LSH4801
PORTFIOLIO
COMPLETE ANSWERS 2024
DUE 22 November 2024
, ACTIVITIES
QUESTION 1 [30] 1.1. Clinical laboratories routinely process specimens containing
pathogenic microorganisms that require precise identification. Explain how you would apply
immunofluorescence to identify Streptococcus pyogenes isolated from a patient sample and
explain how you would differentiate it from other morphologically similar streptococci and
staphylococci. (10) 1.2. Explain the clinical rationale for the use of a rapid test procedure
such as the Enterotube II system for the identification of enteric microorganisms. (10) 1.3.
Your 20-year-old cousin was informed following a physical examination that her blood test
for syphilis was reactive. She indicated that she was a virgin and had never received a blood
transfusion. A repeat Rapid Plasma Regain (RPR) test was positive, but the Treponema
pallidum immobilization (TPI) test was negative. Explain these strange results and the
clinical status of your cousin. (10) QUESTION 2 [20] A patient was admitted to a hospital
with urinary tract infection, and antibiotic sensitive Klebsiella pneumoniae were identified.
During hospitalization the patient became nonresponsive to antibiotic therapy, and the new
isolates of K. pneumoniae were now resistant to ampicillin and kanamycin. Stool cultures of
all patients in the ward revealed that several of them carried E. coli which was also resistant
to ampicillin and kanamycin. You are in charge of determining if K. pneumoniae somehow
acquired an R-plasmid from E. coli. Describe the molecular tools that one would use to prove
the plasmid transfer hypothesis. QUESTION 3 [15] People with acquired immunodeficiency
syndrome (AIDS) are vulnerable to toxoplasmosis caused by the protozoan Toxoplasma
gondii, resulting in infection of the lungs, liver, heart and brain and often leading to death.
About 25% of the world population is infected, usually without developing symptoms. Explain
the underlying reasons why people with AIDS are so susceptible to this disease. QUESTION
4 [15] On returning from a trip overseas, Karabo had a persistent diarrhoea, and she was
later diagnosed with having Entamoeba histolytica infection. Faecal examination reveals the
presence of blood in the stool, suggesting damage to the intestinal mucosa. Explain why and
how the mucosa was compromised by this parasite. QUESTION 5 [20] A female patient
develops candidiasis following prolonged antibiotic therapy for a bladder infection caused by
Pseudomonas aeruginosa. Elaborate on the development of this concurrent vaginal
infection. This study source was downloaded by from CourseH on :35:23 GMT -06:00
PORTFOLIO LSH4801/2024/Portfolio 3 QUESTION 6 [15] The release of phage particles
from the host bacterium always occurs by lysis of the cell and results in the death of the
host. Animal viruses are released by either the lysis of the host cell or exocytosis, a reverse
pinocytosis. Regardless of the mechanism of release, most of the infected cells die, while
other viruses may escape the cell without damaging the host cell. Discuss the mechanisms
of viral release and their impact on host cell survival. QUESTION 7 [35] Read the attached
article ( summary by addressing the following questions: 7.1 What is a retrospective study?
, Please explain in your own words with reference to the article provided. (5) 7.2 Address the
issue of HIV and co-infections with reference to HIV pathogenesis. (10) 7.3 What was the
rationale for carrying out the study? (3) 7.4 Describe the significant outcomes of the study.
(7) 7.5 Criticize the work done by these authors. Explain what you would have done
differently suppose you were the investigator carrying out the study.
PORTFIOLIO
COMPLETE ANSWERS 2024
DUE 22 November 2024
, ACTIVITIES
QUESTION 1 [30] 1.1. Clinical laboratories routinely process specimens containing
pathogenic microorganisms that require precise identification. Explain how you would apply
immunofluorescence to identify Streptococcus pyogenes isolated from a patient sample and
explain how you would differentiate it from other morphologically similar streptococci and
staphylococci. (10) 1.2. Explain the clinical rationale for the use of a rapid test procedure
such as the Enterotube II system for the identification of enteric microorganisms. (10) 1.3.
Your 20-year-old cousin was informed following a physical examination that her blood test
for syphilis was reactive. She indicated that she was a virgin and had never received a blood
transfusion. A repeat Rapid Plasma Regain (RPR) test was positive, but the Treponema
pallidum immobilization (TPI) test was negative. Explain these strange results and the
clinical status of your cousin. (10) QUESTION 2 [20] A patient was admitted to a hospital
with urinary tract infection, and antibiotic sensitive Klebsiella pneumoniae were identified.
During hospitalization the patient became nonresponsive to antibiotic therapy, and the new
isolates of K. pneumoniae were now resistant to ampicillin and kanamycin. Stool cultures of
all patients in the ward revealed that several of them carried E. coli which was also resistant
to ampicillin and kanamycin. You are in charge of determining if K. pneumoniae somehow
acquired an R-plasmid from E. coli. Describe the molecular tools that one would use to prove
the plasmid transfer hypothesis. QUESTION 3 [15] People with acquired immunodeficiency
syndrome (AIDS) are vulnerable to toxoplasmosis caused by the protozoan Toxoplasma
gondii, resulting in infection of the lungs, liver, heart and brain and often leading to death.
About 25% of the world population is infected, usually without developing symptoms. Explain
the underlying reasons why people with AIDS are so susceptible to this disease. QUESTION
4 [15] On returning from a trip overseas, Karabo had a persistent diarrhoea, and she was
later diagnosed with having Entamoeba histolytica infection. Faecal examination reveals the
presence of blood in the stool, suggesting damage to the intestinal mucosa. Explain why and
how the mucosa was compromised by this parasite. QUESTION 5 [20] A female patient
develops candidiasis following prolonged antibiotic therapy for a bladder infection caused by
Pseudomonas aeruginosa. Elaborate on the development of this concurrent vaginal
infection. This study source was downloaded by from CourseH on :35:23 GMT -06:00
PORTFOLIO LSH4801/2024/Portfolio 3 QUESTION 6 [15] The release of phage particles
from the host bacterium always occurs by lysis of the cell and results in the death of the
host. Animal viruses are released by either the lysis of the host cell or exocytosis, a reverse
pinocytosis. Regardless of the mechanism of release, most of the infected cells die, while
other viruses may escape the cell without damaging the host cell. Discuss the mechanisms
of viral release and their impact on host cell survival. QUESTION 7 [35] Read the attached
article ( summary by addressing the following questions: 7.1 What is a retrospective study?
, Please explain in your own words with reference to the article provided. (5) 7.2 Address the
issue of HIV and co-infections with reference to HIV pathogenesis. (10) 7.3 What was the
rationale for carrying out the study? (3) 7.4 Describe the significant outcomes of the study.
(7) 7.5 Criticize the work done by these authors. Explain what you would have done
differently suppose you were the investigator carrying out the study.
