriptions (Janda and Abbott, 2002). Various research laboratory strains have been developed that are based on the type of nutrients a bacterium sens grow on, the kind of toxins or waste products they provoke or how much variation in growth temperature they can patronage and their morphology can be used to distinguish closely related strains of bacteria. Rapid analyze kits have also been developed to identify bacteria in the Enterobacteriaceae genera and other g prejudicial bacteria.Phonotypical appro aches of identifying bacteria does not always provide sufficient in corpseation to set taxonomic boundaries mingled with diametric species the repetition of virtually phenotypic characteristics make it difficult to severalize them. Genotyping is however is more precise when it comes to differentiating bacteria within species that lead to the increment of DNA hybridisation. This is a technique used measure the similarities in sequences among the DNA of an isolate and a known bacteria. Before conducting a phonotypical bacterial identification it is important to have a pure burnish of the bacteria that needs to be identified so that all components of the cells have prominent from a single cell and they are clones of one another also known as Holy Grail (Barrow and Feltham, 1993). The bacterial colonies formed for different types of bacteria have different cultural characteristics on agar plates known as colony morphology these embarrass pigments, size edge, pattern, opacity an d flame therefore macroscopically examining the colonies of bacterial cultures is one of the first important ladders in bacterial identification. There may be drawbacks in this technique as the visual interpretation can differ from person to person therefore it might not nonplus reliable results and also mutations in the bacteria strains occur all the time that may provide slightly different characteristics than normal making difficult or incorrect identification.A issue forth of staining method actings can be used to examine the cultures low a microscope such as cast out staining which stains the background and leaves the cells elucidate so that the shape of the bacterial cells, presence of glistening capsule and presence of a diffusive extracellular substance (EPS) around the cell and the arrangement of cells can be determined. Differential staining is a test that divides bacteria into twain large groups either gram prejudicial or gram lordly. Pink- rose-cheeked stainin g indicates gram negative bacteria and a blue royal staining shows gram positive bacteria cells. Unevenly stained separate surfaces can be formed on the surface of the bacterial cells during gram staining due to the presence of endospores that can be confirmed using spore stain. Acid fast staining is also used if cells appear long, slim and intertwined in order to confirm the presence of acid fast cells which are bacteria in the genera Mycobacteria and Nocardia that are resistant to gram staining.Oxidase, catalase and the faculty of the culture to grow in anaerobic conditions are three tests that are conducted during the first steps of identification. Catalase test is to dip an inoculating needle coat with culture into a droplet of hydrogen peroxide and if the bacteria possesses a catalase enzyme it leave alone break drink down the hydrogen peroxide into water and oxygen that effervesce to form foam. Catalase positive bacteria are usually aerobic while catalase negative bacteri a are anaerobic. Cytochrome oxidase is another enzyme found normally in the negatron transport chains of an aerobic bacteria and this is tested by adding an staged substrate such as para amino di methyl radicalaniline that will produce a dark blushful to black product when oxidised (Cullimore, 2000). alongside these test the cultures can be tested on their abilities to grow under anaerobic conditions which can raise divide them into 4 major groups strictly aerobic, ruby-reduced concentrations of oxygen, both aerobic and anaerobic and strictly anaerobic bacteria.Urease synthesis, colloidal gel hydrolysis and turn utilisation are tests that can be conducted to narrowly distinguish bacteria further to help identify their genera. Urease is produced the bacterial genera proteus, providentia and morgenella to break down urea into century dioxide and ammonia therefore it is a useful test to help distinguish these genera from other gram negative rods during identification. Urease test is carried out by incubating urea broth with samples of gram negative cultures. The presence of ammonia increases the pH hence turning the phenol red indicator to a pink-purple colour for a positive test (Harvey and Champe et al, 2001). The gelatin hydrolysis test identifies the readiness of bacteria to produce gelatinases which can help identification of serratia and proteus. The citrate utilisation tests the ability of the bacteria to utilise citrate as its carbon and energy source used mostly to identify gram negative bacteria.Indole, methyl red- Voges- protease test and fermentation of glucose, sucrose and milk sugar are also test that are conducted to help assist with identification of bacteria. Indole test is preformed to test the ability of bacteria to breakdown amino acid tryptophane and produce indole that can be detected using Kovacs reagent. This method is important in the identification of gram negative enterobacteria. Methyl red-Voges- Proskauer on the other hand are two tests that are conducted together as they both require the use of the same medium. The methyl red test identifies the ability of the bacteria to carry out mixed acid fermentations whereas the VP test determines whether the bacteria fermenting sugars via the notwithstandinganediol pathway by testing for the by-product acetoin. These tests are also useful in differentiating between members of the enterobacteria such as E. coli (Wong, 2005). The ability of bacteria to ferment carbohydrates is also a way to carve up them during identification as fewerer bacteria are able to use disaccharides like lactose and sucrose as a source of energy. This can be detected by checking for release of gaseous by products and metabolous chemicals that are released during the process of oxidation and fermentation of sugars. These tests described in the context above were carried out under standard conditions and results were recorded.Results put back 1 shows test results for Colony Morpholog y for 10 little-known bacterial cultures A to J.Table 2 shows test results for 18 different bacterial identification tests for unknown cultures A to J.Urease, indole, citrate, oxidase, methyl red and Voges-Proskauer test were only carried out for gram negative strains of bacteria and the endospores were only tested for gram positive bacteria. Microphotographs display cell morphologies and gram (+/-) strains for cultures C, D and F are shown in the appendix. For culture C it can be seen that the cells are arranged in word of mouth like structures whereas C is arranged in packets of four. It can also be seen that culture F it can be seen that the cells were single and in chains. treatment being A and B are both gram positive rods that gave positive results for anaerobic, catalase and endospores test however they can both be distinguish as organism B is brown in colour and a glucose fermenter whereas organism A is orange in colour and a non-glucose fermenter. existence B was in a c ooked meat liquid broth which also indicates that the bacterium perhaps part of the Clostridium species that have a few unhealthful bacteria that are responsible for food poisoning and tetanus. organism A is therefore Bacillus Cereus some bacterium in this species are harmless whereas others are pathogenic that may cause foodborne illnesses such as nausea, vomiting and diarrhoea. Organism C has the morphology of pale yellow cocci clusters arranged in packets of four. It is a gram positive bacterium that also shows positive results for glucose fermentation and the catalase test show characteristics of Staphylococcus species which include pathogenic bacteria that causes skin infections, pneumonia and food poisoning. Organism C appeared in clusters that were grape like and is also a gram positive cocci and has a positive result for catalase however it does not ferment carbohydrates but shows positive test results for their metabolous chemical produced and hereby conveying characteri stics of genus Micrococcus species these bacteria are very rarely disease causing and if so some may cause chronic cutaneous infections (Breed and Murray, 1957). Organism E has a white flat mycelial morphology and it is a gram positive glucose fermenter therefore it is a part of the Streptomyces genera that are known to inhibit the crap and causes the common scab in root vegetables.Organism F is a clear gram negative rod bacterium that is glucose and lactose fermenter and produces metabolous chemicals for glucose, lactose. It also produced negative results for tests urease, gelatin, oxidase, Voges-Proskauer (VP) and indole however it showed positive results for catalase, citrate and methyl red and anaerobic tests as shown in figure 2. Analysing these results organism F can be identified as Escherichia coli that consist of many different strains some of which can cause urinary tract infections, diarrhoea, anaemia and even kidney failure. Organism G is a gram negative rod that produc es metabolic chemicals for all three carbohydrates glucose, lactose and sucrose however bubbles were only present for lactose and sucrose. It also shows positive results for tests urease, indole anaerobic and VP but negative results for catalase, oxidase, gelatin and methyl red. Organism G showed similar results to organism F however unlike organism F it is urease positive therefore it can be a bacterium from the Proteus genera that also contain a few pathogenic bacteria that can cause urinary tract infections, kidney stones and cystitis. Organism H is only a glucose fermenter but does not produce any metabolic chemicals. It demonstrates positive test results for urease, gelatin, citrate, anaerobic catalase and oxidase but negative for both methyl red and VP as well as indole tests. It is possible that this bacterium perchance be a part of the Pseudomonas genera with different bacterial strains that may cause respiratory tract infections, dermatitis and bone and joint infections.O rganism I is also a gram negative rod and had a clear pigmentation on an agar medium that is a glucose fermenter but however it produces metabolic chemicals for glucose, lactose and sucrose. It also produces positive results when being tested for citrate, anaerobic, catalase and methyl red but not for urease, gelatin, indole, oxidase and VP this indicates that organism I could be Salmonella typhimurium a pathogenic bacteria that causes gastroenteritis that leads to diarrhoea. Organism J is another gram negative bacterium that produces no bubbles for glucose, lactose or sucrose fermentation but produces metabolic chemicals for glucose and sucrose. It is also positive for gelatin, citrate, anaerobic, catalase and VP however it is negative for urease, indole, oxidase and methyl red tests. The red pigmentation of the bacterial culture and the other tests results indicates that organism J maybe Serratia marcescens that are associated with many different types of diseases some of which in clude bacteraemia, sepsis and meningitis. In order to conduct more specific identification of these bacteria further tests can be carried out that will help to distinguish each(prenominal) bacterium more accurately. Other tests that can be carried out include starch hydrolysis, lipid hydrolysis, motility (SIM) deeps, beta galactosidase, nitrate, coagulase, mannitol salt, osmotic cart and haemolysis.ReferencesBarrow, G. I., Feltham, K. A. R. (1993). Crowan and Steels manual for the identification of medical bacteria salmagundi and nomenclature. 1-6. linked Kingdom Cambridge university press.Breed, R. S., Murray, G. D. E., Smith, N. R. (1957). Bergeys manual of determinative bacteriology. 695- 800. United States of the States Baltimore Williams and Wilkins co.Cullimore, D. R. (2000). Practical atlas for bacterial identification initial stages of the identification of the bacterial culture. 1-7. United States of the States CRC press LLCHarvey, R. A., Champe, P.C., Fisher, B.D. (200 1). Microbiology identification of bacteria. 24-27. United Stated of America Lippincott Williams and Wilkins.Janda, J.M., Abbott, S. L. (2002). Bacterial identification for publication when enough is enough? Journal of clinical microbiology. Vol. 40 no. 6, (1887-1891).Wong, T. (2005). Introduction to microbiology laboratory exercises for Allied Heath students The IMViC tests. 48-50. United States of America Author House.AppendixCulture C Culture DCulture F

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