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Researchers Use Temperature to Control the Activity of Modified Bacteria

Elizabeth Fox
14th November, 2016

A team of scientists has developed a method to make it easier to control bioengineered microbes. The therapeutic bacteria, which can deliver medications, can be modified to sense and respond to temperature changes. This would allow doctors to direct the bacteria to specific parts of the body. The findings are in a paper that was just published in the journal Nature Chemical Biology. Genetic engineering can be used to create modified bacteria that are capable of delivering medicine to different parts of the body. This technology has the potential to help treat a number of medical problems, including infections and cancerous tumors. There are a few challenges, however. It’s difficult to engineer bacteria that will only release medication in the proper places, for example. There are also concerns about modified bacteria being released into the environment when a person defecates. Researchers developed bacteria with temperature-based “switches” to address the current problems of using therapeutic microbes in medical treatments. The modified bacteria responded to thermal signals and could be shut off or instructed to self-destruct when the temperature reached a certain threshold. The team was able to use ultrasound to warm up specific parts of the body enough to activate the bacteria, for example. Bacteria could also be modified to inactivate when the patient’s body temperature got too high due to fever, a symptom that could signal that the treatment isn’t going as planned. Another application of this new technology is the development of bacteria that self-destruct once they’re outside of the body. This would prevent modified bacteria from spreading out into the external environment. The team’s study shows that temperature can be used as a sensor to control therapeutic microbes. Bacteria can be activated or inactivated at preset temperatures. The technology can be used to develop bacteria that will release medications in a specific part of the body. The team’s method also prevents genetically modified bacteria from entering the outside environment since they can be programmed to self-destruct when the temperature drops. REFERENCE Piraner et al. Tunable thermal bioswitches for in vivo control of microbial therapeutics. Nature Chemical Biology (2016).