Frequently, the college will present the candidate with some of this information; eg. "this is a Gram-negative rod in the anaerobic bottle. What could it be?" Thus, the SAQ becomes a game of "Name That Microbe". The table below lists selected organisms which for whatever reason seemed to be of interest. Needless to say, the list is not definitive.
Gram-positive organisms |
Gram-negative organisms |
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Cocci |
Bacilli |
Cocci |
Bacilli |
| Obligate aerobes | |||
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| Facultative anaerobes | |||
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| Obligate anaerobes | |||
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Strictly speaking, "microaerophilic"
True anaerobe:
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Non-Gram-stained organisms: the Atypical Pneumonia Group |
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Yeasts and fungi: |
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Protozoa: |
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Viruses: |
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There are certain key words in the SAQ text which might alert one to a specific pathogen.
For instance, one immediately forms an opinion about the febrile traveller returning from Thailand with purulent urethral discharge. One doesn't even need to hear about their polyarthropathy.
To simplify revision, all such previously examined scenarios (as well as ones which have never been seen before) are collected together into one table. Where appropriate, links point to the specific SAQs.
Pathogen |
Unique historical features |
| Seafood poisoning; fishermen, "coastal slipways", wounds inflicted by angry sea organisms. | |
| AKA "Q fever"; Abattoir workers, cattle farmers; haemoptysis, pneumonia, heart failure and infective endocarditis. | |
| Encephalitis following a flying fox bite | |
| Melioidosis: Gram negative sepsis in a patient recently returned from Papua New Guinea during the wet season | |
| Meningitis in a post splenectomy patient | |
| Listeria monocytogenes | Meningitis with a Gram-positive rod in the CSF |
| Cattle farmers with arthralgia, pneumonia and endocarditis | |
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Hantavirus |
Febrile rat owner or rodent enthusiast |
| Returning African missionary | |
| Decreased level of consciousness (+/- seizures) in a febrile bushwalker | |
| Black nasal discharge and cranial nerve palsy |
(this is found in Question 23.3 from the first paper of 2013, and Question 25.3 from the second paper of 2009. References are available.)
A good free full-text article is available to discuss the origins of nonspecific pulmonary inflitrates on the chest Xray of the AIDS patient. Not surprisingly, in 97% of cases the pulmonary infiltrates are infectious in nature.
In order of frequency:
Billot-Klein, D., et al. "Modification of peptidoglycan precursors is a common feature of the low-level vancomycin-resistant VANB-type Enterococcus D366 and of the naturally glycopeptide-resistant species Lactobacillus casei, Pediococcus pentosaceus, Leuconostoc mesenteroides, and Enterococcus gallinarum." Journal of bacteriology 176.8 (1994): 2398-2405.
Bax, H. I., et al. "Brucellosis, an uncommon and frequently delayed diagnosis."Neth J Med 65.9 (2007): 352-355.
Segal, Leopoldo N., et al. "HIV-1 and bacterial pneumonia in the era of antiretroviral therapy." Proceedings of the American Thoracic Society 8.3 (2011): 282-287.
Feldman, Charles. "Pneumonia associated with HIV infection." Current opinion in infectious diseases 18.2 (2005): 165-170.
Arora, V. K., and S. V. Kumar. "Pattern of opportunistic pulmonary infections in HIV sero-positive subjects: observations from Pondicherry, India." The Indian journal of chest diseases & allied sciences 41.3 (1998): 135-144.
Benito, Natividad, et al. "Pulmonary infections in HIV-infected patients: an update in the 21st century." European Respiratory Journal 39.3 (2012): 730-745.