Hannah writes:

Dear TWiM hosts (and associated microbiomes),

I came across this heartbreaking News & Views article in Nature yesterday and thought it would be worth talking about on TWiM: http://www.nature.com/nature/journal/v544/n7650/full/544300a.html

Here’s a link to the associated paper: http://www.nature.com/nature/journal/v544/n7650/full/nature22059.html

In short, it’s about the aptly-named chytrid fungus Batrachochytrium salamandrivorans, which has, in just a few short years, nearly obliterated fire salamanders (Salamandra salamandra) from a few regions in Northern Europe. The fungal disease is 96% fatal, salamanders are unable to develop an immune response, the spores persist in the environment for an extremely long time, virulence has not been decreasing over time, and there are several European reservoir hosts. The only good news is that the fungus is a relatively new arrival and hasn’t spread far yet, but judging by this paper, the prognosis is grim.

I think this is my first time writing in to TWiM, though I’ve written in to TWiV and TWiP a few times and have been listening to all three podcasts religiously for years.

A bit about me: I’m a Canadian biology Master’s student studying at the Free University Berlin, and although I’m not doing microbiology per se, I’ve been working with Eastern subterranean termites (Reticulitermes flavipes) and the entomopathogenic fungus Metarhizium anisopliae, focusing on the mechanisms that termites use to protect their colonies from fungal infection. For decades, people have tried to use this fungus to control subterranean termites, but because termites are amazing and have something called social immunity, it hasn’t worked.

While I’m on this tangent, here are some more cool termite facts for a microbiology-inclined audience: R. flavipes, like other “lower” termites, has a specially adapted hind gut that’s PACKED with the biggest, most beautiful flagellates you’ve ever seen, plus loads of bacteria, some of which live as ectosymbionts on the flagellates and propel them around. The flagellates, and to a lesser extent the bacteria, help the termite digest wood.

“Higher” termites don’t have flagellate symbionts, just plenty of bacteria, but one group, the Macrotermitinae, live in a special symbiotic relationship with another type of microbe: the fungus genus Termitomyces. They build and tend fungus gardens inside their nests – a bit like leafcutter ants. We have one Macrotermes species in the lab, but sadly, I have not yet found an excuse to do anything with them (they’re so cool!)

Ok, I’ll sign off now before I get (even more) carried away. Thanks for all your hard work, and I look forward to the next episode!



Joshua Weitz writes:

Dear Vincent, Michael, Michele, and Elio,

My colleagues alerted me today to the TWIM podcast on our immunophage

synergy paper in Cell Host and Microbe. Thanks for taking the time to

reflect on our work. I found the conversation quite stimulating and hope

our future efforts can address some of the questions raised.


At one point, the podcast raised a question on the details of the models.

Given the access issues noted for CHM, we just posted the following github

link on our group page, it should have all the relevant simulation code

in case you are interested or know folks who want to see the details

underlying the mathematical concepts:


Note that even more details on the proof of concept model are available

in a related paper in J. Theor. Biol.:





Joshua S. Weitz

Professor, School of Biological Sciences

Courtesy Professor, School of Physics

Director, Interdisciplinary Graduate Program in Quantitative Biosciences

Georgia Institute of Technology

Anthony writes:

McDonald’s developing species specific antibiotic use policies


Sara writes:

Hello TWIXers!

I’m finally writing my first email – only took me 5 years… I’ve been listening since 2012 when in my second year of undergraduate studies at the University of Glasgow I encountered your series of podcasts through my courses in microbiology. At this point I was still on track for a degree in Anatomy, but after being spellbound by our Micro courses I decided to change and get my degree in Parasitology instead. I was of course further inspired by your podcasts (of which, no offense to the others, TWiP remains my absolute favourite) and I quickly listened to the very long list of episodes I had missed in my ignorance. The TWiX podcasts have kept me entertained on train commutes, flights home to Sweden and on holiday travels with my husband (who has endured many long and somewhat one sided discussions on various topics). The podcasts have not only helped teach my husband more than he ever wanted to know about worms, bacteria and viruses, but they helped me tremendously with my studies by making lots of information more accessible and they of course kept up my motivation and science interest on those dark days when no experiments would work. Most recently the podcasts have taken on a new role of keeping me more widely informed (and entertained on my daily 40 min walk to- and from work) as I in my career focus on a slightly more narrow topic: after my getting my BSc Hons + MSci I gained employment as a research technician in a UoG CVR lab last November (Vincent may remember us, he was a recipient of the Stoker Price a few years back – sadly I wasn’t here!). It’s ironic but I now work on viruses (my least favourite of infectious agents – sorry Vincent!) instead of my beloved parasites, but I actually love it. Our area of research is what prompted this very lengthy first email as Vincent mentioned using Wolbachia endosymbionts in mosquitoes as a potential population control strategy and a method to reduce transmission of viral diseases like ZIKV and DENV. This is what we work on! I mainly spend my days in our insectary taking care of and experimenting on our many mosquitoes (with all the delightful TWiX-hosts as company), but I also do some cell work and once in a while even a plaque assay! It’s nice to have a cell break sometimes when you work with fussy, tropical mosquitoes that must be kept at 28°C and 80% humidity! Vincent might like the humidity, but for a northern Swedish person it takes some getting use to!

Anyways, sorry about the long email – I guess it’s what happens when you don’t write for 5 years – and my sincerest thanks to you all for your excellent work and dedication to these podcasts, they really are a treat to listen to and I recommend them to anyone who will listen (scientists or not!).


Sara from Scotland

P.S. I subscribe on all of our devices, it’s dead easy and everyone should do it, if only so that Vincent can stop pleading

Anthony writes:

Small Things Considered recently had a post on stromatolites


These are found in NJ


They are in Central, NJ, too:


Stromatolites give us a peephole into a time billions of years ago when new developments were not McMansions but vast tracts of mats of microorganisms.


Mark writes:

The true purpose of microbiology.

Hello Elio, Michele, Michael, and Vincent,

Greetings from a long time listener from San Jose CA. The California harvest and winemaking season is underway. This Saturday we receive and will crush a few tons of Chardonnay from Alexander Valley. I am currently buying yeast and nutrients for its primary fermentation, and bacteria for secondary malolactic fermentation.

The true purpose of microbiology is to crest all those little bugs that make delicious beer, cheese, bread, and wine.

Enjoy the attached picture.


Wine yeast