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MMB621S - MEDICAL MICROBIOLOGY 2B - 1ST OPP - 2025 |
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MMB 621S - MEDICAL MICROBIOLOGY 28: 1st OPPORTUNITY EXAMINATION PAPER NOVEMBER 2025
nAm I BIA UnJVERSITY
OF SCIEnCE Ano TECHnOLOGY
FACULTY OF HEALTH, APPLIED SCIFNCES AN D NA fURAL RESOURCE:S
SU IOOL o r HEALTH SCIENCES
DEPARTMENT OF- CLINICAL HE:ALTH SCIENCES
QUALIF ICATION: BACHELOR of MEDICAL LABORATORY SCIENCES
QUALIFICATION CODE: 08BMLS
LEVEL: 7
COURSE: MEDICAL MICROBIOLOGY 2B
COURSE CODE: MMB621S
DATE: NOVEMBER 2025
SESSION: 1
DURATION : 3 HOURS
MARKS: 110
EXAMINER:
MODERATOR:
FIRST OPPORTUNITY: EXAMINATION PAPER
MRS FREDRIKA ENGELBRECHT
MS VANESSA Tl/JENDA
INSTRUCTIONS:
1. Answer all questions on t he separate answer sheet.
2. Pl ease w rite neatly and legibly.
3. Do not use the left side margin of the exam paper. This must be allowed for the
exa m i n e r.
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 Ca lculator
ATTACHEMENTS
1. NONE
THIS QUESTION PAPER CONSISTS OF 8 PAGES (Including this front page)
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MMB 621S - MEDICAL MICROBIOLOGY 28: 1st OPPORTUNITY EXAMINATION PAPER NOVEMBER 2025
SECTION A
QUESTION 1
Choose the correct answer and report only the suitable letter next to the relevant
question number.
1.1 The I<antigens of enterobacteriaciae is associated with:
A) The flagellar proteins.
B) The lipopolysaccharides in the outer membrane.
C) Components of the polysaccharide capsule.
D) The types of linkages between suga r component s.
1.2 The causative organism of Lyme disease is:
A) Borrelia burgdoferi.
B) Treponema pallidum.
C) Leptospirosis icterohaemorrhagie.
D) Borrelia recurrentis.
1.3 Quinolone antibiotics act on organisms t hrough:
A) Inhibiting folic acid synthesis
B)
Inhibiting DNA synthesis.
C)
Inhibiting cell wall synthesis.
D) Inactivating enzymes.
1.4 Virulence factors found in 5. pneumoniae that damages host cells are:
A) Autolysins.
B) The polysaccharid e capsules.
C) Neuramidases.
D) The pneumolysins.
1.5 A bacterial pyuria can be defined as:
A) Urine containing excess pus cells and numerous bacteria.
B) Urine containing excess pus cells and a st erile culture.
C) Urine containing numerous bacteria with no pus cells.
D) Urine containing no bacterial and no pus cells in the.
1.6 The foll owing organism can be identified as a lactose fermenter w hen grown on
MacConkey agar.
A) N. meningitidis.
B) P. aeruginosa.
C) £. coli.
D) P mirabi/is.
(35)
[20)
(1)
(1)
(1)
(1)
(1)
(1)
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MMB 621S - MEDICAL MICROBIOLOGY 28: 1st OPPORTUNITY EXAMINATION PAPER NOVEMBER 2025
1.7 A short course {48hrs) of Glycopeptide antibiotic would be used to treat a:
A) 5. aureus infection acqui red from an intravenous catheter.
B) Coagulase-negative staphylococcal infection acqu ired from an
intravenous catheter.
C) Corynebacterial infection acquired from an intravenous
catheter.
D) Both A and C.
{1)
1.8 Leptospira can be classified as:
A) A strict aerobe.
B) A commensal of the human intestine.
C) A strict anaerobe.
D) As a fastidious organism.
{1)
1.9 The lag between t he onset of infection and prod uction of antibodies can be
define as:
A) The time when a person is already infected, but antibodies are
not yet produced.
B) The time when a person is not yet infected w ith and organism.
C) The time when a person's immune syst em cannot cope w it h an
infection.
D) The time when a person's body do not recognise the infection
as foreign.
(1)
1.10 Identify the organism that is motile at 22°C and not motile at 37°C.
A) Clostridium perfringens.
B) Salm onella paratyphi.
C) Stenotrophomonas maltophilia.
D) Yersinia enterocolitica.
{1)
1.11 Bacitracin sensitivity assists in t he positive identification of:
A) 5. bovis.
B) 5. pneumoniae.
C) 5. agalactiae.
D) 5. pyogenes.
(1)
1.12 The causative organism of tick bite fever is:
A) Treponema pal/idum.
B) Chlamydia trachomatis.
C) Ureaplasma species.
D) Rickettsia connori.
{1)
1.13 Brucella is an organism known to be:
A) Oft en transferred from person t o person.
B) A zoonotic infection.
C) Only causing infections amongst an imals.
D) Not a pathogenic organism.
{1)
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MMB 621 S - MEDICAL MICROBIOLOGY 28: 1st OPPORTUNITY EXAMINATION PAPER NOVEMBER 2025
1.14 Antibiotic synergy can be defined as:
A) The presence of plasmid-mediated resistance for 1 mechanism
results in resistance to numerous drugs.
B)
The utilisation of a combined effect of antibiotic for therapeutic
success.
C) The interaction between drugs with each drug counteracting the
other.
D) The same resistance mechanism affecting several antibiotics.
(1)
1.15 In the asymptomatic phase ofthis disease, the pathogen clears from most areas in
the body, except for the eyes, brain and kidneys:
A) Leptospirosis.
B) Murine typhus.
C) Boutonneuse fever.
D) Epidemic typhus.
(1)
1.16 Post-operative sepsis of the abdomen is associated with
A) Escherichia coli.
B) Campylobacter species.
C} Bacteroidesfragilis.
D) Bordetella pertussis.
(1)
1.17 From a rice water stool sample one expects to isolate:
A) Campylobacter species.
B) Vibrio cholera.
C) Enteroinvasive E.coli.
D) Haemophi/lus ducreyi.
(1)
1.18
The toxin produced by C. diphtheria:
A) Penetrate into the deeper tissues of the host, causing tissue damage.
B) Results in only a localised infection.
C) May spread through the blood stream to other parts of the body.
D) Cause cellulitis at the area of introduction.
(1)
1.19 A positive test for clindamycin inducibility indicates that:
A) That clindamycin can be reported as sensitive.
B) That both clindamycin and erythromycin is sensitive.
C) That both clindamycin and erythromycin should be reported as
resistant.
D) That erythromycin can be reported as sensitive.
(1)
1.20 The most common organism responsibl e for gas gangrene is known to be:
A) An anaerobic spore forming gram positive bacilli.
B) An aerobic spore forming gram positive bacilli.
C)
An anaerobic gram-negative bacilli.
D)
An aerobic gram-negative bacilli.
(1)
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MMB 621S - MEDICAL MICROBIOLOGY 28: 1st OPPORTUNITY EXAMINATION PAPER NOVEMBER 2025
QUESTION 2
Assess the following statements and decide whether they are true or false. Write
only the number of the question and next to it TRUE for a true statement and FALSE for a
false statement and give a reason for calling a statement FALSE.
[15)
2.1 Pseudomembranous colitis is associated with the organism Corynebacterium
perfringens.
2.2 Transient bacteraemia is presence of bacteria in the blood over severa l
hours/days.
2.3 Boric acid is a bacteriostatic agent that inhibits the growth of organisms
when it is added to urine to give a final concentration of 1.8%.
2.4 R. prowazekii directly causes human infection.
2.5 Coxiel/a burnetii is associated with Q fever.
2.6 Acinetobacter species typically present as gram negative cocci usually in pairs
(diplococci) with flattened adjacent sides "Kidney bean"/" Coffee bean" shape.
2.7 lndole differentiates between Proteus vulgaris and Proteus mirabilis.
2.8 Beta-lactamases is an antibiotic that inactivated the B-lactam ring.
2.9 lgM antibodies will indicate that the patient is in the conva lescent stage
of the disease and that he has been previously exposed to the
micro-o rganism.
SECTION B
QUESTION 3
3.1 Categorize the following antibiotics according to its mechanism of action it uses to
have a bacteriocin or bacteriostatic effect.
(35}
[9]
3.1.1 Vancomycin
(1)
3.1.2 Aminoglycosides
(1)
3.1.3 Tetracyclines
(1)
3.1.3 Quinolones
(1)
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MMB 621S - MEDICAL MICROBIOLOGY 28: 1st OPPORTUNITY EXAMINATION PAPER NOVEMBER 2025
3.2 Analyse and evaluate the reactions illustrated in the micro titre plate below and
answer the questions that follows:
F i g . 23-2
cef azolin
a mpicillin
ciproflox acin
s
C)
32
C)
32
~
a
C)
G
@
"16
C)
"16
~
4
C)
a
C)
a
~
2
C)
4
C)
4
~
...
C)
2
~
2
~
0.5
C)
...
~
...
~
µg/ml
µg/ml
0.25 µg/ml
C)
3.2.1) As a scientist, can you consider the results from the micro titre plate to be
accurate? Justify your answer.
(3)
3.2.1 Which antimicrobial agent and at what concentration would effectively
treat the patient when you interpret the results of the micro titre plate.
(2)
QUESTION 4
[19]
4.1 Match the following organisms with its associated disease. Write only the number
and the corresponding letter on your answer sheet.
4.1.1 Enterotoxigenic E.coli
A) Bloody diarhoea in all ages.
4.1.2 Vero cytotoxin-producing E.coli
B) Dysentery-like disease in all ages.
4.1.3 Enteroinvasive E.coli
C) Diarhoea in infants, rarely in
adu lts.
4.1.4 Enterpathogenic E.coli
D) Infant and adult watery diarhoea.
(4)
4.2 Compare the pathogenesis and clinical manifestations of primary and secondary
syphilis.
(15)
QUESTION 5
[7]
5.1 Suggest how a scientist can differentiate between E.coli 0157:H7 from the other
E.coli species in the diagnostic laboratory.
(7)
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MMB 621S- MEDICAL MICROBIOLOGY 2B: 1st OPPORTUNITY EXAMINATION PAPER NOVEMBER 2025
SECTION C
{40)
QUESTION 6
[20]
6.1 A 12-year-old Caucasian boy, always walking bare foot on the farm, presented with
a one-week history of general malaise, mild fever, indolence, and anorexia. He
subsequently developed dysphagia and difficulties opening the mouth and
eventually dehydration. Due to parental concerns about the boy's refusal of fluids,
a paediatrician was consu lted. At that time of presentation, he showed signs of
trismus and muscle rigidity. Together with the lack of immunization and a toenail
infection, the doctor suspected generalised tetanus.
6.1.1 Identify the causative pathogen of generali sed tetanus.
(1)
6.1.2 Illustrate by means of a drawing the gram stain morphology and gram
reaction you expect for this organism.
(2)
6.2 A 1-day old baby presented with an eye infection. Her doctor collected an eye swab
and submitted it to the diagnostic medical microbiology laboratory for URGENT
analysis. Evaluate the slides below, presenting the laboratory findings from the
baby's eye swab culture and answer questions 6.2.1- 6.2.6 based on the case study.
1) Gram stain result from the
eye swab:
i
I
"f
I
2) The culture from the eye swab
on a blood agar after incubation .
I
I~
...
..
II
. \\'
3) Catalase test result:
4) Additional test that was
preformed:
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MMB 621S- MEDICAL MICROBIOLOGY 28: 1st OPPORTUNITY EXAMINATION PAPER NOVEMBER 2025
6.2.1 Report your findings on the gram-stained slide, presented in image 1.
(3)
6.2.2 Report your findings of the growth seen in image 2.
(2)
6.2.3 Report the catalase results from the test presented in image 3.
(1)
6.2.4 Identify the reagent used for the catalase test.
(2)
6.2.5 Discuss the principle of the catalase test.
(3)
6.2.6 Name the test that was performed and presented in image 4. Using a
labelled illustration of the test, explain the principle of the test.
(6)
QUESTION 7
[20]
7 .1 Design a flow chart for the identification of gram-positive cocci, starting with gram
positive cocci seen on the gram-stained slide and ending at specie level
identification.
Please ensure to include all crucial steps in the flow-chart.
(20)
TOTAL: 110 MARKS
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