Our initial project aim was to express a single protein, CqsA, the cholera autoinducer synthase. CAI-1, the cholera autoinducer is known to cause a population wide shift to avirulence in virulent strains of V. cholerae. Although not all of the possible effects of CAI-1 on every organism are known, it is currently thought not to be of significant concern to researcher, public or environmental safety. Other quorum sensing parts we have used, most belonging to the Lux quorum sensing system are well understood and not expected to pose any hazards.
We aimed to create registry standard parts proving a concept that could then be applied to produce a probiotic that would confer resistance to cholera. This would require ingestion of our genetically modified bacteria by humans and does raise safety concerns due to possible unforeseen effects. This has been investigated in mice, but as a small scale study, additional animal trials would need to be carried out before clinical trials in humans began.