[DrScientist]

> My point was that a bacteria engineered to target a malignant tumour, to be very treatable with antibiotics or bacteriophage, and to have a strongly reduced rate of mutation, is extremely unlikely to evolve into a pandemic, and is likely to be much safer than chemotherapy and radiation.

Did you know bacteria have horizontal gene transfer? ie antibiotic resistance isn't just evolved and passed to children ( vertical ), it can be passed to peers horizontally.

It also happens outside bacteria - but bacteria have active mechanisms to enable this - that's how antibiotic resistance spreads - not just from parent to child, but peer to peer like a meme :-).

Safety is a complex topic, and you'd need to consider on a case by case basis - PhD students engineer bacteria every day ( something that had a self imposed ban in the 1970's I think ) - however that's within the context of standard platforms and each and every one should have a risk assessment.

Don't get me wrong, I think it could be done, but there is a Genie and a bottle here and it's best to think twice.

I'd like to see both a kill switch ( beyond antibiotics ) and some sort of growth external dependency - ie they need something you provide to survive as well.