About Shawna Gallegos
Major Microbiology
College Arts and Sciences
Accomplishments 1st Place Poster Presenter at the Texas Branch American Society for Microbiology
About the Project
Title The Competitive Nature of Polymicrobial Interactions in Biofilms
Presentation Watch the research video
Mentor Dr. Kendra P. Rumbaugh
Surgery, Texas Tech University HSC
Comments
Great talk Shawna! Reading some of your responses has made me wonder how does in vitro as opposed to in vivo change the relationship between S. aureus and P. aeruginosa from antagonistic to synergistic?
Thank you! When organisms are together in vivo,they have more than each other to worry about – the host immune response can be a bigger threat to survival than another organism. There are also a number of different enzymes and such that are not necessarily present in vitrothat can change how the organism responds to its environment. Depending on the organisms present, they may be able to “team up” if you will in order to better survive the host immune response. If you are a student at TTU and get the opportunity to take Dr. Wakeman’s biofilms course I highly recommend it. It’s a great foundation for understanding polymicrobial interactions.
Thank you! When organisms are together in vivo,they have more than each other to worry about – the host immune response can be a bigger threat to survival than another organism. There are also a number of different enzymes and such that are not necessarily present in vitrothat can change how the organism responds to its environment. Depending on the organisms present, they may be able to “team up” if you will in order to better survive the host immune response. If you are a student at TTU and get the opportunity to take Dr. Wakeman’s biofilms course I highly recommend it. It’s a great foundation for understanding polymicrobial interactions.
Hi Shawna,
I loved your talk. Biofilms seem interesting and somewhat questionable in how they work. Why do you think that Pseudamonas prefers to be the dominant species when grown in co-culture?
Hey! Biofilms are definitely an interesting and complex area of study. While we have learned a great deal about them, there is still plenty that we don’t understand. Bottom line, when there is a biofilm present in an infection it is going to be considerably harder to clear with antibiotics and the host immune response. This is why early detection and treatment is so critical.
As for why Pseudomonas prefers to be the dominant species in the experiments we did for this talk, it’s basically just a competition for survival. Pseudomonas “senses” something from these other organisms that makes it go into hyper drive if you will, to be sure the other organism isn’t able to dominate the environment and therefore the available resources. Interestingly some organisms created a greater response than others. It’s important to note that these were in vitroexperiments. There can be a considerable difference in how these organisms interact when they are present in vivowith a host immune response. Where some may be competitive and/or antagonistic on a petri plate, when present in a wound with a host immune response some of these organisms can become highly symbiotic.
Biofilms, microbes, immune compromise, From your research, are there certain pathogens that are usually found together and have synergistic effects as opposed to the antagonistics effects of PA? or pathogens that produced larger biofilms when combined with a pathogen other than PA?
Interestingly, the interaction of S. aureus and P. aeruginosa is an antagonistic one when looked at in vitro. However, in vivo these two organisms have a symbiotic relationship and coexist quite effectively. Our challenge in researching chronic wound pathogens is understanding numerous levels of interactions. We must expand our knowledge not only of how these organisms behave on their own and also how they behave when another organism is present, and does that interaction change when there is a presence of a host immune response.
Exciting! Thank you for the follow up! I wonder how many nonpromising in vitro studies would actually work in vivo. Keep it up!