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AMB821S - ADVANCED MICROBIOLOGY - 1ST OPP - NOVEMBER 2023 |
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nAmlBIA UnlVERSITY
OF science AnDTeCHnOLOGY
Facultyof Health, Natural
Resourcesand Applied
Sciences
School of Health Sciences
Department of Clinical
Health Sciences
13 Jackson Kaujeua Street
Private Bag 13388
Windhoek
NAMIBIA
T: +264 61 207 2970
F: +264 61 207 9970
E: dchs@nust.na
W: www.nust.na
QUALIFICATION: BACHELOR OF SCIENCESHONOURS
QUALIFICATIONCODE: 08BOSH
COURSE:ADVANCED MICROBIOLOGY
DATE: NOVEMBER 2023
DURATION: 3 HOURS
LEVEL:8
COURSECODE: AMB821S
SESSION: 1
MARKS: 100
FIRST OPPORTUNITY EXAMINATION : QUESTION PAPER
EXAMINER:
MODERATOR:
Dr Munyaradzi Zivuku
Prof Jane Misihairabgwi
INSTRUCTIONS
1. Answer all questions in section A and any three questions from section B.
2. Each question must be answered on the separate answer sheet.
3. Please write neatly and legibly.
4. Do not use the left side margin of the exam paper. This must be allowed for the
examiner.
5. No books, notes and other additional aids are allowed.
6. Mark all answers clearly with their respective question numbers.
PERMISSIBLE MATERIALS
1. Non-Programmable Calculator
This paper consists of 4 pages including this front page
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SECTION A: (40 MARKS)
QUESTION 1 (20)
1.1 You wish to determine the number of bacteria in an actively growing broth culture of
E. coli. To do this you remove 1.0 ml of the culture from the flask and dilute this in 9
ml of nutrient broth to obtain 10-1 dilution. You then serially dilute the sample further
o- until you obtain a range of dilutions between 10-2 and 1 6. From each dilution you then
spread plate 0.1 ml of suspension onto the nutrient agar and incubate overnight. The
next morning you has the following results.
Plate
Dilution
Colonies on plate
number
1
Neat
Too many to count
2
10-1
Too many to count
3
10-2
Too many to count
4
10-3
280
5
10-4
27
6
10-5
2
7
10-6
0
Determine how many bacteria per ml there were in the original sample taken from the
overnight culture.
(5)
1.2 You adjust the density of the cell suspension so that there are 1 x 106 bacteria per ml in
broth and add 1 ml of this to a new culture flask. Assuming exponential growth and a
doubling time of 30 minutes, how many bacteria will be in the flask after 5 hours.
Show your working.
(5)
1.3 A minimum inhibitory concentration (MIC) test was carried out using the results and
the MIC was found to 3.1 ug/ ml of ampicillin drug. Briefly detail how the test is
performed.
(10)
QUESTION 2 (20)
2.1 Briefly evaluate the principle underlying the IMViC test in the differentiation and
identification of specific microorganisms?
(8)
Advanced Microbiology (AMB 821S)
1st Opportunity November 2023
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2.2 Imagine, you are hired as a consultant microbiologist to solve a dispute that has arisen
between the local resident of a town X and the town authorities. The resident is claiming
that the authorities are supplying untreated raw water to the community and
consequently which has led to outbreak of diarrhoea in the community. Furthermore,
they are claiming the water is contaminated with many germs that cause diseases.
Briefly describe the advice you would give to the municipal authorities and the
community to ascertain that water if free from pathogens.
(12)
SECTION B [60 MARKS]
Answer only three questions from this section. Each question carries 20 marks
QUESTION 3 (20)
3.1 Outline the main characteristics to be considered when selecting an organism for
industrial use.
(4)
3.2 Briefly define the term coliforms and discuss their role in the diagnostics of waste water
treatment.
(8)
3.3 Discuss how protoplast fusion has been used to manipulate microorganisms genetically
for industrial use.
(8)
QUESTION 4 (20)
4.1 The basic reproductive number, (Ro), defines the mean number of individuals directly
infected by an infectious case through the total infectious period, when introduced to a
susceptible population, is given by the equation
• Ro=p. c. d
Define the terms p, c, d and how they can be used to combat infections such sexually
transmitted diseases (STI).
(4)
4.2 Briefly evaluate the implication of Ro as used in epidemiology.
(6)
4.3 Discuss five factors leading to the emerging of infectious diseases in the
2!51 century.
(10)
Advanced Microbiology (AMB 821S}
1st opportunity November 2023
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QUESTION 5 {20)
5.1 Outline the benefits of the human gut microbiome.
(10)
5.2 Briefly describe the changes in antibody concentrations following the initial dose of
the Covid-19 jab and how that leads to conferment of long lasting immunity to an
individual.
(10)
QUESTION 6 {20)
6.1 Discussthe role of lactic acid bacteria in the production of hard cheese such as
Gouda.
(10)
6.2 A conglomerate Mine in Southern part of Namibia has been mining, copper, gold,
manganese and iron for the past 60 years using conventional open pit and later
underground mine methods. The management of the mine are contemplating the
closure of the mine since the minerals are now of low grade. However, one the
director of the mine still believes that the life of the mine can be extended by SOyears
if they venture into other methods of mining. You have been hired as a consultant to
give advice on how they can utilize other methods to mine the low grade ores and
extend the life of the mine. Detail the advice you will give to the mine authorities to
convince them to continue to mine at the same premises.
(10)
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END OF QUESTION PAPER
Advanced Microbiology (AMB 821S)
1st Opportunity November 2023
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