DMF MSE 1 2007

1

Which ONE of the following features distinguishes bacterial cells from eukaryotic cells most reliably?


2

Which ONE of the following statements about exotoxins is INCORRECT?


3

Which ONE of the following statements about endotoxins is CORRECT?


4

Which ONE of the following statements about capsules is INCORRECT?


5

A pregnant pig was immunised with K88 fimbriae from an enterotoxigenic strain of E. coli (ETEC). Another pregnant pig was left unimmunised. Each sow gave birth to 16 piglets, eight of which were immediately given to the other pig to suckle (breast feed). After six days the piglets were inoculated with one of two different ETEC strains. One strain carried the K88 antigen on its fimbriae, and the other carried K99, an antigenically different type of fimbriae.

The number of piglets with diarrhoea / number inoculated is shown in the table below.

Which ONE of the following conclusions about the experiment is CORRECT?


6

You have set up a solid phase assay to determine the presence of IgM antibodies to rubella virus in a pregnant woman.

Which of the reagents listed below is the FIRST reagent you would attach to the wells of a micro-titre tray, if the second reagent was the patient’s serum, the third reagent was rubella antigen, the fourth reagent was enzyme labelled anti-rubella immunoglobulin, and the final reagent was the enzyme’s substrate?


7

Which ONE of the following statements regarding the clinical importance of bacterial plasmids is CORRECT?


8

Gram positive cocci have developed several strategies to enable resistance to antibiotics that act on peptidoglycan synthesis, such as the beta-lactam and glycopepetide groups of antimicrobials.

Which ONE of the following is NOT KNOWN to be one of the resistance strategies to either penicillin G or vancomycin?


9

Which ONE of the following the BEST describes the mechanism of action of clavulanic acid?


10

In a suspected outbreak of infection with enterohaemorrhagic E. coli (EHEC), which ONE of the following will NOT be useful in determining if EHEC isolates obtained from different patients are related?


11

Select the site from where you would be MOST LIKELY to isolate Pseudomonas aeruginosa:


12

Which ONE of the following statements about innate immunity is INCORRECT?


13

Delegates at a Microbiology Society meeting attended the first night cocktail party where they were provided with sandwiches and other finger foods, and alcoholic and non-alcoholic drinks. However, 3 – 4 hours later around one quarter of those at the party developed severe abdominal cramps, nausea and profuse vomiting; a small number of those affected also developed diarrhoea.

Which ONE of the following microorganisms is the MOST likely to be associated with these symptoms?


14

Mrs G.B., aged 25 yrs, presents with a two day history of frequency and dysuria. She has no relevant past medical history or allergies, and is not taking any medications, apart from an oral contraceptive. She had these symptoms one month ago, when she had just returned from her honeymoon, but they resolved after the doctor she visited gave her some medication.

Which ONE of the statements below would be MOST consistent with the diagnosis of urinary tract infection?


15

Two months after surgery to place a prosthetic heart valve, Mr. A.F presented with symptoms suggestive of endocarditis. Blood cultures were collected and sent for microbiological examination. 24 hours later, the laboratory reported that a coagulase negative staphylococcus had been grown from the blood cultures. Antimicrobial susceptibility testing suggested that the organism was susceptible to methicillin.

Which ONE of the following statements is CORRECT?


16

One hundred and fifty persons who live in the City of Yarra were diagnosed with Chlamydia trachomatis urogenital infection during March 2004. Typically, approximately 360 persons from this Local Government Area are diagnosed with this infection in the course of each year.

Which one of the following is an UNLIKELY explanation of the above finding?


17

The following steps are important parts of a typical outbreak investigation conducted by a State Health Department.

A: Analyse data by time, place, person and pathogen
B: Conduct a case-control study
C: Confirm that the number of cases exceeds the expected number
D: Conduct surveillance for additional cases
E: Generate hypotheses for an analytic epidemiological study
F: Verify the diagnosis of some cases

In what order should the activities listed above be conducted?


18

For Clostridium perfringens food poisoning, the minimum incubation period is 8 hours, and average incubation period is 10 to 12 hours. Based on the graph below, when were most cases probably exposed to the contaminated food?


19

Which of the following BEST describes the difference between an adverse event and an adverse outcome?


20

Which ONE of the following statements about adverse outcomes is CORRECT?


21

Which ONE of the following questions is an "open ended" question?


22

When taking a patient history, which ONE of the answers below BEST describes the activating trigger for the patient's chest pain?