Hi Madison!
No new classes of antibiotics have been developed since the 1980s. There’s actually a lot of reasons for this. Antibiotic research can be pretty expensive, and patients aren’t on these medications very long term. This means it’s not cost effective for pharmaceutical companies to fund research into antibiotics. Also, most of the simple antibiotic target pathways have been discovered. So, it’s difficult to find new pathways that aren’t super complex or also present in human cells.
Hi Nicole!
This is such a great question. I have a lot of answers but I’ll try to focus on the biggest thing I wish we did differently. I think we could have investigated another strain of bacteria commonly found in GI tract like some strain of Bifidobacteria. I think if we had tested this bacteria as well, we may have had more success with culturing as it may have preferred more medias than Lactobacillus. I also think we discounted the probiotic too quickly. We spent a lot of time waiting for the KWIK-STICK because we believed the probiotic was a lost cause. In fact, hydrating the probiotic was done at the very end of the course when the KWIK-STICK delivery was delayed.
Hi Emily!
L. Acidophilus has really specific and robust nutrient needs. We speculated that this is because it has evolved in such nutrient rich environments like the digestive tract. LB media is much more simple and just doesn’t have nearly as many nutrients as MRS media. So, Lactobacillus species can’t grow on it.
Why do you think it was so difficult to grow L. acidophilus in culture? Do you think there could have been some procedure in your methods that made this bacteria so hard to grow even though you tried so many different methods?
Hi Carter,
This is a great question. When we kept running into problems with culturing L. Acidophilus we did some research and troubleshooting on what was going on, a lot of which couldn’t make it on the poster or in the presentation! What we found was that L. Acidophilus is very picky in terms of it’s nutrient needs. So only a few medias, most of which are very niche, will support it’s growth. Ironically, we also found that L. Acidophilus does really well under stressful conditions. It likes hot, anaerobic, acidic environments. So, I think if we had access to some of these things (for example a CO2 incubator) and some more time, we may have had more success culturing. Also, it might have been difficult to culture from the probiotic since they’re unregulated supplements.
Awesome presentation! In your research did you find a different bacteria that could have been less problematic in a co-culture with L. Acidophilus that was too expensive or too out of reach to use for this class/ lab or was there not much else you could have done to make this experiment easier?
Hi Sophie,
Thank you! I think we were really attached to using a strain of Lactobacillus since it has so much evidence supporting it’s antagonistic properties. The problem with the bacteria that live in the gut is that they’re used to complex, nutrient rich environments. So, it seems like co-culturing these bacteria with S. Typhimurium would be difficult. There is potential in non-pathogenic E. coli, but it’s unclear if this would be completely safe or within the reach of this course.
why do you think that no new antibiotics have been developed since the 1980s?
Hi Madison!
No new classes of antibiotics have been developed since the 1980s. There’s actually a lot of reasons for this. Antibiotic research can be pretty expensive, and patients aren’t on these medications very long term. This means it’s not cost effective for pharmaceutical companies to fund research into antibiotics. Also, most of the simple antibiotic target pathways have been discovered. So, it’s difficult to find new pathways that aren’t super complex or also present in human cells.
If you could retake this class, what would you do differently?
Hi Nicole!
This is such a great question. I have a lot of answers but I’ll try to focus on the biggest thing I wish we did differently. I think we could have investigated another strain of bacteria commonly found in GI tract like some strain of Bifidobacteria. I think if we had tested this bacteria as well, we may have had more success with culturing as it may have preferred more medias than Lactobacillus. I also think we discounted the probiotic too quickly. We spent a lot of time waiting for the KWIK-STICK because we believed the probiotic was a lost cause. In fact, hydrating the probiotic was done at the very end of the course when the KWIK-STICK delivery was delayed.
What properties of L. acidophilus prevent it from growing on LB?
Hi Emily!
L. Acidophilus has really specific and robust nutrient needs. We speculated that this is because it has evolved in such nutrient rich environments like the digestive tract. LB media is much more simple and just doesn’t have nearly as many nutrients as MRS media. So, Lactobacillus species can’t grow on it.
Why do you think it was so difficult to grow L. acidophilus in culture? Do you think there could have been some procedure in your methods that made this bacteria so hard to grow even though you tried so many different methods?
Hi Carter,
This is a great question. When we kept running into problems with culturing L. Acidophilus we did some research and troubleshooting on what was going on, a lot of which couldn’t make it on the poster or in the presentation! What we found was that L. Acidophilus is very picky in terms of it’s nutrient needs. So only a few medias, most of which are very niche, will support it’s growth. Ironically, we also found that L. Acidophilus does really well under stressful conditions. It likes hot, anaerobic, acidic environments. So, I think if we had access to some of these things (for example a CO2 incubator) and some more time, we may have had more success culturing. Also, it might have been difficult to culture from the probiotic since they’re unregulated supplements.
Awesome presentation! In your research did you find a different bacteria that could have been less problematic in a co-culture with L. Acidophilus that was too expensive or too out of reach to use for this class/ lab or was there not much else you could have done to make this experiment easier?
Hi Sophie,
Thank you! I think we were really attached to using a strain of Lactobacillus since it has so much evidence supporting it’s antagonistic properties. The problem with the bacteria that live in the gut is that they’re used to complex, nutrient rich environments. So, it seems like co-culturing these bacteria with S. Typhimurium would be difficult. There is potential in non-pathogenic E. coli, but it’s unclear if this would be completely safe or within the reach of this course.