UNIVERSITY OF EAST ANGLIA School of Pharmacy Main Series UG Examination 2012-13 PHARMACEUTICAL MICROBIOLOGY PHA-2HH1 Time allowed: 2 hours Part ONE. Answer ALL questions. For each question, there is ONE correct answer. Use the answer sheet provided for ALL your answers. Part TWO. Answer THREE of the FOUR questions. Write each answer in a SEPARATE answer book. The mark allocation for the paper is: Part ONE carries 40% of the total mark Part TWO carries 60% of the total mark Graph paper for Q 34 will be provided. This paper consists of 12 pages in total. Dictionaries are not permitted in this examination. Notes are not permitted in this examination. Do not take this question paper out of the examinations room. Do not turn over until you are told to do so by the Invigilator. (PHA-2HH1) Module Contact: Dr Sheng Qi, PHA Copyright of the University of East Anglia Version 1
2 PART ONE 1. Which of the following statements is TRUE? The host for the causative agent of toxoplasmosis is the: A) Cat B) Dog C) Bird D) Horse E) Cow 2. Which of the following statements about endogenous retroviruses is FALSE? A) Endogenous retroviruses are derived from ancient infections of germ cells in humans, mammals and other vertebrates B) Human endogenous retroviruses comprise around 5-8% of the human genome C) They are passed on to the next generation in the form of proviruses D) Endogenous retroviruses have been linked with some autoimmune disease like multiple sclerosis E) Endogenous retroviruses are the causative agent of chickenpox 3. Which of the following statements about prions is FALSE? A) Prions cause transmissible spongiform encephalopathies B) Prions can be transmitted via tissue transplants C) Prions do cause inflammation in the brain of infected patients D) Prions consist solely of protein E) Prions have a long incubation period before the onset of disease 4. Which of the following statements about fungi is FALSE? A) Fungi are composed of filaments called hyphae B) Fungi have cell walls composed of chitin C) Fungi have a unique method for lysine synthesis D) The cell membrane of fungi contains ergosterol E) Fungi have flagella to move towards food sources 5. Which of the following statements about viruses is TRUE? A) All viruses contain DNA as their genetic material B) All viruses have a cytopathic effect on infected cells C) Some viruses can integrate into the human genome after infection D) Some viruses can replicate outside a host cell E) All viruses have an envelope
3 6. Which of the following statements about pyrogens is FALSE? A) Endotoxins are a type of pyrogens B) Pyrogens will elicit a rise in body temperature when injected into a mammal C) The physiological effect of pyrogens depends on the route of administration D) The LAL test is a very sensitive test to detect pyrogens E) Pyrogens can be removed from liquids by boiling the solution for 15 minutes 7. Which of the following statements about Staphylococcus aureus is TRUE? A) They are Gram negative bacteria B) They are important for the production of yoghurt C) They can cause food-poisoning D) They live on skin and nasal membranes E) They can cause dental plaque 8. Which of the following statements about Chlamydia trachomatis is FALSE? A) Chlamydia trachomatis is a leading cause of blindness B) Chlamydia trachomatis are unable to produce enough ATP to survive outside of a host cell C) A Chlamydia trachomatis infection often shows no symptoms D) Chlamydia trachomatis is classified as a sexually transmitted disease E) Chlamydia trachomatis lacks a cell wall 9. Which of the following statements about Gram positive bacteria is TRUE? A) They have a periplasmic space which contains enzymes that can hydrolyse penicillin B) They contain lipopolysaccharides in their outer membrane C) They will show a red colouring after a Gram stain D) They are no susceptible to lysozyme E) They have a thick peptidoglycan layer 10. Which of the following statements about bacterial metabolism is TRUE? A) Chemotroph bacteria use chemical reactions to cover their energy needs B) Auxotroph bacteria need only one organic substance as nutrients C) Lithotroph bacteria use an organic compound as their hydrogen donor D) Autotroph bacteria use an organic compound as their carbon source E) Heterotroph bacteria use an inorganic compound as their hydrogen donor TURN OVER
4 11. Which of the following statements about obligate anaerobe bacteria is TRUE? A) They will only grow in the presence of oxygen B) They do not tolerate any oxygen C) They tolerate oxygen, but do not need it D) They produce oxygen E) They have a symbiotic relationship with algae 12. Which of the following statements about transformation is TRUE? A) Transformation is the injection of DNA into bacteria via bacteriophages B) During transformation, bacteria pick up fragments of DNA from the environment C) Transformation is the exchange of DNA between two bacteria via a sex pilus D) During transformation, bacteria start to produce viral particles E) Transformation occurs only in bacteria when they have run out of nutrients 13. Which of the following is NOT an appropriate agent for use as a disinfectant in aseptic production units? A) Ethyl alcohol B) Methyl alcohol C) Sodium dichlorisocyanurate D) Chlorine gas E) Hydrogen peroxide 14. Which of the following would be an appropriate agent for the eradication of a bacterial spore contamination within an aseptic production unit? A) Ethanol B) Chlorhexidine C) Peracetic acid D) Triclosan E) Chlorhexidine 15. Which of the following properties should be considered when choosing a preservative for an eye drop formulation? A) Sporicidal activity B) Antibacterial activity at low ph C) Volatility D) Aqueous solubility E) Activity against Pseudomonas aeruginosa
5 16. After performing a Gram stain you identify round shaped prokaryotic cells that stain violet in colour. From this you can conclude which of the following? A) The bacterial cells are Gram positive rods B) The bacterial cells are Gram positive cocci C) The bacterial cells are Gram negative rods D) The bacterial cells are Gram negative cocci E) The cells are Gram positive filamentous bacteria 17. Which of the following tests that can be used in the monitoring of clean room environments assesses the viability of microorganisms? A) The Gram stain B) The spore stain C) Settle plate sampling D) The DOP challenge test E) Airflow velocity test 18. Which of the following terms refers to a specific procedure used to prevent unwanted microorganisms from contaminating a drug preparation? A) Disinfectant technique B) Sterilising technique C) Sanitising technique D) Aseptic technique E) Autoclave technique 19. Which of the following statements concerning the advantage of isolators over laminar air flow cabinets is FALSE? A) Non sterile clothing can be used by operators in isolators B) The transfer hatch in an isolator can include a time interlock C) Negative pressure isolators provide near perfect operator protection D) Isolators must be sited in a minimum grade B environment E) An isolator provides a total barrier to the external environment 20. Which one of the following statements concerning the disadvantage of isolators over laminar airflow cabinets is FALSE? A) They are uncomfortable poor ergonomics for operators B) They are more difficult to clean C) It is more difficult to get equipment in & out of isolators D) They are more expensive than conventional laminar air flow cabinets E) The operators in an isolator need to work up close to the HEPA filter TURN OVER
6 21. Which of the following statement is FALSE? A clean room (e.g. for an isolator-based aseptic activity) has the following design features: A) No cracks and crevices B) Easily cleaned smooth surfaces C) A HEPA air supply D) Access via a Grey / White changing room E) Negative pressure room air 22. Which of the following statements is FALSE? Clean room hatches (linking a clean room to a support room): A) Must be flush fitting on the clean side B) Must have doors which interlock so that both sides cannot be opened simultaneously C) Must be completely air tight D) Must be easy to clean E) Should preferably have glass doors 23. Which of the following statements about sterilised medicines is FALSE? A) The medicine must be packaged in a sealed container B) The medicine may be sterilised by filtration C) The medicine can be sterilised using heat D) The medicine is sterilised in its final sealed container E) The medicine must not contain micro-organisms prior to sterilisation 24. Which of the following is not a pharmacopoeal grade of water? A) Purified water in containers B) Water for injections in bulk C) Sterile water for injections D) Potable water E) Water BET
7 25. Which of the following statements is TRUE concerning the F 0 concept? A) Escherichia coli is used as a standard when discussing the F 0 concept B) The BP states that a sterilisation process must have a F 0 value of not less than 6 C) The F 0 concept ignores the heating-up and cooling-down parts of the sterilisation cycle D) The F 0 value is the time it takes at 115 C to completely eradicate bacteria from a product E) The F 0 concept allows prediction of the time required at a specific temperature to produce a specific reduction in bioburden 26. Which one of the following statements is FALSE concerning the Z value of a sterilisation process? A) Z is defined as the "the change in temperature required to cause a 10-fold change in the D value" B) Z values are different for different micro-organisms C) Z values tend to be around 1 to 3 C in the temperature range 100 to 130 C D) Z values can be used to predict the effect of different sterilisation temperatures on the rate of kill of micro-organisms E) Z values must be used in conjunction with D values 27. Which one of the following is NOT an advantage of using ionizing radiation as a method of sterilisation? A) Ionizing radiation is a powerful technique for inactivating various types of micro-organisms B) Ionizing radiation is effective against a large number of different types of bacteria, yeasts, moulds and some viruses C) Ionizing radiation can be used for thermo-labile samples D) Ionizing radiation is a terminal technique E) Ionizing radiation removes the non-viable microbial material and pathogens from the sample 28. Which one of the following types of medicinal products can be sterilised using dry heat sterilisation? A) Injections containing thermally liable drug B) Disposable syringes C) Metal instruments D) Wound irrigations E) Eye ointments TURN OVER
8 29. Which of the following statements is FALSE concerning validation in pharmaceutical manufacturing? A) It is necessary to prove that any procedure, process or system leads to the expected result B) It is very important for computerised systems C) It can determine the level of sterility assurance for an aseptic fill process D) It is an alternative to routine quality control E) It is equally applicable to hospital pharmacy manufacturing as for industrial scale 30. Which of the following statements concerning filtration sterilisation is FALSE? A) Filtration sterilisation is a terminal sterilisation method B) Depth filter is absolutely retentive C) Screen filters are commonly made of cellulose acetate D) Filtration method often cannot remove virus E) Filtration can be used to sterilise thermolablie products END OF PART ONE
9 PART TWO 31. Answer ALL parts: (a), (b) (c) and (d). a) The growth of a bacterial culture is described by the following formula: G= t/(3.3xlog10(b/b)) where: G = generation time (time for the cells to divide) t = time interval in hours or minutes B = number of bacteria at the beginning of a time interval b = number of bacteria at the end of the time interval What is the generation time in minutes of a bacterial population that increases from 8 cells to 20,000 cells in 16 hours of growth? Show all your workings. [30%] b) Use the formula above and calculate how many bacteria will be there after 12 hours, if 3 bacteria grow with a generation time of 23 minutes. Show all your workings. [30%] c) In the laboratory, you are given a vial containing a bacterial suspension. The total volume of this suspension is 20 ml. Your task is to find out how many bacteria are in this 20 ml suspension. Therefore you plate 0.4 ml of a 10-6 dilution of this suspension on a suitable nutrient plate and incubate overnight at a suitable temperature. The next day you count 53 colonies on the nutrient plate. How many bacteria were present in the 20 ml of your stock suspension initially? [20%] d) With the aid of an appropriate diagram show a typical growth curve for Bacillus anthracis. Include in your diagrams details about what will happen if nutrients run out in the solution. [20%] TURN OVER
10 32. Answer ALL parts: (a), (b) and (c). Malaria is a tropical disease which accounts for 1-3 million deaths per year. a) Describe which pathogens cause malaria and with the aid of an appropriate diagram explain the differences in the disease symptoms they cause. [25%] b) With the aid of an appropriate diagram explain in detail how the parasite proliferates and how it infects mankind. [50%] c) Evolutionary pressure on our genome means that some mutation are the cause of disease but at the same time they can be beneficent in preventing infections with parasites. Describe TWO (2) such mutations and how they affect the people when they are present in the genome. [25%]
11 33. Answer BOTH parts: (a) and (b). a) Define the term pharmaceutical preservative. Describe and discuss the properties of an ideal pharmaceutical preservative. [50%] b) Describe the British Pharmacopoeial test for the Efficacy of Antimicrobial Preservation. [50%] TURN OVER
12 34. Answer ALL parts: (a), (b), (c) and (d). A new intramuscular injection formulation of Drug X is sterilised using autoclave at 121 C for killing Soccibalia toralia spores. The viable count of Soccibalia toralia spores measured at specified time intervals are shown in the table below. Time after start of Number of viable micro-organisms process (minutes) (cfu / ml) 1 3.63 x 10 6 3 4.02 x 10 4 5 5.26 x 10 2 7 3.12 x 10 0 a) Explain the terms sterility and SAL. [10%] b) Describe the advantages and disadvantages of steam sterilisation, e.g. autoclave. [20%] c) It is known that the Z value of the Soccibalia toralia spores is 5 C. Use an appropriate graphical method (graph paper is supplied) to calculate the viable count in the same product after 18 minutes of sterilisation, if it was processed at 116 C. [40%] d) Calculate how long it would take to reduce the bioburden of Soccibalia toralia spores in this formulation from 10 7 to 10 1 cfu/ml using a sterilisation process at 126 C. [30%] END OF PAPER