http://2008.igem.org/Team:NTU-Singapore

What happens if the suicide bacteria attack beneficial bacteria in our gut or the gut of cows.

All we need to do is to look at how Monsanto’s gene has migrated to understand the potential for this to get out of hand.

I agree that “some” of the virus in phage therapy will be eliminated by our host immune system but not all of them, there are viruses which are designed with human protein coating (camouflage of sorts) which will trick the host immune system into recognizing it as a host cell, it could then proceed to do its work in targeting its cell of interest. These viruses are currently used in a lot of phage therapy studies in targeting bacterial cells and also host cells in counteracting genetic diseases.

Another aspect of this study is the reliance of the expression of pyocin towards LasR, which is one of the quorum sensing molecules in Pseuds. LasR is used by bacteria to control their gene expression under the influence of cell-population density. It enables the coordination and synchronization of the activities of a large group of bacterial cells in an environment such as a biofilm. So LasR is required in a large concentration to be able to trigger the production of the pyocin in the E. coli and for that the researchers must make sure that the E. coli must travel to the site of infection (biofilm) in order for the E. coli to work its magic.

Besides that, we wouldn’t know what will happen to the E. coli after it enters our body, will it travel to the site of infection? Will it cause a drastic change in our gut microflora which will lead to other unforseen infections? Moreover, the pyocin released during the lysis of the E. coli might also be a concern as it might trigger an immune response as well, so there are still lots to think about in the in vivo aspect of this study.

There are still a lot more factors to consider besides the ones I’ve mentioned here before an in vivo study could be carried out as it is not as straight forward as it seems. But it is still a step forward in our battle against antibiotic resistant bacterias.

Cheers!

I’m entering a drug study for something called M-Pex, which is a similar type of inhaled solution but it doesn’t take as long and is supposedly more effective than inhaled Tobi. Still, any news of a new weapon against Pa is pretty awesome. I’ll have to ask my doctor about this and see what he thinks of it.

Thanks for the head’s up, Ed!

However, the bigger picture here is that patients with significant Pa infections usually don’t have sufficient immune systems to properly deal with invading pathogens anyway (e.g. CF patients don’t tend to mount good responses in lungs which is why Pa films flourish there in the first place).

Additionally, could you provide some links to papers demonstrating “It can only be used once – after that, the host developed antibodies against the viruses”. I’m curious if any of those works were performed in immune-suppressed animals (the nature of Pa infections suggests that most Pa patients would be immune-suppressed in some manner, i.e. burn, trauma, sepsis, CF, etc); I could understand though how that might be an issue in healthy individuals. The reason I ask is that I have a feeling that having all those PAMPs floating around in sensitive tissues would be a bad idea (SIRS and shock risks) and I tend to think that phage would be a safer route.

@Amphiox – Surely E.coli is a common enough commensal that this isn’t really a big problem.