Talmudic Question #22
by Elio
Pseudomonas aeruginosa is notorious for causing disease across vast taxonomic terrain (insects, worms, vertebrates, plants). Which viruses have a comparably wide host range?
Elio adds later:
The comments on this Talmudic Question have been both enlightening and varied. I should now pipe in with another candidate for a virus that has a particularly wide host range, the Vesicular Stomatitis Virus (VSV, Rhabdoviridae). I had long known that VSV infects mammals and insects, but then some time ago I heard Sean Whelan from Harvard mentioning that it can be induced to infect yeast as well, although this is certainly not a natural host. He supplied the following references:
The original description of the yeast experiments:
Makarow, M., L. T. Nevalainen, and L. Kaariainen (1986) Expression of the RNA genome of an animal virus in Saccharomyces cerevisiae. Proc Natl Acad Sci U S A 83: 8117–21.
The virus also replicates in C. elegans (for which there are currently no known natural viruses).
Schott, D. H., D. K. Cureton, S. P. Whelan, and C. P. Hunter (2005) An antiviral role for the RNA interference machinery in Caenorhabditis elegans. Proc Natl Acad Sci U S A 102:18420–4.
Wilkins, C., R. Dishongh, S. C. Moore, M. A. Whitt, M. Chow, and K. Machaca (2005) RNA interference is an antiviral defence mechanism in Caenorhabditis elegans. Nature 436:1044–7.
Hmmmm. The answer is "none", isn't it? As I recall from virology class, with only one exception that I know of, all viruses require fairly specific "receptor" molecules on their victim cells to attach to. And even then, once inside the cell, most viruses rely heavily on their host cell having particular capabilities that it can hijack, and won't necessarily be able to replicate even if it's somehow artificially injected into a cell type that it doesn't normally infect.
The one exception to all of this that I know of is plant viruses, which as far as I know do not rely on specific cell "receptors" and can only infect plant cells when the plant tissue is damaged. Even then, the need for particular host processes tends to mean a relatively narrow range of potential hosts for a particular plant virus.
I'm assuming you're not including prions despite the fact that a few decades ago they were called "slow viruses". Since we know now that prion proteins aren't really related to viruses at all, the fact that they seem to be able to "infect" a wide range of species doesn't count here, does it?
P.S. Would it be out of place for me to ask, while I'm at it, that readers consider voting for me[1] — one of only a few science bloggers and I believe the only microbiologist who is a finalist — in the college blogging scholarship competition?[2] (If this is out of line, feel free to delete this last bit before posting it. Thanks.)
[1] "Sean Clark"
[2] http://www.collegescholarships.org/blog/2007/10/08/announcing-the-finalists-for-the-2007-blogging-scholarship/
Single virus? None, because of the virus-receptor specificity involved in infection.
However, if you want to allow virus families, the Reoviruses are pretty darn good, infecting plants all the way up the evolutionary scale to Moselio Schaechter!
I don't know if any animal viruses quite compare, but there are numerous examples of viruses that infect taxonomically distinct hosts . Many viruses replicate in both an insect vector and a mammalian host as part of their natural lifecycle, the arboviruses being the best examples. However, if I had to place a bet, it would be on the rhabdoviruses: members of this family are found in invertebrates, vertebrates and plants, the entry protein of VSV can mediate entry into virtually any eukaryotic cell, and VSV itself replicates in both insect and vertebrate hosts. It may also be that our view of virus host range is limited by the fact that we must grow any virus on a host cell in the laboratory to identify it in the first place, limiting us to viruses that can be grown on cells that can be grown in culture — said cells often being whatever is convenient or available. Thus, for any given virus we may not be aware of the true extent of its ecological host range. Also, the majority of viruses that have been identified and isolated are those that cause an overt phenotype in a particular host, so there may well be viral families that are widespread in nature but which are as yet undetected or unstudied. Again, if anything is going to fit the bill, I am betting it will be a rhabdovirus. Finally — and this may or may not be related to the original Talmudic question — the ecological host of ebolavirus, which obviously replicates in humans and other primates, remains a mystery...
Ah, good point about the rabies viruses. Also, now that I come to think of it, doesn't Hantavirus infect both mice and humans?
As far as arboviruses that infect humans (e.g. West Nile virus) — I can't remember, do they actually replicate in mosquitoes or do the mosquitoes merely transport the virus from one infected host to another host?
SMC asks whether arboviruses actually replicate in the mosquito vector — they do — and there is a really cool bit of history that the Microbloggers will appreciate, so if I may: Yellow Fever is now known to be transmitted by mosquito bite, but the mosquito hypothesis was a tough sell. A hundred years ago, most thought the idea was preposterous (it was variously attributed to things like "miasma" or "bad air"), and those who tested the hypothesis failed for the simple reason that they did not allow an incubation period between the time the mosquito fed on an infected volunteer and the time the same mosquito was applied to a healthy volunteer (imagine getting the IRB these days?). Walter Reed finally proved the mosquito vector hypothesis, simply by allowing several days to pass between the first and second step — which we now know is necessary for the virus to infect, multiply and spread to the salivary glands of the mosquito. Jesse Lazear, who worked with Reed, actually died as part of these experiments (and there is speculation that he experimented on himself), and if you go to the University of Virginia's online Walter Reed collection, you can view an image of Lazear's actual fever chart and the telegram that was sent to his wife after his death, along with hundreds of other letters, photos, etc..
http://yellowfever.lib.virginia.edu/reed/collection.html
I can't resist- endogenous retroviruses have infiltrated our genomes and likely have spread through many evoutionary trees following entry into common ancestors. Some can be traced through large phylogenetic groups, perhaps limited only by our ability to recognize a particular family.
I agree with the idea that I think we will find some fairly extensive host ranges, noting that viruses can quickly sort into different strains upon entering new hosts with different selection pressure. Of course, when is a virus "species" diverged enough to be a different one complicates the question.