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TWiM regularly receives listener email with corrections, comments, suggestions for show topics, requests for clarification, and additional information. A selection of these is archived on this page.
Great HAI work! I'm not through it yet. I want to question, though, whether fomites are really important in influenza transmission. I don't think so.
Wink Weinberg (ID)
[flu can transmit by fomites in guinea pigs: http://jid.oxfordjournals.org/content/199/6/858.full ]
I'm a second year microbiology undergraduate and I very much enjoy all of your podcasts; they are a great pleasure to listen and I wait for the new ones every week.
Since the last episode was all about copper I would thought it would be appropriate to point out this paper published in Nature in 1984- "Why whip egg whites in copper bowls?".
Who would have thought that a paper about copper bowls and cooking could've been published in Nature :)
I also think that this paper could be shortly discussed one one of the podcast: traditional mutational study but seems quite perspective- what do you think?
"Identification of Salmonella Pathogenicity Island-2 Type III Secretion System Effectors Involved in Intramacrophage Replication of S. enterica Serovar Typhimurium: Implications for Rational Vaccine Design"
Thanks again for your podcasts and keep them coming!
I formerly developed a oxygen radical (not ozone) surgical instrument sterilizer so have dealt with the difficulties of disinfection and HSAs. Successfully sold to Stryker Instruments.
You mention the problem of economically obtaining copper hardware due to the pervasive use of plastic. If you think about our common household plumbing fixtures, it is clear that plastic can be plated with many metals and shipped around the world by air.
Plastic plumbing fixtures are typically plated with electroless copper followed by nickel then chromium. Air shipment is not an issue so your former plating vendor simply did not have the technique/knowledge to give you a sturdy uncontaminated injection molded part. I was involved on the development of many of these processes in the 70s. Rhom & Haas is still a major supplier of plating solutions and methods.
Similarly, any metal part can be easily plated in whole or in part with copper or copper alloys by the OEM. A quick swipe with ammonia will remove finger oils which could allow bacterial film growth and will expose fresh copper surface.
Despite all this antimicrobial furor, I look forward to the "omic" studies identifying how many HSAs are from the environment vs. the patient. Microbiome studies seem to be showing that microbial diversity balance rather than eradication is often the key mechanism of maintaining health.
Thanks to all you TWIV, TWIP & TWIMmers for creating and maintaining one of the most educational, accessible and plain old FUN scientific forums ever!
I was amazed to see note 13 in the caption for this article out of Apr/May 2013 AARP magazine about use of copper alloys on frequently touched surfaces. Copy of that page attached as a PDF.
I love your show, especially the recent episode about the use of copper in hospitals.
I am a nursing student at University of Nevada, Las Vegas and I am always cleaning patient bed rails and call lights. Patient hands are not the only thing that comes in contact with bed rails. The rail is also frequently used by nurses to temporarily hang pieces of tape while inserting an IV or changing a dressing. The tape, with all its germs attached, is removed from the bed rail and taped onto the patient's skin in close proximity to an open wound.
A future study might include the pathogens transmitted by stethescopes. People are pretty good about washing their hands, but I never see anyone cleaning their stethescope. It is my very unscientific, empiric observation that the stethescope is one of the biggest fomites in any hospital. I have seen copper writing pens for sale, but I am not aware of anyone who makes a copper coated stethescope.
Another possible fomite is employee badges, they come in contact with our patients when we lean over them (I stuff mine in my pocket so it does not contact the patient.)
Hello TWIM friends!
Jennie here - a long time fan of TWIV, then TWIP and of course happily learning from your great TWIM podcasts.
Thanks to Michael Schmidt's fascinating discussions - including those regarding copper and microbes - which have really got me thinking. (Copper's natural anti-microbial activity can lower nosocomial infections by decreasing pathogens on hospital surfaces. To plagiarize Mr. Schmidt's own site at the Department of Microbiology and Immunology at the Medical University of South Carolina: "The 4th leading cause of death in the United States, behind heart disease, cancer and stroke, is Hospital Acquired Infections (HAI) where approximately five percent of the patients admitted to US hospitals will acquire an infection. Very little is known of what fraction of these infections result from a microbial contribution obtained from objects present in the built environment."
It appears that copper does have a contribution to make - and I can imagine that there will be some formidable costs in changing surfaces from plastic & alloy & steel to copper.
To decrease costs of switching to copper surfaces for commonly touched fomites (microbe carrying objects) like IV poles and steel hospital infant bassinet units - you're talking to an OB nurse here - I began to think about a 6th or 7th grade experiment we did in school when I was a youngster with copper plating.
With that in mind - I did a quick search for a video on copper plating on Youtube and found this video - which just gives you a peek at how easy it can be to copper plate existing metal surfaces. I'm wondering if this could potentially be a cost saving application for some institutions. Will it be necessary for institutions to re-purchase when perhaps they could resurface?
Of course, I hope that you realize how very much your team has done and is doing to increase our understanding of the tiny denizens without and within us. What an adventure!
Special thanks to you Vincent for sparking greater excitement and transparency in science. Thanks to Jo Handelsman - soil microbes are so vital and so unknown - thanks for the recent apple orchard soil discussion and for her deeply appreciated advocacy for women - Yay! Of course Elio Schecter and Stanley Maloy - fantastic!
Yours with warmest regards
Jennie BSN RN
“In the world through which I travel, I am endlessly creating myself.”Frantz Fanon
Saw this media release from the Australian Institute of Marine Science about researchers isolating a combination of probiotic bacteria to assist in the prevention of Vibrio infections of spiny lobsters in aquaculture and thought of TWiM.
Keep up the good work,
12 December 2012
Winning combination of bacteria found to combat deadly marine pathogen
Research conducted at the Australian Institute of Marine Science (AIMS) has delivered promising results in combating Vibrio owensii - a bacterium that is responsible for mass mortalities of cultured ornate spiny lobster larvae.
The high commercial value of the ornate spiny lobster (Panulirus ornatus) means it has the potential to be an important product of the Australian aquaculture industry. However, nutritional deficits and bacterial disease during the long larval phase of the species makes captive rearing difficult.
Scientists from AIMS and the University of New England (UNE) have been able to isolate a large number of bacterial cultures – or probiotic candidates – from wild lobster larvae and their natural prey items, and from the lobster aquaculture system at AIMS in Townsville. After successive tests, they found that a combination of two probiotic bacteria, referred to as PP05 and PP107, provided the most effective protection against the pathogen Vibrio owensii, enhancing survival of the larvae by as much as 80 per cent.
AIMS Research Scientist, Dr Lone Høj, who led the project, said “Our work has uncovered a winning combination of “good” bacteria that appear to dramatically improve larval survival. In a further study we looked at how and why these two bacteria were so effective when working together against Vibrio owensii.”
UNE PhD student Evan Goulden said “This research highlights the value of identifying biocontrol agents that are able to intercept the infection cycle of a serious aquaculture pathogen, as such the study represents a milestone in proving the value of using probiotic mixes to prevent microbial diseases.”
“Disease management is critical in food production systems and this is particularly true for seafood produced in aquaculture systems. The development of alternatives to the antibiotics currently used in such systems is becoming a national priority in countries around the world” says AIMS Principal Research Scientist, Dr Mike Hall.
‘Identification of an Antagonistic Probiotic Combination Protecting Ornate Spiny Lobster (Panulirus ornatus) Larvae against Vibrio owensii Infection’ is published in PLOS One: http://dx.plos.org/10.1371/journal.pone.0039667
‘Probiont niche specialization contributes to additive protection against Vibrio owensii in spiny lobster larvae’ is published in Environmental Microbiology Reports:http://onlinelibrary.wiley.com/doi/10.1111/1758-2229.12007/abstract
The authors are Evan Goulden (AIMS/UNE), Mike Hall (AIMS), Lily Pereg (UNE), Brett Baillie (AIMS), and Lone Høj (AIMS).
Dear TWiM team,
Since the topic of patent law came up on episode 48 I wanted to add my two cents. Six months ago, I switched to a career in patent law after 12 years as a bench Virologist. I have found this job to be very challenging and rewarding, and I'm currently experiencing a rather steep learning curve. However, the reason I'm writing is because I did want to mention that one does not have to be a lawyer, or even plan to go to law school to practice patent law. Many firms are willing to hire PhDs with no prior experience in patent law as science advisors or patent agents and train them on the job. The reason they're willing to do that, is because of their extensive background in science, which is imperative in this particular legal field. In our firm, all of our six science advisors have PhDs, and three of our five attorneys do as well. Although learning the law is pretty difficult, in my opinion, it is much easier to learn the law on the job than it would be to learn the science, and I have tremendous respect for the two attorneys in our firm who do not have PhDs, because they seem to be so well versed in the science as well. I recently asked one of our partners (who has a PhD) how much of what he learned in law school he has actually applied to this particular job, and he said “zero”! On the other hand, attorneys do make a lot more money, and there are certain things that they can do that a patent agent can't do, but my point is that a PhD is more than enough to have a rewarding career in patent law. Personally, I have absolutely no desire to go to law school!
Thanks again for continuing to provide so many different stimulating and thought-provoking topics.
Post-Sandy seems an appropriate time for a TWIM devoted to mold since the storm generated many opportunities to deal with it? I'm also battling it in my ventilation ducts to the extent that we replaced all the supply lines beneath the house and some of the returns in the attic, and installed an electrostatic filter upstream from a HEPA-type filter, plus a UV light by the heating/cooling coils. Over the years I've inspected the ductwork for integrity and cleanliness and just didn't think we had conditions that allowed mold growth until we found 7 of 23 supply lines each of which that looked inside like they were spray-painted with black primer over a good many feet. Meanwhile outside we've been unable to prevent black mildew from growing in playing-card patches on treated wood coated with mildewicide-infused stain and exposed to sunlight about eight hours a day.
I bought five mold collection kits containing petri dishes and growth medium just before detecting the seven register lines. At first they seemed a good idea to apply now and perhaps in the spring or summer, but then I found this site with considerable mold information that seems reputable. My interpretation of what the site says is that conditions and materials contributing to mold must be removed to fix problem. While removing bad ductwork helps I don't think it corrects the condition problem(s). The site says sprays and chemicals don't work! And sampling with my kits followed by lab work to identify mold types won't tell if harmful mold is at levels requiring action. In addition, unless you use laboratory grade filtration, it won't reduce the presence of mold to livable levels, and UV radiation is only good directly under the light, not particulates flying by. Electrostatic filters apparently only remove a small amount of mold-related material as do good filters, but not all and probably not enough for sensitive people, plus they work best if the ventilation fan runs continuously. Much harmful mold material is too heavy to get sucked into any ventilation system, anyway, and is only removed by vacuuming often, mopping and washing fabrics. Finally, only an expensive, trained environmental specialist can do a good evaluation, prescribe corrective action and determine if that action has been effective. This site shows we have just one such specialist in my state,Virginia, about 300 miles away.
Do you folks agree our best approach would be to napalm the house and replace it with a stainless steel cube, or wear environmental protection suits, or move to who-knows-where....? Of course the guys doing all the ventilation work used no respiration protection, but then they were all in their 20's and 30's versus our 70's.
So what's going on with mold nowadays, anyway? Is there more of it? I've no problem understanding why you need to remove wet and moldy plasterboard and carpeting, but have seen home shows where mildew-stained woodwork behind the wallboard is sprayed with something which they implied would fix the problem. You're the only really reliable source of complete and competent knowledge on the topic, so many of your listeners should appreciate your comments.
When do we get to hear the results of Michael's experiments and interventions with copper and microbes?. The suspense is killing me, or did I miss it? Please continue your marvelous podcasts.
Vincent, TWIV, TWIP amd TWIM are wonderful for a retired person like myself. I worked in IT, but started out with a biology undergrad that instilled my interest in biology many years ago. I always look forward to the next podcast. I have discovered that dinner conversation about TWIP is not as well received as a discussion about my latest project from the course I am taking at the College of Craft and Design. You will enjoy this
Hello, I am a big fan of all your podcasts. Copper is used as an anti- parasite agent in marine aquariums. It is toxic to all invertebrates and is deadly to them so it is used in fish only quarantines. This is perhaps why there is a concern about copper in the marine environments as it will not only kill microbes but snails, crabs, squid ect.
Hey guys, love your show so far. I have a few thoughts on the last episode concerning B. anthracis, particularly the lack of variance in anthracis. I found it very interesting to learn that spore-forming species have characteristically more genetic variance than non-spore formers. Does the lack of genetic variance have something to do with the fact that anthracis forms endospores, and not spores in a fungal sense? Fungal spores are easily released into the air for dissemination, while anthracis endospores seem fit to persist in the soil and dead bodies of infected animals. Do fungal spores show more genetic variation in a strategy to survive in a more diverse environment? Maybe Bacillus anthracis spores are less inclined to disseminate throughout the environment because the cattle and sheep they typically infect die within a few days and are generally confined to the field of the farmer who owns them.
Thanks, keep up the great work!
Hello Professors and Expert,
I am hoping for an upcoming episode on resistant bacteria or upcoming antibiotic drugs in the pipeline?
Your fellow cytogenetics friend,
Northwestern Memorial Hospital
I love this new podcast, and I especially enjoyed this episode. This is a nice example of both the strength and weaknesses of scientific forensic evidence, I think--you can get useful information out of it (the anthrax strains in Ivins' lab are very likely the source of the anthrax used in the attacks), but not the critical questions you care about (was it Ivins who made the spores and mailed them, or was it someone else; if it was Ivins, did he have any help?) I suppose we will never really know for sure, since Ivins is dead and the FBI's investigation is over.
Assuming Ivins was the attacker, this raises an interesting point with respect to the threat of bioterrorism: Ivins was a US government biological weapons researcher, working on defending against a potential attack. He had expertise, equipment, training, supplies, and access to information at a level that it's hard to imagine any other terrorist having. And yet, his total body count was quite small, as these things go. Some nut with a gun in a crowded mall might manage to kill about that many people! The attacks were quite effective at spreading terror, especially among people at the top of government and media, but they weren't actually all that deadly.
My question is, does this suggest that bioterrorism is overblown as a threat? Or is it just that this attack wasn't targeted at killing large numbers of people, or that we got lucky and things might have ended up far worse? My understanding is that anthrax isn't really much of a risk to spread after it has been used, and once you know people have been exposed you can give them antibiotics that will save them, so the attacks were probably self-limiting. Maybe the situation would have been different, had the attacker had access to a different agent?
This link, http://www.thermus.org/e_index.htm , is a good source of information about Japanese activities, has links to seminars, abstracts, software information that's being used, project background, 3D visualizations and progress reports, all in English. Might be of interest to listeners who wish to see what is going on in East.
There is an effort underway to ban Triclosan and I would like to hear TWIM discuss the risk / benefit to using anti-bacterial agents, particularly their widespread use in consumer products. Any info on how useful Triclosan is whether we'd miss it if was banned would be appreciated.
Kerry (Loyal laymen listener toTWIV, TWIP and now TWIM)
I just wanted to comment on your short discussion of nomenclature for Salmonella. Panama is not a serovar of enteriditis. Salmonella is currently recognized as having two distinct species, Salmonella enterica and Salmonella bongori. Salmonella enterica has 6 subspecies, of which subspecies enterica is the most clinically relevant. Within Salmonella enterica subspecies enterica, there are many serovars, of which Panama is a representative. Enteriditis is also a serovar of Salmonella enterica subsp. enterica. Therefore the proper name for this outbreak strain would be Salmonella enterica subspecies enterica serovar Panama. Whenever Salmonella Panama is used, or Salmonella Enteriditis, it implies that the serovar is a member of the enterica subspecies enterica family.
Vincent and everyone else on TWiM, I have throughly enjoyed these podcasts, they are perfect entertainment while I am stuck spinning down large culture volumes. I especially enjoy the format, focusing on just a few papers/topics really allows for in depth discussion.
Please continue your coverage on all the human microbiome work, it is a fascinating topic. As a undergrad at Cornell I was lucky enough to take the first offering of a course devoted solely to our microbiota, especially its positive impact. The course sold me on the importance of this field and its potential to change the way we look at some of the most important diseases that afflict us today.
Also, I am looking forward to your coverage of bacteriophages and phage related therapy, especially the future of its use in medicine.
The matriarch of a hunter-gatherer band might prefer males to be assigned to specialised training in hunting skills. So the subconscious bias probably goes back a couple of million years to the early days of Homo before sapiens.
Saw this paper in my inbox this morning and thought It might be a good fun discussion paper on an upcoming TWiM episode!
Dear Dr Racaniello,
I do not have the talent for a M.D-Ph.D. at Columbia, but I am definitely a huge fan:)
It's striking how and where the interaction of antibody and bacterium occurs (TWIM #48)! Learned a lot from listening to your interpretation of the paper. Many Thanks!
Just have a question about one antibody and one bacterium. Is it commonly considered more than one antibody molecule per bacterium?
Many Thanks, again!
P.S. Can this finding extent to the interaction between virus (e.g. HIV) and neutralizing antibody? It might be we just look at the wrong place for all those years!
Hello Racaniello et al.,
I am a plant pathologist for a vegetable seed company in Washington state. I listen to TWIM, TWIP and TWIV podcast while I read extensive disease resistance screens. I started out studying microbiology as an undergrad and discovered plant pathology that allows me to study microbes and plants together. Listening to these podcasts keeps my mind engaged while looking at thousands of potentially disease baby plants. I really appreciate what you all do to put together such intellectually stimulating topics.
If I may suggest a topic as well. Iron sequestration and uptake in bacteria is very fascinating and affects many aspects of bacterial life. I may be biased as I worked on iron uptake during my Ph.D. I have listened to many of the TWIM podcasts and iron pops up in discussion now and then. It would be nice to listen to a discussion of this topic from your perspective.
Keep up the good work,
Episode 2 had a career inquiry from a listener. The listener was considering additional graduate work, but was not sure which way to go or whether to invest the required time and energy in an MBA or Ph.D.
May I suggest intellectual property as a career path? Most patent attorneys are former "lab rats." Patent attorneys enjoy a good salary and interaction with some very intelligent and interesting people. Though considerable work is required, intellectual property can be a very rewarding career.
Quick follow-up from Twim 47.
It seems that many bacteria have means to take up foreign DNA and integrate it Into their own chromosomes. This definitely can provide a selective advantage depending on the nucleic acids being taken up. On the other hand, transferring your own DNA to another cell seems to be quite unselfish. For example, if I had some form of an antibiotic resistance gene, why would I give it away to others that would, in the end, compete with me for nutrients? In essence, what is the selective advantage for giving away nucleic acids?
Thanks a lot and have a happy holiday!
I love all your series (TWIM,TWIV, and TWIP) and learn immensely from them. I am a Clinical Research Nurse and work at NIH in the National Institute of Allergy and Infectious Disease (NIAID) unit that houses the KPCR patients that you may have recently read about.
I'd like to hear a discussion about this isolate as you educate everyone so thoroughly. Our hospital has worked diligently to track and eliminate this organism from our hospital and we've just about succeeded but I'd still like to be better informed about KPCR. Thanks.
P.S. Please Please Please start a TWIB!! We work with so much that I still need to be educated about various bacteria.
Thanks immensely for all the education you give us.
Hi Vincent and Friends,
Thank you very much for the informative and often imaginative discussions that take place in TWiM. It's a real pleasure to listen to such a quality, fun, easily accessible (and free!) source of microbial material. I'm sure you are often thanked for taking the effort to put it out there, but I wanted to add my voice. As a cell and molecular biology student it offers some wonderful connections and points of interest to my education.
My question relates to a recently published book by Trudy M. Wassenaar that I have been reading, titled "Bacteria: The Benign, the Bad, and the Beautiful." Has anyone read this book, and if so what are their thoughts on it? I would recommend it to those with a broad interest, or who need an introduction, like students such as myself. It offers an incredibly interesting and diverse description of bacteria and is easy to understand. I actually picked it up because it was recommended by the google+ "Microbiology" account (https://plus.google.com/u/0/109102265263486263584/posts).
Thanks again, and warm regards.
TWiM Audio File with Interactive Transcription
Here is a link to a partial, video I created from the TWiM 06 audio file: http://www.youtube.com/watch?v=JtOXD_X6g_w. I created a video file from the audio file so that I could use the YouTube captioning tool to import an interactive transcript -- minutes five (5) through twelve (12). I created the time-coded transcript using an online tool called Subtitle-Horse, (http://subtitle-horse.com).
If you click the interactive transcript button on the button-bar (Like, Dislike, Add to, etc) just below the video player, you can see how the transcript works. The transcript is indexed, time coded to the audio.
Potential Benefit of Interactive Transcription
The time-coded transcript text could be parsed and placed in a database for easy query. Then all included audio/video files are text searchable and associated to the segment of the source audio/video clip.
On TWiV a number of people have completed or are working on transcripts. In my experience, transcription is a time intensive process. To lighten individual time commitment, it would be nice to get several people to work collaboratively to transcribe one TWiV audio/video. Although far from perfect, the subtitle-horse online transcription tool could be used for this.
Volunteer to Help TranscribeAs a first step, if interested, I’d be interested in coordinating a collaborative transcription of a TWiV session with one to three others.
Hello TWIMers - In TWIM 26 I heard the listener email asking if you would consider offering continuing education credit for your podcasts, and you understandably cited the work that would you need to do (such as writing learning objectives, tests etc) as a real barrier to that. I was wondering if you would consider "contracting" that kind of work out to some of your listeners; being a teacher of a microbiology class at a community college, I spend a large amount of time coming up with learning objectives, tests etc anyhow, and it would help me to generate fresh material for my students from your podcasts. I wouldn't be surprised if there were others in your listening base who might feel the same. This still would add work for you, so I understand if its a no-go.
In a separate vein: quite a while ago I was doing dishes and listening to a TWIM. As I was using a sponge to wipe off the counter a ridiculous question popped into my head (as opposed to my toe, I guess): are there strains of bacteria that can provide a protective commensal role on environmental surfaces? A counter top is nothing like a biological surface, as only the latter should have organic material to eat on it, but still, is there any evidence in any situation that something like this happens? Please read the following sentence with extra emphasis: I am not fishing for an excuse to get out of doing the dishes, and I regularly boil our kitchen sponges and use bleach to clean the counters.
Keep up the great work!
Greetings from a longtime listener and fan of all three TWI-podcasts. I'm a biotechnology Masters student at the University of Helsinki, Finland, but I earn my living as a part-time driver in the world's most northern metro. Your podcasts help me pass the dull hours at work so that I feel like I'm doing something to advance my studies as well.
I've been thinking of writing for quite a while. Now that I'm finally doing it, I have a rather general suggestion and a link. The suggestion is, I'd like to hear more about the archaea - maybe even an entire episode dedicated to them. They seem like such a mystery. At least at my home university, they're almost always just mentioned as an aside, while the bacteria get all the attention. The one time they were actually discussed on a course, I learned that they are not just extremophiles, but actually all around us, just like bacteria. This made the fact that there are no pathogenic archeae seem even more curious to me.
As for the link, it's for the Earth Microbiome Project: http://www.earthmicrobiome.org/
I just ran across it today, and don't remember this project being mentioned on TWIM before. I think the idea is awesome, not to mention really ambitious, maybe even overly so. What do you think, is creating even a rough map of the microbiome of our entire planet an attainable goal? And would it be a useful resource for research?
Thanks for the inspiring and informative podcasts,