I would like to point out that the idea of "Fitness Factors" was originally published by Brussow et al 2004 (Microbial Molec Biol Reviews68:560) and did not originate from Michael Schmidt as was suggested in your last podcast.
I think it is important to keep all forms of scientific information as accurate as possible and since your podcast is likely heard by students and perhaps lay-people who might not check the accuracy of claims as often as a scientist may, I bring this to your attention so that you can publicly set the record straight.
I listen to all three of your podcasts and find two of them of high distinction. TWIP in particular is excellent and TWIV generally deserves an honorable mention. TWIM on the other hand is not so well developed for accuracy or claims of originality.
When I heard the "fitness factors" comments I immediately recalled this paper and its citation in many subsequent papers.
The way it was presented on the podcast made it sound as though is was your colleague's idea. Clearly this is not the case.
I am third year Medical Student at the University of Cambridge currently doing a BA in parasitology, parasitism, immunology and microbiology. I very recently discovered TWiP et al and am now harboring a full scale addiction from my girlfriend.
I have a number of questions and suggestions, which are relevant across the TWi platform.
I have just finished listening to TWiM 25. I found the discussion of magnetotactic bacteria fascinating, especially as I am also a technophile so the prospect of a bacteria powered smart phone blew me away! On the question of where to find soil inhabiting magnetotactic bacteria; perhaps industrial sites that produce large electromagnetic fields would be a good place to start. E.g. big electricity transformers, or power stations?
I was also interested by the discussion of TDR TB . I am currently writing my dissertation on human infection with Bovine TB (which is increasingly recognised as a misnomer). Mycobacterium bovis is generally intrinsically resistant to pyrazinamide, and often carries resistence to isoniazid (both first line human TB drugs). Given that there is no good way of differentiating M. bovis and M. tuberculosis infection without culture and PCR, I would suggest that M. bovis infection in humans has played an as yet unquantified role in the poor management of TB infection that has lead to the development of resistance. However, there is very little data on what proportion of TB infection can be ascribed to M. bovis infection, with reports ranging from 0% (Brazil, Rocha, 2011) to 21% (Tanzania, Kazwala 2001 in Lymphadenopathy patients). To compound this, it is suggested that there is a large degree of under-reporting of M. bovis because labs are not using pyruvate supplemented media to culture, preventing its growth. The aim of my dissertation is to identify antigens that could be used for differentiatial diagnosis in resource-poor setting (e.g. by card test) where the majority of M. bovis infection seems to be found.
Also in TWiM 25, Peter's letter discussed the role of the microbiome in mosquito attraction. Michael Schmidt replied that it was unfortunately smelly short chain fatty acids produced by bacteria that would likely be the repellent. However, in my Biology of Parasitism Class (taught by Dr Sheelagh Lloyd), we were taught that Anopheles gambiae are attracted to Limburger cheese, which contain Brevibacterium linens that produces short chain fatty acids in cheese, and is closely related to Brevibacterium epidermis on the skin. Similarly,Corynebacterium and Melessazia spp. on the skin also metabolize triglycerides to short chain carboxylic fatty acids that are attractive for A. gambiae. The other main attractants to mosquitoes (depending on the species) are carbon dioxide, lactic acid, acetone, 1-octen-3-ol and nonanal .
There are two specific questions that I have:
Whilst I recognise that the three TWi shows are increasingly showing more overlap, I wondered whether there was room for a 4th niche? It would be great if you could produce a podcast in the TWiP format that focuses on Immunology. Whether looking at the subject as a whole, or more specifically the interactions between infection and immunity rather than autoimmunity, cancer and pregnancy, I think this subject area would provide an essential underpinning to the wide and varied discussion found on your current podcasts. I look forward to hearing your thoughts on TWiII (This Week in Infectious Immunity).
Thank you again for the sustained propagation of scientific values through your podcast, and in particular, making parasites accessible and exciting! It is a good antidote for an unfortunately common attitude that restricts the unilluminated to a reaction of disgust and aversion, when in actuality the lives of these parasites demonstrate a beauty and elegance beyond the most highly choreographed ballet.
I have been slowly trying to catch up with TWIM from the beginning and my memory was jogged by one of the letters at the end of TWIM #13 suggesting a collaboration between TWIM and an astrophysics podcast. I read an article in Popular Science recently about this "Extra-Terrestrial" Arsenic Bacterium (http://www.popsci.com/science/article/2011-09/scientist-strange-land), and the article left me with more questions then answers. It would be great to hear your thoughts on the matter, I would love to hear you guys talk about it in a future podcast.