Selective vs. Differential Media Essay Example for Free

Selective vs. Differential Media Essay state the avocation questions as you work your way through the laboratory material typing in your final results. thus submit your finished lab report as a Microsoft Word document. This lab report is expense 100 points towards your final lab grade. Each Q is worth 2 points unless otherwise noted. Also, per the Honor Code, this work mustiness be your own. This is due Mon. 10/8 at 1159 PM. The theme of this lab is the assignment of unknown bacteria and viruses in a lab.Selective vs. Differential MediaSelective vs. Differential Media give the pursual website to help you answer Q 1 and 2http//www.highlands.edu/academics/divisions/scipe/biology/labs/rome/selectiveunlikeial.htm1. What is a selective median(a)? What makes the sensitive selective? Name 2 examples (3 pts.) A selective strong suit is a medium that contains antimicrobials, dyes or alcoholic drink that supports the growth of certain organisms, while inhibiting the growth of ot hers. Two examples of selective medium atomic number 18 Mannitol salt agar-agar and Phenylethyl Alcohol.2. What is a differential medium? What makes the medium differential? Name 2 examples (3 pts.) Differential medium is distinguishing microorganisms from one another based on growth characteristics. A medium is differential when you are capable to visibly see the differences in growth patterns of organisms. Differential media include blood agar and Eosin methylene radical Blue.Steps Used in Identifying an Unknown Bacterium in a LaboratoryI. In a lab situation you would take you inoculum and perform a streak plate in evidence to separate out individual cells enough to obtain a pure culture(see Atlas p. 5) 3. What is the most(prenominal) frequent streaking method? (2 pts.) The most common streaking method is the discharge plate method, while the most common streaking technique is the quadrant method. The quadrant method incubates an agar victimisation a four-streak pattern.4 . What is the principle behind the Streak Plate Method of Isolation? (2 pts.) The Streak Plate Method of Isolation is use to obtain a pure culture in order to isolate a certain organism. This method allows for the organism to bring about individual colonies on an agar plate.II. After incubating your streak plate you would perform a constant of gravitation lubricating oil as you learned in Lab 1 The Virtual gm Stain. Im directing you to the Virtual guanine Stain website from the Univ. of Michigan. Click on View Example. You go out need to move your cursor over the visitation thermionic valves to see what separately contains. Then click on the ladder tubes in the correct order to press the program this is really cool http//vudat.msu.edu/gram_ defacement/5. What were the results of your Virtual g-force Stain, i.e. describe what you see on the slide as to color, Gram Stain result and morphology? (4 pts.) The gram stain was ostracize. The shape was bacilli and had purple s pores present.III. Using the dichotomous keys provided as MSWord Documents in this lab, you would carry out specific tests utilizing selective and differential media in order to identicalness your bacterium. In a microbiology lab you would use Bergeys Manual of Determinative Bacteriology. This book includes all tests and their results to concern in the identification of unknown bacterium. Use the following websites to answer these questions http//www.saskschools.ca/curr_content/biology20/unit3/unit3_mod1_les2.htm http//www.uiweb.uidaho.edu/micro_biology/250/IDFlow maps.pdf6. What is a dichotomous key? (4 pts.)A dichotomous key is a key utilise to help s of all timealize bacteria using attend to of elimination testing in order to detect each bacteria characteristic.7. Based on the schooling Flow Charts from Bergeys Manual of Determinative Bacteriology Page 2, answer these questions (4 pts) a. What is the FIRST test that is performed in a lab to pick out between groups of bac teria? The first test preformed to differentiate between bacteria is Gram stain testing.b. If you looked at your slide with the 100X oil immersion objective, what is the next thing that you would observe based on the tuition in the flow chart? The next step in identification is morphology.8. The remaining flow chart varlets will show you how dichotomous keys are used in bacterial identification. Scroll down to page 7 and look at the Family Enterobacteriaceae which is comprised of Gram contradict rods. (4 pts.) a. What is the first test that may be performed to start differentiating among the individual species? The first test that may be performed to start differentiating among the individual species is Lactose Fermentation.b. Use of a dichotomous key allows you to perform the next test needed to identify your mystery hemipterous insect based on the results of the test you just performed, i.e. were the results domineering + or negative -. Using the flowchart, what would be the germ which has these test results Lactose positive (+), Indole positive (+) and change state negative (-)? The microbe would be Escherichia Coli.ATLAS piece 2 SELECTIVE MEDIA.I would like for you to read over the different types of selective media and then answer the following questions. Remember that selective media promote the growth of some bacteria while actively deter the growth of others.9. For what is Chocolate II agar used? ( 2 pts.)Chocolate II agar is used for isolation and cultivation of Neisseria and Haemophilus.10. Based on the information in the Principle section, Phenylethyl Alcoholnutrient agar will select for the growth of which bacteria? What does the alcohol actually do? (2 pts.) Phenylethyl Alcohol Agar selects for the growth of positive organisms. The Alcohol in the agar interferes with the deoxyribonucleic acid synthesis of Gram-negative organisms which inhibits growth.ATLAS dent 7 derivative MEDIAPlease read over this section. Differential media usually distinguish or differentiate different species of bacteria based on the color of the individual colonies or the areas surrounding them. Look up these tests and answer the following questions Blood Agar, Catalase, Citrate, Coagulase, Indole, Methyl Red, Motility, TSI, Urea, 11. What is a hemolysis and what type of bacteria produce it? (2 pts.) Hemolysis is the exotoxin of gram positive cocci (streptococcus, enterocus, and aerocccus) that destroy RBCs and hemoglobin.12. What are the 3 major types of hemolysis and their descriptions? (2 pts.) The three types of hemolysis are B, A, Y. B is complete clearing or destruction of the RBCs or hemoglobin and it results in a clearing of the medium around the colonies. A is partial destruction and a green color forms around the colonies. Y is non-Hemolysis and shows plain growth and no change to the medium.13. When would you use the Catalase test? (2 pts.)This test should be used when trying to identify organisms that produce catalase. It is us ed when differentiating between Catalase positive micrococcaceae and catalase negative streptococcaceae and some variations of the catalase test are for mycobacterium.14. The Citrate Tests is part of what test series? What is the color of a positive Citrate Test? (2 pts.) The citrate tests are part of the IMVIC (Indole, Methyl Red, Voges-Prokauer and Citrates tests) and are used to distinguish between enterobacteriaceae and other gram negative rods. A positive Citrate test will turn blue.15. What is the purpose of the Coagulase Test? Why is it to S. aureus prefer to produce this enzyme? (2 pts.) The coagulase test is used to differentiate between staphylococcus aureus and other gram positive cocci. Coagulase forms a shield with fibrin barriers to resist phagocytoses and other cellular attacks.16. The Indole test will help differentiate what group of bacteria? Using the Methyl Red test, what color indicates a positive result? (2 pts.) The Indole test help differentiate enterobacteri aceae and a positive Methyl Red test result is red.17. What is the principal behind the TSI agar test? The shallow slant and deep butt allow for what? (2 pts.) Triple Sugar Iron Agar test or TSI is loaded with nutrients to help distinguish between enterobacteriaceae and other gram negative rods on the basis of glucose fermentation, lactose fermentation, sucrose fermentation and sulfur reduction. A slanted test tube with a deep butt is used. The agar contains beef and yeast ex portions as well as peptone for degree Celsius and nitrogen sources. Also, Sodium thiosulfate for reducible sulfur. Phenol red as a Ph indicator and atomic number 26 in ferrous sulfate as a hydrogen sulfate indicator. The basis is as something is digested the changes in ph and hydrogen sulfate will cause the color to change.18. What pathogens potentiometer be identified using the Urease test? What color is a positive result?(2 pts.)Identified pathogens come from the genus Proteus. These hydrolyze urea with a nd enzyme called urease. A positive result will be pink.Watch this program that will walk you through the assist of identifying a foodborne pathogen that has made citizenry sick. Follow the instructions, clicking where indicated to start the activity. Once the file opens, click first on Gram Stain and you will see how it works. Then answer the following questions. http//www.swtafe.vic.edu.au/toolbox/lab_ops/laboratory/studynotes/snFlowChartIdentProcBac.htm 19. What Gram positive cocci were discovered using the Gram Stain? (2 pts.) The Gram positive cocci discovered using the Gram Stain are staphylococcus, Micrococcus, Streptococcus.20. The positive results of the Catalase Test indicated the possible presence of which Gram + bacteria? (2 pts.)The Catalast test indicated the possible presence of micrococcus and Staphylococcus bacteria.21. The Oxidation/Fermentation test was positive for which Gram + bacteria? (2 pts.) The Oxidation/Fermentaion test was positive for staphylococcus b acteria.22. The Coagulase test specifically identified which species of Staphylococcus? (2 pts.) The Coagulase test specifically identified the species aureus.Now using the Dichotomous Keys provided in the Blackboard section for Lab 3, identify these bacteria based on their test results. Then provide a brief description of each from the Atlas Section 12. (4 pts. each)23. Test Results Gram + coccus, Catalase negative, Alpha Hemolysis Bacteria are S. pneumoniae. S. pneumoniae ia an ac-hemolytic, nonmotile, encapsulated, facultatively anaerobic, Gram-positive coccus. It is a significant cause of community-acquired bacterial pneumonia and menigitis in adults. There are at least 80 different serotypes and are defined by antigenically by their capsules. Typically starts in the nasopharynx and from there spread to the lungs and bring forths into pneumonia or is harbored symptomless for months.24. Test Results Gram + coccus, Catalase positive, Coagulase negative, Beta Hemolysis Bacteria a re S. epidermis. S. epidermis are non-motile, facultatively anaerobic, non-hemolytic, gram-positive coccus. normal inhabitant of human skin that has become a significant nosocomial pathogen, some strains produce a slime layer that may enable them to attach to certain hospital apparatus used in surgical procedures, thereby gaining entrance into the body. Most infections at the site of prosthetic implantation are from S. epidermis, can be severe or fatal.25. Test Results Gram rod, Lactose negative, Urease positive Bacteria are P. genus Mirabilis. P. mirabilis are straight, facultatively anaeroic, highly motile (swarming), Gram-negative rod. It is a normal inhabitant of our intestinal folder and is in some other animals as well. It is also common in soil and contaminated water. Is has the swarming motility characteristics ad produces a series of visible concentric rings. Common nosocomial pathogen isolated from septic wounds and Urinary tract infections. You get it from direct cont act with the source. It can lead to other complications like kidney stones and Proteus Septicemia.26. Test Results Gram rod, Lactose positive, IMViC ++ (= negative, negative, positive, positive), Urease positive Bacteria are K. pneumoniae. K. pneumoniae are nonmotile, encapsulted, facultatively anaerobic, Gram-negative rod. It is found in soil, water, grain, fruits, vegetables and intestinal tracts of a variety of animals including humans. It is in the nasopharynx and oropharynx in humans and is often transmitted as aerosol droplets from person to person. It is a very common nosocominal pathogen. Common infections caused by K. pneumoniae are pneumonia, urinary tract infection, bronchitis, surgical wound infections, biliam tract infections and hospital associated bacteremia. The bacteria are becoming more antibiotic resistant and harder to treat in modern years.ATLAS SECTION 9 MOLECULAR TECHNIQUESToday a pathogenic microbe can be identified very quickly using molecular techniques s uch as DNA Extraction, dielectrolysis, Polymerase Chain chemical reaction and DNA Sequencing. Answer the following questions using the information in this section of your Atlas.27. What are the 3 rudimentary steps in DNA extraction? (2 pts.)The 3 basic steps in DNA extraction are-1. Detergent (Sodium Dodecylsulfate-SDS) is used to lyse cells andrelease cellular contents. 2. Heating-dentures proteins and other cell components3. Water-soluble DNA is precipitated in wintry alcohol as a whitish, stringy mass.28. What does electrophoresis do? What is added to the gel to make the results visible? (2 pts.) Electrophoresis is a technique where molecules are separated by size and electrical charge in a gel. Coomassie blue is added for protein staining and ethidium bromide (fluorescent dye) is used for nucleic acids.29. What enzyme is used in PCR and why? (2 pts.)The enzyme used in PCR is DNA Polymerase. It is used because it is able to attach the free nucleotides to complementary bases o n the template and create a beloved copy.THE VIRTUAL BACTERIA ID LABfrom the HOWARD HUGHES MEDICAL INSTITUTEhttp//www.hhmi.org/biointeractive/vlabs/index.htmlOpen this website and click on The Bacterial recognition Lab. Following the instructions, work your way through this lab.30. Following the instructions, identify your bacterium and write the species elevate here. (To do so, you will need to read the page entitled Nucleotide Sequence (1410 letter) and click on Descriptions. Then click on the top Accession Code. Move down to the 7th line Organism.) (8 pts.) Our bacterium species name is Bartonella henselae31. Now, on the CDC website (http//www.cdc.gov/healthypets/diseases/catscratch.htm) , look up the information on this bacterium and write a 2 paragraph (4-5 sentences per paragraph) answer on the disease that it causes. (8 pts.)The disease that our bacterium Bartonella henselae causes is cat scratch disease (CSD). Most people that are bear on in CSD have been scratched or bi tten by a cat that is carrying it. They develop an infection at the site of injury. The lymph nodes, typically the ones around the neck, head and upper limbs become swollen. Some of the symptoms people with CSD have are fever, headache, fatigue and poor appetite. There are also some rare complications of this bacterium like bacillary angiomatosis and Parinauds oculolandular syndrome.Cats and kittens can spread CDS bacterium to people through bites and scratches. About 40% of cats are carrying CDS at some point in their lives. Cats with CDS do not display and signs of the illness and you cannot restrict which cats have it and which do not. You can reduce your risk of contracting CDS by avoiding rough play with cats, laundry cat bites and scratches immediately with soap and water, not letting the cat lock open wounds and controlling fleas. You motive to call the doctor if an infection occurs after a bite or scratch. Generally CSD is not serious. medical examination treatment is no t usually needed. Sometimes treatment with antibiotics like azithromycin is helpful in clearing the infection. forecast is good.On a side note, I actually had this as a child. I got it from a order kitten scratch. I developed large swollen lymph nodes under my arms, fever and soreness. I am not sure if not as much was known back then but my Dr. did surgery to hold the lymph node from under my left arm and drained the other. It was the only surgery (excluding my c-ections) that I have ever had. I never had any further complications after the surgery and was fine immediately afterwards.ATLAS SECTION 10 VIRUSESViruses cannot be grown on media as bacteria can because they are obligate intracellular parasites and need host cells for reproduction. Therefore their identification in a lab is much more difficult. a good deal immunological tests are used and you will learn about these in a future lab.32. attain the HIV virus. What specific human cells does it infect? (3 pts) The HIV virus is the cause of AIDS. Two forms of the virus exist, HIV-1 and HIV-2. both are retroviruses and have the ability to make DNA from and RNA template. HIV infects cells with CD4 membrane receptors, normally used for antigen recognition, but by HIV for attachment. A subpopulation of T cells, the T4 helper cells are most commonly affected and die. Other types of cells infected can be dendritic, macrophages and moncytes, HIV can be transmitted through somatic fluids to include blood, breast milk, semen and vaginal secretions.33. What is the principle behind development viral host cells in a lab? What happens after the virus is introduced to the cell culture and what is the result? (5 pts.) The principle behind growing viral host cells is to attain presumptive identification of a virus, how host cells replicate, how quickly it causes impairment, and the type of damage it produces. The virus inflicts damage upon the host cell, which in called the CPE (cytopathic effect). It can take as lo ng as 4 days or up to 4 weeks to start seeing damage. Most often they start as small spots (foci) in the cell layer and spread outwards. Common damage to cells includes rounding (small or large), change in texture, or formation of syncytium (the fusion of infected cells).