Scientists Sequence Black Death Bacteria

First time accepted submitter Quince alPillan writes "The bacteria behind the Black Death has a very unusual history. Its ancestor is an unassuming soil bacterium and the current strains of Yersinia pestis still infects thousands of people annually, but no longer causes the suite of horrifying symptoms associated with the medieval plagues. The radical differences, in fact, had led some to suggest that we had been blaming the wrong bacteria. Now, researchers have obtained DNA from some of London's plague victims, and confirmed that Y. pestis appears to be to blame. But the sequences also suggest that the strains of bacteria we see today may be different from the ones that rampaged through Europe."

Comments

The Black Death isn't coming back

[elrous0]

the Black Death was ugly. Imagine half the population of your entire city or town dying off in 1 or 2 years. Nasty business that.

But, that said, people really should take a more reasoned approach to disease alarmism these days. All this "This latest pandemic is going to kill us ALL!!" Chicken Little shit gets tiresome. The Littles always cite the Black Death and 1918 pandemic as if that's what we could expect from a pandemic today--all without noting the MASSIVE improvements in sanitation, medical science, vaccine research, etc. that make this scale of pandemic highly unlikely in the modern era.

The Black Death could have been stopped in its tracks if those 14th-century peasants had even an inkling of the basic medical/sanitation knowledge that even the biggest idiots among us know today. Basic stuff like "Wash your hands regularly," "Cover your mouth when you cough," and "Don't let your goddamned flea-infested farm animals wander around through your living area, moron" are surprisingly recent bits of common sense that the developed world today takes for granted. Of course, there are still some third-world shitholes where people think that a witch-doctor rubbing feces on an open wound will ward off the evil spirits. But even those places usually have a FEW among them with some basic sense (and soap).

Re:The Black Death isn't coming back

[phrackwulf]

There is a legitimate point to considering the technological ability to both communicate more rapidly about a highly infectious disease and approach a new and lethal strain with modern decontamination and medical systems. That doesn't rule out the possibility of certain very specialized and nasty toxins such as Bacillus anthracis and other hybrid biological weapons. The real danger is in a strain of bacteria that can infect a host, cause relatively mild and temporary symptoms, then reinfect and spread after a period of time leading to a lethal toxicity in the effected patient and the people they have probably come into contact with. Obviously, the really virulent diseases like Ebola Zaire are so nasty that they burn themselves out fairly rapidly because the infected population dies before they can spread the virus. As our knowledge of DNA sequencing and protein structures increases though, we start to arrive at a set of tools that could lead to truly frightening weapons and bacterial/viral hybrids. Diseases that can switch on and off based on environmental triggers. Or how about a bacteria that multiplies rapidly and uncontrollably under a certain PSI of air pressure in one's lungs?

Re:The Black Death isn't coming back

[Rob the Bold]

All this "This latest pandemic is going to kill us ALL!!" Chicken Little shit gets tiresome. The Littles always cite the Black Death and 1918 pandemic as if that's what we could expect from a pandemic today--all without noting the MASSIVE improvements in sanitation, medical science, vaccine research, etc. that make this scale of pandemic highly unlikely in the modern era.

I don't think I read the same summary and article as you did.

Re:The Black Death isn't coming back

[mcmonkey]

the Black Death was ugly. Imagine half the population of your entire city or town dying off in 1 or 2 years. Nasty business that.

But imagine the morning commute. Or finding a parking spot at the mall. Getting a last minute table at your favorite restaurant.

Just saying.

Re:The Black Death isn't coming back

[robthebloke]

Very true. To recover the corpses of the plauge victims, they dug up some ash, unburnt it to get back to original bodies, and were able to extract samples of the original bacterium from that. It's remarkable what technology can do these days don't you think?

Re:The Black Death isn't coming back

[dkleinsc]

Of course, there are still some third-world shitholes where people think that a witch-doctor rubbing feces on an open wound will ward off the evil spirits.

I'm not sure where you got that image of how those sorts of shaman/healer types do their jobs. They'll usually go with attempts at herbal treatment that have a chance of working that is slightly better than a placebo, based on learning from previous generations who figured out that rubbing feces on wounds was a good way to cause the patient to get even sicker and die. They tend to pick their herbs for apparent effectiveness, and often have chosen things with the right chemical compound or physiological effects, just not at as high a concentration or as good a delivery system as Western medicines.

Those healers from isolated tribes today, and our cavemen before us, were the brainy folks in their societies, and there's no reason to think they were any stupider than we are. They are just working with very limited tools, and are quite ignorant.

Re:The Black Death isn't coming back

[Dog-Cow]

I think I saw that on an episode of CSI:Miami!

Re:The Black Death isn't coming back

[oldmac31310]

What happened was labour was in short supply so the peasants got to name their price for the work they did. Previously they were considered lucky to have a roof over their heads and enough to eat.

Not necessarily

[Moraelin]

Well, the actual question is: exactly how different. Yes, it's clear that some mutations are inevitable, but unless there's some clear evolutionary pressure, you may still find a bacterium that works by and large just like its ancestors.

Now it may seem that for a parasitic bacterium, not killing its host would be an advantage. And indeed in some other bacteria we can see a sort of a survival-of-the-sickest kind of selection.

But this is a soil bacterium. If it ends up in some host and kills it, worst that can happen is that it ends up back in the soil. It has nothing to lose by killing its host, and in fact everything to gain, since once the host is dead there's no more immune system killing the bacteria.

This kind of bacteria that have nothing to lose by killing the host are the most deadly and dangerous. Not just this, but see for example cholera too. That's a bacterium that not only has nothing to gain by peacefully staying inside you and not killing you, but is actually trying to get out of your body ASAP. Whether you live or die in the process, meh, it makes no difference for that one.

Additionally, for Y Pestis, the capability of clotting blood and forming colonies that plug blood vessels actually helped it spread too. The same mechanism makes it plug the stomach of fleas. The flea then will literally starve to death no matter how much blood it sucks, and driven by hunger, will go infect another host too.

So we have a bacterium for which the plasmid that kills its host:

1. isn't detrimental to the bacterium, since it can live just as well in a dead host or in soil, and

2. is actually beneficial to the bacterium, since it makes fleas spread it around.

That's one tough combo to evolve out of. There is no real survival benefit in losing those genes.

So while, yes, you would expect that bacteria can and will mutate in time, but it's not clear at all why this one would change in exactly that aspect.

Yet something seems to have changed. What and why? Those are the questions.