Arete Posted October 23, 2019 Share Posted October 23, 2019 16 hours ago, CharonY said: Good points, though I would add that in contrast to resistance, susceptibility is a rather difficult concept. For the most part it is more the absence of a resistance mechanisms than a proper trait in itself. Beyond that, the ability to deal with antibiotic stress is highly dependent on factors such as nutritional status. I.e. a strain on minimal medium will be much more susceptible than in rich medium. Mutations associated with higher susceptibility will likely also result in lower viability and/or competitiveness. Yes - you're right. In my lab we've been experimenting with disabling known resistance genes by inserting frameshift mutations to revert resistant strains back to susceptible phenotypes, but that is distinct from generating susceptible strains of inherently resistant wild type strains. Link to comment Share on other sites More sharing options...
CharonY Posted October 23, 2019 Share Posted October 23, 2019 19 minutes ago, Arete said: Yes - you're right. In my lab we've been experimenting with disabling known resistance genes by inserting frameshift mutations to revert resistant strains back to susceptible phenotypes, but that is distinct from generating susceptible strains of inherently resistant wild type strains. That's interesting, in my lab we were taking sensitive wild-type strains and try to figure out which 'regular' metabolic functions are required to proliferate under sub-lethal concentrations. Link to comment Share on other sites More sharing options...
Sensei Posted October 23, 2019 Share Posted October 23, 2019 @CharonY and/or @Arete Dimreepr on the first page of this thread showed YouTube video where it has been shown how different amount of the same antibiotics affect bacteria. https://www.scienceforums.net/topic/120340-antibiotic-resistance-suggested-tactics/?do=findComment&comment=1120983 Could you make and upload to YouTube similar video but to show people how temperature influences them? Make long petri dish, like authors of the above did, but different parts of it heat with steps +0.5 C or +1 C more than previous one. In range +36 C ... +44 C or +45? and eventually with negative temperature steps. I am thinking about visualization for viewers how different pathogens react with varying temperature of environment. Link to comment Share on other sites More sharing options...
CharonY Posted October 23, 2019 Share Posted October 23, 2019 16 minutes ago, Sensei said: @CharonY and/or @Arete Dimreepr on the first page of this thread showed YouTube video where it has been shown how different amount of the same antibiotics affect bacteria. https://www.scienceforums.net/topic/120340-antibiotic-resistance-suggested-tactics/?do=findComment&comment=1120983 Could you make and upload to YouTube similar video but to show people how temperature influences them? Make long petri dish, like authors of the above did, but different parts of it heat with steps +0.5 C or +1 C more than previous one. In range +36 C ... +44 C or +45? and eventually with negative temperature steps. I am thinking about visualization for viewers how different pathogens react with varying temperature of environment. I have no idea what a video would do as data would be static (e.g. final titer or growth rate). A gradient on a plate would not tell you much either, as up to lethal temperatures all you would see is that the colonies are smaller as they start growing more slowly. But I can tell what you are going to expect. Depending on the bacteria, you will see increase in growth rate up to their optimum temperature and then a decline and finally death. In other words, you won't see nice inhibition zones as for antibiotics. For many environmental bacteria the optimum is around 30C. For those living on warm blooded organisms the temperature is unsurprisingly close to body temperature (e.g. ca. 37C for most mammals, but ~40-42C in many birds). Whether they are pathogenic or not is of secondary relevance. However, some of these bacteria also have heat resistance genes, often acquired by mobile genetic elements which allow them to survive for several minutes in temperatures up to 80C. While there is not a lot of evidence that those provide any benefits during infections (in case of pathogens), they were increasingly found in food-borne bacteria, where they survive sterilization efforts. Link to comment Share on other sites More sharing options...
StringJunky Posted October 24, 2019 Share Posted October 24, 2019 (edited) On 10/22/2019 at 9:37 PM, mistermack said: Why don't you either address the OP and stop trying to derail the thread, or open a thread on your suggested topic. As a moderator, you shouldn't be trying derails. As far as this thread goes, your attempts to appear an authority are not at all convincing, I've never fallen for your bluster. Your posts give you away because you get the wrong end of every stick. The condescending attitude just doesn't come off. If Charon was in error, Arete would pick him up on it and vice versa. Along with Hyper, who's strong in biochem, you've got three people more than adequately knowledgeable together to answer your question. Edited October 24, 2019 by StringJunky 2 Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now