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MMB711S - MEDICAL MICROBIOLOGY 3 - 2ND OPP - JULY 2023 |
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nAm I Bl A UnlVE RS ITY
OFSCIEnCEAno TECHnOLOGY
FACULTYOF HEALTH,APPLIEDSCIENCESAND NATURALRESOURCES
SCHOOLOF HEALTHSCIENCES
DEPARTMENTOF CLINICALHEALTHSCIENCES
QUALIFICATION:BACHELOR OF MEDICAL LABORATORYSCIENCES
QUALIFICATIONCODE: 08BMLS
LEVEL:7
COURSECODE: MMB711S
COURSENAME: MEDICAL MICROBIOLOGY 3
SESSION:
JULY 2023
PAPER:
THEORY
DURATION: 3 HOURS
MARKS:
101
SECONDOPPORTUNITYEXAMINATION QUESTION PAPER
EXAMINER{S) Ms. V Tjijenda and Dr Markus Schuppler
MODERATOR: Prof R.T. Mavenyengwa
INSTRUCTIONS
1. Answer ALL the questions
2. Write clearly and neatly
3. Number the answers clearly
THIS QUESTION PAPERCONSISTSOF 9 PAGES(Including this front page)
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SECTION A (25)
QUESTION 1
[20]
Evaluate the statements below and determine whether each statement is true
or false. If you state false, provide the correct statement.
1.1 Xpert MTB/RIF is a nucleic acid amplification test.
1.2 Acid fastness is a property associated with all mycobacterium species.
1.3 Mycobacterium canetti forms part of the non-tuberculosis mycobacterium
1.4 Tuberculin skin test is negative in latent TB infection
1.5 A negative Xpert MTB/RIF in a 3-year-old suggest no TB infection.
1.6 lateral-flow lipo-arabinomanan Antigen (LAM) Ag is a TB urine test signifying
active TB disease.
1.7 Extensively drug resistant TB is defined as resistance to any fluoroquinolone,
and at least one of three injectable second-line medicines (capreomycin,
kanamycin and amikacin), in addition to resistance to rifampicin.
1.8 Mono resistance is defined as resistance to at least one anti-TB medicine.
1.9 Tuberculoid leprosy is non-infectious with a spontaneous recovery.
1.10 18 acid fast bacilli in 10 fields are scored a 1+ during Auramine O staining.
1.11 gyrA mutation is suggestive of resistance to one of the aminoglycosides.
1.12 lnh mutation is suggestive of a drug resistant mutation and can therefore not be
treated with isoniazid.
QUESTION 2
[S]
2.1 Choose the correct answer and report only the suitable letter next to
the relevant question number.
(5)
2.1.1 With increased levels of oxidizable organic materials in wastewater,
the biochemical oxygen demand (BOD) will:
(1)
A. increase
B. decrease
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C. remain the same
D. increase or decrease depending on the nature of the materials involved
2.1.2 Microbes are involved in which step(s} of wastewater treatment?
(1)
A. primary and secondary
B. primary and tertiary
C. secondary and tertiary
D. secondary only
2.1.3 Which microorganisms produce CH4 during anoxic sewage treatment? (1}
A. Archea
B. Bacteria
C. Mould
D. Protozoa
2.1.4 Which bacterium is used as an "indicator organism" in drinking water
analysis?
(1)
A. Staphylococcus aureus
B. Legionel/a pneumophila
C. Enterococcus faecal is
D. Rhanel/a aquatilis
2.1.5 Which bacterium is not a waterborne pathogen?
(1)
A. Campylobacter jejuni
B. Vibrio cholerae
C. Shigella flexneri
D. Staphylococcus aureus
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SECTIONB (60)
QUESTION 3
3.1 Use the below images to answer the questions that follow:
I
[20]
Figure A
Figure B
3.1.1 Complete the following table for the fungi above
Identify the fungi
Type of spore
Type of Hyphae
Reproduction
Colony colour
Figure A
(a)
(c)
(e)
(g)
(i)
(10)
Figure B
(b)
(d)
(f)
(h)
(j)
3.2
Rachel went to visit her local doctor and explained that she had a problem
'down below'. She was feeling very sore, and had noticed some sticky white
discharge on her pants. She had also noticed that there was some stinging
when she urinates. She further indicated that she only had one regular
boyfriend and had never had sex with anyone else. Upon investigation the
vulva was swollen and red, and there was a thick white discharge coming
from the vagina. A high vaginal swab was collected, labelled, and sent to the
laboratory for culture.
3.2.1 What is the suspected infection and the causative agent?
(2)
3.2.2 Discuss the expected results on culture and gram stain.
(2)
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3.2.2
Explain the diagnostic test will you perform to confirm the infection
in 2.2.1
3.2.3 What is the expected results of on chromogenic agar.
QUESTION 4
(5)
(1)
[21]
4.1 Identify the parasite (Genus and species were relevant) from information
given below.
4.1.1 A 63-year-old male from rural village with a village with a hydatid cyst (2)
4.1.2 A parasite with freshwater snails as intermediate host and which may be
detected in a properly collected urine specimen of infected patients.
(2)
4.1.3 A stool specimen containing adult worms resembling whips and ova with
prominent bipolar plugs.
(2)
4.1.4 Acid fast parasite routinely stained for in stool specimen of children with
diarrhoea.
(2)
4.1.5 A tissue amebae responsible for causing PAM.
(2)
4.1.6 Obligate intracellular parasite that can be transmitted congenitally
when the tachyzoites cross the placenta.
(2)
4.2
The sample below was collected from a patient who has a history of travelling to
South Asia to visit his family. The patient recalls being bitten by mosquitos.
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4.2.1 Identify the organism to specie level.
4.2.2 What stage of the parasite is this?
4.2.3 Mention the disease associated with this pathogen.
4.2.4
Discuss the organism under the following:
(a) red blood cell size
(b) inclusion bodies
(c) number of merozoites in schizont
red blood cell size
inclusion bodies
number
of
merozoites
in
schizont
P. vivax,
4.2.5 Perform a parasitaemia count on the two fields below.
(1)
(1)
(1)
(3)
(3)
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QUESTION 5
[19]
5.1
A patient visited his doctor and presented with yellowing of the skin and
eyes (jaundice), dark urine, extreme fatigue, nausea, vomiting and
abdominal pain. A sample was taken and sent to the laboratory for
analysis. The following tests were performed and results are shown:
Viral Serology for Hepatitis B.
Marker
HBsAG
HBeAG
lgM Anti-H Be
lgG Anti-HBe
lgG Anti-HBs
HBV-DNA
Result
-·
Positive
Positive
Positive
Negative
Negative
Positive
5.1.1 Discussthe laboratory findings and the significance of each marker.
(12)
5.2 Compare and contrast between Influenza A, Corona Virus and Respiratory
Syncytial Virus using criteria:
(7)
5.2.1 Type of infection they cause
5.2.2 Patient group mostly affected
5.2.3 Surface proteins
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SECTIONC (16)
QUESTION 6
[16]
6.2 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
(10)
6.2.1 Cereulide is the heat stable emetic-type toxin produced by Bacillus
cereus during growth of the bacteria in the small intestine.
6.2.2 Cereulide is the heat stable emetic-type toxin of Bacillus cereus, which
is synthesized independent from ribosomes.
6.2.3 Members of the Bacillus cereus group (ACTgroup) have rather similar
metabolic and biochemical characteristics and can only be distinguished
due to their specific virulence factors.
6.2.4 The light chain of the BoNT protein is responsible for the translocation
of the heavy chain into the target cells.
6.2.5 Different C/ostridium botulinum neurotoxin (BoNT) types cleave different
proteins of the SNAREcomplex.
6.2.6 Molecular mimicry in Campy!obacter jejuni means the bacteria produce
a lipo-oligosaccharide that contains components that are similar to the
ganglioside in nerve cell membranes.
6.2.7 Campy/obacter jejuni produce a cytolethal distending toxin (Cdt) that leads
to damage in mitochondria.
6.2.8 Besides the stx genes most EHECstrains also contain a pathogenicity island
that encodes a "type Ill secretion system".
6.2.9 Listeria monocytogenes feature temperature dependent regulation
of virulence gene expression to make sure that virulence factors are
only produced in warm blooded animals.
6.2.10 Listeriosis is in particular dangerous for humans belonging to
the YOPI risk group, meaning: Young, Old, Pregnant, Incontinent.
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r
6.3.1 Label the components of the image below accordingly.
(5)
1
2.
Antigen presenting cell (APC)
02015 Pe.uson Educa!ion. lr.c.
6.3.2 What important characteristic of Staphylococcal Enterotoxins is responsible
for the frequent occurrence of food poisoning by this toxin?
(1)
END OF EXAMINATION
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