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MMB621S - MEDICAL MICROBIOLOGY 2B - 2ND OPP - JANUARY 2024 |
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nAm I BIA un IVERSITY
OF SCIEnCE AnDTECHnOLOGY
Faculty of Health, Natural
Resources and Applied
Sciences
School of Health Sciences
Department of Clinical
Health Sciences
13Jackson Kaujeua Street
Private Bag 13388
Windhoek
NAMIBIA
T: +264 61207 2970
F: +264 61207 9970
E: dchs@nust.na
W: www.nust.na
QUALIFICATION: BACHELOR of MEDICAL LABORATORY SCIENCES
QUALIFICATIONCODE: 08BMLS
LEVEL:6
COURSE:MEDICAL MICROBIOLOGY 2B
COURSECODE: MM8621S
DATE: JANUARY 2024
SESSION: 1
DURATION: 3 HOURS
MARKS: 100
SECOND OPPORTUNITY: EXAMINATION QUESTION PAPER
EXAMINER:
MODERATOR:
MRS FREDRIKAENGELBRECHT
MRS CARA-MIA DUNAISKI
INSTRUCTIONS:
1. Answer all questions on the separate answer sheet.
2. Please write neatly and legibly.
3. Do not use the left side margin of the exam paper. This must be allowed for the
examiner.
4. No books, notes and other additional aids are allowed.
5. Mark all answers clearly with their respective question numbers.
PERMISSIBLE MATERIALS:
1. Non-Programmable Calculator
ATTACHEMENTS
1. None
This paper consists of 6 pages including this front page.
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ISECTKJNA: MULTIPLECHOICEAND TRUE/ FALSE
QUESTION 1: MULTIPLECHOICEQUESTIONS
(10 MARKS]
Evaluate the statements in each numbered section and select the most appropriate answer
or phrase from the given possibilities. Fill in the appropriate letter next to the number of the
correct statement/phrase on your ANSWERSHEET.
1.1 The K antigens of enterobacteriaciae is associated with:
A) The flagellar proteins.
B) Components of the polysaccharide capsule.
C) The lipopolysaccharides in the outer membrane.
D) The types of linkages between sugar components.
(1)
1.2 Mycoplasma can be defined as:
A) a gram-negative bacillus.
B) an intracellular parasite.
C) the smallest self-sufficient bacteria.
D) a common causative organism of eye infections.
(1)
1.3 Bacterial cross-resistance refers to:
A) Resistance constantly expressed.
B) One change that result in resistance to several drugs.
C) Resistance expressed when micro-organism is exposed to a specific
drug.
D) Resistance expressed by an entire population.
(1)
1.4 Durham tubes are used in microbiology in order to:
A) Interpret the ability of a specific organism to produce gas.
B) Interpret carbohydrate utilization by a specific organism.
C) Interpret the ability of a specific organism to change the pH of
media.
D) Interpret whether an organism ferments or oxidize a carbohydrate.
(1)
1.5 The cytokines released during an infection with 5. typhi results in:
A) Leucocytosis.
B) Inflammatory reaction in the Peyer's patches.
C) Spread of the organism to the mesenteric lymph nodes.
D) Bacteraemia.
(1)
1.6 The following organism ferment lactose when grown on MacConkey agar
A) N. meningitidis.
B) £. coli.
C) P. aeruginosa.
D) Proteus mirabilis.
(1)
Medical Microbiology 2B (MMB621S) 2nd Opportunity Examination Paper- January 2024
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1.7 The sample required for diagnosing the causative organism for infective
endocarditis is a:
A) nasopharyngeal swab.
B) urine sample.
C) blood culture.
D) tissue biopsy.
(1)
1.8 Novobiocin are used to distinguish between:
A) Staphylococcus epidermidis & Staphylococcus saprophyticus.
B) Staphylococcus aureus & Staphylococcus saprophyticus.
C) Streptococcus spp and Staphylococcus spp.
D) Staphylococcus aureus & Staphylococcus epidermidis.
(1)
1.9 Virulence factors of Streptococcus pyogenes that aids the organism to
escape host defense is(are):
A) The outermost capsule of hyaluronic acid.
B) Streptokinases A & B lyse.
C) Hyaluronidase.
D) All of the above.
(1)
1.10 The Salmonellae Vi antigen:
A) Is an acidic polysaccharide antigen that overlay the O antigen.
B) Exhibit the property of diphasic variation
C) Are fimbria antigens
D) Are determined by the complete sugar sequence.
(1)
QUESTION 2
[15)
Assessthe following statements and decide whether they are true or false. Write only the
number of the question and next to it TRUEfor a true statement and FALSEfor a false
statement and give a reason for calling a statement FALSE.
2.1 C. diphtheria to only pathogenic when it is infected with the tox gene via a
bacteriophage.
2.2 Bacillus species is only causing infectious and is always harmful to society.
2.3 Citrate utilization should be incubated anaerobically for accurate results.
2.4 Bacteroides fragilis is an aerobic organism usually responsible for conjunctivitis.
2.5 Clostridium perfringens is the causative organism of Bubonic plaque.
2.6 The anthrax toxin causes an increase in vascular permeability resulting in shock.
2. 7 Permease is the enzyme that transport glucose into cells.
Medical Microbiology 28 (MMB621S) 2nd Opportunity ExaminationPaper-January2024
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2.8 Citrate utilization should be analysed in anaerobic conditions.
2.9 Scientists rely on the K-antigens of Shigella species to serologically distinguish
between the different Shigella species.
;SECTION B: SHORT/LONG ANSWER QUESTIONS __.,...,
Please answer ALL of the questions in this section.
(75 MARKS]J
QUESTION 3:
3.1 Categorize the following antibiotics according to its bacterial targets:
A) Vancomycin
B) Aminoglycosides
C) Tetracyclines
D) Quinolones
(16 MARKS]
(1)
(1)
(1)
(1)
3.2 Differentiate between C. perfringens and C. tetanus under the following headings:
A) Gram reactivity,
(2)
B) Spores form and location,
(2)
C) Haemolysis,
(2)
D) Motility,
(2)
E) Lecithinase production and
(2)
F) Glucose fermentation.
(2)
QUESTION 4
[8]
4.
A patient is presenting with the following clinical symptoms illustrated in the image
below:
f,,,.. [ SBiSITMTYTO
·7 ")l Ua«
f fEVBI.S£VfBfHEADACHE.
.... FCIOTSN.LROJSSISOOSFNWc.tlPNISNCEISOSU, SNESS
Sllff NECK
Bm OBPURPlfRASH
f'Ch•t... ..,,"l~-hiiwl
y.u~•••O
.-.{. ctllD HANDS& FEET)
{ MUSCL&EJOIHPTAIN)
4.1) Point out what specimen should be collected to identify the causative pathogen? (1)
Medical Microbiology 28 (MMB621S) 2nd Opportunity Examination Paper- January 2024
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4.2) Illustration, what you expect so see on the gram stain slide from the specimen? (2)
4.3) Suggest tests which will enable you to identify the organism, and give the expected
results.
(4)
4.4) Predict the expected pathogen responsible for the presented clinical symptoms.
QUESTION 5
[12]
5.1 Justify and explain why the TPHA is considered a specific serological test.
(4)
5.2 Summarize some of the mechanisms used by bacteria to resist the effects of
antibiotics and give an example for each of the mentioned mechanisms.
(8)
QUESTION 6
[24]
6.1 Using a labelled illustration indicate how a scientist will test for the presence of a
toxin producing C. diphtheriae AND explain the principle of the test.
(9)
6.2 Propose factors affecting the quality of the final microbiological report, and
explain why these factors affect the quality.
(4)
Medical Microbiology 28 (MMB621S) 2nd Opportunity Examination Paper- January 2024
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6.3 A pregnant woman presented with a vaginal discharge but with no further
symptoms of infection. Her doctor collected a vaginal swab and submitted it to
the diagnostic medical microbiology laboratory for analysis.
Study the slides below presenting the laboratory findings from the pregnant
patient and then answer the questions.
Image 1: Gram stain result from
the swab vaginal swab:
vr-~
~-
t~'c;;;;.L,.~~~-~- ·. -~ -(
<&\\.- . ,) /···-··I ·'
- ,,(1 ' ('r~~
iM y~
!:
Image 2: The culture from the vaginal
on a blood agar after incubation.
Image 3: Catalase test result:
Image 4: Additional test that was
performed:
6.3.1) Report your findings on the gram-stained slide, presented in Image 1. (3)
6.3.2) Report your findings of the growth seen on Image 2.
(2)
6.3.3) Report the catalase results from the test presented in Image 3.
(1)
6.3.4) Identify the reagent used for the catalase test.
(2)
6.3.5) Discussthe principle of the catalase test.
(3)
QUESTION 7
[15]
Briefly identify the important steps in diagnosing typhoid fever in the
microbiology laboratory.
(15)
END OF EXAMINATION PAPER
Medical Microbiology 2B (MMB621S) 2nd Opportunity Examination Paper- January 2024
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