Steve writes:
Hi Microbophiles,
Here’s an interesting little historic snippet from The Lancet.
Venerable bacteria: In another interesting history of science piece, The Lancet gets bully over Koch’s bovine TB samples–but not over the tragedy of him advising that this form of the pathogen was not significant for human health, and thus delayed the introduction of basic meat and milk hygiene and testing.
http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(16)31420-9/fulltext?elsca1=etoc
It seems that the good and the great nearly always put their foot in it somewhere!
All the best,
Steve
luton
England
Where it has been hot and sticky for some days (and nights: most people don’t have air conditioning in UK homes.). Incidentally: how does one get black mould stains out of pillowcases? Yes: that sticky! :/
Anthony writes:
http://www.bbc.com/news/science-environment-37287715
“The plague of 1665-1666 was the last major outbreak of bubonic plague in Britain, killing nearly a quarter of London’s population.
It’s taken a year to confirm initial findings from a suspected Great Plague burial pit during excavation work on the Crossrail site at Liverpool Street.
About 3,500 burials have been uncovered during excavation of the site.
…
In Germany, molecular palaeopathologist Kirsten Bos drilled out the tooth pulp to painstakingly search for the 17th century bacteria, finally obtaining positive results from five of the 20 individuals tested from the burial pit.
“We could clearly find preserved DNA signatures in the DNA extract we made from the pulp chamber and from that we were able to determine that Yersinia pestis was circulating in that individual at the time of death,” she said.
“We don’t know why the Great Plague of London was the last major outbreak of plague in the UK and whether there were genetic differences in the past, those strains that were circulating in Europe to those circulating today; these are all things we’re trying to address by assembling more genetic information from ancient organisms.”
Steve writes:
Hi TWiM team,
Just to say thanks for your interesting discussion of the points I raised regarding uses of gut gas analysis/fingerprinting, and hand hygiene in the context of declining use of copper coinage.
One or two of my points weren’t expressed very well:
I hadn’t intended to convey the sense of a general increase in the spread of infectious diseases, but more in the increase and spread of antibiotic resistant strains. The widespread use of antibiotics and antiseptics in hand and surface cleaners has, most likely, produced the general decline in infection that the team noted, but, previously, there would have been a good deal of copper in circulation on people’s hands in addition; and bacteria on the fingers would frequently be brought directly into contact with copper metal, which would kill them before they could be passed on. This may have held back the spread of antibiotic resistance.
It does strike me, that, from what I hear in your podcasts, antibiotic resistance does not have to arise denovo very frequently: it is a part of the general variation which just needs to be selected by knocking out the remainder. Also, you have noted that horizontal transfer, even between unrelated bacterial species, begins almost immediately, when they are mixed together. Given this, it seems to me that antibiotic resistance has taken a surprising long time to spread and become a major health concern. It could be, that the metals in our environment were holding it back, until recently, when our metal pipes and handrails were replaced with plastic and plastic coatings, and we reduced our use of coins in favour of plastic cards, paper, and electronic transactions.
The second remark–about mosquito’s stance on it’s legs–left me puzzled as to why it wasn’t understood by the team. Having spent many a night scanning my walls and ceilings for nearly invisible mozzies, that whine in one’s ear, as soon as the light is turned off, and then vanish again when it’s turned back on, I had become very familiar with the, two back legs in the air, stance of the common mosquitoes, here.
https://static01.nyt.com/images/2016/06/01/health/well_mosquito/well_mosquito-facebookJumbo.jpg
I had assumed this was a general thing among those that hold themselves at an angle to the surface, but, following your team’s confusion, I checked more Google images, and see that there are, indeed, as many pictures where all six legs are used, as there are of those where the back legs are held aloft or just left loose. I don’t know how many species I’m looking at though.
One could imagine that the back legs might be needed for purchase while the proboscis was penetrating the skin, but then can be relaxed as grip is transferred to the proboscis itself; but those on my walls hold their back legs aloft though they are not feeding, so it seems to be a preference, or have a specific purpose. I had speculated that the raised legs may serve as aids to sensing air currents, and so contribute to the mozzie’s uncanny ability to avoid swatting hands! Possibly the stripy legs of some species could be used in signalling too.
Anyhow, I have always found this stance an interesting observation. I further note, that the same places where the mozzies land, are frequented by Pholcus ‘daddy long legs’ spiders, but they rarely get caught. Both the spider and the mozzie have the same habit of doing high speed push-ups on their spindly legs, from time to time. I hope it’s not catching! 🙂
Hope this explains my points a bit better.
Many thanks for your, always thought provoking, podcasts.
Steve.
(Weather now uniformly grey, cool, and still.)
from Kristen Bernard at UW-Madison:
Mosquitoes often don’t use the last pair of legs, but will use all six for balance especially once blood fed.