Your comment about viruses reminds me of something from Lives of a Cell which is one of my favorite books and perhaps worth quoting on the subject of the scales of life. I certainly didn’t appreciate the fact that bacteria were susceptible to viral infections before reading this:

In real life, however, even in our worst circumstances we have always been a relatively minor interest of the vast microbial world. Pathogenicity is not the rule. Indeed, it occurs so infrequently and involves such a relatively small number of species, considering the huge population of bacteria on the earth, that it has a freakish aspect. Disease usually results from inconclusive negotiations for symbiosis, an overstepping of the line by one side or the other, a biological misinterpretation of borders.

Some bacteria are only harmful to us when they make exotoxins, and they only do this when they are, in a sense, diseased themselves. The toxins of diphtheria bacilli and streptococci are produced when the organisms have been infected by bacteriophage; it is the virus that provides the code for toxin. Uninfected bacteria are uninformed. When we catch diphtheria it is a virus infection, but not of us. Our involvement is not that of an adversary in a straightforward game, but more like blundering into someone else’s accident.

He also says some interesting things about how our bodies respond to gram-negative bacteria, and I see that H. pylori is one. My recollection of Thomas on it now is that gram-negative bacteria aren’t inherently harmful (as far as they could tell at the time), but they provoke a bad response from the immune system that causes more harm than the invader itself. The book is old enough that I’m sure some parts of it aren’t accurate any longer. He did get me fascinated by mitochondria though. I just started reading Power, Sex, Suicide: Mitochondria and the Meaning of Life.

I definitely agree that prions are the one of the scariest things we know about.

P.S. Thank you for adding the list of allowed HTML tags below the comment submission form :)

A much more frightening thought to me personally is that we KNOW our existing standard sterilization systems do not deactivate prions. So if they operate on someone with Creutzfeldt-Jakob or Mad Cow Disease without knowing it and use the same ostensibly sterilized equipment on you, you can get a fatal brain wasting disease!

Thanks, and ask away sdutchen! Email me off site, if you like. My address is on my Portfolio page.

As a budding science blogger (which, I’m learning, is different from my other blogging), one of these days I’d like to ask you about how you put together these posts and how long it takes.

“Mr. Jack, fire 1 torpedo. Fire 2 torpedo…. Fire 1,395,023 torpedo.”

“H glaciei isn’t a pathogen and is not harmful to humans”, Dr Loveland-Curtze added, “but it can pass through a 0.2 micron filter, which is the filter pore size commonly used in sterilization of fluids in laboratories and hospitals. If there are other ultra-small bacteria that are pathogens, then they could be present in solutions presumed to be sterile. In a clear solution very tiny cells might grow but not create the density sufficient to make the solution cloudy”.

On the other end of the scale, the BBC recently recorded the “greatest animal battle on the planet”, the female humpback whale heat run. Maybe there’s something there for females to be pleased about?