I teach parasitology and have been frustrated at the dearth of exercises involving living systems (as opposed to viewing prepared slides). Collecting hosts that are already parasitized has been hit or miss. Ideally, if both host and parasite could be maintained in the lab this would open up lots of possibilities. Can anyone recommend such a system? I’m open to all ideas, although I’d rather avoid maintaining mammals. Thanks in advance.
One of the best is Heligmosomoides bakeri. Easy to maintain in mice. If you are not interested in mammals try flour beetles and spirurid nematode Protospirura muricola.
Check work done by Prof. Behnke from University of Nottingham. Best wishes!
http://www.nottingham.ac.uk/~plzfg/pdf%20files/2014%20Schutgens_et_al.pdf
http://www.parasitesandvectors.com/content/3/1/123
Article Heligmosomoides bakeri: A model for exploring the biology an...
How about parasitic plants such as dodder, broomrape and Striga?
From my experience with broomrape (holoparasitic, totally rely on host root), if you put broomrape seeds along host plant roots, it will take several months to see the beautiful flowers aboveground. Although it takes long, broomrape flowers also last long. And broomrape can even keep host plants alive and let them grow longer than they should. Imagine a very big pot with a single rapeseed plant surrounded by multiple purple flowers for several years! I've seen this in our greenhouse for 4 years!
Or go to find and keep a tree surrounded with dodder? :)
Perhaps you should consider using the insect-parasitic nematodes (genera Steinernema and Heterorhabditis) these nematodes can be easily isolated from soil and maintained in the lab. The insect host Galleria mellonella is also easily cultured and in some cases can be purchased in pet stores or online. The EPN with the aid of their mutalistic bacterium cause insect host mortality and reproduce inside the insect cadaver. Nematode infection can be visualized between 24-48hrs, infected insects can be placed onto White traps and subsequently nematodes can be harvested from insects once their life cycle is complete (within 14 days).
There is a great deal of information available online, but this website may be a good start:
http://entnemdept.ufl.edu/creatures/nematode/entomopathogenic_nematode.htm
I like the old stand by Hymenolepis diminuta in Rattus. Also, easily useable are gregarines in Tenebrio. Scott
Like Scott, we used H. diminuta in practicals when I was an undergrad. You can use salt flotation on rat faeces to get the eggs, students can see them under the microscope and with a bit of trypsin you can encourage them to hatch. Also, you can use the intermediate insect host Tenebrio because they undergo a behavioural change and are slower to hide than uninfected beetles. This will mean maintaining rats though, but the students won't be working with them. I wasn't sure if your objection was to using mammals, or trusting students with them.
At Leicester we do some research with a parasitoid wasp Nasonia which lay eggs in the pupae of large flies such as Blowflies. The wasps are fairly easy to maintain and are kept on blowfly pupae here as they're easily available from fishing tackle companies as bait. Egg to adult time is 14 days at 25°C and the larvae/pupae are visible by eye with a simple dissection of the host pupae. A dissecting microscope can give a better view though.
Some mycophagous species of Drosophila are prone to a parasitic nematode called Howardula. This is again a great interaction as the female is ingested by the fly and lays eggs inside and as the numbers grow it eventually becomes fatal. Dissecting a fly to see these worms isn't too difficult, but I don't know how easy it would be to source the flies and the parasites. There are a number of people who work on the interaction though
There is no one size fits all "host parasite model" for either helminths or protists, since both span multiple phyla and occupy different niches in their hosts. Parasitic plants, phage:bacteria systems or even bacterial or viral infections don't really bear mentioning in discussions of host-parasite relationships, if one is interested in accuracy, since these infections are all so radically different from eukaryote parasitic infections. Insect parasites and parasitoids are also not useful, if one is genuinely studying host-parasite relationships in vertebrates. As an old-time parasite immunologist, I also MUST say here it's totally invalid to compare anti-cestode and anti-trematode immune responses to anti-nematode responses. Despite some comments and despite its frequent use as a model, Heligmosomoides polygyrus really does not induce typical GI nematode responses for immune responses, although it is useful for studying hypobiosis (arrested nematode development). What many administrators and/or IACUC committee people don't like is the fact parasitology really needs to be studied in vertebrates and involves infecting (and often killing animals). Thus, the paperwork involved in using Plasmodium berghei infections in a class is ludicrous and will make your head spin, even if you're going to cure the mouse after infection and don't kill it. If you can stand working with chickens or other birds, the coccidia are quite well described and easy to maintain. Some Eimeria spp. in chickens complete their life cycles in just a few days. You can also work with Plasmodium gallinaceum (or P. lophurae, in ducks) and there are many nematodes and tapeworms you can study in birds, all of which are very well-described. Just find a farm flock in a very rural area and you can find all of these in their feces. JPCaruso, PhD, Veterinary Parasitology, 1983, University of Georgia
Screening aquatic snails for trematode cercariae is easy to manage and very didactic. Furthermore, you can keep infected snails in aquarium or outdoor pool even for longer time. If you have a proper host, you can infect it with cercariae and dissect it with students to find the parasite at site of its final localisation. Considering protists, Monocystis sp. are common in seminal vesicles of earthworms and Cryptobia sp. can be found in receptacula seminis of helicid snails.
If you are in areas with white-tailed deer, its relatively easy to find deer feces during the winter by following deer trails. Prevalence of liver flukes, Fascioloides magna, is approximately 30% in many populations, and the procedure for isolating their eggs from feces is fairly simple using FlukeFinder. Eggs are very easy to view under a microscope.
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