MicrobeWorld App


Microbes After Hours

Click for "Microbes After Hours" videos

Featured Image

Featured Video


New from ASM Press


Join MicrobeWorld


ASM House 200X200

Subscribe via Email


TWiV 129 Letters

Bryce writes:

I enjoyed your discussion of the Molecular Therapy paper in this week’s TWiV. My lab (and others) have worked on using virus particles as scaffolds to increase the immunogenicity of various targets for quite some time. One thing that wanted to point out (and to correct one of the comments of Rich, I believe), is that this strategy actually IS effective at targeting self-antigens—we can efficiently overcome the mechanisms of B cell tolerance by displaying self-antigens on virus particles. My lab has done a number of studies in animal models, and a Swiss company, Cytos, has actually run clinical trials of virus-particle-based vaccines targeting self-molecules involved in various diseases (Alzheimer’s and hypertension).

Thanks again for the enjoyable podcast.


Associate Professor

Dept. of Molecular Genetics and Microbiology

University of New Mexico


Jim writes:

Brandeis study shows economic impact of dengue virus in Americas

Dengue illness, the most common mosquito-borne viral disease in the world, has expanded from its Southeast Asian origins and is resurgent in countries such as Argentina, Chile and the continental United States.

Daniel writes:

I am a graduate student in biophysics who discovered your podcast in December after finding your blog, all while working on a term paper about EBOV vaccines for my mammalian viruses biochemistry course... Despite my physics background, i have been interested in viruses since reading "The Hot Zone" in junior high.

I just listened to twiv 119, and after looking at some of the comments posted below 119, i have wondered what consideration has been taken to produce a vaccine based on a killed virus via formalin or oxidizing radiation, or attenuation. But i must be jumping ahead, since i have not done any journal search about whether or not the virus has been cultured (e.g. HeLa, monkey kidney cells).

I have been working backwards through the TWIV archive, and have yet to get to the double digits, but so far i do not recall if yourself and the other hosts have mentioned that topic about XMRV. If XMRV has crossed the species barrier into humans, then it seems likely that most of the population would have antibodies against it, much like the Epstein Barr V, given that mice follow humans everywhere (there are no rats in alberta).

Good show overall. Keep up the good work, eh.


Peter writes:

Congratulations on your great netcast.

I will shortly commence my Virology course for 2011, and I have 165 students, up from 74 last year. I'm thrilled and delighted to have discovered TWIV, which covers so much of the exciting, stimulating stuff that I talk about to my students.

I will be telling them to go straight to your site, so please keep it up.

By the way, if either of you are ever in Adelaide, Australia, let me know. You will be in grave danger of being dragged in to talk to my students, to tell them just how fascinating viruses are,

with best regards

Peter Speck, PhD


School of Biological Sciences,

Flinders University

South Australia.

John Terry MD writes:

With regard to Nebraska, my individual 30 year radiology experience (many chest X-rays) is Cavitary TB 5 cases, lung cancer 300 cases. Your personal experience based of knowing many more lung cancer victims then TB victims is verified.

Vince writes:


This week in science, there was an article way at the bottom concerning a phenomenal display of virus/host evolution.


This study found that metastasizing Leishmania parasites actually harbor a virus that stimulates the immune system creating an inflated inflammatory response in the human host, which was seen to lead to a higher reproductive success for the parasite. WOW! From a wider lens in virology, this may not seem to be surprising, as in bacteria this is more common. Phage can transfer many beneficial genes to help bacteria to adapt to many diverse environments, including humans. Although in this particular case were talking about a different type of assistance, dsRNA mediated inflammatory enhancement. Furthermore, in a article on a science news website(http://www.physorg.com/news/2011-02-virus-parasite-combine-humans.html), the authors said “This is the first reported case of a viral infection in a pathogen of this type leading to increased rather than reduced pathogenicity,”. This raises many questions concerning other protozoan parasites and whether their virus partners (exogenous...or endogenous?) assist their parasitic lifestyle. Certain virologists have long assumed that viruses assist symbiotic interactions between distant species (such as Luis Villarreal at UCI), where for example, they extend gene addiction to a possible mechanism of mutualism generation.

How widespread do you think this phenomenon is? Could viruses be used as defense, phage from our normal microbiome that possibly infect invading bacteria? Or, persistent viruses like TT viruses, which possibly infect cellular pathogens? No evidence for that however....



Benjamin writes:

I noticed a set of strange coincidences related to your most recent podcast (TWiV #120) related to Egypt. Here they are:

1) Your podcast was recorded on February 11 (the day Mubarak stepped down)

2) You recorded the podcast in Alexandria, Virginia, which shares its name with the second largest city in Egypt

3) Your guest was named Ed Niles (I know, corny)


Julie writes:

Thanks so much for your podcasts. I always learn a lot from you. I just finished listening to your interview with David Tuller, which I enjoyed.

You made a number of confident statements about the certainty that science will figure out what's really going on with XMRV. I'd love to hear more about your perspective on Elaine Defreitas's work on an HLTV2-like retrovirus from a long time ago, because one of the discouraging things about what I've heard about that story is that it seemed like science didn't figure out what was really going on. I'd love to hear if you agree with that perspective or if there's more to the story than what I understand.

Thanks so much for your work.



Freelance Math and Science Writer

Math Columnist for Science News: http://bit.ly/mathtrek

and Wired: http://bit.ly/wired_equation

Amit writes:

Dear TWiV hosts,

I enjoy your program for several weeks. I enjoy it very much (including TWiP). I find it very interesting, even for people which are not from the discipline. I wish to give something back, so I have several suggestion which, I think, will make it even better.

The podcast is usually very long, and un-edited. It will be nicer if every episode will be specific for limited number of topics which can be discussed during up to one hour.

The topic of discussion should be cleared at the beginning. New terms and method should be explained at the first mention. Vincent does it in TWiP, and maybe forget it in TWiV, because he is so familiar with the subject, he forget that not every body are.

No need for reading all e-mails in the podcast :-)

Hopefully, I will start my own science podcast (the first Hebrew one), inspired by you, and other podcast on the sciencepodcasters.org

and one last thing before wishing best regards and closing this letter, use Celsius degrees (or Kelvin), out of the US no one can understand if it cold or warm there :-)

Best regards and have a nice week


Technion - Israel Institute of Technology



Martin writes:

Hi Vincent,

Here is a study showing transmission of yellow fever, the same yellow fever strain used in the vaccine is found to be infecting babies from mothers milk.

Do you still think it is a good idea to vaccinate pregnant women

Best as always,



David writes:

Hi Twiv

Im listening to twiv #118, one of the emails asked about virus like particles used in vaccines and you discussed that capsid proteins are capable of self assembly. I believe it was Allan that said it was like a bag of magnets coming together to form the structure. Here is a link to a video of magnetic "capsid proteins", which when shaken in a container eventually form an icosahedral shell. I use it in my virology class to demonstrate what I mean by self assembly.



David Esteban

Biology Department

Vassar College



Mike writes:

I have an MS in biology & chemistry but it is from the late 1960's and I've been a self-employed programmer for the last 30+ years after 10 years in a hospital lab. Many things have changed in the last 40 years! I don't know if Kudo's is still used in protozology, but it was my favorite text.

I began listening to TWiV to learn the current state of understanding of XMRV because my wife has had Fibromyalgia/Chronic Fatigue for about 2 1/2 years. This was diagnosed at the Mayo Clinic in February 2010. I found your podcasts dealing with XMRV interesting and educational and have become hooked on TWiV and TWiP (have my TWiV coffee mug ordered) and am in the process of listing to all the back episodes.

I also wanted to let you know about the website bookfinder.com. In episode #9 you mentioned a book named Fever by John G Fuller. It is not currently in print, but you can get used copies through bookfinder. I collect first edition speculative fiction (science fiction) and use this site daily. If it has been published you can probably find it here.

Love TWiV - keep up the great wool,


Ilya writes:


A few weeks ago I defended my PhD thesis and this is the photo of the last slide with gratitudes.

Last line says: "To prof. V.R. Racaniello for inspiration" and that couple of times, when I thought my project was going to fail, you and all the wonderful people on TWIV indeed inspired me to carry on.


Chumakov's Inst. of Poliomyelitis and Viral Encephalitis, Russian Academy of Medical Sciences

Marc writes:


That was a great episode. I love it when there are guests on TWIV that get into the 'oral history' of different viral subjects. I debating whether I should assign you intro about TRIM to my virology class this week. I wonder if anyone would object to having a podcast as an assignment? I'm already having them update virology entries on wikipedia for extra credit.


If you ever have Alan Rein on again should ask him to tell you about how the word 'pseudotyping' was coined. It's another really interesting science history story that I don't believe has been written down anywhere.

Marc Johnson

Assistant Professor, Molecular Microbiology and Immunology

University of Missouri

Columbia, MO

Penny writes:

It's being reported on Facebook that neither Frank and Sandra Ruscetti nor Judy Mikovits has been invited to the upcoming CROI conference. The committee also rejected at least one of their abstracts on XMRV and immune dysfunction.

While there will be discussion of XMRV at the conference the emphasis will be on contamination and negative studies. The absence of Mikovits and the Ruscetti means that they will not be able to offer even a critique of these arguments, let alone defend their own work.

I've appreciated your programs on XMRV and the last one with David Tuller, even if sometimes I've been critical of things you've said. But how much faith can a lay person like me have in the "scientific process" if important views are marginalized. Where does the debate take place if not at a meeting like this?



Michael writes:

Dear TWiV Team,

My name is Michael Walsh and I am on the faculty at SUNY, Downstate in the the School of Public Health in the Department of Epidemiology and Biostatistics. I have enjoyed listening to your podcasts for quite sometime. I find TWiV, TWiP, and now TWiM, very engaging. I really appreciate the personalities of each of you four, Vincent, Dickson, Rich, and Alan, and the casual, yet unflinching approach taken with each topic.

As an epidemiologist, one of my primary areas of research is the interface between infectious disease, climate, and geography. I use the application of GIS methods frequently in my work and was quite interested by a recent paper in the American Journal of Tropical Medicine and Hygiene reporting on land use and West Nile virus, a focus of some of my own work here in New York State. I found the results interesting, though as a skeptic and a bias-wary epidemiologist, I think it is difficult to draw inference from county level data of WNV cases. And as we all know, correlation does not equal causation. When I was reading this paper, I immediately thought of Dickson. I have listened to the many discussions you've had on TWiV regarding WNV and I've always quite appreciated Dickson's point of view with respect to the complex ecology of this infection. For example, I think the hypothesis that increased incidence of human WNV infection can result from drier weather that provokes greater bird dispersal leaving humans as a more available mosquito host is well-founded. I would like to see (or undertake) some better studies that combine population-based epidemiology and multi-species ecology to get at a better understanding of this process. As regards the paper, I'd like to hear Dickson's opinion on the juxtaposition of an "Eastern" and "Western" WNV in the United States, based on the former being an urban disease and the latter being a rural disease as described by the authors. The authors posit that regional differences in the distribution of human WNV incidence between the eastern US and western US can be delineated by distinctions in land cover across these two regions (developed/urban land versus rural land). Moreover, they suggest that these land cover differences correspond to similar differences in the distributions of Culex pipiens and C. tarsalis between the two regions. The authors attribute differences in WNV incidence to the exploitation of different local environments by the two culicine mosquitoes. I am interested to hear your thoughts, particularly with respect to how such regional distinctions, if true, may fit with the overall dissemination of the virus from east to west across the United States from 1999 to 2006. I am wary of the aggregate data which were used to measure incidence, and we also do not get a clear picture of the finer resolution of the mosquito and bird ecologies that must also be at play. Nevertheless, I do think it is an interesting hypothesis-paper.

Keep up the excellent quality of your podcasts. All four of you provide a true gem to anyone interested in virology, infectious disease, or science in general. You do a great public service and I, for one, very much appreciate your efforts.

Also, I have a blog on infectious disease called Infection Landscapes, at http://infectionlandscapes.blogspot.com/

The idea behind this blog is to discuss the epidemiology and ecology, and the physical and social landscapes of infectious disease. Have a look and see what you think. I do weekly postings.



Michael Walsh, PhD, MPH

Assistant Professor, Epidemiology and Biostatistics

School of Public Health

State University of New York, Downstate

Brooklyn, NY 11203


Garren writes:

Greeting Semi-divine TWiV hosts

I have a quick podcast recommendation for everybody. We all want more science, so what I would like to recommend is basically what TWiE should be (This Week in Engineering). The podcast is called Omega tau and can be found at http://omegataupodcast.net/category/podcast-en/ The host is German but is kind enough to do a fair number of really interesting English podcasts. The show is a bit like Futures in Biotech in style (ie interviews vs panel). Topics range from quantum computing to flying the space shuttle to electron microscopes. Check it out.



Manuel writes:

Dear TWiV,

Could it be that viruses are implied in a wider range of diseases than we currently think? Sciencedaily published an article today where they state that ALS could be caused by a human retrovirus. I know that we are in a discussion right now, where XMRV could turn out not be the cause of CFS or some other disease but this does not have to be true for other diseases and retroviruses. Please keep up the great work and I'd love to hear you guys talk about it.

Best Wishes


The Sciencedaily article: http://www.sciencedaily.com/releases/2011/03/110302121911.htm

The full study: http://onlinelibrary.wiley.com/doi/10.1002/ana.22149/pdf

Kari writes:

Hello Vincent, Dick, Alan, and Rich,

My name is Kari. I am currently a graduate student in the Baric lab at UNC Chapel Hill in the Department of Microbiology and Immunology. I love listening to your podcast, being turned onto it by Eric Donaldson whom you have had on to talk about the bat virome. Eric's work on bats is great, but equally great is his work with noroviruses. I may be a little bit biased, working on noroviruses and all, but I think it's high time you do an episode on this virus since it affects pretty much everyone at one point or another (I like to call it the puking/pooping virus). In the United States alone, over 23 million people get norovirus each year! I could go on and on about my virus, but I would rather have you guys do that on an upcoming episode :) Thanks again for doing TWIV! I love it!

Best Regards,


UNC-Chapel Hill

Didier writes:

here is a new english music group " The Vaccines" ...http://www.myspace.com/thevaccines

can't be ignored by twiv !!!!!maybe a "pick of the week"


(o o)



Virologie Moléculaire et Structurale

Gif sur Yvette France

Marcia writes:

Several weeks ago I had occasion to speak with Dr Judy Mikovits. I mentioned your podcast show to her, and she said that she and Frank (I assume she meant Dr Frank Ruscetti) would be willing to be guests on TWIV. I think it would be fascinating to have both of them on the same show, and hear your usual free-ranging chat between you regulars and the two of them. From what I understand from our conversation, WPI has finally been able to raise enough funds to buy their own sequencer, and they have a lot of ideas about what they'd like to investigate in regards to XMRV, polymorphic forms, etc.

I am including the contact information for the Whittemore Peterson Institute below, in case it would be useful to you. In my experience trying to speak to Dr Mikovits, the "guardians at the gate" are diligent in screening her calls. If you don't have any luck arranging something through the media contact below, you might succeed by speaking to Dr Mikovits directly, since she did clearly say in our conversation that she'd be interested in talking with you. (I eventually got through to her by doing some name dropping, "Dr Klimas suggested i..." etc. I'm not proud--whatever works!)

Disclaimer: Although I listen to all episodes of TWIV and find them fascinating, I have a particular interest in XMRV because I tested positive for XMRV via serology (antibodies). This was through WPI and participation in one of their studies. I've been ill for many years with CFS, and I follow as much as I can of the science relating to CFS. I don't know whether XMRV will turn out to be the answer, but it certainly is interesting. The work with spinal fluid proteins associated with CFS and fibromyalgia is also very promising. I was raised with a scientific background, and I hope very much that CFS will become understood and effective treatments available some day.

Again, thank you for a very interesting show.



Sophie writes: (with respect to 'The decline effect and the scientific method')

I think this article is quite disturbing. Even if the author is right I have a serious problem with sentences like: "If replication is what separates the rigor of science from the squishiness of pseudoscience, where do we put all these rigorously validated findings that can no longer be proved? Which results should we believe?" It seems to me that it is a problem at the moment, for the general public to distinguish between real science and more alternative things (like homeopathy) and I think this article might give, as Mr. Marc Crislip puts it: "The alternative wackaloos" even more ammunition, even though it is unwarranted. I also think it is a big problem that, as Alan points out, the beginning is sensational, because if somebody doesn't read the article through, they might draw the wrong conclusions.

Besides that I find it really interesting, and would like you guys to talk more about it. At least in Denmark, it isn't a problem most science-students know about and it isn't discussed in class and I think it should, to avoid bachelor students ending up finding out about this in their first really important paper/assignment.

In general I think there should be more focus on the problems with science, so we are prepared to handle these things before we get out in the "real world".

We just had a case of a cheating brain-scientist, who now has been convicted of using research money for clothes and stuff, trying to blame this on one of her students and faking mouse-experiments results. It was quite clear that the system isn't really geared towards handling these cases. Both this and the MRI-autism study might have been caught way earlier, if scientist were more aware of potential problems.

Please discuss and sorry for the rant:)

Sincerely Sophie

Ina writes:

Hi Vincent, Dick, Alan, et al.

In TWIV 70 you talked about host manipulation by 'outside invaders', i.e., viruses, parasites, etc. An article giving many examples of this type of manipulation can be found in the Scientific American of March 2003. The author of this article is Robert Sapolsky & is entitled 'Bugs In The Brain'.

I enjoy TWIV immensely & was introduced to TWIV by a friend whose daughter took a virology course at Columbia University. Listening to TWIV was part of her assignments. I, myself, am an alumna of Barnard & have worked extensively in various areas of cardiovascular physiology. Keep up the great programs of TWIV & TWIP.

Respectfully submitted,

Ina P., PhD

Michael writes:

Hi Vincent and gang,

First I would like to say thank you for a great podcast. I am a parasitologist who recently started a job in Virology and I found twiv after watching your lecture series at http://microbiology.columbia.edu/w3310.html (thanks for that too!). I drive for 2 to 3 hours a day, depending on traffic, and twiv and twip have been keeping me sane as well as brushing up my science.

By the way, I am now up to date with twip - 1 month is too long to wait for the next one! So my question relates to a statement you made about growing influenza in cell culture. You said that in order to get a high titre of virus from a cell monolayer you had to start with a low MOI. This is general question but I work with avian influenza and I can't understand why this would be the case. This is why: There are a limited number of cells in the monolayer Influenza causes lysis of the cell and presumably there is a limit to the number of virus particles produced by each cell Therefore the MOI will only affect how fast the final virus titre is reached. The variability in final virus titre may therefore be due to when the flasks are harvested. If I have got this wrong I would gladly be corrected.

I have not finished listening to all twiv episodes (thank goodness as it really does help with the driving), so you may have answered this question.

Thanks and keep up the good work,


John writes:

Dear TWiVtastic Four,

I must disclose that I thoroughly enjoyed this most recent episode (#124).

I think it had a nice mix of detailed science, some insight into how science in the modern age works, a nice nuanced discussion of what to do about smallpox and plenty of puns. If people think in anyway similar to me they think of some nebulous 'smallpox' vials kept in cold storage somewhere like the DNA was in Jurassic Park, where security is as weak as having just one Wayne Knight as the IT guy. Obviously that's a bit of a caricature but I think you get the idea. When the listener e-mail about funding came up in my head I was already rambling similar to what Alan said so I was quite pleased to hear him articulate my reactionary thoughts better than I was rambling internally. Speaking of Alan, I knew this would be a good episode due to a critical measure in TWiV quality. That is the time-to-pun measure. When Alan is in top form it's nice and low. And there was Dick right at the end for the walk-off victory with the vertical farming quip.

So in summary, great guest, great topics, great to have everyone back and to know that Dick has no escape from the podcasting. Someone send him a fishing video game so he won't have to travel.



Sven-Urban writes:


In the latest epi... Oh, by the way, why am I able to address you like that? Why not "Ladies and Gentlemen"?... Sorry, that was a glitch, let's reboot:


In the latest episode as of this writing, #124, you were once again talking about the possibly pending call for destruction of all known smallpox virus stocks. You also mentioned that nowadays, as the genetic code is known (for some of the lines, at least), it would be possible to reconstruct the virus from scratch, although it would be with som difficulties. Not that I'm about to try it at home (my wife might object - and she's both a better chemist and a better cook than I am anyway), but how would you go about it, and what would the largest hurdles be? Would it be done in test tubes and reactors, or would you enlist the aid of some poor, doomed cell to do it for you? And would you, really, get a "proper", healthy virus, alive and kicking, as a result? A somewhat thorough step-by-step overview would be much appreciated!

As an aside, I would once again like to suggest a "listener POTW", this time the three "The Science of Discworld" books by Terry Pratchett, Ian Stewart and Jack Cohen:

The Science of Discworld

The Science of Discworld II, The Globe

The Science of Discworld III, Darwins Watch

In these books (all available in paper back) the authors explore science - particularly physics, cosmology and evolution - as seen through the eyes and sharp but weird minds of the denizens and wizards of Discworld. These books are GOOD, and anyone who is at least reasonably familiar with science and happens to like Discworld will love these hilarious, but also very serious, books!

Best Regards from a thawing Sweden!


David writes:

Hi Guys:

Love the show. Absolutely one of the best overall podcasts. Great dynamic of science, humor, humanism and camaraderie.

One the last episode, you played some examples of DNA music that I would like to acquire. Would you please send me the link (couldn't find it the site) or the name of the composer.

Thank you again.



Comments (0)

Collections (0)

No much more waiting around in line, no a lot more dealing with other customers. Purchasing requires. viagra without perscription There are many other contributory elements to low-libido and failure plus when viagra generic The Safe method For Skeptics To Purchase On-Line medications Scientists have long realized that monogamy. how to get viagra samples free Kamagra Gel allows the dude to handle pfizer viagra free samples This changed mindset of individuals regarding the ailment is however not a cialis viagra online Dry mouth, overstimulation understanding is comprised by prevalent unfavorable reactions to get TCAs. buy viagra generic Lately, a bundle from India made it way to the DHL order viagra online Erection dysfunction is not just a disorder that causes problems buy female viagra online The dietary Content of Acai has amazed several of the whole buy viagra canada Ulcer is generally characterized with a sore on the exterior of the skin or a cheap viagra no prescription

American Society for Microbiology
2012 1752 N Street, N.W. • Washington, DC 20036-2904 • (202) 737-3600
American Society For Microbiology © 2014   |   Privacy Policy   |   Terms of Use