This week in microbiology episode #1

I just finished listening to the first episode of an exciting new podcast series, This Week in Microbiology. It’s hosted by Vincent Racaniello, Cliff Mintz, Michael Schmidt, and Stanley Maloy. Overall I thought it was great and am looking forward to future casts.
Some highlights:

– The future of personalized medicine will have to not only include patient genomes, but also their microbiomes which are unique in composition and contribute greatly to a persons well being. Microbes in the gut are especially important,as they play a key role in modifying some of the metabolites made by humans, a symbiotic relation where humans and bacterial enzymes are needed to create metabolic end products.

– Human DNA integrated into neisseria gonorrhoeae, the first time a transfer of human DNA to a bacteria has been seen. The sequence is the LINE 1 retrotransposson, which comprises as much as 20% of the human genome and is generally thought to be useless. The fact that the DNA has been maintained in the bacterial genome, and that based on RNA PCR it appears be transcribed, suggests it might be doing something. No antibody test was done to check for translation. Since we at the Redfield lab deal with competence we’ve been good scientists and have already briefly discussed this paper. I was puzzled that this was the first time this has been seen, given how prevalent horizontal gene transfer is in bacteria and how much human DNA a bacteria living inside a human host would be exposed to. Now that I think about it, if human DNA transfer did occur, and was somehow beneficially and spread to fixation within the bacteria wouldn’t we just call it a homolog?  However related to the first point about gut microbe symbiosis, it’s conceivable that if the transfer occurred a long time ago the gene could disappear from the human genome, a little reminiscent of mitochondrial DNA transfer.
Our bacteria, HI, while naturally competent preferentially takes up DNA that includes a species specific motif called the USS. There’s a thermophile bacteria that is competent and doesn’t have sequence specificty, but it wouldn’t be encountering human DNA in it’s natural environment. However it’s not hard imaging that in the course of lab experiments picking up a little something something
– “Dry copper kills bacteria on contact”. The antimicrobial properties of copper have been long known, the ancient Phoenicians used it to disinfect wounds and the Egyptians used copper pots to make potable water from the Nile. Only Metallic copper works, and only if it’s dry, not copper in solution. It’s an immediate effect, obliterating cells in seconds. Metallic copper has a partial plus state, and could be disrupting the cell membrane ion balance by stripping the electrons. Copper is now being examined to see if it can be used on hospital surfaces to lower hospital acquired
infections.
The hosts request questions for future episode. “Send your microbiology questions and comments (email or mp3 file) to twim@twiv.tv , or call them in to 908-312-0760. You can also post articles that you would like us to discuss at microbeworld.org and tag them with twim.”
I’m also currently listening to anouther podcast, Dan Carlins Hardcore History, Death Throes of The Rebuplic. It’s a story of politics, corruption and violence. The first part focused on two complicated men, brothers, and the circumstances that would make the eventual fall of the Roman Republic inevitable. I’m very excited for this series and highly recommend his other documentaries, especially Ghosts of the Ostfront(not for kids) and the Punic Wars, which includes one of my favorite quotes of all time; “salt the earth so that nothing would ever grow again”.
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2 Comments (+add yours?)

  1. Trackback: “This Week in Microbiology” | Sphaerula
  2. Conrad Halling
    Feb 28, 2011 @ 17:48:38

    Thanks for the tip. I have now subscribed, and I look forward to listening to the first podcast this evening.

    Reply

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