Alex writes:

Dear TwiM People!

I finished episode 185 “There’s no moa Moa” during my weekend and needed to comment on your argument about the relevance of acquired resistance of bacteria against alcohol disinfection.

As I see it, Elio had a point when he said we do not have a problem regarding isopropanol resistant bacteria. At this point of time, isopropanol concentrations are sufficiently high to handle even most resilient strains. But, there are caveats. The authors of the paper in question were able to show a trend I consider similar to those we all wish we had seen before the rise of MRSA and others. It may be quite possible that, in future, we might indeed get those hard-to-disinfect superbugs Michele mentioned.

Some factors involved are for example:

– Inappropiate application of disinfectants, like using low dosages or shortening exposure times leads to decreased effective concentration or incomplete killing, respectively.

– Wrong handling and storage might lead to evaporation of alcohols and other effects which decrease the efficacy of disinfectants.

– These factors occur even more often because of the inflationary usage of disinfectants in households by people not familiar with their appropriate application and storage.

Especially the last point should be all too familiar from problems encountered in antibiotic medication. How often do we tell friends and family to just take them as the doctor ordered instead of quitting as soon as they feel better?

Last but not least I do want to point out that there is scientific data which suggests a connection between resilience against disinfectants and resistance against antibiotics. By acquiring the former, bugs could indeed passively acquire the latter as a side effect.

I do not fancy giving information the TWiM gods were not already aware of. But it’s worth to try a lucky shot. Should some of this actually be helpful: you’re welcome!

Continue the great work!

Best wishes,


Ayush writes:

Dear Vincent et al.,

I truly enjoyed your discussion on ‘Increasing tolerance of Enterococcus to handwash alcohols’. Such lively discussions make doing science even more fun. This work also highlights how scientific findings get lost in translation by popular media. Thus we need more and more platforms like yours where scientists explain such findings to the public.  One thought from this paper, do we know how fast the alcohol evaporates from hand sanitizer bottle? I looked at the hand sanitizer bottle in my office while listening to your podcast and turns out it is way past the indicated expiration date (which may or may not mean anything) which may mean that the actual alcohol concentration in this bottle may be less than the indicated 62% (which is what we seem to be using in Canada). Based on this study, the take home message for me was perhaps to make sure that the hand sanitizer that I use in my office is not too old.

As always great job! Btw, everyone in my lab is big fan of your podcast. Our graduate seminar this week was inspired by the TWiM 170 (Ectoparasites and Plague).




Ayush Kumar, PhD

Associate Professor | Department of Microbiology

University of Manitoba

Winnipeg | Canada

Richard writes:

Dear TWIM team,

Thanks for all the great science. Thanks especially for the eureka moment when you recently described how a diminished and fragmentary intracellular bacterial parasite is distinguished from a giant virus. It would be delightful if an exception were found.


Homewood, Illinois

Sonia writes:

Hello TWiM team!

I am so grateful to have found these amazing series!

Please enter my name into the book give away contest!

I have been working in a pharmacy as a pharmacy technician for the past 14 years and was always interested in researching bacteria, viruses, and parasites.  I enrolled in university (York University in Toronto, Ontario, Canada 🇨🇦) at age of 29 and am currently in my 2nd year of my biology undergrad. I am wanting to pursue a masters and maybe PhD in microbiology. This book would be of great interest to me! I wanted to thank the TWiM team for taking the time to make this series and others available for the the general public! It’s sad that microbiology is not in our high school curriculum I truly think the unseen world would spark interest in many young minds.

Thank you so much for all informative talks!

Mike writes:


Thank you for always putting great effort and entertainment into the podcast. The Idexx VBNC question perked my ears up as I monitor wastewater and drinking water laboratories using the method. In my experience the Idexx methods have always seemed sufficiently sensitive (probably more so than membrane filtration alternatives), besides Enterolert. Hopefully I can win the book and learn some more about antibiotics here in sunny Hamilton, NJ where it is 29 degrees Celsius, and most importantly not humid.