Solved Micro II Prac Cat2 2023 PDF

SOLVED MICRO II PRAC CAT2- 2023 DEPARTMENT OF MICROBIOLOGY AND IMMUNOLOGY SEMESTER 3 MODULE TWO CONTINUOUS ASSESSMENT PRACTICAL EXAMINATION (MI 201.02) 08 FEBRUARY 2023 GENERAL INSTRUCTIONS 1. This examination consists of 25 spots 2. Two minutes are all...

SOLVED MICRO II PRAC CAT2- 2023 DEPARTMENT OF MICROBIOLOGY AND IMMUNOLOGY SEMESTER 3 MODULE TWO CONTINUOUS ASSESSMENT PRACTICAL EXAMINATION (MI 201.02) 08 FEBRUARY 2023 GENERAL INSTRUCTIONS 1. This examination consists of 25 spots 2. Two minutes are allocated for each spot 3. Your required to attempt all questions 4. The slide will automatically change to the next question after every two minutes 5. Write your registration number and answers on the provided answer sheet Qn.1 Mention four (4) serological techniques used in diagnosis of viral infections (Any four) 1. ELISA 2.Antigen/Antibody Rapid diagnostic test (ROT) 3.Complement Fixation Test 4.Hemagglutination Inhibition (HAI) 5.Western blot 6.Immunostaining. Qn. 2 You provided with the item below commonly used in Microbiology laboratory a) identify the item (1 mark). Tissue culture flask/bottle b) Give the use in Microbiology laboratory [1 mark) Virus isolation c) Mention two medium that can be used for the purpose in (b) above (2 marks) i. Roswell Park Memorial Institute medium (RPMI) 1640) ii. Dulbecco's modified eagle's medium (DMEM) www.webrand.co.tz Solved With Love by Walter  SOLVED MICRO II PRAC CAT2- 2023 Qn.3 When viruses infect susceptible cells, they induce some specific cellular changes. Mention 4 cytopathic effects (CPE) induced by viruses 1. Rounding up and detaching of cells 2. Cell lysis 3. Swelling of nuclei 4. Formation of fused cells called syncytia 5. Inclusion bodies, which are intracellular masses of virions or unassembled viral components in the nucleus or cytoplasm. Qn. 4 HIV Rapid tests are useful in diagnosis of HIV infection. Provide four (4) advantages of the test. Any four; i. Detects both antigen and antibody ii. Cheap iii. Easy to perform iv. Rapid results- within 30 minutes v. Easy to store www.webrand.co.tz Solved With Love by Walter  SOLVED MICRO II PRAC CAT2- 2023 Qn.5 Provide four (4) disadvantages of rapid diagnostic tests used for diagnosis of viral infections. i. Only effective after window period ii. Dependent on antibodies production iii. Provides Qualitative results only iv. Cross-reactivity... false positive Qn.6 Embryonated eggs are among the most useful form of living animal tissue for the isolation of viruses. Mention one virus which can be grown in each of the following sites; Site Virus growth Chorioallantoic membrane Poxy virus, herpes simplex virus Allotonic membrane Influenza virus, Mumps virus Amniotic sac Influenza virus, mumps virus Yolk sac Herpes virus www.webrand.co.tz Solved With Love by Walter  SOLVED MICRO II PRAC CAT2- 2023 Qn. 7 You are provided with results of an HIV ELISA test. a) What is the long form of ELISA? (1 mark) ✓ Enzyme linked Immunosorbent assay. b) How does the colour reaction develops? (1 mark) ✓ Substrate conjugate reaction. c) Name two enzymes commonly used in HIV ELISA (2 marks) 1. Horseradish peroxidase 2. Alkaline phosphatase Qn. 8 www.webrand.co.tz Solved With Love by Walter  SOLVED MICRO II PRAC CAT2- 2023 You are provided with immunoassay test results; a) What is the titer of a patient numbered 8 (1 mark)? 1/4. b) What is the titer of a patient numbered 4 (1 mark)? Negative. c) In which patient was a prozone effect observed? (1 mark) ✓ Patient no 6 d) How does a prozone phenomenon affect the results of an antibody test? (1 mark) ✓ Will lead to a false negative result Qn. 9 List four (4) roles of public health microbiology laboratories; 1. Investigation of specimens from patients to detect outbreaks of disease 2. Investigating environmental samples including water, foods, milk, beverages 3. To conduct research in communicable diseases. 4. During epidemics- to conduct microbiological investigations to confirm etiology and determine sources and modes of spread of diseases. Qn. 10 Number of tubes giving MPN counts/100ml of water Interpretation positive reaction out of 5, Coliforms not E.coli 10mls each a) 16.0 b) 5.1 c) 9.2 d) 1.0 a) What is the use of the most probable number (MPN) table? (1 mark). ✓ To determine the suitability of water for human consumption. b) Interpret the results in row (a) (1 mark). ✓ Unsatisfactory. C) How do you confirm the presence of E. coli in tubes with positive reaction? (2 marks) ✓ Performing IMVIC tests. www.webrand.co.tz Solved With Love by Walter  SOLVED MICRO II PRAC CAT2- 2023 Qn. 11 A test was performed to assess the sterility of milk. The result was as shown above; a) Which milk is safe for human consumption? (A or B)? (1 mark). A b) Describe the principle of the test (2 marks) Methylene blue dye is decolorized by bacteria in the milk. The rate of decolorization is a measure of the degree of bacterial contamination. c) Mention one other test which can be used to determine sterility of milk (1 mark). The Phosphatase tests. Qn. 12 Two weeks after having unprotected sexual intercourse with an HIV positive woman, John decided to test for HIV. Parallel testing was performed using two different rapid tests. The results were as shown above; a) Interpret the results (1 mark) ✓ Discordant results b) Mention two possible causes for the above results (2 marks) Any two: 1. Window period, 2. expired test kit, 3. low sensitivity of the test kit, 4. sample contamination. c) Which further test will you perform to resolve the situation? (2 mark) ✓ ELISA or PCR www.webrand.co.tz Solved With Love by Walter  SOLVED MICRO II PRAC CAT2- 2023 Qn. 13 Determine the blood groups of the following four patients (PT1-PT4): A tick indicates agglutination has occurred. X means no agglutination DONOR’S BLOOD GROUP O A B AB PT 1 X X X X RECEPIENT PT 2 X X √ √ PT 3 X √ x √ PT 4 X X X √ ✓ PT 1: Blood group AB, PT 2: Blood group A, PT 3: Blood group B, PT 4: Give a free mark to all. Qn.14 Mention two advantages of Kirby-Bauer technique over other disk diffusion methods; a) Well standardized and widely evaluated... (2 marks) b) Yields data that can reliably predict the in vivo effectiveness of the drug..... (2 marks) www.webrand.co.tz Solved With Love by Walter  SOLVED MICRO II PRAC CAT2- 2023 Qn.15 a) Identify the technique (1 mark) E-test b) What is the use of the test? To determine antibiotic the minimum inhibitory concentration (mic) for the isolates (1 marks) c) Describe its principle of the test (2 marks).. The E-test uses a principle of AGAR DIFFUSION to perform QUANTITATIVE testing. Antibiotic diffuses from a plastic strip onto an agar media to provide quantitatively rapid and reproducible MICS results for tested isolates. Qn.16 Mention 4 factors determining the zone sizes in agar diffusion test 1. Media (types, depth) 2. Quality of antimicrobials disks 3. Inoculum size 4. Incubation time www.webrand.co.tz Solved With Love by Walter  SOLVED MICRO II PRAC CAT2- 2023 Qn. 17 You are provided with a disk diffusion method for the antibiotic susceptibility test; a) Provide the name of the test (1 mark) Kirby Bauer disk diffusion b) Which medium was used for this test? (1 mark) MHA c) How are the results of the test determined? (1 mark) Diameter of inhibition zone d) What does the test determine? (1 mark) qualitative MIC Qn.18 You are provided with a setup for antimicrobial sensitivity testing: a) Name the test (1 mark) www.webrand.co.tz Solved With Love by Walter  SOLVED MICRO II PRAC CAT2- 2023 Broth or agar dilution b) Read and interpret the finding (2 marks) MIC 8 ug/ml c) what does the test determine? (1 mark) quantitative MIC Qn.19 This setup is used for determining the body fluid antibiotics a) Name the test (1 mark) Diagnostic Sensitivity Test using giant agar plate b) Mention at least three settings/situations where the setup can be used (3 marks) 1. determine the concentration of an antimicrobial agent, 2 study the pharmacokinetics of a new drug. 3. verify if therapeutic concentrations are achieved. Qn. 20 This is the setup of the precipitation reaction www.webrand.co.tz Solved With Love by Walter  SOLVED MICRO II PRAC CAT2- 2023 a) Identify the type of precipitation reaction seen (1 mark) Tube precipitation test b) Mention one use of this method (1 mark)... Measure the amount of immunoglobulins in the blood plasma. What is the reason for the lack of precipitation on top of the tube (1 mark) Post prozone phenomenon (excess antigens) Qn.21 This is the result of the antigen-antibody reaction of tests A, B, and C 1. Which test is likely to be a false positive? (2 marks) A and C 2. Which precipitation phenomenal is shown in test C? (2 marks) post zone phenomenon Qn.22 Proteins from animal blood, A and B, were tested by the double- diffusion test in agar against antibodies to bovine albumin. www.webrand.co.tz Solved With Love by Walter  SOLVED MICRO II PRAC CAT2- 2023 a) Which sample(s) contain horse blood? (2 marks) ✓B b) What type of line is found between sample A and bovine albumin? (2 marks) ✓ Pattern of identity Qn.23 The antibody is mixed with agar before pouring it onto plates, a well is punched in the agar, filled with antigen. After 24 hours of incubation, the line was found around the well a) Mention the type of precipitation reaction (1 mark) Single diffusion b) How is the result determined? (1 mark) Diameter of precipitation line c) What is the test used for? (2 marks) Determine the concentration of antigen Qn. 24 This is the result of the antibody (Ab) and Antigen (Ag) reaction a) identify the type of precipitation reaction seen [2 marks) Double diffusion b) Describe the principle of the technique (2 marks) Antigen and antibody diffusion and reaction form a line when the proportion of the antigen and antibody is equivalent. www.webrand.co.tz Solved With Love by Walter  SOLVED MICRO II PRAC CAT2- 2023 Qn. 25 Mention two reasons for performing assays of antimicrobial agents in body fluids; 1. To ensure adequate concentrations of antimicrobials in the tissues (2 marks) 2. To prevent toxic concentrations of the agents (2 marks) ====Best wishes=== www.webrand.co.tz Solved With Love by Walter