Processes Used in Conduction of the Guthrie Test - Assignment Example

Course Work XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX Biology XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX Name XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX Course XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX Course instructor XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX Date submitted Processes used in conduction of the Guthrie test Guthrie test is a test done on babies testing for serious disorders and is done when the baby is between 48 and 72 years old. This test help find out a condition or a disease for early treatment to prevent mental retardation, any disability or even death. The identity of the infant is confirmed and written on the filter paper. When performing this test the baby is pricked at the heel and a few drops of blood on a special filter paper. The filter paper is then allowed to air dry and sent to the laboratory where several tests are undertaken. The blood sample is incubated with bacteria called bacillus subtilis plus a chemical named b-2- tienylalanine which stops development within the bacteria by acting for phenylalanine agonist. It prevents the bacteria from feeding from the phenylanine inside culture medium. Blood spot from heel on filter paper The infant’s heel is cleansed using rubbing alcohol; warm the heel to increase blood flow. The using a sterile lancet the plantar surface of the heel is punctured a depth of less than 2.0 mm. the first drop is wiped because it might be diluted. A gentle pressure is applied with the thumb and the printed side of the filter paper is touched to the blood and allowed to soak and fill the pre-printed circle. 5ml spot allowed dry Once the blood spot are successively spread on the card, they are allowed to air dry. Without flap on over the sport, in a clean place free from insects and direct sunlight, it is allowed to dry for at least for hours. Incase of places with higher humidity, overnight is advised. Heating, stacking or allowing the card to touch other surfaces are not allowed during the drying period. Filter paper infused with growth medium with Phe specific inhibitor Guthrie test uses mutant E. coli strain that is Phe. This means that it cannot sysnthesise phenylalanine on its own. The growth of bacteria on the plate states high presence of phenylalanine, phenylpyruvate and phenyllactate. On a minimal culture media the growth of bacterium bacillus subtilis (ATCC 6051) is inhibited by the compound B-2 Thienylalanine. If phenylalanine. Phenylpyruvate and /or phenyllactate are added to the medium, the growth continues. These compounds are present in infant’s wit PKU. The growth of the bacteria means that the test is positive for PKU. Sample provides Phe to encourage growth If extra phenylalanine leaches from the impregnated filter paper, the bacteria will grow for the inhibition will be overcome. Within one day, the growth of the bacteria is visible to the eye. Visual inspection for positives The visible growth of those bacteria is measured as the diameter of the colony is equal to the phenylalanine in the serum. Growth is measured by comparing the diameter of each sample filter colony to colonies of a series of reference disks with a standard phenylalanine which is in each plate. Theoretical basis of the oxidase test An oxidase test is procedural test for confirming the availability of pseudomonas aeruginosa or Neisseria species. Cytochrome oxidase transports electron chain by transferring them from a donor molecule to oxygen. An Oxidase reagent has chromogenic compounds that changes color when oxidized. If the test produces Cytochrome oxidase, the oxidase reagent turns blue or purple in 30 seconds. Using s sterile wooden stick, get 2-3 colonies from each culture to be tested and spread it on a filter paper. Add a drop of spot test (TPD) reagent on the spot. If the organism is oxidased, it will turn to purple within 30 seconds. Oxidase positive bacterium Maraxella is an example of appositive bacterium. Maraxella catarrhalis causes lower respiratory infection in adults with lung disease and otitis media, sinusitis and conjunctivitis in children. Also aerobic organism has oxygen based metabolism to oxidize substrates to obtain energy. Oxidase test used as a phenotypic character to identify bacterial strains, and whether that bacterium produces cytochrome oxidases; aerobe always test positive for oxidase. Using a light microscope to identify bacteria After preparing a slide and labeling it, mount it with smear and focus at lo power on the etching. Move the slide so as the lens gets over the smear. Then move the objective away from the slide until the upper surface is the one focused. A bacteria smear at low power looks like a patch of dirt. Focusing on it at 40x then 100x and finally 400x in bright field mode. At 400x there are some visible shapes and colors of bacteria which are distorted. Immunohistochemistry is more accurate method of histological diagnosis that standard tissues dye. People differ very much in the way they respond to a given pharmaceutical therapy. This is because of genetic variation between people. Pharmacogenetics (PGx) is a field of research that aims at applying new data about genetic variations and understanding differing drug response. Differing drug efficacy means that the drugs given to the patient did not provide the intended benefits. This results to adverse drug reactions (ADRs) which are contributed by genetics factors. Therefore, Edna Green could not have responded to the prescribed medicine because of her genetic make up resulting to drugs efficacy. Histological analysis is done by examining a thin section of tissue under optical or electron microscope. Immunohistochemical has resulted to kevels of distinction between diagnoses which were previously not possible. This is because it gives information that is important in guiding therapy. Immunohistochemisrty has proved to be the most valuable adjunct to hematoxylin and Eosin (H & E) staining in diagnostic histopathology. Immuohistochemistry is effective on antibodies to paraffin embedded tissues which dyes had limitations. 6. Explain the pathological difference between benign and malignant neoplasia. Benign and malignant are terms that are often used interchangeably. However, they are poles apart as malignant is the used to refer to the affected cells that in the body are cancerous. Malignant tumors can attack the cells in the surrounding regions and spread out to the other parts of the body. Benign tumors are on the other hand not cancerous but might grow in size. However, benign tumours will not spread to the other body parts. This implies that unlike the benign tumours which might only grow in size the malignant tumours grow and extend to other body parts. If for instance one has a malignant tumour in the colon, it will grow and extend to the other parts of the colon and even to the other body locations. This activity of growth is referred to as metastasizing. Malignant tumours grow at a faster rate than the benign tumours. Unlike the malignant tumours, the benign tumours can contain themselves and is normally painless. In addition, it never causes damage to the other surrounding body tissues unlike the malignant tumour which continues to grow for as long as it is in contact with healthy tissues. Malignant tumours will progress in growth for as long as there is a healthy tissue in its surrounding. Lastly, pieces of tissues can break off from the malignant parent tumour and continue to grow and spread out in the assorted body parts unlike the benign tumour tissues. 2. Discuss the use of rapid API test strips in the identification of bacteria. The identification of the bacterial strains mainly those of aquatic sources have proven to be labor intensive. Phenotypic traits are the mainly used in the numeric taxonomic analysis in the development of protocols for the identification of particular types of bacteria. Clinical bacteriology has been the utilized in the identification of the bacteria from the aquatic and terrestrial habitants. The Analab Products, Plainview, NY (API Rapid NFT) profile index was developed to intensify the identification of the gram-negative non-fermentative bacteria in species such as the Pseudomonas and other related genera. The NFT is known to allow the identification of some non-enteric bacteria that is fermentative. These include: the vibro and the aeromonas spp. The 20 individual cupules contained in the rapid NFT examination strip are substrate freeze dried. The bacteria suspension is normally added to the substrates to rehydrate them. The test has nine enzymatic assays needed for it to give effective dependable results. These include: NO3 reductase, tryptophynase, ureas, sculin hydrolase and cytochrome among others. These are carried out on each test strip. The test results show difficulty in the identification of the carbohydrate assimilation tests in the NFT preliminary evaluation for the identification of few selected marine strains of bacteria. The positive interpretation is based on the foundation of developed turbidity. The interpretation confirms the growth on the source of the sole carbon. AUX mediums are utilized the tests of inoculate assimilation. The results on these cases are normally opaque thus rendering it ambiguous in the determination as the results are difficult. The substitution of the AUX medium modifies the test system with a dilute phenol red. This is normally in the form of phenol red broth base. This makes it easier to interpret the test based on the pH induced color change. The judgment to practice this modification type is based founded on the understanding that a bacterium that is fermentative is preponderate in some sections of the oceans. Rapid API is thus essential in the identification and classification of cultural heterotrophic nautical bacteria. Factors that must be considered when setting up a new screening program for disease Screening programs are conducted with an aim of detecting the target condition within a given population of interest. The basic aim of conducting the screening process is mainly to be able to detect the conditions affecting a given population and going ahead to offer early interventions since with the complication of a disease condition or even the spread being diffuse at the cost of treatment will be increasing with the advancement of the disease, the screening process targets to cut this cost of treatment by identifying the risk groups and managing their conditions early. The mobilization of the resources will require both the staff and the equipment for the screening program. The presence of able and trained personnel will greatly influence the credibility of the screening process as the desired results will be achieved. The right equipment which is not faulty will also be able to offer the accurate results and diagnosis that will be aimed at. The screening process should also be very effective and this will be achieved by having less false negative and slow less false positive results when the process is conducted. The false negatives or the false positives will influence greatly the management plan due to the diagnosis being missed and this will affect the patient’s health or even in the long run waste the resources which could have been used by the patients who are really diagnosed with the condition respectively. The screening process should also offer clearly expected outcomes and also solutions and the steps one will take after the screening process has been carried out. The screening should also be that which can identify a particular condition that can be able to be screened in order for the screening process to make sense. The screening processes should not go against the ethics as this will lead to violation of the rights of the patients and hence most patients will keep away from the screening process in order to avoid their rights such as the confidentiality of the information being violated. Read More