ZOOL 452 January 7, 2014 (Introduction)
o Tuesdays are for the lecture. Thursdays are for the discussion. This starts
on January 14
o Presentation information has been added as an annotation to the syllabus
o Labs start on January 16, 2014.
o Should take about 1.5 – 2 hours to read the papers at the beginning. May
take more time.
Come with a lab coat every week
General outline for the lectures (each lecture will be framed in this way)
Finding the host
Establishing in the host
Living in the host
Pathology/pathogenesis (associated with the parasite in question)
Maintenance of parasites in a lab
• You have to have a ready source of parasites in the lab. This is difficult in Canada.
• Experimental parasitologists maintain the parasites in the laboratory settings
o Must also maintain the host
o If it is a direct life cycle, that is easy to do. Just passage the parasites
through the natural host.
o For helminthes, which need intermediate hosts, this is difficult.
Eg: Hymenolepis diminuta, which is a rat tapeworm, has an
intermediate host called the flour beetle. Those beetles also have to
be maintained so that parasites can be removed from the flour
beetles and used to infect the rats
• Maintenance of parasites = super expensive. Reduction of costs ▯culture the
parasites in vitro.
o Eg: Giardia intestinalis, human Giardia, can be maintained in the lab.
o Problem: after prolonged cultivation in vitro, parasites can change. The
parasites may be drifting away from what is actually happening in nature.
o The initial isolates are frozen so that the “natural parasites” can be
compared to the parasites that are being continually passaged
o Parasites have incompletely defined media. Eg; “yeast extract”. We don’t
know what the components are or what components are necessary for the
growth of the parasites
o Not knowing the media components may prevent you from being able to
do certain biochemical studies.
• Leishmania paper that was assigned for today
o Promastigotes = easy to culture o Amastigotes =harder to culture
• How do you determine the effectiveness of the in vitro culture? You examine its