BSc Plant Science with Industrial/Professional Experience / Course details

Principles of Infectious Disease will provide you with a broad understanding of the biology of microbial infections, with an emphasis on bacterial human infections. You will study the mechanisms of bacterial pathogenicity, starting with pathogen transmission and entry into the host, progressing through adhesion and invasion, to cell and tissue damage and host responses to injury. The diseases studied will include tuberculosis, cholera, listeriosis. salmonellosis, gonorrhoea and pseudomembranous colitis.

 

BIOL21192 Pre- & Co-requisites are BIOL10532

To explore the fundamentals of how microorganisms cause disease and the interactions that occur between a pathogen and host during infection. To study the mechanisms of microbial pathogenicity (focussing on bacteria), starting with pathogen transmission and entry into the host, progressing through adhesion, invasion and pathogen survival strategies within a host, to cell and tissue damage and host responses to infection. To gain a detailed understanding of the mechanisms of pathogenesis and disease for exemplary human pathogens.

On successful completion of this unit, students should be able to:

• Define the key host defences in preventing microbial infections and explain how they protect against bacterial pathogens.
• Describe the strategies used by bacteria to penetrate host external defences and explain, using examples, the mechanisms used in host colonisation and/or invasion.
• Describe, including examples, bacterial strategies for avoiding killing by phagocytes and explain how they function.
• Describe bacterial strategies for evading complement and antibodies and explain the mechanisms involved.
• Outline key factors that contribute to opportunistic infections.
• Define the structural features of bacterial products that contribute to the pathology of infectious disease (including endotoxin, exotoxins, lipoarabinommannan, pili, polysaccharide capsules, urease, invasins and secreted effector proteins. Use this information to explain how they function.
• Illustrate the mechanisms of action of bacterial exotoxins. Compare and contrast their structures and mechanisms of action.
• Explain the mechanisms of pathogenesis of selected human pathogens in detail (these representing paradigms of pathogen-host interactions) and analyse how these mechanisms promote survival within a host.
• Describe the main classes of antibiotics and their targets and discuss examples of antibiotic resistance.
• Interpret and analyse primary research papers.    

Basic concepts of microbial pathogenicity and virulence

• Colonisation and invasion of the host: Routes of entry and exit.
• Host surface defences and bacterial mechanisms of colonisation and invasion
• Specific examples of diseases associated with colonisation via pili: uropathogenic Escherichia coli and Neisseria gonorrhoea
• The normal microbiota & opportunistic infections
• Encounter with innate immunity: Phagocytic effector cells and complement, mechanisms of microbial killing. Microbial strategies for overcoming innate immune defences
• Encounter with adaptive immunity: Pathogen adaptation to growth in the host and antibody avoidance

Mechanisms of cell and tissue damage

• Introduction to toxin types and septic shock
• Toxins in specific diseases (diphtheria, botulism, tetanus, cholera & whooping cough)

Selected human infectious diseases in detail

• Survival in macrophages: Mycobacterium tuberculosis and the disease TB
• Gastro-intestinal disease: Diarrheagenic Escherichia coli
• Salmonellosis: Salmonella enterica serovars Typhimurium and Typhi
• Colonisation of the stomach mucosa by Helicobacter pylori
• Intracellular survival and spread: The food-borne pathogen Listeria monocytogenes and listeriosis

Emerging diseases

• Clostridium difficile and pseudomembranous colitis
• Borrelia burgdorferi and Lyme disease

Infectious disease treatment

• The main classes of antibiotics: History, targets and resistance

eLearning Activity

An eLearning (ePBL) based coursework module will be set using Blackboard and will be based upon a published research article on a topical subject related to course content. This should be undertaken during week 5 of the course. This eLearning exercise will form part (10%) of the overall assessment of the unit. In addition, lecture slides and materials that support the lecture material will also be posted on Blackboard.

 

Written examination (90%):

1 hour 30 minute written examination consisting of two sections; A, short answer questions (50%, 4 out of 6 questions) and B, essay (50%, 1 out of 4 questions)  

Set exercise – Online coursework assessment (10%):

Online e-learning assignment based upon reading a research paper (single online test regarding comprehension of the paper comprising 10 multiple answer and true/false questions)

 

Feedback will be given on the eLearning coursework exercise and by end of semester exam marks. This will include: (i) formative individual feedback to all students regarding performance in the eLearning activity, and (ii) general feedback on exam performance by releasing a document addressing general strengths and weaknesses of answers and how questions were answered, and (iii) individual feedback on exam performance will be given by a drop-in session run by the unit coordinator or by individual correspondence (written or verbal) upon request.

Students will also be provided with the opportunity (non-assessed) to write a practice exam essay/short answer prior to the exam and will be given individual formative feedback. Optional (non-assessed) e-learning quizzes will also be available throughout the course for students to gain formative feedback on their understanding of lecture material.

 

 

Wilson, BA, Salyers, AA, Whitt, DD & Winkler, ME, Bacterial Pathogenesis: A Molecular approach (3rd edition), ASM Press, 2010, Chapters 1, 2, 3, 4, 5, 6, 7, 11, 12, 13, 15, 16, 18 & 19 (Recommended)

 

Details of up-to-date relevant reviews will also be provided during the course as optional reading