LS5008 (Infection and Immunity)
The work is based upon the microbiology practical and a copy was given to you at a recent meeting.

The work should be submitted using 12point Arial font with double line spacing for your body text, although tables and accompanying

legends can be single-spaced.

This work will be submitted electronically to the drop box in the coursework area within the assignments section of the module on

StudySpace by

If for any reason you cannot submit this electronically, please e-mail me your submission (a.kelly@kingston.ac.uk). I will upload it

onto the StudySpace site where it will be checked for similarities through Turnitin.
NB Please read the notes attached carefully to avoid plagiarism, especially self-plagiarism. This piece of work should be

entirely original from that submitted in the reassessment period (August 2015).
Do not submit the diagrams or additional information at the end of this work.
You are reminded of the Faculty Late Submission policy:
For work submitted outside the timescale above:
• Up to a week late a maximum mark of 40% will be awarded
• More than 1 week late zero given
If you are ill or have problems affecting your studies, the University Mitigating Circumstances policy may apply. You will need to

contact SST, complete a form and provide suitable independent documentation. They will then liaise with the module leader.

Remember if you submit a piece of work or attend an examination, you have judged yourself fit to undertake the assessment and cannot

claim mitigating circumstances retrospectively.

Please reference in the Harvard style and cite references throughout your text where necessary (details available on Library website or

front page of My Kingston). You will be penalised for not referencing correctly.
Thework is based upon the material and flow charts provided. Additional information is can be found at the end of this work and you

may also find the practical protocol and the Microbiology Virtual lab on StudySpace useful.

Scenario:You work in a hospital microbiology laboratory and are working towards your IBMS portfolio. Your microbiology lab has

processed fivepatient samples and gained the following test results (Table 1);

Table 1. Results obtained for laboratory tests from five separatepatient samples.

Test undertaken Patient 1 Patient 2 Patient 3 Patient 4 Patient 5
A.Microscopic analysis
Gram stain reaction Negative Positive Positive Negative Negative
Cell shape Rod Coccus Rod Rod Rod
Refractive bodies – – √ – –
B. Biochemical tests
Catalasetest Positive Positive Positive Positive Positive
Oxidasetest Negative Negative Negative Positive Negative
Ureasetest – – – – Positive
Coagulase test – Positive – – –
C. Growth on agar
Growth on NA √ √ √ √ √
Growth on MAC √ √ √ √ √
Colour of growth on MAC Red Light pink Cream Cream Cream

Key: √ = confluent growth; – = not applicable
NA = Nutrient agar(Oxoid Ltd, Cat no. CM0003)
MAC = MacConkey agar(Oxoid Ltd, Cat no. CM0007)

NB:Additionally, an API 20E test was carried out for an isolate from patient 1.
Answer all of the following questions based upon microbiological practice and the results in the table above.

Each question has been allocated marks.
Part 1. Lab tests and protocols

1. What’s the difference between cell morphology and colony morphology?

4 marks

2. What is purity/streak plating and how does it work?
4 marks

3. What does a positive catalase test show?
4 marks

4. What does a positive catalase reaction tell you about the microorganism under test?
4marks

5. How doesthe urease test work?
4 marks

6. What would happen if E. coli was inoculated into nutrient broth and incubated at 37C for 24 hours?
4 marks

7. What would happen if Proteus spp. was inoculated into urea broth and incubated at 37C for 24 hours?
4 marks

8. What is the principle behind the oxidase reaction and what does it tell you about the microorganism under test?
8 marks

9. Why is the oxidase test time dependent?
4 marks

10. Explain how and why one isolate produced red colonies on the MacConkey agar?
4 marks

11. Explain what the API 20E testsfor.
4 marks

12. What happens to the wells filled with paraffin in this test?
4 marks

13. The Gram stain is a differential stain; what information can a microbiologist get from viewing a Gram stain?
8 marks

14. Why is Lugols iodine used in the Gram stain?
4 marks
Part 2. Bacterial identification

15. Using the flow diagrams provided below identify the microorganisms from patients 1 to 5 to genus level.
4 marks

16. What are the refractile bodies in sample 3?
4 marks

The following questions do not relate to the table above but the flow diagrams below.

17. If you were presented with a Gram positive rod identify what this organism is likely to be.
4 marks

18. If you were presented with aGram positive coccus that is catalase positive although coagulase negative identify what this

organism is likely to be.
4 marks
Part 3. Safety

19. What is aseptic technique and why is it important in microbiology?

4 marks

20. What are the important practical aspects of aseptic technique when pouring an agar plate?
4 marks

21. What happens in terms of microbial flora, when we wash our hands?

4 marks
22. Discuss what you would do with the materials after you have finished all the tests mentioned in the above table.
8 marks
Please read carefully.

Points to Remember.
1. This assessed piece of work should be typed with lines 1.5 or double spaced.
2. Do not forget that an academic skills module is available in Studyspace and that the sections on essays and plagiarism may be useful

for you to complete this reassessment coursework.
3. It is also vital that you remember some key points when you are writing Latin names, such as bacterial names. All Latin names

should be in italicsorunderlined. Remember, that when reporting a bacterial name the first part of the name (Genus) has a capital

letter and the second part (species) does not. For Example Salmonella typhi or Salmonella typhi are correct where as Salmonella

Typhi,Salmonella Typhi, Salmonella typhi, Salmonella Typhi and salmonella typhi are all incorrect and should never be reported. Be

sure that the spelling of the names you report are correct, you can check them in any of the text books or journals that you use.

USE OF INTERNET SOURCES
A word about electronic/internet reference sources – whilst the internet is a great potential source of information it must be used

wisely. Just because a webpage exists does not mean that it is correct and accurate. Be sure of your sources and as far as possible

use academically related sites. You should not use non-peer reviewed sources such as Wikipedia or similar sites, or indeed company

sites. These sites may possibly contain inaccurate and/or misleading/biased material. Use of such sites is not acceptable and will

result in a loss of marks or possibly even failure of the given piece of coursework.
You must also reference any internet resource you use in the same way as indicated for literature references. In your

bibliography/reference list you must include a full and accurate internet address for the site in question i.e. URL as well as the date

it was accessed. All referenced sites will be checked and if they are inaccessible you may be penalised.
It is always best to use primary literature i.e. peer reviewed published papers in written work and many of these are available through

the University’s e-journals section on the website.

Plagiarism.
Plagiarism whether from each other, books, journals or internet resources will result in failure. Kingston University will not

tolerate plagiarism in any form; if suspected, you will be interviewed, and if proved a note will be placed on your permanent record

and the piece of coursework will receive zero.

Referencing.
When writing any scientific essay or report it is essential to include references in the text to indicate the source of the information

you are using. Throughout the body of the report references should be cited in a standard format with the author(s) surname(s) and

date of publication in the text, and then listed in full in alphabetical order at the end of the report.

Once again, failure to correctly implement this requirement into all work WILL result in penalty.

An example being,

In the text:
Cardiovascular disease is the leading cause of death and disability in the western world (Ross, 1993). It has been estimated

that about 50% of mortality in the UK is due to the effects of atherosclerosis, the major determinant of cardiovascular disease. The

consequences of atherosclerosis include both myocardial and cerebral infarction as well as gangrene and loss of function of the

extremities. Epidemiological studies have identified a number of factors which are associated with an increased risk of developing

atherosclerosis, including hyperlipidaemia, hypertension, cigarette smoking and lack of exercise (Woolf, 1986). Large population

studies indicate the link between blood cholesterol levels and the frequency of atherosclerotic heart disease in man (Stamler et al.

1986). Two large clinical trials have indicated that morbidity and mortality from ischaemic heart disease (IHD) are reduced by blood

cholesterol lowering therapy (Lipid research clinics results, 1984; The coronary drug project research group, 1975).
In the reference list at the end of the report in alphabetical order:

References
Coronary drug project research group: clofibrate and niacin in coronary heart disease. (1975). JAMA231: 360 381.

Lipid research clinics: coronary primary prevention trial results. (1984). JAMA251: 351 364.

Ross R.(1993). The pathogenesis of atherosclerosis; a perspective for the 1990s. Nature362: 801 809.

Stamler J, Wentworth D, Neaton JD. (1986). Is relationship between serum cholesterol and risk of premature death from coronary heart

disease continuous or graded? Findings in 356 222 primary screenees of the Multiple Risk Factor Intervention Trial (MRFIT). JAMA256:

2823 2828

Woolf N. (1986). Cell tissue and disease: the basis of pathology. 2nd edition. Baillière Tindall, London.