Medical Microbiology
Relevant information
• Knowledge on the roles of pathology laboratories, reference laboratories and PHE in the prevention and control of infectious diseases is highly required.
• Critical review of aetiology and pathogenic mechanisms, of some microbial pathogens, their pathogenesis, symptoms and treatment.
• Appraisal of laboratory techniques used to diagnose infectious diseases.
• Coherent and logical presentation of answers.
• Illustrative diagrams (hand drawn or using a drawing software) are recommended where necessary but must be clearly labelled.
• Avoid repetitions as this would be considered means of increasing words
• Source of reference ranges for tests must be cited
• There will be a plagiarism check on this work.
CASE STUDY 1
A 50-year-old woman went to their GP complaining of nausea, shaking chills, loin pain and a burning sensation on passing urine, which she was doing more frequently than normal.
On examination, her doctor observed that she was a bit pale with some suprapubic tenderness. A urine dipstick test was positive for nitrites, leukocytes and protein.
Pyelonephritis was suspected, and the patient was started on oral antibiotics. A mid-stream urine sample was sent to the local hospital laboratory for confirmation. The laboratory results revealed a pyuria of >105 WBC ml-1, and a pure culture of Escherichia coli > 105 CFU ml-1.
QUESTIONS
Discuss considerations around sample quality and transport and how it affects laboratory results. Discuss the tests performed by the laboratory on a urine sample, how test results confirm a diagnosis of urinary tract infection and provide an example of an automated technology currently in use in diagnostic laboratories. (max 500 words)
CASE STUDY 2
The patient was a 58-year-old man who was seen in the HIV clinic for the evaluation of a new rash. He was taking antiretroviral therapy and had an undetectable HIV viral load and a normal CD4 count of 631cells/ml. Two months before the evaluation the man had had anonymous unprotected sex with another man. At presentation, he complained of two weeks of mild temperature elevation, general achiness and a diffuse rash. On examination, he was afebrile and was covered in innumerable popular, red lesions on his extremities, torso palm and soles of his feet. There were no oral lesions. A presumptive diagnosis of Treponema pallidium (Syphilis) was made.
QUESTIONS
a) What is the pathogenesis of the disease, which this organism causes in human hosts?
(maximum 250 words)
b) What is the role of virulence factors or virulence associated proteins in this disease?
(maximum 250 words)
