Download Some homework to help you prepare for your event:

Some homework to help you prepare for your event:
Microbiologists study the microorganisms, the acellular viruses as well as the cellular microbes: the prokaryotic bacteria and
archaea and the eukaryotic microbes, the fungi (this includes the moulds and the yeast) and those collectively referred to as
the “protists” (subdivided into the algae and the “protozoa”). Before you come to Guelph, you should know some of the basic
details about these various groups, as described below.
For those entering the senior event:
1. What are the basic structural features of each of these groups?
2. For each of the following representatives, determine the average size and based on the scale, whether a dissecting microscope,
light microscope (+/- staining) or an electron microscope would be best to view the entire microorganism:
Influenza
virus
Size
(mm, um, nm)
Method of visualization
(dissecting microscope,
light microscope, electron
microscope)
Morphology/appearance
upon microscopic
examination
Bacterial cell:
Listeria
monocytogenes
Archaeal cell:
Methanobrevibacter
ruminantium
Eukaryotic:
Giardia
lamblia
Eukaryotic:
Spyrogyra
species
Eukaryotic:
Aspergillus
fumigatus
Eukaryotic:
Candida
albicans
3. Bacteria can be further subdivided into three basic groups, using differential staining approaches (hint: Gram staining). What are
these three different groups? What different cellular morphologies might you see looking at stained microscopic smears of a few
bacterial representatives?
4. Do all of the above groups and sub-groups contain organisms that are pathogenic to humans or animals?
5. Only for the representative organisms in the above table that are pathogenic to humans or animals, investigate the basic
mechanism of pathogenesis – i.e. mode of transmission, critical virulence factor(s) (if any), symptoms, method of
diagnosis/pathogen identification, method of treatment (if any), patient’s prognosis.
6. Make sure you understand why you would use something like penicillin to treat a particular bacterial infection and why this would
not be effective in treating an infection by another class of microorganism (e.g. virus).
For those entering the junior event:
1. What are the basic structural features of the bacteria and the viruses?
2. For the following representatives, determine the average size and based on the scale, whether a light microscope (+/- staining) or
an electron microscope would be best to view the entire microorganism:
Influenza
virus
Size
(mm, um, nm)
Method of visualization
(light microscope,
electron microscope)
Morphology/appearance
upon microscopic
examination
Bacterial cell:
Listeria
monocytogenes
3. The bacteria can be further subdivided into three basic groups, using differential staining approaches (hint: Gram staining). What
are these three different groups? What different cell shapes might you see looking through the appropriate type of microscope?
4. For the two representative organisms in the above table, investigate the basic mechanism of pathogenesis – i.e. how it spreads
from one host to another, how it gives rise to symptoms (if known), typical symptoms of infection, how doctors diagnose the cause
of the illness, method of treatment (if any) and the likely outcome of infection.
5. Make sure you understand why an antibiotic used to treat a bacterial infection would not be used to treat a viral infection and vice
versa.